JPS6056410A - Circuit for removing roll eccentricity - Google Patents

Abstract

PURPOSE:To extract only the component of sheet thickness in a sheet-thickness detecting signal even when the rolling speed changes remarkably, by performing a control by detecting the displacement of a gauge roll; in a circuit where the component of eccentricity of the gauge roll which is contact with a sheet is removed by a filter. CONSTITUTION:When the rolling speed of a rolling sheet 21, with which gauge rolls 10, 11 are in contact, is R1; a tachogenerator 18 outputs a detecting signal S9 of the number of revolutions corresponding to said speed R1, and a bias circuits 20 outputs a control signal S12 corresponding to the signal S9. Accordingly, a voltage-control-type filter circuit 16 filters a sheet-thickness measuring signal S11 by a cut-off frequency f01 corresponding to the value S12. In this way, only the eccentricity component in the signal S11 is attenuated, and the sheet-thickness component of the signal S11 is outputted from the circuit 16 as it is. Next, when the rolling speed is increased to R2, the frequencies fR2, fH2 of the roll-eccentricity component and sheet-thickness one in the signal S11 are increased with the increase of speed R2, but the value S12 increases also and the cut-off frequency of circuit 16 attains f02 to satisfy the equation always. Accordingly, the signal is outputted from the circuit 16 in the same manner as mentioned above.

Description

[Detailed description of the invention]

The present invention relates to a roller eccentricity removal circuit that removes frequency components caused by the eccentricity of the gauge roller from the output of a gauge roller that is in contact with a plate such as a steel plate through a filter circuit, and in particular, the number of rotations of the gauge roller. The present invention relates to a roller eccentricity removing circuit that can continuously vary the cut-off frequency of a filter according to the change in the cut-off frequency of the filter. Roller-type running thickness gauges are installed in cold rolling mills, continuous inspection machines, etc., and are used to measure the thickness of plates processed by these cold rolling machines, continuous inspection machines, etc. A pair of gauge rollers is placed in contact with the bottom surface, and the distance between the shafts of these gauge rollers, which is determined according to the thickness of the plate, is converted into an electrical signal by a transducer such as a differential transformer, and this is displayed on a meter. , the plate thickness measurement results are output for controlling the cold rolling mill and the like. By the way, in such a roller-type running thickness gauge,
As shown in FIG. 1, when each gauge roller], 2 is eccentric with respect to the corresponding rotation axis 3, 4, a transducer 5 detecting the displacement of these gauge rollers], 2 is used to detect the displacement of the plate. The thickness signal S (see Figure 2 (a)) is superimposed with a frequency component (eccentricity component) B2 (see Figure 2 (b)) caused by the eccentricity of the gauge rollers 1 and 2, resulting in a measurement error. Resulting in. For this reason, conventionally, the output signal S3 of this transducer 5 (k in FIG. 2) is
This signal S3 is separated by frequency discrimination using a low-pass filter.
However, since the frequency of the eccentric component S2 changes depending on the speed of the rolled material (plate) 7, if the speed of the plate 7 changes greatly, the plate thickness in the signal S3 It is not possible to separate the signal S1 and the eccentric component S2. That is, as shown in Fig. 3, when the rolling speed is R+ m/min, the plate thickness frequency is fn,
(Hz) The roller eccentric frequency is f R, (R2), but when the rolling speed becomes R2, the plate thickness frequency becomes r R
2 (R2), the roller eccentric frequency becomes f B2 (Hz), so this is set as its cutoff frequency f. If the discrimination was performed using a low-pass filter with a constant (Hz), the plate thickness frequency component would also be attenuated (-A2') when the rolling speed was R27Q/speed.
dB), which makes it impossible to measure the exact thickness of the plate, so its cutoff frequency f is determined depending on the rolling speed. the frequency f. , ~ fon has been developed, but in this case, the filter switching points and the number of filter switching stages are increased, and the cutoff frequency of this filter is changed frequently according to the rolling speed.

[Highly accurate measurements cannot be performed unless this switch is made.] In view of the above-mentioned circumstances, the present invention separates the plate thickness measurement result by the gauge roller into the plate thickness component and the roller eccentricity component, and calculates only the roller eccentricity component even when the speed, width, and height change. It is an object of the present invention to provide a roller eccentricity removing circuit that can remove only the plate thickness component from the plate thickness measurement result. In order to achieve this object, the roller eccentricity removing circuit according to the present invention includes a plate thickness detecting means for detecting the displacement of the gauge roller and outputting the detection result as a plate thickness measurement result, and a plate thickness detecting means for detecting the displacement of the gauge roller and outputting the detection result as a plate thickness measurement result. The apparatus further comprises a filter means having a modified cutoff frequency uf for filtering the output, and a rotational speed detection means for detecting the rotational speed of the gauge roller and continuously varying the cutoff frequency of the filtering means in accordance with the detection result. It is characterized by The present invention will be described below with reference to embodiments shown in the drawings. FIG. 4 is a block diagram showing a circuit purchase example of the J embodiment of the roller eccentricity removing circuit according to the present invention. In this figure, I O, ] are gauge rollers, and these gauge rollers 10. Each rotation of II 1111bl 2. ]
The interval of 3 is determined by the differential transformer 14 [Thus, it is converted into a thickness measurement signal SIO and supplied to the detection circuit 15. The detection circuit 15 removes the excitation component contained in the thickness measurement signal SIO, and the output of this detection circuit 15, that is, the rotation axis]2. ] Plate thickness measurement signal S indicating the interval between 3
l+ is the signal input terminal 16 of the voltage controlled filter circuit J6
supplied to a. The voltage-controlled filter circuit 16 has its cutoff frequency f depending on the magnitude G of the control signal S12 applied to the control input y111 element 16c. is f. MIN to f. It has a variable cutoff frequency type low-pass filter that changes up to MAX, and the cutoff frequency f is determined according to the magnitude of the control signal SI2. signal input terminal 16
The plate thickness measurement signal 8+1 supplied to a is filtered and output from the output terminal 16b. Further, J8 is a tacho generator that detects the rotation speed of the gauge roller] 0.11, and the output (rotation speed detection signal) of this tacho generator 18 is sent to the bias circuit 20 via the gain adjustment amplifier] 9. A predetermined bias is applied here, and the resulting signal is applied to the voltage-controlled filter circuit 16 as a control signal SI2.
is supplied to the control input terminal 16c of. Next, the operation of this embodiment, which was purchased as described above, will be explained with reference to the filter characteristic diagram shown in FIG. First, the rolled plate 2 which is in contact with the gauge rollers 10, 1]
When the rolling speed of No. 1 is R+W, the tacho generator J8 outputs a rotation speed detection signal s9 corresponding to this speed R1V, and the bias circuit 20 outputs a control signal s1□ corresponding to this. , the voltage-controlled filter circuit 16 receives this control signal SI2 as shown in FIG.
The cutoff 1M wave number f according to the value of. , (f R,) fo
, ≧ fH, where rR, , fH, are the rolling speed RITIV71), the frequency of the eccentric component of the corresponding roller, and the frequency of the plate thickness component). As a result, only the roller eccentric component in the plate thickness measurement signal Sll is attenuated, and the plate thickness component of the plate thickness measurement signal Sl+ is outputted from the pressure-controlled filter circuit J6 with the same magnitude. Next, increase this rolling speed and make this R2V [
As a result, the frequency of the roller eccentric component and the frequency of the thickness component in the plate thickness measurement signal Sll increase to fR2 and fH2, respectively. In this case, the value of the control signal SI2 increases accordingly. The cutoff frequency of [voltage controlled filter circuit] 6 is f. 2, fH2> fo
2≧fH2 is always

[I'm satisfied. Therefore, in this case, even if you leave it alone! Pressure control type filter circuit] 6 attenuates only the roller eccentric component in the plate thickness measurement signal Sll, and outputs the plate thickness component in the plate thickness measurement signal Sll as is. In this embodiment, as the rolling speed increases, the frequency fH of the plate thickness component in the plate thickness measurement signal Sll increases.
When the frequency fR of the roller eccentric component increases, the cutoff frequency f of the voltage-controlled filter circuit J6 increases accordingly. becomes high, and the relationship fH>fo≧fR always holds true. Therefore, only the roller eccentric component in the plate thickness measurement signal Sll is attenuated, and the plate thickness component is output with the same magnitude. I can do it. In this case, the frequency fH4 of the plate thickness component when the rolling speed is R+my'y), the frequency fR of the roller eccentric component, and the frequency fH of the plate thickness component when the rolling speed is R21 min.
2. The frequency f R2 of the roller eccentric component is f H, f
R2, , , , , (g RIfR2 There is a relationship, so as shown in Fig. 5, the amount of attenuation of the roller eccentric component when its frequency is f R, and the amount of attenuation of the roller eccentric component when its frequency is f When R2, σ] is equal to the attenuation amount of the roller eccentricity component. FIG. 6 is a circuit block diagram showing a second embodiment of the roller eccentricity removing circuit according to the present invention. The same reference numerals are given to the corresponding parts.The circuit shown in this figure is different from the circuit of the first embodiment described above in that the rotation of the gauge rollers 10 and 11 is handled by the rotation pulse generator w30. At the same time, this pulse is divided by the divider 31 and supplied to the control input terminal 16-1 (! of the pulse control type filter circuit) 6-1. The cutoff frequency f of the pulse control type filter circuit 16-1 is changed according to the rate. In this way, even if the pulse control type filter circuit] 6-1 is used, the gauge roller 10.11 It is possible to continuously change the cutoff frequency f when filtering the plate thickness measurement signal S11 according to the rotation of the plate thickness measurement signal Sll, thereby attenuating only the roller eccentric component in the plate thickness measurement signal Sll and reducing the plate thickness component. Therefore, the roller eccentricity removal circuit according to the present invention can be applied to equipment in which the measurement accuracy and the thickness control accuracy are proportional, such as equipment that performs automatic plate thickness control (σ). For example, the plate thickness control accuracy can be improved in accordance with the improvement of the measurement accuracy.In addition, in each of the above-mentioned embodiments, the low-pass type voltage-controlled filter circuit J6 and the pulse-controlled filter circuit 16-1 are used. Although the present invention has been described by taking an example of a case in which the roller is used, the same effects as in each of the above-mentioned embodiments can be obtained even if a band-elimination type filter that cuts only the roller eccentricity component is used. As described above, the roller eccentricity removing circuit according to the present invention detects the number of rotations of the gauge roller and uses this detection result to continuously control the cutoff frequency of the filter circuit. The plate thickness measurement signal obtained by detecting the displacement of the gauge roller is filtered, so even if the plate rolling speed changes significantly, only the roller eccentric component in the plate thickness measurement signal is attenuated. , the plate thickness component in the plate thickness measurement signal can be extracted as is, and the measurement accuracy can be improved.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram to explain the principle of plate thickness measurement using a roller-type running thickness meter, Figure 2 is a waveform diagram to explain Figure 1, and Figure 3 is an example of a conventional roller eccentricity removal circuit. FIG. 4 is a block diagram showing the first embodiment of the roller eccentricity removing circuit according to the present invention, FIG. 5 is a filter characteristic diagram for explaining the same embodiment, and FIG. FIG. 2 is a block diagram for explaining a second embodiment of the roller eccentricity removing circuit according to the present invention. 10.11... Gauge roller, ]4... Differential transformer (plate thickness detection means), ]6...' [u pressure control type filter circuit (filter means), 16-,... Pulse control type filter circuit (filter means), 18... tough generator (rotation speed detection means), 21... plate, 30... rotation pulse generator (rotation speed detection means). Patent Applicant Anritsu Electric Co., Ltd. Agent Patent Attorney Toshinori Nishi Main Pole Figure 1 Figure 2 Figure 3 Figure 4 n

Claims (1)

[Claims] plate thickness detecting means for outputting the detected displacement amount obtained by detecting the displacement amount of a caper roller rotating in contact with the plate as a thickness measurement signal of the plate; and a filter for the output signal of the plate thickness detecting means. and a filter means for detecting the number of revolutions of the cage roller in a roller eccentricity removing circuit for removing an eccentric component caused by the eccentricity of the cage roller from the output signal of the plate thickness detecting means. The roller comprises a number detection means, the filter means is a variable cut-off frequency filter means, and the cut-off frequency of the variable cut-off frequency filter is controlled according to the rotation speed of the cage roller. Eccentricity removal circuit.