JP2607772B2 - Flux filling rate detection method for flux cored welding wire - Google Patents

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]

2. Description of the Related Art A flux-cored welding wire (hereinafter referred to as "composite wire") is, for example, a steel strip as shown in FIG.
(Outer skin) A concave groove having a semicircular cross section (or U-shape) is formed while running 1 in the longitudinal direction, and after filling the concave groove with flux 2, the concave groove is further rounded and then drawn. It has a predetermined wire diameter.

However, in the above-described forming process of the composite wire, a drawback mechanism of the wire drawing device or a flux supply portion of the flux supply device is disadvantageous, and the filling rate of the flux 2 (the flux weight per unit length weight of the composite wire). Ratio) may change. for that reason,
Conventionally, a fixed length sample is cut out from a formed lot of composite wire, 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. The weight of the outer skin 1 alone is measured. Then, calculate each calculated weight according to the following formula,
The flux filling rate (%) is calculated.

Flux filling rate (%) = {(total weight of sample composite wire−weight of outer skin) / (total weight of sample composite wire)} × 100

[0005] However, the above-mentioned sampling and destructive inspection method cannot cope with variations in the manufacturing process, and it is difficult to say that sufficient quality control can be performed. In the above-described destructive inspection method, post-production inspection is performed on the product after the completion of the production, or the production line is temporarily stopped and the intermediate inspection is performed. In the former case, the response is slow. In the latter method, not only the operating rate decreases, but also a new defective product may be generated due to a change in conditions after the restart.

[0006]

The inventors of the present invention have studied a method capable of continuously measuring the total length of the flux supplied to the steel strip during the manufacturing process.
If the running speed of the steel strip at the flux filling position and the amount of flux supply at the position are constant, it has been conceived that the thickness of the flux placed in the groove, that is, the filling height of the flux, becomes constant. Also, when the filling height in the case of a semicircular groove in the cross section was substantially at the center or when the groove was a U-shaped cross section, it was considered that there was a linear functional proportional relationship between the flux level and the flux filling rate. Then, the present inventors can detect the change in the filling height to know the flux filling rate, and thereby detect an abnormality in the running speed of the steel strip or the amount of supplied flux, which can contribute to uniform quality of products. As a result of further study based on the findings of the above, a new flux filling detection method was proposed in Japanese Patent Publication No. Sho 61-50717.

The method according to Japanese Patent Publication No. 61-50717 is a method for detecting a flux filling rate during a manufacturing process of a flux-cored welding wire. After forming the groove and filling the concave groove with flux, using a photoelectric sensor that detects the distance to the non-measurement object according to the intensity of the reflected light, the distance from the minimum value of the voltage output in the operation area of the photoelectric sensor is used. A method of detecting the filling rate of the flux by bringing the photoelectric sensor close to the filling flux level so as to be also at a short distance and continuously measuring the filling height of the flux in the concave groove with the photoelectric sensor. It is.

However, in this method, the intensity of the reflected light is converted into a voltage by using a photoelectric sensor, so that the projection ability and the light receiving sensitivity are changed due to the contamination of the lens surface and the light receiving surface due to the scattering of the dust of the flux. However, the period during which measurement can be performed normally becomes short. Further, it is conceivable to detect and correct the degree of dirt, but it is complicated and has a problem in accuracy.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is capable of performing a long-term measurement with a high degree of resistance to contamination of a measuring device, and highly accurately filling a flux-cored welding wire with a flux. It is an object to provide a method capable of detecting a rate.

[0010]

In order to solve the above-mentioned problems, the present inventor has conducted intensive studies on a measurement system which is not affected by contamination of a measurement device such as a lens. The present invention has been made here by using a displacement sensor such as that described above.

That is, the present invention is a method for detecting a flux filling rate during a manufacturing process of a flux-cored welding wire, comprising forming a substantially constant-shaped concave groove while running a strip-shaped steel material in a longitudinal direction. After filling the groove with the flux, use a displacement sensor that irradiates a laser beam and detects the distance to the object to be measured based on the position of the reflected light from the flux , and the displacement sensor determines the flux filling height in the groove. The gist of the present invention is a method for detecting the flux filling rate of a flux-cored welding wire, characterized in that the flux filling rate is detected by continuously measuring.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

【Example】

FIG. 2 is a perspective view showing an arrangement example of an optical displacement sensor such as a laser type used in the detection method of the present invention. The filling height of the flux 2 supplied to the outer skin 1 running in the direction of the arrow ( Flux placement level) displacement sensor 4
It is configured to measure with. Reference numeral 5 indicates both a power supply for the displacement sensor and an output display.

That is, the level measurement by the displacement sensor 4 is performed by 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 via the light projecting lens 11 is reflected by the light position detecting element 1 via the light receiving lens 12.
4 and move the position of the reflected light (A in the case shown).
', B') are converted into voltages so that the position of the reflected light can be detected as a change in the distance between the non-measured object and the displacement sensor 4.

The displacement sensor 4 includes an output voltage of the displacement sensor 4 and a distance between the displacement sensor 4 and a non-measurement object.
(Operating distance) and a characteristic having a relationship as shown in FIG. 4 are used. FIG. 5 shows that when the horizontal axis (x) indicates the filling height of the flux and the vertical axis (y) indicates the output voltage, the portion indicated by the solid line (between points C ′ and D ′) is substantially y. = Ax +
b, the output voltage is C '
An accurate determination cannot be made in an area larger than the point or lower than the point D '.

Since the distance to the powder is measured instead of the distance to the flat plate surface, there is a factor that causes measurement errors due to irregular reflection of light and the like. It was found that if various constants were determined in advance, a measurement result with considerably high accuracy could be obtained.

That is, in an actual production line, arbitrary (x ₁ , y ₁ ) points and (x ₂ , y ₂ ) points which should be on the line of y = ax + b are experimentally obtained, whereby a, b Is determined, y =
Since ax + b can be set in a correct form, the measurement accuracy is extremely high. For example, in the first order function of y = ax + b, when the output voltage of the displacement sensor is 1.2 V, the flux filling rate is 12.6%, and when the output voltage is 1.6 V, the flux filling rate is 15.6%. If so, from these values, a = 7.5 and b = 3.5 are obtained. In the end, the above primary function is y = 7.5x + 3.5. For example, a test line as shown in FIG. 6 can be set on the basis of the thus obtained primary function.

In implementing the detection method of the present invention configured as described above, prior to the start of detection, first, an optimum flux filling rate is obtained by calculation, and an allowable range of the flux filling rate is set. After converting the upper and lower limits of these allowable ranges into electrical pulses, they are stored digitally.

Next, the detection of the flux level by the detection displacement sensor 4 is started, and the molding is performed while comparing whether the detected level is within the allowable range. Then, when the flux level is out of the allowable range, an alarm is issued, an abnormality in the molding is notified, and appropriate measures are taken.

[0020]

The present invention is constructed as described above, so that the formed composite wire can be inspected without destruction, and the whole length can be continuously inspected during the manufacturing process. Occurrence is prevented as much as possible, the reliability of the product is extremely high, such as lowering the operation rate and not causing a large number of defective products, and of course, the same effect as the conventional technology can be obtained. Since the distance of the non-measurement object is detected by the change in the position of the reflected light, the detection accuracy is hardly affected even if the light amount changes (decreases) due to contamination of the light receiving surface or the light projecting surface, and correction is not performed It is unnecessary, and the flux filling rate can always be accurately detected.

[Brief description of the drawings]

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

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

FIG. 3 is a diagram illustrating an operation principle of level measurement by a displacement sensor.

FIG. 4 shows the output voltage of the displacement sensor 4 and the displacement sensor 4
FIG. 6 is a diagram showing a relationship between the distance between the object and a non-measurement object (operating distance).

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel strip (skin) 2 Flux 3 Joint 4 Displacement sensor 10 Light source 11 Light emitting lens 12 Light receiving lens 13 Optical position detecting element

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takao Shimazaki 100-1 Urakawachi, Miyama-ji, Fujisawa-shi, Kanagawa Prefecture Inside Fujisawa Works of Kobe Steel, Ltd. 1 Kobe Steel Fujisawa Works, Ltd. (56) References JP-A-64-82943 (JP, A) JP-A-2-144711 (JP, U) JP-B-61-50717 (JP, B2)

Claims (1)

(57) [Claims] 1. A method for detecting a flux filling rate in a manufacturing process of a flux-cored welding wire, comprising forming a substantially constant-shaped groove while running a strip-shaped steel material in a longitudinal direction, and forming a flux in the groove. Irradiates laser light after filling
Then, by using a displacement sensor that detects the distance from the object to be measured based on the position of the reflected light from the flux, and continuously measuring the flux filling height in the concave groove with the displacement sensor, the flux filling rate can be reduced. A method for detecting a flux filling rate of a flux-cored welding wire, characterized by detecting.