JPS6116004B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bar cross-sectional area determination device that determines the cross-sectional area of a hot bar running on a rolling line or the like in real time and compares it with a reference cross-sectional area to determine the difference. It is something.

Generally, when rolling steel bars, etc., the maximum and minimum diameter,
Warranty items related to dimensions include diameter deviation, finished product length, etc., but in recent years, it has become common for exporters to guarantee the weight of finished products. In other words, even if the maximum and minimum diameters are within the tolerance, the weight per unit length must exceed the standard value. In this case, the reference value is obtained from the product of the nominal diameter and the nominal density.
However, in the case of steel bars, it is nearly impossible to measure each finished product one by one, so actual performance guarantees are sometimes performed for each bundle in a bundled state. Therefore, in the rolling process, in order to meet such requirements, samples are taken, their maximum and minimum diameters are measured using a micrometer, and the dimensions are adjusted so that the minimum diameter is greater than the nominal diameter (standard diameter). Since it is local, a considerable amount of leeway is allowed. In recent years, optical thickness gauges have become popular, and the dimensions of bars can be monitored from two directions, vertical and horizontal.
Even when such a thickness gauge is used, only the diameters in two orthogonal directions can be measured, so the dimensions are adjusted so that the smaller of these diameters becomes the reference diameter.

As described above, in the conventional method, the minimum diameter that can be measured in the rolling process is adjusted to be larger than the standard diameter, and then, in the finishing process, the finished product is checked with a limit gauge to see if it is larger than the standard diameter to ensure weight. Actual cutting of each bundle is often omitted because equipment costs increase. As described above, in the conventional method, it is necessary to roll the material to a large size, resulting in a large yield loss.
For example, if the dimensional tolerance is ±1.5% and the dimensional variation is 1% for weight guarantee material, the average diameter will be more than +0.5%, which is half of the 1% variation, in order to make the minimum diameter greater than the standard diameter. Therefore, the cross-sectional area is approximately +
It will be 1%. This results in a yield loss of 1% compared to a bar whose average diameter is controlled exactly to the standard value.

The present invention has been made in view of these drawbacks of the conventional method, and is intended to calculate the cross-sectional area of a bar in real time and guide the operator to accurately adjust the dimensions to approach the reference cross-sectional area. That is, the object of the present invention is to spirally measure the diameter at various positions on the cross section of a bar being transported on a rolling line or the like using a rotary thickness gauge, and then to measure the diameter of the bar based on the diameter measurements thus obtained. An object of the present invention is to provide a device that calculates the cross-sectional area of a material, determines the difference from the reference cross-sectional area, and displays the difference.

The details of the present invention will be explained below with reference to the drawings. Figure 1 shows the principle of the diameter measuring device. The light emitted from the light source 2 passes through the lens 3 and becomes a parallel ray,
The shadow of the bar 1 passes through the light receiving lens 4 and forms an image on the photoelectric conversion element array 5. Photoelectric conversion array elements using a charge coupled device (CCD) or a bucket bridge gate device (BBD) are known, but in the present invention, a CCD is used, and a 1728-bit array is used. The measurement error at this time is approximately 60 μm when the measurement span is 100 mm, which is sufficient for practical use. Also, if the object to be measured is small (maximum diameter is 20
mm), sufficient accuracy can be obtained even with 512 bits. Bar material 1 projected onto photoelectric conversion array element 5
According to the shift pulse applied from the transmitter 6, the diameter image is outputted from the array element 5 in the form of a pulse train corresponding to brightness and darkness, and is counted by the counter 7. This counting operation is repeated at a predetermined period and averaged. The diameter converted into a pulse count value is transmitted to the arithmetic unit 9. 8 is a spring.

FIG. 2 shows a specific configuration of the device of the present invention. That is, the aforementioned light source 2, lens 3, lens 4, photoelectric conversion array element 5, slip ring 8, and the transmitter 6 and counter 7 in FIG. , are continuously rotated in one direction by a motor 10 around a fixed shaft 11.
Power is supplied to the rotating body and signals are exchanged through a slip ring 8 and a brush (not shown) on the rotating body side. In this example, counting is performed inside the rotating body, and the results are transmitted to the stationary ground side by the signal exchange means between the slip ring 8 and the brush, but it is also possible to carry out counting on the stationary ground side by transmitting shift pulses and signal pulses good. Further, transformer coupling may be used for transmitting and receiving signals. Next, the timing of measuring the diameter will be explained.

The drive motor 10 is equipped with an angle detector 13 that generates a signal every time the measuring members 2 to 5 rotate by a predetermined angle θ from a reference direction (for example, a vertical line). Here, in the case of a projection type measuring machine, the diameter of the same part is measured every time it rotates 180 degrees, so θ is 180
Take ゜ equal to the number divided into n equal parts. That is, θ=180°/n (deg) …………(1). Next, the method of approximating the cross-sectional area will be explained with reference to FIG. The one-dot chain line a in FIG. 3 indicates the vertical diameter portion, and this is taken as the reference direction.
Now let the diameter measurement value in this reference direction be D ₁ , then the measurement value in the direction rotated clockwise by θ is D ₂ ,
Similarly, if the measured value of the azimuth rotated by (n-1) θ is D _o , D _o+1 becomes the diameter of the azimuth equal to D ₁ . Considering that the material 1 is now at rest, the cross-sectional area of the bar 1 can be expressed in the form of the sum of sector shapes as follows using the diameter data D ₁ to _{D o} obtained in this way.

Therefore, the difference ΔS with respect to the standard cross-sectional area S ₀ when the standard diameter D ₀ is Further, Di can be expressed in the form of the sum of the reference diameter D ₀ and the deviation ΔDi as Di=D ₀ +ΔDi ……(4) Since ΔDi is smaller than D ₀ , or It can be expressed as Therefore, the error ratio ΔR with respect to the standard cross-sectional area is expressed by equations (3), (5), and (6). It can be expressed in either form. That is, (3)′, (5)′,
(6)' is in the form of the sum of squares, the sum of deviations, and the sum of each diameter value, in order. Which form to use to express the cross-sectional area error is determined by the ease of processing time programming in the arithmetic unit, but if there is no problem with the error, the method of (6)' in which the measured diameters are summed is the method used. Easiest. FIG. 4 shows the processing flow of the arithmetic processing unit in the case of equation (6)'.

Next, the error when calculating the cross-sectional area by dividing it into sectors will be explained with reference to FIG. Figure 5 shows the data obtained by measuring the cross section of an 80φ steel bar at 5° intervals, and the deviation from the reference circle is enlarged and displayed for ease of viewing. Now, if we change the angle θ of a round bar with such a cross section and calculate the cross-sectional area deviation rate ΔR using equation (5)' (considering the vertical direction fixed as an example), n= as shown in Figure 6. n=9 for 36
(θ = 20°), the sampling error is small on almost both sides, but when n = 6 (θ = 30°) or less, the error becomes 0.1 to 0.15%. n=2 corresponding to the thickness gauge
(θ=90°), the error will be 0.2 to 0.7%. Therefore, it can be seen from this figure that n should be 9 or more. However, although FIG. 6 shows the deviation rate based on the vertical axis in FIG. 5, when the number of channels n becomes small, a large error occurs depending on which axis is selected as the reference. Therefore, in order to avoid such errors, the number of channels (number of divisions) n
should be as large as possible, and in the example of the present invention, n=30 (θ=6°).

Regarding the dimensional variation in the longitudinal direction of the strip, Fig. 7 shows an example of the dimensional variation of 25φ and 65φ. According to the same figure, it is approximately 25φ and 5.5m except for a part of the front and rear ends, and 65φ is approximately 5.5m.
It can be seen that there is no large variation in sampling every 10 m, and therefore, the dimensional variation within the sample length can be almost ignored. On the other hand, the final stage speed is this 25φ
7.35m/s, and 2.04m/s for 65φ, so if the rotation speed of the rotating support 12 is m (rpm), then ∴m40r.pm, but considering the margin, the device of the present invention uses 45r.pm.
It was set as pm. As this rotational speed increases, a strong centrifugal force acts on the rotating support 12 in FIG. 2, so at this stage it can be said that 45 rpm is close to the limit speed. Thus, the measuring members 2, 3, shown in FIG.
4, 5, and 8 rotate every 0.66 seconds, and the diameter value of the 30-division angle is determined every moment in a spiral manner.
As shown in the flowchart of the figure, when the diameter of each angular position is added up and the completion of half a rotation is detected by the angle detector, (6)′
Calculate the cross-sectional area deviation rate ΔR using the formula. At this time, if the object is a hot strip, it goes without saying that it is necessary to actually measure or predict the temperature and correct the dimensions.
The cross-sectional area deviation rate ΔR obtained in this way is informed to the operator from time to time by, for example, the number of Nixie tubes or lamps lit in 0.1% increments, so the operator can take actions such as changing the roll gap according to the value and change of this deviation rate. Take. Also, partially the deviation rate ΔR
If there is a negative point, that point can be tracked by a higher-level process computer (not shown) and rejected in the shearing process.

Here, in the present invention, one measuring body is used, but if two orthogonal channels are used, it goes without saying that the cross-sectional area can be determined every 1/4 rotation.

As described above, according to the present invention, it is possible to roll a strip with an accurate cross-sectional area or unit length and weight, and it is extremely effective in terms of commercial transactions and effective use of resources.

[Brief explanation of the drawing]

Fig. 1 is a principle diagram showing the configuration of the present invention, Fig. 2 is an explanatory diagram of the mechanism, Fig. 3 is an explanatory diagram of diameter sampling, and Fig. 4 is an explanation of the processing procedure of the arithmetic device of the present invention. Flow chart, Figure 5 is a diagram showing an example of the profile of a bar, Figure 6 is a graph showing the relationship between the number of divisions and the cross-sectional area error rate, and Figure 7 is a graph showing the relationship between the number of divisions and the cross-sectional area error rate.
Figures a and b are graphs showing examples of changes in longitudinal dimensions of bars. 1: Bar, 2: Lamp, 3, 4: Lens, 5:
Photoelectric conversion array element, 6: Transmitter, 7: Counter, 8: Slip ring, 9: Arithmetic unit, 10:
Motor, 11: Ground fixed axis, 12: Rotating axis, 1
3: Angle detector.

Claims (1)

[Claims] 1. Projected diameter that continuously rotates around a running hot bar about a pass line and measures each diameter value at an angular position that divides the half rotation into n equal parts (n > 9 ). A measuring device and n diameter measurements Di (i=1~
n) and the reference diameter D ₀ , the deviation of the measured cross-sectional area S from the reference cross-sectional area S ₀ is ΔS=S−S ₀ =π/4n(〓〓/
Di ² −nD ² ₀ ) and a cross-sectional area deviation rate ΔR=ΔS/S ₀ every half rotation of a diameter measuring device, and an arithmetic device that displays the results.