JPH09304187A - Method and apparatus for measurement of temperature of welded part of electric resistance welded steel pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely measure a temperature even when water is poured on a temperature measuring part. SOLUTION: An apparatus measures temperatures before and after a welded point 2c in the manufacture of an electric resistance welded steel pipe. The apparatus is constituted so as to be provided with a CCD sensor 11 as a temperature measuring means which captures images in a desired temperature measuring range 12 in the circumferential direction before and after the welded point 2c and which measures the temperatures in the temperature measuring range 12 by computing the images, with a converter 13, with an ultrasonic displacement sensor 14 which measures the thickness of water existing on the electric resistance welded steel pipe in a desired place inside the temperature measuring range 12 and with a personal computer 15 which corrects the temperatures with reference to measured results to be sent from the temperature measuring means on the basis of the thickness of the water to be sent from the ultrasonic displacement sensor 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature measuring device capable of accurately measuring a seam temperature before and after a welding point when manufacturing an electric resistance welded steel pipe.

[0002]

2. Description of the Related Art When manufacturing an electric resistance welded steel pipe, it is particularly important to control the temperature of a welded portion. The temperature control of this weld is
Previously, it relied on the operator's visual inspection, but now automatic heat input control has been introduced to control the quality of welds. However, it is needless to say that stable measurement of the temperature of the welded portion is essential even in this automatic heat input control.

By the way, a two-color thermometer described in Japanese Patent Publication No. 60-28590 and a thermometer described in Japanese Patent Laid-Open No. 62-39734 have been proposed to measure the temperature of the welded portion. There is. Among them, Japanese Examined Sho 60-2859
The two-color thermometer described in No. 0 is for performing two-color temperature calculation by using an optical filter, and is disclosed in JP-A-62-397.
The thermometer described in No. 34 measures the temperature of the weld bead portion of the electric resistance welded steel pipe with a heat radiation temperature sensor array using a glass fiber. These Japanese Patent Publications Sho 60-28590
Two-color thermometer described in Japanese Patent Publication No. 62-39734.
The thermometers described in No. 4 are excellent as thermometers.

[0004]

However, when manufacturing a small-diameter thick-walled product having an outer diameter of about 20 to 30 mm,
Since the welding heat is not concentrated on the edge part but goes around the entire steel pipe and the water inside the steel pipe supplied to remove the beads on the inner surface of the steel pipe is heated, as shown in FIG. Is blown back, and the blown-back water 1 covers the both edge portions 2a and the welded portions 2b of the open pipe 2 which is the temperature measuring portion. Further, as shown in FIG. 5 (b), the cooling water 4 of the squeeze roll 3 also splashes on the welded portion 2b, as described above. In this way, when water is applied to the temperature measurement site, the spectral radiance is attenuated, and the measured temperature is lowered as shown in FIG. 6A as compared with the case without water shown in FIG. 6B. However, there is a problem that accurate temperature measurement cannot be performed. In addition, in FIG. 6, a CCD sensor is used in the vicinity of the welding point, other conditions are kept constant, the temperature is measured without supplying water, and then the temperature is measured by artificially supplying water to the surface of the steel pipe. However, it is a measurement result (chart output) obtained by measuring a temperature change between the case where water is present on the surface of the welded part and the case where water is not present. In this case, a temperature decrease of about 30 ° C. occurs.

The present invention has been made in view of the above-mentioned conventional problems, and provides a welded portion temperature measuring device for an electric resistance welded steel pipe capable of performing accurate temperature measurement even when water is splashed on the temperature measuring portion. The purpose is to do.

[0006]

In order to achieve the above object, the welding temperature measuring device for electric resistance welded steel pipe of the present invention is provided with a sensor for measuring the thickness of water in the temperature measuring range. By measuring the water thickness in the temperature measurement range with this sensor and converting the attenuation amount of the spectral radiance based on the water thickness into the temperature decrease amount and correcting it, accurate temperature measurement can be performed. it can.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The welded portion temperature measuring device for an electric resistance welded steel pipe of the present invention captures an image of a desired temperature measurement range in the circumferential direction before and after the welding point of the electric resistance welded steel pipe, and calculates the image to obtain the image. Temperature measurement means for measuring the temperature of the temperature measurement range, a sensor for measuring the thickness of water present on the electric resistance welded steel pipe at a desired position within the temperature measurement range, and the temperature measurement means And a calculation means for correcting the temperature of the measurement result based on the thickness of the water sent from the sensor.

The method for measuring the temperature of the welded portion of the electric resistance welded steel pipe of the present invention captures an image of a desired temperature measurement range in the circumferential direction before and after the welding point of the electric resistance welded steel pipe, and calculates the image to calculate the temperature measurement range. And the thickness of water existing on the electric resistance welded steel pipe at a desired position within the temperature measurement range is measured. Then, temperature correction based on the thickness of the water is performed on the measured temperature result.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The welding temperature measuring device for electric resistance welded steel pipe of the present invention will be described below based on an embodiment shown in FIGS. FIG. 1 is a schematic configuration diagram of a welded portion temperature measuring device for an electric resistance welded steel pipe according to the present invention, FIG. 2 is a diagram showing a relationship between water thickness and temperature change amount,
FIG. 3 is a measurement result diagram after correcting the water thickness, FIG.
FIG. 4 is a diagram showing a result of obtaining a temperature profile of an electric resistance welded steel pipe by using the device of the present invention.

In FIG. 1, 11 is a CCD sensor, which is a temperature measuring range 1 in the circumferential direction before and after the welding point 2c.
The second image is captured and the image is output to the converter 13. The converter 13 calculates an image from the image sent from the CCD sensor 11 and converts it into a temperature. In this embodiment, the CCD sensor 11 and the converter 13 form a temperature measuring means. Reference numeral 14 denotes, for example, an ultrasonic displacement sensor, which measures the thickness of water at a desired location within the temperature measuring range 12 and outputs the measured value to the personal computer 15 which is a calculating means.

The personal computer 15 inputs the temperature output signal from the converter 13 and the water thickness signal sent from the ultrasonic displacement sensor 14, and determines the attenuation amount of the spectral radiance based on the water thickness. As will be described later, the amount of temperature decrease is converted and corrected. Then, the corrected result is output to and recorded in the recorder 18, and the current temperature measurement location of the CCD sensor 11 is displayed on the monitor 17.

That is, the present inventors have found that the water thickness is 0 to 9 mm.
When we investigated the effect on temperature when present,
As shown in FIG. 2, it was found that even when a small amount of water was present, the temperature instruction suddenly decreased, and thereafter the temperature instruction decreased according to the water thickness. Therefore, from the results shown in FIG. 2, for example, a temperature correction table shown in Table 1 below is created, and the calculator 13 performs the correction based on the temperature correction table.
The temperatures shown in FIG. 2 are the results measured by a monochromatic thermometer.

[0013]

[Table 1]

If necessary, the personal computer 15 can perform various calculations such as the temperature profile, maximum value, and average value based on the corrected results, and the results are printed out on the printer 16. . In FIG. 1, 19 is a slide mechanism for changing the temperature measurement location in the CCD sensor 11, and 20 is a work coil for heating the edge portion 2a of the open pipe 2.

The welded portion temperature measuring device of the electric resistance welded steel pipe according to the present invention has the above-mentioned structure. Next, a method for measuring the temperature of the welded portion of the electric resistance welded steel pipe using the welded portion temperature measuring device will be described. To do.

First, the ultrasonic displacement sensor 14 is attached, for example, at a height position 300 mm above the measurement site, and the temperature measurement range 12, that is, the surface of the open pipe 2 is set to the zero point in the first state without water. Set to. Then, in the measurement state, the temperature of the temperature measurement range 12 is measured by the CCD sensor 11, and the water thickness is measured by the ultrasonic displacement sensor 14 with a resolution of 0.1 mm, for example.

In the personal computer 15, the temperature in the temperature measuring range 12 sent from the converter 13 is input, and the correction based on the thickness of the water sent from the ultrasonic displacement sensor 14 to this input temperature is performed. The temperature correction table of 2 is used. At this time, the corrected measurement result as shown in FIG. 3 is output to and recorded in the recorder 18, and the current temperature measurement range of the CCD sensor 11 is displayed on the monitor 17.

Further, the personal computer 15 can calculate the temperature profile as shown in FIG. 4, for example, based on the corrected measurement result, and print the result on the printer 16. Although the CCD sensor 11 is used in the present embodiment, the present invention is not limited to this, and for example, an image pickup tube, a fiberscope or the like may be used.

[0019]

As described above, according to the welding temperature measuring device for electric resistance welded steel pipe according to the present invention, the temperature measuring range in which water cannot be practically prevented is excluded from the influence of water. It is possible to measure with high accuracy, and it is possible to greatly improve the quality at the time of manufacturing ERW steel pipe.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a weld temperature measuring device for an electric resistance welded steel pipe according to the present invention.

FIG. 2 is a diagram showing the relationship between water thickness and temperature change amount.

FIG. 3 is a measurement result diagram after correction of water thickness.

FIG. 4 is a diagram showing a result of obtaining a temperature profile of an electric resistance welded steel pipe by using the device of the present invention.

5 (a) and 5 (b) are explanatory views of a water thickness generation state at a welded portion of an electric resistance welded steel pipe, in which (a) shows blowback of high-pressure water and (b) shows cooling water of a squeeze roll.

FIG. 6 is a diagram showing the influence of water by temperature measurement, (a)
Shows the case where water exists, and (b) shows the case where water does not exist.

[Explanation of symbols]

 2c Welding point 11 CCD sensor 12 Temperature measurement range 13 Transducer 14 Ultrasonic displacement sensor 15 Personal computer

Claims (2)

[Claims] 1. A method for measuring the temperature before and after a welding point in the production of an electric resistance welded steel pipe, wherein an image of a desired temperature measurement range in the circumferential direction before and after the welding point is captured, and the image is image-calculated to obtain the image. Along with measuring the temperature of the temperature measurement range, the thickness of the water present on the electric resistance welded steel pipe at the desired location within the temperature measurement range is measured, and the temperature based on the thickness of the water is the measured temperature result. A method for measuring a weld temperature of an electric resistance welded steel pipe, which comprises performing correction. 2. An apparatus for measuring a temperature before and after a welding point during the production of an electric resistance welded steel pipe, wherein an image of a desired temperature measurement range in the circumferential direction before and after the welding point is captured and the image is calculated to perform the temperature calculation. Temperature measurement means for measuring the temperature of the measurement range, a sensor for measuring the thickness of water present on the electric resistance welded steel pipe at a desired location within the temperature measurement range, and a measurement sent from the temperature measurement means A welded part temperature measuring device for an electric resistance welded steel pipe, comprising: a calculation means for correcting the temperature based on the thickness of water sent from the sensor as a result.