JPH04371393A - Detection of packing ratio of flux in welding wire including flux - Google Patents

Abstract

PURPOSE:To enable measurement for long time under intense resistance to contamination of mesureing instrument and to detect packing ratio of flux in a welding wire including flux at high accuracy. CONSTITUTION:In the method for detecting the packing ratio of flux in manufacturing process for the welding wire including the flux, recessed groove having almost a fixed shape is formed while running a strip steel 1 in the length direction, and after packing the flux 2 in this recessed groove, by using a displacement sensor 4 for detecting distance of the material to be measured with the position of reflecting light to continuously measure the packing height of flux in the recessed groove, the packing ratio of flux is detected. As the displacement sensor, laser beam type, etc., is used.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a flux filling rate in a flux-cored welding wire.

0002

[Prior Art] Flux-cored welding wire (hereinafter referred to as "composite wire") is manufactured by, for example, as shown in FIG. ) is formed, and after filling the groove with flux 2, the groove is further rounded and wire drawn to form a predetermined wire diameter.

However, during the above-mentioned forming process of the composite wire, a problem occurred in the wire take-up mechanism of the wire drawing device or the flux supply section of the flux supply device, and the filling rate of flux 2 (flux weight per unit length weight of the composite wire) ratio) may change. Therefore,
Conventionally, a sample of a certain length is cut out from one lot of composite wire that has been formed, and after measuring the total weight of the sample, the mating surface 3 of the welding wire is opened and the wrapped flux 2 is removed. Measure the weight of only the outer skin 1. Then, calculate each weight obtained according to the following formula,
The flux filling rate (%) is calculated.

[0004] Flux filling rate (%) = {(total weight of composite wire in sample - weight of outer skin)/(total weight of composite wire in sample)}×100

However, the sampling destructive inspection method described above cannot deal with variations in the manufacturing process, and it cannot be said that sufficient quality control is achieved. In addition, with the above destructive inspection method, a post-inspection is performed on the product after manufacturing is completed, or an intermediate inspection is performed by temporarily stopping the production line, but in the former case, the response is slow, so in the worst case, the entire product may have to be discarded. However, the latter method not only reduces the operating rate but also may result in new defective products due to changes in conditions after restarting.

[0006]

[Problems to be Solved by the Invention] Therefore, the present inventors researched a method that can continuously measure the entire length of the flux filling rate supplied to the steel strip during the manufacturing process, and found that the flux filling rate of the steel strip at the flux filling position We have come up with the idea that if the running speed and the amount of flux supplied at the position are constant, the thickness of the flux placed in the groove, that is, the filling height of the flux, will be constant. Further, it was considered that when the filling height is approximately at the center in the case of a semicircular groove in cross section, or in the case of a U-shaped groove in cross section, there is a linear proportional relationship between the flux level and the flux filling rate. The inventors believe that by detecting changes in the filling height, the flux filling rate can be determined, which can detect abnormalities in the running speed of the steel strip or the amount of flux supplied, contributing to uniform product quality. As a result of further studies based on this knowledge, we previously proposed a new flux filling detection method in Japanese Patent Publication No. 50717/1983.

The method disclosed in Japanese Patent Publication No. 61-50717 is a method for detecting the flux filling rate during the manufacturing process of flux-cored welding wire, and is a method for detecting the flux filling rate during the manufacturing process of flux-cored welding wire. After forming a groove and filling the groove with flux, a photoelectric sensor is used to detect the distance to a non-measurable object based on the strength of the amount of reflected light. A method characterized in that the filling rate of the flux is detected by placing a photoelectric sensor close to the filling flux level so that it is at a short distance, and continuously measuring the height of the flux filling in the groove with the photoelectric sensor. It is.

However, since this method uses a photoelectric sensor to convert the intensity of the amount of reflected light into voltage, the light emitting ability and light receiving sensitivity may change due to dirt on the lens surface and light receiving surface due to scattering of flux dust. However, the period during which normal measurements can be made becomes shorter. It is also possible to detect the degree of contamination and correct it, but this is complicated and has problems in terms of accuracy.

[0009] The present invention has been made to solve these problems, and is capable of resisting dirt on measuring equipment, enabling long-term measurement, and highly accurate flux filling of flux-cored welding wire. The purpose of this invention is to provide a method by which the rate can be detected.

0010

[Means for Solving the Problems] In order to solve the above-mentioned problems, the inventor of the present invention has conducted intensive research into a measurement system that is not affected by dirt on measuring instruments such as lenses, and has developed a laser-based measurement system instead of a photoelectric sensor. We have discovered that this is possible by using a displacement sensor such as the above, and have hereby accomplished the present invention.

That is, the present invention is a method for detecting the flux filling rate during the manufacturing process of flux-cored welding wire, in which a concave groove of a substantially constant shape is formed while a steel strip is running in the length direction, and a concave groove of a substantially constant shape is formed. After filling the groove with flux, a displacement sensor that detects the distance to the object to be measured based on the position of reflected light is used to continuously measure the height of flux filling in the groove. The gist of the present invention is a method for detecting a flux filling rate of a flux-cored welding wire, which is characterized by detecting the filling rate of a flux-cored welding wire.

The present invention will be explained in more detail below with reference to the drawings.

【Example】

FIG. 2 is a perspective view showing an example of the arrangement of an optical displacement sensor such as a laser type used in the detection method of the present invention.
Displacement sensor 4 determines the filling height (flux placement level) of
It is configured to measure. Note that 5 serves as both a power source and an output display for the displacement sensor.

That is, level measurement by the displacement sensor 4 is performed using a light source 1 such as a laser, as shown in FIG.
The reflected light of the light projected from 0 to the surface of the non-measurement object through the light projection lens 11 is transmitted to the optical position detection element 1 through the light reception lens 12.
4, and move the position of the reflected light (A' in the case shown)
, B') is converted into a voltage, and the position of the reflected light can be detected as a change in the distance between the non-measurable object and the displacement sensor 4.

The displacement sensor 4 has characteristics as shown in FIG. 4 between (1) the output voltage of the displacement sensor 4, and (2) the distance between the displacement sensor 4 and the non-measurable object (operating distance). use. In Fig. 5, when the horizontal axis (x) is the flux filling height and the vertical axis (y) is the output voltage, the portion shown by the solid line (between points C' and D') is approximately y
Although the relationship is a linear function represented by =ax+b, accurate determination cannot be made in a region where the output voltage is higher than point C' or lower than point D'.

Note that since the distance to the powder is measured rather than the distance to a flat plate surface, there is diffuse reflection of light, which can cause measurement errors. It has been found that fairly accurate measurement results can be obtained if various constants are determined in advance.

That is, on the actual production line, any (x1, y1) that should be on the line y=ax+b above
If the constants a and b are determined by experimentally determining the point and (x2, y2) point, the measurement accuracy will be extremely high because y = ax + b can be set correctly on the production line. Become. For example, 1 of y=ax+b
In the following function, when the output voltage of the displacement sensor is 1.2V, the flux filling rate is 12.6%, and the output voltage is 1.6
Assuming that the flux filling rate at the time of V is 15.6%, a=7.5 and b=3.5 are obtained from these values, and the above linear function formula is finally y=7.5. It becomes 5x+3.5. Based on the linear function obtained in this way, a verification line as shown in FIG. 6, for example, can be set.

In carrying out the detection method of the present invention constructed as described above, before starting detection, the optimum flux filling rate is first determined by calculation, and the allowable range of the flux filling rate is set. The upper and lower limits of these tolerance ranges are converted into electrical pulses and then stored digitally.

Next, the detection displacement sensor 4 starts detecting the flux level, and the molding is continued while comparing whether the detected level is within the above-mentioned allowable range. If the flux level is out of the allowable range, an alarm is issued to notify the molding abnormality and take appropriate measures.

[0020]

[Effects of the Invention] Since the present invention is configured as described above, it is possible to (1) inspect the formed composite wire without destroying it; and (2) to inspect the entire length continuously during the manufacturing process, thereby making it possible to It goes without saying that the same effects as conventional technology can be obtained, such as preventing the occurrence of non-defective products as much as possible, ensuring extremely high reliability of the product, and not causing a decrease in operating rates or the production of a large number of defective products. Furthermore, since the distance to the non-measurable object is detected by changes in the position of the reflected light, detection accuracy is hardly affected even if the light intensity changes (decreases) due to dirt on the light receiving surface or the light emitting surface. No correction is required, and the flux filling rate can always be detected with high accuracy.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the manufacturing procedure of a flux-cored welding wire.

FIG. 2 is a perspective view showing an example of the arrangement of displacement sensors used in the detection method of the present invention.

FIG. 3 is a diagram illustrating the operating principle of level measurement using a displacement sensor.

[Figure 4] Output voltage of displacement sensor 4 and displacement sensor 4
FIG. 3 is a diagram showing the relationship between the distance and the distance between non-measurable objects (operating distance).

FIG. 5 is a diagram showing the relationship between the filling height of flux and the output voltage of a displacement sensor.

FIG. 6 is a diagram showing the relationship (verification line) between the flux filling rate and the output voltage of the displacement sensor.

[Explanation of symbols]

1 Steel strip (outer skin) 2 Flux 3 Seam 4 Displacement sensor 10 Light source 11 Flood lens 12 Light receiving lens 13 Optical position detection element

Claims (1)

[Claims] 1. A method for detecting flux filling rate during the manufacturing process of flux-cored welding wire, in which a concave groove of a substantially constant shape is formed while a strip-shaped steel material is running in the longitudinal direction, and flux is applied to the concave groove. After filling the groove, a displacement sensor that detects the distance to the object to be measured based on the position of the reflected light is used to continuously measure the flux filling height in the groove, thereby determining the flux filling rate. A method for detecting a flux filling rate of a flux-cored welding wire.