KR101481618B1 - Apparatus and method for estimating welding quality of strip - Google Patents

Abstract

The present invention relates to an apparatus for determining a welding quality of a strip. The apparatus includes a welding head movably installed in a width direction of the strip at an upper portion of the strip, the welding head generating a welded portion of the strip to which the strip is welded; A photographing unit installed at a rear side of the welding head in a traveling direction of the welding head, for converting an image signal photographed by the welding unit into an image and outputting the image; An analysis unit for calculating a size of the welding hole included in the image input from the photographing unit and outputting the calculated size; And a determination unit determining a welding quality of the strip to be defective when the size of the welding hole input from the analysis unit exceeds a predetermined size.

Description

TECHNICAL FIELD [0001] The present invention relates to a welding quality determining apparatus,

The present invention relates to an apparatus and method for determining weld quality of a strip, and more particularly, to a method and apparatus for determining weld quality of a strip in real time by analyzing the size, number and position of a weld hole occurring when a strip is butt- And more particularly, to a welding quality judging device and a judging method of a strip having a plurality of strips.

The Laser Line Welder (LLW), which welds wires and trailing coils, is a core facility that enables continuous operation in electric steel sheets and cold rolling lines such as CAL, RCL, PCM. Failure to ensure good weld quality in such LLWs can lead to unexpected strip failure in subsequent work such as tension leveling, rolling, pickling, side trimming, annealing, etc., which can lead to serious productivity loss and cumulative operator fatigue .

Therefore, in order to prevent the plate breakage of the welded part that may occur in the post-welding operation and to enable stable operation, the weld quality of the welded part having the tensile and bending strength higher than the base part should be secured. If the welding quality is not good, it is necessary to provide a judgment criterion to the driver in real time so that welding can be performed quickly.

Korean Patent Publication No. 2003-0089896 (November 28, 2003)

SUMMARY OF THE INVENTION It is an object of the present invention to provide a welding quality judging device and a judging method of a strip capable of preventing plate breakage of a welded portion which may occur in a post-welding post-welding operation in advance and stably operating the same.

Another object of the present invention is to provide a welding quality judging device and a judging method of a strip capable of providing a judging criterion so that re-welding can be performed quickly when the welding quality of the strip is not good.

According to an aspect of the present invention, there is provided a welding apparatus including: a welding head movably installed on an upper portion of a strip in a width direction of the strip, the welding head generating a welded portion of the strip; A photographing unit installed at a rear side of the welding head in a traveling direction of the welding head, for converting an image signal photographed by the welding unit into an image and outputting the image; An analysis unit for calculating a size of the welding hole included in the image input from the photographing unit and outputting the calculated size; And a determination unit for determining that the welding quality of the strip is defective when the size of the welding hole input from the analysis unit exceeds a predetermined size.

Here, the predetermined size may be calculated according to the following formula (1) according to the thickness of the strip.

[Equation 1]

Y = 2.9085 * ln (X) + 6.5702

(Where Y is the predetermined size and X is the thickness of the strip to be welded).

The photographing unit may include a camera installed at an upper portion of the strip and converting the image signal photographed by the welding unit into the image and outputting the image; And a lower illuminator installed at a lower portion of the strip and irradiating the welding portion with the first light, wherein the analyzer senses the first light included in the image to calculate the size of the welding hole have.

Further, the photographing unit may further include an upper illuminator disposed on one side of the camera, the upper illuminator being disposed on the upper side of the strip and irradiating the second light to the welding unit, The optical frequencies are different from each other.

In addition, the analysis unit may calculate the number of the welding holes included in the image, and the determination unit may determine that the welding quality of the strip is bad if the number of the welding holes having the predetermined size or more exceeds a predetermined number.

The apparatus further includes an input unit for inputting the predetermined size and the preset number of strips, And a storage unit for storing the size, number, predetermined size, and the predetermined number of the welding holes.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: a conversion step of converting a video signal obtained by photographing a welded portion of a strip into an image; A calculation step of calculating a size of the welding hole included in the image; And determining that the welding of the strip is determined to be defective when the size of the welding hole exceeds a predetermined size.

Here, the predetermined size may be calculated according to the following formula (1) according to the thickness of the strip.

[Equation 1]

Y = 2.9085 * ln (X) + 6.5702

(Where Y is the predetermined size and X is the thickness of the strip to be welded).

The calculating step may further include calculating the number of the welding holes included in the image, wherein, when the number of the welding holes having the predetermined size or larger exceeds a predetermined number, .

Effects of the apparatus and method for determining weld quality of a strip according to the present invention will be described as follows.

First, there is an advantage that the plate breakage of the welded portion which can occur in the post-welding post-welding operation can be prevented in advance and the operation can be performed stably.

Second, there is an advantage that a judgment criterion can be provided so that the re-welding can be performed quickly when the welding quality of the strip is not good.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a welding hole formed in a laser welding part B and a welding part B of a thin strip. Fig.
Fig. 2 is an enlarged view of a portion C in Fig. 1; Fig.
3 (a), 3 (b) and 3 (c) are views showing the case where one, two and four welding holes 1 are formed, respectively.
4 (a) to 4 (f) are diagrams showing the result of performing a tensile strength test according to the size and the number of the weld holes.
5 shows tensile strength test values according to the size of a weld hole of a strip of a specific thickness.
6 is a view showing the allowable size of the welding hole according to the thickness of the strip.
7 shows an input section in which a reference of an acceptable weld hole can be input;
8 (a) and 8 (b) are diagrams showing the configuration of an apparatus for determining weld quality of a strip according to an embodiment of the present invention.
9 is a view showing a welded portion actually measured and a weld hole generated at this time.
10 is a control block diagram of an apparatus for determining welding quality of a strip according to an embodiment of the present invention.
11 is a control flow diagram of a method for determining a weld quality of a strip according to an embodiment of the present invention.
12 is a flowchart of a method for determining a weld quality of a strip according to an embodiment of the present invention.

The present invention relates to a method and a system for monitoring and analyzing a welding hole occurring when a thin material (usually having a thickness of 1 mm or less) is welded and performing sum / negative determination of welding quality in real time. When thick materials are to be welded (usually more than 1mm thick), the two objects to be welded are mainly arranged in the order of concavity, convexity, mismatch, undercut and underfill, which are aligned before and after welding. Though the shape of these strips is important for the material re-welding, a thin plate having a thickness of 1 mm or less often causes pinhole-type defects due to poor gaps, surface conditions, and welding materials. Depending on the test results such as tensile strength, bending strength, etc., the thickness of the strip to be welded depends on the thickness of the strip. Therefore, it is necessary to monitor the welding hole in real time and analyze the size, number, and position of the welding hole to provide feedback in real time. In the present invention, a method of determining the welding quality by determining the allowable size of the welding hole according to the thickness of the thin plate to be welded and monitoring it in real time.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, with reference to the accompanying drawings, an embodiment of a welding quality determining apparatus and a determination method of a strip according to the present invention will be described.

1 to 12, a description will be given of a welding quality determining apparatus for a strip according to an embodiment of the present invention. The apparatus for determining the welding quality of a strip according to the present embodiment is for determining the welding quality of a welding portion B as a portion where the strip S and the strip S are welded to each other and includes a welding head 10, An analysis unit 200, a determination unit 300, an input unit 400, a storage unit 500, and a display unit 600.

8 and 10, the photographing unit 100, the analysis unit 200, the determination unit 300, the input unit 400, the storage unit 500, and the display unit 600 are electrically connected to each other It is connected through a wired or wireless network.

The welding head 10 is installed on the upper portion of the strip S so as to be movable in the width direction of the strip S and creates a welded portion B as a portion where the strip S and the strip S are welded to each other.

8, the photographing unit 100 is provided behind the welding head 10 in the traveling direction of the welding head 10 and converts the image signal photographed by the welding unit B into an image And may include a camera 110, an upper illuminator 120, and a lower illuminator 130.

The camera 110 is installed on the upper part of the strip S and converts the image signal of the welded part B welded by the welding head 10 into an image and outputs it to the analysis part 200. At this time, the camera 110 preferably has a resolution of 20 탆 or more so that the welding portion B can be observed immediately after welding at a welding speed of 10 to 15 MPM.

The upper illuminator 120 is installed on one side of the camera 110 and is disposed on the upper side of the strip S, and irradiates the welding portion B with light. At this time, the light frequency of the upper illuminator 120 and the light illuminance of the upper illuminator 120 are adjusted so that the light of the lower illuminator 130 transmitted through the welding hole 1 and the light of the upper illuminator 120 reflected by the weld B can be clearly distinguished on the image. It is preferable that the optical frequencies of the lower illumination 130 are different from each other. That is, the welding hole 1 is easily detected on the image due to the difference in the optical frequencies of the light of the upper illumination unit 120 and the light of the lower illumination unit 130.

The lower light 130 is provided at a lower portion of the strip S, and irradiates the welding portion B with light. The camera 110 senses the light transmitted through the welding hole 1, which can be formed in the welding portion B, so that the welding hole 1 is sensed.

The analysis unit 200 calculates the size of the welding hole 1 included in the image input from the photographing unit 100 and outputs the calculated size to the determination unit 300. The analysis unit 200 may calculate the number of the welding holes 1 included in the image input from the photographing unit 100 and output the calculated number to the determination unit 300. The analysis unit 200 may determine the position of the welding hole 1 included in the image input from the photographing unit 100 and output the detected position to the determination unit 300.

The determination unit 300 determines that the welding quality of the strip S is satisfactory when the size of the welding hole 1 input from the analysis unit 200 is less than a predetermined size, If the size is exceeded, the welding quality of the strip S can be judged to be defective. Here, the preset size can be calculated by the following equation (1).

[Equation 1]

Y = 2.9085 * ln (X) + 6.5702

(Where Y is a predetermined size and X is the thickness of the strip to be welded).

The determination unit 300 may weight the size of the welding hole 1 according to the position of the welding hole 1 input from the analysis unit 200. [ For example, as shown in the following formula (2), depending on whether the welding hole 1 is positioned at a percentage (%) from the center of the strip S with respect to the half of the entire length of the strip S, The weight of the hole 1 can be weighted.

&Quot; (2) "

Da = Db * (1 + La / (L / 2))

La is the distance from the center of the strip S to the weld hole, L is the total width of the strip S, and D is the width of the welded hole.

In addition, if the number of the weld holes equal to or larger than the predetermined size exceeds a predetermined number, the determination unit 300 may determine that the quality of the welded portion of the strip is defective.

The input unit 400 is for inputting a predetermined size and a predetermined number of the above-described welding holes. The predetermined value and the preset number can be inputted by the user.

The storage unit 500 may store the size, number and location of the welded holes calculated from the analysis unit 100. In addition, the storage unit 500 may store a predetermined size and a predetermined number of the welding holes inputted through the input unit 400. At this time, the predetermined size and the predetermined number of the welding holes stored in the storage unit 500 can be inputted according to the thickness of the strip to be welded.

The display unit 600 is for displaying an image taken by the photographing unit 100 or a converted image and the operator can visually observe the welded portion B of the strip S through the display unit 600. [

Hereinafter, with reference to Figs. 11 and 12, a method of determining the weld quality of a strip according to an embodiment of the present invention will be described.

First, a photographing unit 100 photographs a welded portion B, which is a welded portion of the strip, and then converts the image signal into an image and outputs a converted image (S10).

Next, the calculating unit 200 calculates a size of a welding hole included in the image input from the photographing unit 100 and outputs the calculated size. At this time, the analysis unit 200 may calculate and output the number and position of the welding holes included in the image.

Next, when the determination unit 300 determines that the size of the welding hole inputted from the analysis unit 200 exceeds a predetermined size, a determination step of determining that the welding of the strip is defective is performed (S30). At this time, when the size of the welding hole input from the analysis unit 200 is less than a predetermined size, the determination unit 300 can determine that the welding quality of the strip is good. Here, the predetermined size Y can be calculated by the above-described equation (1).

The determination unit 300 may assign a weight to the size of the welding hole according to the position of the welding hole inputted from the analysis unit 200. [ For example, as shown in the above-mentioned formula (2), depending on whether the welding hole 1 is positioned at a percentage (%) from the center of the strip S with respect to the half of the entire length of the strip S, The weight of the hole 1 can be weighted.

The determination unit 300 may determine that the welding quality of the strip is defective when the number of the welding holes having the predetermined size or more exceeds the predetermined number.

12, when the welding quality of the strip is determined to be defective, the determination unit 300 determines whether the welding head 10 is in a reverse direction to the welding head 10 so that the welding head 10 can re- The above steps may be repeatedly performed again when the welded portion B is re-welded.

Hereinafter, preferred embodiments according to the present invention will be described.

[Example]

In the present embodiment, the tensile strength test was performed on the portion of the welded specimen shown in FIG. 1 where the weld hole 1 was formed as shown in FIG. 2, according to the size and number of the weld hole 1. The tensile strength test is to measure the yield strength of the elastic deformation by pulling the tensile specimen and the tensile strength, which is the maximum stress the tensile specimen can withstand.

Figs. 4 (a) to 4 (f) are diagrams showing the results of performing tensile strength tests according to the size and number of welded holes. Fig.

Referring to FIG. 4, it can be seen that, in the case of a well-welded good article, the base material is blown by the tensile force rather than the welded portion B, and when the size of the weld hole 1 becomes larger than a certain size, have. Specifically, when the size of the welding hole 1 is 0.5 mm in diameter, the base material portion is blown, whereas when the size of the welding hole 1 is 1 mm or more in diameter, it can be seen that the welding portion B can not withstand the tensile force and bursts .

On the other hand, it was confirmed that even if the size of the welding hole 1 was less than 1 mm in diameter, the welding quality was deteriorated depending on the number of the welding holes 1. These results depend on the type and thickness of the base material to be welded, and the 0.17 mm thick base material tested in the present invention has the same result as in FIG. Specifically, the welding quality is good when the size of the welding hole 1 is 1 mm in diameter. However, when the diameter exceeds 1 mm, the base material tensile strength is lower than the lower limit (510 MPa). Therefore, when the welding quality is to be determined, an allowable criterion is determined according to the size and the number of the welding holes 1, and when welding failure occurs, feedback is performed in real time.

6 is a view showing the allowable size of the welding hole according to the thickness of the strip. 6, when the thickness of the strip S is 0.15 mm, the allowable size of the welding hole 1 is 1 mm or less in diameter, and when the thickness of the strip S is 0.17 mm, The diameter of the welding hole 1 is 1.5 mm or less and the allowable welding hole size is 2 mm or less when the thickness of the strip S is 0.22 mm. At this time, the estimated graph is calculated by connecting the sizes (points a, b, c) of the allowable weld holes measured according to the thickness of the strip S, and the result of the estimation graph is as shown in Equation (1) Could reach. That is, it can be seen that as the thickness of the strip S increases, the allowable size of the weld hole also increases according to Equation (1).

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims and their equivalents. Of course, such modifications are within the scope of the claims.

B: welding part (welding bead) 1: welding hole
100: photographing unit 110: camera
120: top lighting 130: bottom lighting
200: analyzing unit 300: judging unit
400: input unit 500: storage unit
600:

Claims (9)

A welding head movably installed in a width direction of the strip at an upper portion of the strip, the welding head generating a welded portion that is a portion of the strip to which the strip is welded;
A photographing unit installed at the rear of the welding head in a traveling direction of the welding head, for converting an image signal photographed by the welding unit into an image and outputting the image;
An analysis unit for calculating and outputting a size of the welding hole included in the image input from the photographing unit;
And a determination unit determining that the welding quality of the strip is defective when the size of the welding hole inputted from the analysis unit exceeds a predetermined size,
Wherein,
A camera installed on the strip to convert the image signal photographed by the welding unit into the image and output the image;
A lower illuminator installed at a lower portion of the strip for irradiating the weld with the first light; And
And an upper illuminator disposed on one side of the camera and disposed on the upper portion of the strip for irradiating the weld with a second light having a different optical frequency from the first light,
The analyzing unit,
And the size of the welding hole is calculated by sensing the first light included in the image. A welding head movably installed in a width direction of the strip at an upper portion of the strip, the welding head generating a welded portion that is a portion of the strip to which the strip is welded;
A photographing unit installed at the rear of the welding head in a traveling direction of the welding head, for converting an image signal photographed by the welding unit into an image and outputting the image;
An analysis unit for calculating and outputting a size of the welding hole included in the image input from the photographing unit;
And a determination unit determining that the welding quality of the strip is defective when the size of the welding hole inputted from the analysis unit exceeds a predetermined size,
And the predetermined size is calculated by the following formula (1) according to the thickness of the strip.
[Equation 1]
Y = 2.9085 * ln (X) + 6.5702
(Where Y is the predetermined size, X is the thickness of the strip to be welded) delete delete The method according to claim 1,
Wherein the analysis unit calculates the number of the welding holes included in the image,
Wherein the determination unit determines that the welding quality of the strip is determined to be defective when the number of the welding holes having the predetermined size or more exceeds a predetermined number. The method of claim 5,
The strip quality determination device
An input unit for inputting the predetermined size and the preset number;
And a storage unit for storing the size, number, predetermined size, and the predetermined number of the welding holes. An irradiation step in which a first light is irradiated onto an upper surface of a welded portion of the strip, and a second light having a different optical frequency from the first light is irradiated to the lower surface of the welded portion;
A converting step of converting a video signal photographed on the upper surface of the welding portion into an image;
Calculating a size of the welding hole by sensing the first light included in the image;
And judging that the welding of the strip is judged to be defective when the size of the welding hole exceeds a predetermined size. A converting step of converting a video signal obtained by photographing a welded portion of the strip into an image;
A calculation step of calculating a size of the welding hole included in the image;
And determining that welding of the strip is determined to be defective when the size of the welding hole exceeds a predetermined size,
Wherein the predetermined size is calculated according to the following formula (1) according to the thickness of the strip.
[Equation 1]
Y = 2.9085 * ln (X) + 6.5702
(Where Y is the predetermined size and X is the thickness of the strip to be welded). The method of claim 7,
Wherein the calculating step further includes calculating a number of the welding holes included in the image,
Wherein the determining step determines that the welding of the strip is defective when the number of the welding holes having the predetermined size or more exceeds a predetermined number.

Images