JPH1190658A - Manufacturing device for welded tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing device for a welded tube which capable of optically detecting the position of a butted part and the temperature of a preheated edge part and capable of manufacturing the welded tube of excellent quality. SOLUTION: A light source 4 comprises a lamp 5 to emit a light beam in which the intensity of the light component of a wavelength in the vicinity of 0.65 μm is sufficiently weak and the intensity of the visible light component of the wavelength of >=0.38 μm to below 0.78 μm is sufficiently strong and a filter 6 to remove a light component whose the wavelength is>=0.65 μm, the light component of the wavelength of >=0.65 μm is removed while the light radiated from the lamp 5 transmits a filter 6 and the light is led to an optical head 8 through an optical fiber 7. A first image pick-up device 1 to detect the position of a seam part 18 and a second image pick-up device 2 to detect the temperature of a preheated edge part E are arranged between a high frequency heater 15 and a laser beam torch 9, the plane light irradiated from the optical head 8 is made incident to the first image pick-up device 1 and the thermally radiated light is made incident to the second image pick-up device 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preheating an edge portion of an open pipe formed by bending a strip-shaped metal plate into a cylindrical shape, abutting the preheated edge portion, and applying an energy beam to the abutting portion. The present invention relates to an apparatus for producing a welded pipe by irradiation.

[0002]

2. Description of the Related Art FIG. 8 is a schematic perspective view showing an apparatus for manufacturing a welded pipe using a laser beam, where S is a metal band. The wound metal band S is fed to the leveler 51 by the uncoiler H, and the leveler 51 straightens the metal band S and sends it to the forming roll. The forming rolls include breakdown rolls 52, 52, ... which are horizontal rolls, cluster rolls 53, 53, ... which are vertical rolls, and fin pass rolls 54, 54, ... which are horizontal rolls. The metal strips S are arranged so as to form a pair, facing the transfer area of the metal strips S, at a predetermined distance in the transfer direction.
In the process of passing through the forming roll, the metal strip S is formed into an open pipe OP that is curved so that both side edges E, E in the width direction face each other.

An open pipe OP is provided downstream of the forming roll.
A pair of squeeze rolls 5 that abut both edges E, E
5, 55 are arranged. Slightly upstream of the squeeze rolls 55, a high-frequency heater 67 for induction heating the edges E, E of the open pipe OP is provided facing the moving area of the edges E, E. A laser torch 67 for irradiating a laser beam to the seam portion is provided opposite to the seam portion which is abutted by the squeeze rolls 55 of the open pipe OP. The open pipe OP preheats the edge portions E, E to a required temperature by induction heating of the high frequency heater 67, and the preheated edge portions E, E are squeezed roll 5
Charged at 5,55. The open pipe OP is welded into a welded pipe 17 by abutment by the squeeze rolls 55, 55 and melting by irradiating a laser beam from the laser torch 67 to the seam, and is transferred to a finishing roll (not shown).

[0004]

In an apparatus for continuously manufacturing a welded pipe by welding a seam portion of an open pipe formed with a metal band, so-called rolling, in which the open pipe rotates in the circumferential direction, occurs. . As described above, in a device for manufacturing a welded pipe by laser beam irradiation, since the spot diameter of the laser beam is small, when rolling occurs, the seam portion deviates from the spot of the laser beam and unwelding occurs. easy. Therefore, it is important to detect the position of the seam portion that swings by rolling with high accuracy and adjust the position of the laser beam emitted from the laser torch 67.

Further, when the temperature of the preheated edge portion changes due to a change in environmental temperature, the melting depth of the seam portion by the laser beam changes, and poor welding such as a decrease in the strength of the welded portion occurs. It is also important to measure the temperature of the edge portion with high accuracy and control the output of the high-frequency heater, the output of the laser torch, or the transfer speed of the open pipe based on the result.

[0006] When detecting the position of the seam and measuring the temperature of the preheated edge, an optical pipe that does not come into contact with the open pipe is used to prevent the temperature of the seam from changing. It is required to be performed by the device. The temperature of the preheated edge can be measured optically by measuring the heat radiation from the edge. On the other hand, in order to optically detect the position of the seam portion, the present inventor has disclosed in Japanese Patent Application Laid-Open No. H9-182984:
An apparatus has been proposed in which light is projected onto an appropriate region including both edges of a preheated open pipe to capture an image of the region, and a position of a seam portion is calculated based on the obtained image. In such an apparatus, the position of the seam can be detected with high accuracy without being affected by the shape of the edge of the open pipe.

However, when simultaneous measurement of heat radiation for measuring the temperature of the preheated edge portion and imaging of the edge portion for detecting the position of the seam portion are performed, heat radiation from the edge portion is required. Since the position where the edge is measured and the position where the edge is imaged are close to each other, the reflected light projected on the edge interferes with the heat radiation, and the temperature of the preheated edge cannot be accurately measured. Was. Therefore, one of the two methods must be performed by the contact method, and in this case, the temperature of the seam portion changes, which may cause poor welding due to the laser beam, which may cause deterioration in the quality of the welded pipe.

The present invention has been made in view of the above circumstances, and an object of the present invention is to apply a visible light component from light irradiation means for irradiating light having a predetermined wavelength characteristic to both preheated edges of an open pipe. Irradiating light of a predetermined wavelength band including the light, and detecting the position of the abutting portion based on an image obtained by imaging the region by the imaging means, and detecting the wavelength component light related to the heat radiation from the preheated edge portion. Is detected by the detecting means,
By calculating the temperature of the edge portion based on the signal output from the detection means, the position of the abutment portion and the temperature of the preheated edge portion can be optically detected, and high-quality welding can be performed. An object of the present invention is to provide an apparatus for manufacturing a welded pipe capable of manufacturing a pipe.

[0009]

According to a first aspect of the present invention, there is provided an apparatus for manufacturing a welded pipe, wherein an opposed edge portion of an open pipe formed by bending a strip-shaped metal plate into a cylindrical shape while transferring the strip-shaped metal plate in a longitudinal direction. Between the preheater and the open pipe,
A pair of rolls for abutting the preheated edge portion, an energy beam irradiator for irradiating an energy beam to the abutting portion abutted by the roll of the open pipe to melt the abutting portion, and the abutting portion Position detecting means for detecting the position of the, based on the detection result, comprising an adjusting means for adjusting the irradiation position of the energy beam, in a device for manufacturing a welded pipe by fusing the preheated abutting portion, The position detection means, imaging means for imaging both preheated edges of the open pipe, light irradiation means for irradiating light of a predetermined wavelength band including a visible light component to the imaging field of view of the imaging means, the imaging means Based on the image obtained by imaging, comprising a position calculating means for calculating the position of the abutting portion, to detect the light of the wavelength component related to the heat radiation from the preheated edge portion of the open pipe, the Detecting means for outputting a signal corresponding to the intensity; temperature calculating means for calculating the temperature of the edge portion based on the signal output from the detecting means; and manufacturing of the welded pipe based on the calculated temperature. It is characterized by comprising adjusting means for adjusting the condition.

[0010] The apparatus for manufacturing a welded pipe according to the second aspect of the present invention comprises:
In the present invention, the light irradiation means has a weak wavelength component of 0.65 μm or more, and emits light containing a wavelength component of a required intensity or more in a wavelength band of about 0.38 μm or more and less than 0.65 μm, and / or 0.65 μm. It is characterized by including a filter that reduces the intensity of wavelength components of μm or more and transmits light.

In the apparatus for manufacturing a welded pipe according to the present invention, 0.1 mm
The intensity of wavelength components of 65 μm or more is weak, and is approximately 0.38 μm or more.
A lamp that emits light containing a wavelength component having a required intensity or more within a wavelength band of less than 65 μm, for example, a metal halide lamp,
And / or using a light irradiation means having a filter that transmits light by reducing the intensity of the wavelength component of about 0.65 μm or more,
Light in the above-described wavelength band is irradiated to the edge portion preheated from the outside or inside of the open pipe. When such light is radiated, a visible light component of about 0.38 μm or more and less than 0.65 μm is contained, so that an image including images of both edges of the open pipe is formed by the imaging means. Then, a collision point is obtained by calculating a midpoint between the two edge parts or by calculating an intersection of the ridge lines of the two edge parts, and the energy beam irradiation position is moved to the position of the collision point.

On the other hand, when an image pickup device is used as the detecting means, the detecting means forms an image of the edge portion preheated by, for example, monochromatic light having a wavelength of 0.65 μm. Since the intensity of the plurality of pixels that form this image increases as the temperature increases, by using a relational expression that expresses the relationship between the two,
The temperature at each position of the image formed by the detecting means is obtained. As the detecting means, in addition to the imaging device that forms a two-dimensional image as described above, a scanner that forms a one-dimensional image and a radiation thermometer that is arranged at a predetermined distance in the circumferential direction of the open pipe may be used. it can.

By the way, the light emitted from the above-mentioned light irradiation means has a weak wavelength component of 0.65 μm or more.
Even if this light is incident on the second imaging means, it hardly affects the temperature measurement of the edge portion. Thereby, the position of the abutting portion of the preheated edge portion and the temperature of the preheated edge portion can be optically detected. Then, based on the detected temperature of the edge portion, the output of the preheater is adjusted, the output of the energy beam irradiator is adjusted, or the transfer speed of the open pipe is adjusted, or a combination thereof is used to manufacture a welded pipe. Adjust the conditions. Thereby, a high quality welded pipe can be manufactured.

[0014]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a schematic side sectional view showing a configuration of a main part of a welded pipe manufacturing apparatus according to the present invention, and FIG. 2 is a schematic sectional view taken along line II-II of the apparatus shown in FIG. Open pipe OP with a metal band formed into a cylindrical shape
Has been transported in the direction of the arrow. A pair of left and right squeeze rolls 25, 25 are provided facing the transfer area of the open pipe OP, and the open pipe OP is inserted between the squeeze rolls 25, 25.

On the peripheral surface of the open pipe OP inserted between the squeeze rolls 25, 25, the top pressure rolls 26, 26 for applying an appropriate rolling force to the open pipe OP are opened so as to have a predetermined opening angle. Rolled in the circumferential direction of the pipe OP at a distance from each other.
Further, the opposing edge portions E (E) of the open pipe OP are abutted by the top pressure rolls 26, 26.
A laser torch 9 for irradiating the laser beam 19 to the seam portion 18 is an open pipe on the seam portion 18 which is the abutting point.
It is arranged to swing freely in the circumferential direction of the OP. Laser torch 9
Are driven in the circumferential direction by a servo motor 10, and the driving operation of the servo motor 10 is controlled by a drive controller 11.

A high-frequency heater 15 for applying a high-frequency alternating magnetic field is provided upstream of the laser torch 9 at an edge portion E.
(E), the high frequency heater 15 is supplied with a high frequency current from the oscillator 16.
The edge E (E) of the open pipe OP is a high-frequency heater 15
And induction heating to the required temperature. The output of the oscillator 16 is controlled by the temperature controller 21.
The open pipe OP whose edge portion E (E) is preheated by the high-frequency heater 15 is charged into the squeeze rolls 25, 25 and the top pressure rolls 26, 26, and is abutted as described above, and irradiated from the laser torch 9. The welded laser beam 19 melts the seam portion 18 to form a welded tube 17 continuously.

A cylindrical mandrel bar 31 is inserted into the open pipe OP, and the tip of the mandrel bar 31 extends slightly downstream from the seam portion 18 described above. A tool 33 is provided upright on the peripheral surface near the tip of the mandrel bar 31, and the inner bead of the welded pipe 17 is cut by the tool 33. A rectangular concave portion is provided between the high-frequency heater 15 of the mandrel bar 31 and the laser torch 9 and opposing the gap between the opposing edge portions E (E) of the open pipe OP.
On the bottom surface of the concave portion 32, a resin (for example, an acrylic resin) having a light diffusing property is formed into a rectangular shape, and an optical head 8 that emits planar light is fixed. .
Light of a predetermined wavelength is incident on the optical head 8 from the light source 4 via the optical fiber 7, and the planar light emitted from the optical head 8 is transmitted from the inside of the open pipe OP. The gas is discharged to the outside of the open pipe OP through the gap between the facing edge portions E (E).

The light source 4 is a lamp 5 which emits light having a sufficiently low intensity of a light component having a wavelength around 0.65 μm and a sufficiently high intensity of a visible light component of 0.38 μm to less than 0.78 μm, such as a metal halide lamp. And a filter 6 for removing a light component having a wavelength of 0.65 μm or more. The light radiated from the lamp 5 is transmitted through the filter 6 so that the light component having the above-described wavelength is removed. The light is guided to an optical head 8 by a fiber 7.

Between the high-frequency heater 15 and the laser torch 9, the first image pickup device 1 for picking up an image of an opposing edge E (E) for detecting the position of the seam 18 is provided by an optical head 8.
Are arranged to face each other. The planar light emitted from the optical head 8 is radiated from the inside of the open pipe OP to the outside of the open pipe OP through the gap of the preheated edge portion E (E) as described above, and the first imaging device 1, and an image of the edge portion E (E) is formed on the first imaging device 1. Further, in order to detect the temperature of the edge portion E (E) preheated by the high-frequency heater 15, a second camera such as a monochromatic thermometer camera having a measurement wavelength of 0.65 μm is provided near the first imaging device 1. The image pickup device 2 has a preheated edge portion E (E)
The heat radiation light from the edge portion E (E) is incident on the second imaging device 2.

FIG. 3 is a graph showing the spectral characteristics of light emitted from a metal halide lamp, and FIG. 6 is a graph showing the spectral characteristics of light emitted from a halogen lamp.
In both figures, the vertical axis indicates light intensity, and the horizontal axis indicates wavelength. 2. Description of the Related Art Halogen lamps are widely used as lamps of light projectors that project light onto an object when the object is imaged by an imaging device. However, the spectral characteristic of the light emitted from the halogen lamp has a parabolic shape having a peak at approximately 0.65 μm, as is apparent from FIG. 6, and such light is incident on the second imaging device 2. In this case, since the light from the halogen lamp interferes with the heat radiation from the edge portion E (E), the temperature of the edge portion E (E) cannot be measured accurately.

On the other hand, as is apparent from FIG. 3, the light emitted from the metal halide lamp has a spectral characteristic of 0.45 μm.
Although there are peaks in the visible light wavelength band near m and around 0.55 μm, the intensity of the infrared light wavelength band of 0.65 μm or more is weak. E (E) hardly interferes with the heat radiation light.

Further, in the light source 4 shown in FIG. 1, since the intensity of the light component having a wavelength of 0.65 μm or more is reduced by the filter 6, the light emitted from the light source 4
The intensity of the infrared wavelength band of 0.65 μm or more is 0.55 μm
The intensity is reduced to approximately 1/100 or less of the intensity in the visible light wavelength band near m.

The first image pickup device 1 forms an image including an image of the opposing edge portion E (E) by the light emitted from the optical head 8 and supplies the image to the drive control device 11 described above. The CPU 12 of the drive control device 11 captures an image provided from the first imaging device 1 at a predetermined cycle and stores it at a predetermined address of the memory 13. The CPU 12 binarizes the image stored in the memory 13 and generates a binarized image to obtain the ridge lines of the facing edge portions. CPU
12 calculates the coordinates of the midpoint of the obtained both ridge lines, or calculates the curvature of both ridge lines, respectively, extends the corresponding ridge line with the obtained curvature, calculates the coordinates where the both ridge lines intersect, and calculates the coordinates. The position in the circumferential direction of the seam 18 is determined. And CPU12
Gives a command to the servo motor 10 and determines the seam portion 18
The laser torch 9 is swung so that the laser beam is irradiated to the position.

Further, the second image pickup device 2 converts the incident light by 0.6
By extracting the monochromatic light of 5 μm and performing photoelectric conversion on the monochromatic light, an image signal related to the heat radiation light from the edge portion E (E) is generated and supplied to the CPU 22 of the temperature control device 21.
The CPU 22 captures the image signal provided from the second imaging device 2 at a predetermined cycle, and stores it at a predetermined address in the memory 23. In the CPU 22, for the image stored in the memory 23, a scanning line for scanning in the circumferential direction of the open pipe OP and a conversion formula for converting light intensity into temperature are set in advance,
Each time the CPU 22 captures an image from the second imaging device 2, the CPU 22 converts the light intensity of each pixel on the scanning line of the image stored in the memory 23 into a temperature to form a temperature distribution curve.

FIG. 4 is a graph showing an example of a temperature distribution curve created by the temperature control device 21 shown in FIG. 1. The vertical axis represents the temperature, and the horizontal axis represents the position on the scanning line (in the circumferential direction of the open pipe). Each is shown. As shown in FIG. 4, the temperature distribution curve has two large peaks according to the two opposing edges, and the temperature rapidly increases toward both peaks, and the temperature rapidly decreases from both peaks. doing.

The CPU 22 specifies an area of the heated edge E (E) based on the above-mentioned temperature distribution curve, calculates an average temperature of the area, and determines whether or not the average temperature is within a preset temperature area. Judge. Then, when the temperature of the edge portion E (E) is out of the predetermined temperature range, the CPU 22
A command is given to the oscillator 16 to adjust the output of the high-frequency heater 15.

By the way, when the light source provided with the halogen lamp is used without disposing the filter 6 shown in FIG. 1, the preheated edge portion E (E)
Temperature cannot be determined.

FIG. 7 is a graph showing a temperature distribution curve formed by using a light source having a halogen lamp. The vertical axis indicates temperature, and the horizontal axis indicates a position on a scanning line.
As shown in FIG. 6, the light emitted from the halogen lamp has a parabolic spectral characteristic with a peak at approximately 0.65 μm. Therefore, when the filter 6 shown in FIG. The light emitted from the second imaging device affects the image formed by the second imaging device 2, and as shown in FIG. 7, the temperature distribution curve has a substantially trapezoidal shape. For this reason, it is not possible to specify the preheated regions of both edge portions, and it is not possible to determine the temperature.

As described above, in the welding pipe manufacturing apparatus according to the present invention, the abutting portion 18 of the preheated edge portion E (E) is used.
And the temperature of the preheated edge portion E (E) can be optically detected, and the output of the high-frequency heater 15 is controlled based on the detected temperature of the edge portion E (E). Can be manufactured.

In the present embodiment, the preheated edge portion E is formed by using the second imaging device 2 for forming a two-dimensional image.
The temperature of (E) is measured, but the present invention is not limited to this. For example, a scanner for forming a one-dimensional image and a plurality of radiation thermometers arranged at a predetermined distance in a circumferential direction of an open pipe are provided. It is needless to say that can be used.

In this embodiment, the output of the high-frequency heater 15 is adjusted based on the measurement result of the temperature of the preheated edge portion E (E). The invention is not limited thereto, and it goes without saying that the intensity of the laser beam 19 output from the laser torch 9 may be adjusted, and the transfer speed of the open pipe OP may be adjusted. Furthermore, the output adjustment of the high-frequency heater 15, the output adjustment of the laser torch 9, or the transfer speed adjustment of the open pipe OP may be combined.

In this embodiment, the wavelength is 0.65
The intensity of the light component near μm is sufficiently weak, 0.38 μm or more and 0.78
The light source 4 includes a lamp 5 that emits light having a sufficiently strong visible light component of less than μm and a filter 6 that removes a light component having a wavelength of 0.65 μm or more. It is needless to say that the light source may include only one of the lamp 5 and the filter 6.

In this embodiment, the optical head is attached to the mandrel bar inserted in the open pipe,
Although the light is emitted from the inside of the open pipe to the outside, the present invention is not limited to this, and the light is projected from the optical head disposed outside the open pipe to the field of view of the first imaging device. Is also good.

Further, in the present embodiment, two image pickup devices are used, but the present invention is not limited to this.
As shown in FIG. 5, one imaging device is provided with a first imaging unit that forms an image related to the shape of an edge portion, and a second imaging unit that forms an image related to heat radiation from the edge portion. Needless to say, it is good.

In FIG. 5, the lens 36,
On the optical axis 36, there is provided a reflector 37 that reflects the infrared component having a wavelength of 0.65 μm or more at a substantially right angle and transmits the component having a wavelength of 0.65 μm or less. The first CCD 38 is disposed on the optical axis of the light source, and the second CCD 39 is disposed on the optical axis of the light reflected by the reflector 37. An image including an image related to the shape of the edge portion is stored in the first CCD 38, and the second CCD 38
In 39, an image relating to the heat radiation from the preheated edge is formed. Thereby, the cost required for the imaging device can be reduced.

[0036]

As described above in detail, in the apparatus for manufacturing a welded pipe according to the present invention, the position of the abutting portion of the preheated edge portion and the temperature of the preheated edge portion are optically detected. The present invention has excellent effects, for example, because the manufacturing conditions of the welded pipe are adjusted based on the detected temperature of the edge portion, so that a high quality welded pipe can be manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic side cross-sectional view showing a main part configuration of a welded pipe manufacturing apparatus according to the present invention.

FIG. 2 is a schematic cross-sectional view of the device shown in FIG. 1, taken along line II-II.

FIG. 3 is a graph showing spectral characteristics of light emitted from a metal halide lamp.

FIG. 4 is a graph showing an example of a temperature distribution curve created by the temperature control device shown in FIG.

FIG. 5 is a schematic sectional view showing another embodiment.

FIG. 6 is a graph showing spectral characteristics of light emitted from a halogen lamp.

FIG. 7 is a graph showing a temperature distribution curve formed using a light source including a halogen lamp.

FIG. 8 is a schematic perspective view showing an apparatus for manufacturing a welded pipe using a laser beam.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st imaging device 2 2nd imaging device 4 light source 5 lamp 6 filter 8 optical head 9 laser torch 15 high frequency heater 17 welding pipe 31 mandrel bar OP open pipe E edge part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G01B 11/00 G01B 11/00 H

Claims (2)

[Claims] While transferring a strip-shaped metal plate in the longitudinal direction,
A preheater for preheating the opposing edges of the open pipe formed by bending it into a cylindrical shape, a pair of rolls for sandwiching the open pipe and abutting the preheated edges, and an impulse formed by the rolls of the open pipe. An energy beam irradiator for irradiating an energy beam to the abutting portion to be fused to melt the abutting portion, position detecting means for detecting a position of the abutting portion, and the energy beam based on the detection result. An adjusting means for adjusting the irradiation position of the welding pipe, the apparatus for manufacturing a welded pipe by fusing the preheated abutting portion, wherein the position detecting means, imaging means for imaging both preheated edges of the open pipe and Calculating a position of the abutting portion based on light irradiation means for irradiating light of a predetermined wavelength band including a visible light component to an imaging field of view of the imaging means, and an image obtained by the imaging means; Position detecting means, detecting light of a wavelength component related to heat radiation from the preheated edge of the open pipe, detecting means for outputting a signal corresponding to the light intensity, and output from the detecting means A temperature calculating means for calculating the temperature of the edge portion on the basis of the obtained signal, and an adjusting means for adjusting the manufacturing conditions of the welded pipe based on the calculated temperature. . 2. The lamp according to claim 1, wherein the light irradiating means has a weak wavelength component of 0.65 μm or more and emits light containing a wavelength component of a required intensity or more in a wavelength band of about 0.38 μm or more and less than 0.65 μm; The apparatus for manufacturing a welded pipe according to claim 1, further comprising a filter that reduces the intensity of a wavelength component of 0.65 µm or more and transmits light.