JPH028164Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention proposes a novel thickness measuring device that is capable of measuring the thickness of a rolled material between the stands of a continuous hot rolling mill.

In continuous hot rolling mills, the thickness is generally not measured between stands, but only at the exit side of the final stand. This is because the heating conditions for the rolled material in the heating furnace are good, and the required plate thickness accuracy is also relatively low, and the loop of the strip formed between the stands fluctuates, making it impossible to install a thickness gauge. This is due to things like this. However, in recent years, heating conditions have become stricter in terms of thermal economy, and the required plate thickness accuracy has also tended to become stricter. For this reason, in order to improve the accuracy of rolling control of plate thickness, there is a need for an apparatus that can measure the outlet side plate thickness for each stand, that is, the plate thickness between stands.

The present invention was developed against this technical background, and is a method of correcting the measured value by the thickness gauge according to the attitude of the rolled material between the stands, specifically the angle of inclination with respect to the horizontal plane, to obtain accurate thickness. It is an object of the present invention to provide an inter-stand thickness measuring device that can measure the thickness between stands.

FIG. 1 is a schematic diagram of a thickness measuring device according to the present invention (hereinafter referred to as the device of the present invention). The rolled material (strip) 10 is inserted into a continuous rolling mill and rolled while being transferred in the direction of the arrow. In the figure, 1 and 2 indicate adjacent stands of this continuous rolling mill, the former being located on the upstream side and the latter on the downstream side. A looper 3 is provided between the stands 1 and 2 to apply appropriate tension to the rolled material 10. The present device includes a thickness gauge 11 disposed between the looper 3 and the stand 2 on the downstream side, a distance meter 12 disposed near the upstream side of the thickness gauge 11, and the thickness gauge 11 and the distance meter. 12, and corrects and calculates the thickness of the rolled material 10 (the thickness in the direction perpendicular to the front and back surfaces; hereinafter referred to as the true thickness).

The thickness gauge 11 is a known X-ray thickness gauge, and the X-ray source 11a is located below the passage area of the rolled material 10.
Further, the X-ray detection section 11b is disposed directly above and facing the X-ray detection section 11b. In other words, the rolled material 10 is placed between stands 1 and 2.
It is arranged so that the true thickness can be measured when it moves horizontally. Note that it is also possible to use a radiation thickness meter other than the X-ray thickness meter, or a thickness meter combined with a distance meter. The distance meter 12 is a feedback amplification type eddy current distance meter which is known per se, and has its sensor coil disposed below the passage area of the rolled material 10, and has a distance measurement reference of the sensor coil directed toward the rolled material 10. The distance from the surface to the back surface of the rolled material 10 can be measured. In addition to eddy current rangefinders, microwave rangefinders, laser rangefinders,
Uses an ultrasonic distance meter, etc. that measures the distance between the transducer and the target by forming a water column between the ultrasonic transducer and the target and measuring the length of the water column from the ultrasonic propagation time. It is possible to do so.

As is clear from what will be described later, this distance meter 12 is provided to measure the inclination angle with respect to the thickness measurement direction of the rolled material at the thickness measurement position by the thickness meter, and the inclination angle is 0, that is, the rolled material 10 moves horizontally The deviation between the height position of the rolled material 10 when the plate thickness direction of the rolled material 10 and the measurement direction of the thickness gauge 11 match and the high position of the rolled material 10 when the inclination angle is not 0. The distance is measured, and from this distance the inclination angle and true thickness are determined.

The calculation unit 13 is composed of, for example, a microcomputer, and reads the measurement result h' of the thickness gauge 11 and the measurement result d of the distance meter 12 over time at an appropriate period, and combines these read data with the data given in advance. data [center position of stand 2 and distance meter 1]
2, the separation distance L _R from the center position of 2, the separation distance d ₀ between the measurement reference surface of the distance meter 12 and the back surface of the rolled material 10 when it is moving horizontally, and the correction coefficient f(a) which will be described later. The true thickness h of the rolled material 10 is calculated based on .

Next, the principle of calculating the true thickness h by the calculation unit 13 or the principle of measuring the true thickness by the device of the present invention will be explained.

Figure 2 shows the true thickness h of the rolled material 10 and the thickness gauge 11.
The relationship between the measured thickness or the apparent thickness h' is shown in an enlarged view. Since the thickness gauge 11 is arranged as described above and measures the thickness in the vertical direction, the measured thickness h' when the rolled material 10 is inclined with respect to the horizontal plane as shown in the figure is different from the true thickness h. ,
The angle between the vertical direction and the plate thickness direction (direction perpendicular to the front and back surfaces of the rolled material 10), that is, the angle between the plate thickness measurement direction and the plate thickness direction, in other words, the inclination angle of the rolled material 10 with respect to the horizontal plane is α Then, the following equation (1) holds geometrically between h and h'.

h=h'cosα...(1). Therefore, in order to find the true thickness h, it is necessary to know α. In the present device, the distance meter 12 is used as a means for measuring the inclination angle α of the rolled material. That is, as is clear geometrically from FIG. 1, α is expressed by equation (2) using the measured value d of the distance meter 12 below.

α＝tan ⁻¹ d−d ₀ /L _R …(2) Therefore, based on equations (1) and (2), the constant given in advance
L _R , d ₀ and h′, d that are input sequentially as measurement results
It is possible to calculate h using . By the way, the measurement result of the thickness gauge 11 shows that when the passing range (pass line) of the rolled material 10 deviates from the reference position (in this case, the position of d=d ₀ ) or when the radiation incident angle changes, It is necessary to correct the measured value corresponding to the amount of variation. That is, it is necessary to perform correction according to the amount of deviation d−d ₀ =a.

The calculation unit 13 stores a correction coefficient f(a) using the deviation amount a as an index, and uses this to correct h', and ultimately to correct h. That is, the above equation (1) becomes h=h'・f(a)・cosα (3).

In summary, the calculation unit 13 sequentially calculates h by calculating the following equation (4), outputs it to a display device (not shown) for display, and outputs it to the plate thickness control system as basic data for plate thickness control. be involved in this control.

h=h'・f(a)・cos{tan ^-1 d−d ₀ /L _R } =h′・f(a)・cos{tan ^- ₁ a/L _R } ...(4) Figure 3 is FIG. 3 is a schematic diagram showing another embodiment of the present invention. This embodiment differs from the one shown in FIG. 1 in that the distance meter 12 is placed on the downstream side and the thickness gauge 11 is placed on the upstream side. The looper 3 is also equipped with a looper angle detector 14. Then, the measurement result h' of the thickness gauge 11, the measurement result d of the distance meter 12, and the detection result θ of the looper angle detector 14 are read into the calculation unit 13 at a predetermined period.

The looper angle detector 14 is a well-known sensor used as a sensor in a tension control system, and outputs the angle θ formed between the arm 3a of the looper 3 and the horizontal line as a detected value.
2 is used as a means for measuring the inclination angle of the rolled material 10.

In this embodiment, the arithmetic unit 13 has the above-mentioned
In addition to d ₀ and f(a), the following data are given in advance.

L: Horizontal distance between the center of rotation of the looper arm and the distance meter l: Length of the arm of the looper (length from the center of rotation of the arm to the center of the looper roll 3b) r: Radius of the looper roll And the calculation unit 13 is An operation is performed to obtain h based on the values of L, l, and r, as well as the value of d ₀ and d, h', and θ, which are successively taken in.

In this case, the inclination angle α is expressed by the following equation (5).

α=tan ^-1 lsinθ-(d- _d0 )+r/L-lcosθ...(5) Therefore, from equation (5) and equation (3) above, h can be calculated according to equation (6) below. become.

h＝h′・f(a)・cos{tan ^-1
lsinθ−(d−d ₀ )+r/L−lcosθ} =h′・f(a)・cos{tan ⁻¹ lsinθ−a+r/L−lc
osθ}...(6) As described above, in the case of the present invention, the inclination angle of the rolled material is determined using the measurement result of the distance meter placed near the thickness gauge 11, so the looper 3 and stand 2 Even if the rolled material sag or bulges between the two, the true thickness can be accurately measured without being affected by this.

As described above, the measuring device of the present invention detects the inclination angle of the rolled material at the thickness measurement position using the distance meter 12, that is, the position measuring device of the rolled material in the thickness measurement direction, so it is not affected by loop fluctuations. It is possible to accurately measure the true thickness of rolled material between stands without Especially when measuring the inclination angle of a rolled material using only the looper, the inclination of the rolled material at the measurement position using the thickness gauge between the looper and the stand is due to sagging or bulging of the rolled material that occurs between the looper and the stand. Although the angle cannot be measured correctly, the embodiment shown in Fig. 1, which does not use the looper angle of the looper in this invention, is not affected by the looper angle at all, and the embodiment shown in Fig. 3 also measures the distance halfway between the looper and the stand. 12 in total, and the influence of the sag and bulge mentioned above only includes the relatively short distance from the looper roll 3b to the distance meter 12, and the mode of sag and bulge during this period is linear. is α, and thus has no effect on the true thickness calculation, so the accuracy is significantly improved compared to the case where the measured value of the thickness gauge is corrected only by the looper angle. As described above, according to the present invention, the accuracy of plate thickness measurement is improved, and the control accuracy of plate thickness is also improved thereby, so the present invention has excellent effects on improving the quality of rolled materials and increasing yield. play.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic diagram thereof, FIG. 2 is a diagram explaining the measurement principle, and FIG. 3 is a schematic diagram of another embodiment. 11... Thickness meter, 12... Distance meter, 13... Arithmetic unit, 14... Looper angle detector.

Claims (1)

[Scope of utility model registration request] A thickness gauge arranged between stands of a continuous hot rolling mill to measure the thickness of a rolled material moving between the stands, and for measuring the inclination angle with respect to the thickness measurement direction of the rolled material at the thickness measurement position by the thickness gauge. The method is characterized in that it is provided with a position measuring device for the rolled material in the direction of thickness measurement by the thickness meter, and a computing unit that calculates the thickness of the rolled material based on the measurement results of the thickness meter and the position measuring device. Thickness measuring device.