KR100491019B1 - Multipoint thickness measurement system - Google Patents

Abstract

The present invention relates to a multi-point measurement thickness measuring system, wherein the ionizing box (5) arranged in the detection unit (2) is rotated clockwise or counterclockwise with respect to the flow direction of the measured object (4). It is possible to eliminate the low sensitivity to the radiation existing in the arrangement of the conventional ionospheric zone, i.e., the dead zone, so that the width direction measurement of the measured object 4 can be continuously and precisely performed. It is characterized by providing a multi-point measuring thickness measuring system which enables a more accurate plate thickness measurement with a small difference in radiation sensitivity of an ionizing box in the width direction.

Description

MULTIPOINT THICKNESS MEASUREMENT SYSTEM

The present invention relates to a multi-point measuring thickness measuring system that uses a radiation to measure the thickness of an object to be measured without contact.

In recent years, as the necessity of the shape control of the rolling in the steel industry becomes high, the plate-shaped measuring device more suitable for control is calculated | required. Conventionally, the thickness measurement in the plate width direction has been carried out using a scanning thickness measuring system or the like. However, since the object to be measured mostly moves continuously during the measurement of the plate thickness, it is impossible to obtain the plate shape as it is. Therefore, in many cases, the plate shape is calculated | required by introducing the thickness measuring system which measures a plate center other than a scanning thickness measuring system, and correct | amends based on the data obtained by this.

The multi-point measurement thickness measuring system will be described with reference to FIG. 15. The generator 3 is disposed below the detection unit 2 above the inverted c-shaped frame 1 so as to face the plate-shaped measurement object 4 arranged horizontally at a distance above and below the plate direction. The output signal of the detector 2 is sent to the thickness calculator 7. The detector 2 and the generator 3 are fixed to the inverted c-shaped frame 1. In the detection unit 2, a plurality of cylindrical ionizing boxes 5 are arranged in parallel in the width direction of the object 2 to be measured, and they detect the fan-shaped radiation output from the generator 3, but the ionizing boxes 5 ) Is cylindrical and there is a big difference in sensitivity to radiation at its center and end. This will be further described with reference to FIGS. 16 to 18.

16 is a perspective view showing the positional relationship between the ionizing box 5 and the object to be measured 4. The fan-shaped radiation output from the generator 3 is shown by the broken line. FIG. 17 is a view by an AA ′ arrow showing a state seen directly from the ionosphere 5. The ionizing box 5 is arranged in parallel with respect to the object 4 as shown in FIG. Since the edge part of the ionizing box 5 is lower than a center part, detection of the high spot (defect) of the to-be-measured object 4 is difficult.

FIG. 18 shows a sensitivity distribution when the ionization box 5 is arranged in parallel with the measurement object 4. As shown in Fig. 18, since the sensitivity of the ionizing box 5 is low, there is a dead band periodically in which the plate thickness measurement cannot be performed with high accuracy, and the continuous thickness value in the width direction is not obtained.

In addition, the necessity of a device capable of measuring the edge portion with high resolution and high accuracy is also increasing. However, with a conventional multi-point measuring thickness gauge, precision in an area having low sensitivity to radiation existing between the ionizing box and the ionizing box (hereinafter referred to as dead band) High measurement cannot be performed and it is difficult to obtain a continuous edge shape.

As described above, in the multi-point measurement thickness measuring system, the plate thickness at the measurement position is converted to the plate thickness by calculating the average of the total radiation dose incident in the height direction of the ionizing box. The sensitivity is high, and the sensitivity is low as it approaches the end.

Therefore, when the measuring point is the dead zone, the entire area in the height direction of the ionolysis box becomes the dead zone. For this reason, a sensitivity becomes remarkably low at the said position, and the part which cannot be measured at the time of the plate | board thickness measurement of the width direction of a to-be-tested object arises.

In the case of measuring the thickness of a position at an arbitrary distance from the edge of the object under measurement, the width value of the object to be measured is input to the calculator from a plate center deviation measuring device, which is an external device such as a width measuring system. Although the measurement is performed by moving the multi-point measuring thickness measuring system by the moving device 6 in accordance with the meandering amount, the measurement at the target position cannot be performed until the trolley moves to the target position.

On the other hand, when the ionizing boxes are arranged adjacent to each other, scattering lines from adjacent ionizing boxes are incident on the ionizing boxes, which may adversely affect the measurement results such as deterioration of precision of edges and degradation of resolution.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a multi-point measurement thickness measurement system which reduces the difference in sensitivity to radiation depending on the measurement position and enables better width direction measurement.

In order to achieve the above object, the present invention provides a radiation source, an ionizing box, and a detection means for radiating from a radiation source to pass through the object to obtain an output signal relating to the level of incident radiation and the thickness of the object to be measured from the output signal of the detection means. Comprising a calculation means for calculating the, characterized in that the ionizing box is arranged by rotating at an arbitrary angle with respect to the flow direction of the object to be measured.

According to this invention, it becomes possible to remove the dead zone which existed in the conventional arrangement of the ionizing box, and the width direction measurement of the thickness of a to-be-measured object can be performed continuously with high precision.

In the present invention, in the multi-point measuring thickness measuring system, a width value measured by means for measuring the width of an object to be measured is input, and the edge value or the center position of the object to be calculated is calculated on the thickness calculated from the output signal of the detecting means. It is characterized in that the position from the edge position, or the center position of the object to be measured.

In the present invention, in the multi-point measuring thickness measuring system, an output signal from a means for detecting the edge of an object to be measured is input by the calculating means, and the edge position of the object to be calculated is calculated from the output signal of the detecting means. It is characterized in that the position from the edge position can be specified.

In the present invention, in the multi-point measuring thickness measuring system, the computing means inputs the center deviation amount from the plate center displacement amount measuring device, calculates the center position of the measured object, and calculates the center position of the measured object with respect to the thickness calculated from the output signal of the detecting means. Characterized in that the position from the can be specified.

In the present invention, in the multi-point measuring thickness measuring system, the ionization box is arranged at a predetermined range of positions including a target measuring position, and the computing means measures the width of the measured object, or means for detecting the edge of the measured object, Alternatively, an output signal from the plate center misalignment measuring device is input and the meandering amount of the object to be measured is calculated, and an interpolation function for calculating the thickness value between the measurement positions is calculated based on the thickness values of the plurality of measurement positions. By calculating the thickness value of the position shifted from the meandering amount from the target measurement position.

According to the present invention, the thickness can be measured continuously even when the measured object is shifted from the target measurement position.

In the present invention, in the multi-point measuring thickness measuring system, the ionizing box is a structure in which radiation is incident from the side of the cylinder, and the measured length is determined by using the value of the dead band obtained by multiplying the overall length of the ionizing box by the safety factor by the thickness of the ionizing box side wall. It is characterized in that the rotation angle of the ionizing box that the dead zone disappears with respect to the flow direction of water.

In the present invention, in the multi-point measuring thickness measuring system, the ionizing box has a structure in which radiation is incident from the side of the cylinder, and the dead band value obtained by using the total length of the ionizing box, the inner diameter of the ionizing box, and the gas volume ratio with respect to the center of the ionizing box. It is characterized by determining the rotation angle of the ionizing box that the dead zone disappears with respect to the flow direction of the object to be measured.

In the present invention, in the multi-point measuring thickness measuring system, the ionizing box has a structure in which radiation is incident from the side of the cylinder, and is avoided by using the total length of the ionizing box, the dead band obtained by using the ionizing box outer diameter and the gas filling coefficient. The rotation angle of the ionizing box which eliminates the dead zone with respect to the flow direction of the workpiece is determined.

The present invention is characterized in that the separator is inserted between two adjacent ionization boxes in the multi-point thickness gauge.

According to the present invention, it is possible to perform an excellent measurement without the influence of scattering lines incident from an adjacent ionizing box, and without causing adverse effects on the measurement results, such as a decrease in precision at the edges and a reduction in resolution.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to drawings. In addition, in the following drawings, the figure which shows the conventional example is included, and the same code | symbol shows the same part or the corresponding part.

(1st embodiment)

With reference to FIGS. 1-4, 1st Embodiment of this invention is described.

In FIG. 1, the widthwise movement operation of the reverse c-shaped frame 1 is performed by the multipoint measurement thickness measuring system moving device 6 so as to measure the plate thickness of the plate-shaped object 4. In the inverted c-shaped frame 1, a generator 3 is fixed to the lower side and a detector 2 is fixed to the upper side. In addition, the ionizing box 5 is arranged in the detection part 2.

The radiation output from the generator 3 passes through the object 4 and enters the ionizing box 5. The incident radiation ionizes the gas sealed in the ionization box 5 by photoabsorption, compton scattering, electron pair generation, and the like, and the electric charge generated at this time is attracted to the electrode by an electric field applied between the electrodes. Recombination at the electrode returns to the neutral atom. The current flowing out at this time becomes the output signal of the detection unit 2, and after A / D conversion, is sent to the thickness calculator 7 and converted into the thickness value of the measurement object 4.

In the conventional example, since the ionizing box 5 is arranged in parallel with respect to the to-be-measured object 4 as mentioned above, dead zones exist periodically and the continuous thickness value of the width direction was not obtained. Therefore, in the above embodiment, the arrangement of the ionization boxes 5 is changed to eliminate the dead zone.

2 is a perspective view showing the positional relationship between the ionizing box 5 and the object to be measured 4 according to the embodiment. The fan-shaped radiation output from the generator 3 is shown by the broken line. 3 is a view by the AA 'arrow showing a state seen from directly above the ionospheric box (5). As shown in FIG. 3, the ionization box 5 is arranged at an angle with respect to the object 4 to be measured. In this way, the ionizing box 5 is arranged in a state of being rotated at an arbitrary angle clockwise or counterclockwise with respect to the flow direction of the object 4 on the plane seen from directly above the object 4, It becomes possible to eliminate the dead zone part which existed in the conventional arrangement of the ionizing box, and the width direction measurement of the to-be-measured object 4 can be performed continuously with high precision.

Fig. 4 shows the sensitivity distribution in the above embodiment in which the iono box 5 is rotated clockwise or counterclockwise with respect to the flow direction of the object 4 to be measured. As is clear from the figure, it becomes possible to obtain a sensitivity higher than or equal to the plate width direction of the measurement target object 4. Therefore, when there exists a high spot (defect) locally in the to-be-measured object 4, this can be detected easily.

(2nd embodiment)

5 is a diagram illustrating a configuration of a second embodiment of the present invention. In the above embodiment, the thickness calculator 7 calculates the thickness value of the measured object 4 from the output signal of the detection unit 2 in the same manner as in the first embodiment, and at the same time measures the width measurement system 8. The plate width value is input to the thickness calculator 7 and the plate edge position or the plate center position of the measurement object 4 is calculated.

Therefore, in the calculator 7, it is possible to specify the position from the plate edge position or the plate center position of the measured object 4 with respect to the thickness calculated from the output signal of the detection unit 2.

(Third embodiment)

It is a figure which shows the structure of 3rd Embodiment of this invention. In the above embodiment, the thickness calculator 7 calculates the thickness value of the measured object 4 from the output signal of the detection unit 2 in the same manner as in the first embodiment, and further calculates the signal detected by the edge sensor 9. Input to the thickness calculator (7) and calculate the plate edge position of the object to be measured.

Therefore, the calculator 7 can specify the position from the plate edge position of the object to be measured with respect to the thickness calculated from the output signal of the detector 2.

(4th Embodiment)

It is a figure which shows the structure of 4th Embodiment of this invention. In the above embodiment, the thickness calculator 7 is made of an external calculator made of a higher-level calculator or the like which calculates and simultaneously inputs the thickness value of the measured object 4 from the output signal of the detection unit 2 as in the case of the first embodiment. In the plate center offset amount measuring device 10 which is a device, the plate center offset amount is input to the thickness calculator 7 to calculate the plate center position.

Therefore, the calculator 7 can specify the position from the plate center position of the measurement object 4 with respect to the thickness calculated from the output signal of the detection unit 2.

(5th Embodiment)

8-10 is a figure explaining 5th embodiment of this invention.

FIG. 8 shows a configuration in the case where a multi-point measurement thickness measuring system having the same configuration as in the first embodiment is used to measure the plate thickness at a target position separated by an arbitrary distance from the edge of the object to be measured 4. In order to measure a target position at an arbitrary distance from the edge of the measurement object 4, the multi-point measurement thickness measuring instrument arranges the ionizing box 5 so that the plate thickness can be measured at a predetermined range of positions about the position. do.

In the thickness calculator 7, the plate thickness values 11, 12, 13 at a plurality of measurement positions in a predetermined range near the target measurement position are obtained from the output signal of the detection unit 2, and the width measuring system 8, Alternatively, when the edge position is obtained by the output signal from the edge sensor 9, as shown in Fig. 9, the plate thickness values 11, 12, and 13 respectively correspond to the distances from the edge position to the measurement position. And plot the plate thickness measurement results with an interpolation function (14). Even when the target measurement position is located between the actual measurement positions, the plate thickness value 16 of the target measurement position can be obtained from the interpolation function 14 at an arbitrary distance 15 from the edge position.

In addition, in most cases, the measured object 4 comes to meander in the width direction when it is mailed. The thickness of the output signal indicating the width of the plate from the width measuring system 8, the edge sensor 9, or an external device such as the plate center shift amount measuring device 10, or the edge position, or the center shift amount (meandering amount). It inputs to the calculator 7 and calculates the meandering quantity of the to-be-measured object 4. Then, the plate thickness measurement results in the vicinity of the target measurement position are connected by an interpolation function and graphed as shown in FIG. That is, the interpolation function 20 connects the plate thickness value 17 at the target measurement position with the plate thickness values 18 and 19 at the vicinity thereof. When the plate shift amount, that is, the meandering amount 21 is calculated by the edge position obtained from the width measuring system 8 or the like, the plate thickness value 22 is obtained from the interpolation function 20. By setting this value as the plate thickness value of the target measurement position, it is possible to continuously measure the plate thickness even when the object to be measured 4 is shifted from the target measurement position.

(6th Embodiment)

11-13 is a figure explaining the 6th Embodiment of this invention. The sensitivity to the radiation of the ionizing box 5 is proportional to the amount of gas in the ionizing box 5. Since the amount of gas is small at the end of the ionizing box 5, the sensitivity is lowered, and the sensitivity to radiation is lost at the side wall of the ionizing box 5.

In the above embodiment, the ionizing box 5 has a structure in which radiation is incident from the side surface of the cylinder, and as shown in FIG. 11, the rotation angle of the ionizing box 5 in which the dead zone disappears with respect to the flow direction of the object to be measured. (α) is determined.

First, as a first method of determining the rotation angle α, the total length of the ionizing box and the thickness of the ionizing box side wall can be obtained using the dead band value obtained by multiplying the safety factor. That is, when the total length of the ionizing box 5 is 2L, and the value of the dead zone 11 obtained by multiplying the thickness t of the ionizing box side wall by the safety factor γ is T (= t · γ), The rotation angle α of the ionizing box 5 that the dead zone disappears with respect to the flow direction of the object 4 to be measured is obtained as α = tan ⁻¹ (T / L). Safety factor (gamma) is made into arbitrary integers (for example, 2).

Next, the second method for determining the rotation angle α can be obtained using the total length of the ionizing box, the dead band obtained using the ratio of the inner diameter of the ionizing box and the gas amount ratio to the center of the ionizing box. As shown in FIG. 12, the position where the gas amount ratio becomes c with respect to the center portion O of the ionizing box 5 is a position that is a boundary with the dead zone 11, and the position on the horizontal line passing through the center portion O is shown. Let B be. That is, the position B is a position where l ₁ = c · r when the distance from the position B to the position C of the inner wall above it is l ₁ when the inside diameter of the ionobox is 2r. Further, in the drawing, the position of the inner wall above the center O is defined as A, the distance from the center O to the position B is t ", and the distance from the position B to the position D of the inner wall in the horizontal direction is t '. , The angle formed by OA and OC is β.

Here, l ₁ = c · r, but l ₁ = rcosβ in the drawing, so c = cosβ, and thus, the angle β can be obtained if the gas amount ratio c to the center of the ionization box is given. In addition, since t "= rsinβ in the figure, the value T of the dead zone 11 can be obtained as follows.

Then, the rotation angle of the ionizing box 5 in which the dead band disappears from the value T of the dead band 11 and the total length 2L of the ionizing box 5 obtained in this way with respect to the flow direction of the object 4 to be measured. (α) can be obtained by setting α = tan ⁻¹ (T / L). In addition, the gas amount ratio c with respect to the center of the ionizing box can be any integer (for example, 0.5).

Further, as a third method, it can be obtained using the dead band obtained by using the total length of the ionizing box, the ionizing box outer diameter, and the gas filling coefficient (coefficient of the effective diameter filled with gas). When the outside diameter of the ionizing box is 2R, as shown in Fig. 13, the distance from the center O on the horizontal line passing through the center O of the ionizing box 5 is equal to half the value R of the outside diameter of the ionizing box. The position E of the value multiplied by the fullness coefficient c 'is defined as the boundary with the dead zone 11, and the value T of the dead zone 11 is obtained as follows.

Then, from the value T of the dead zone 11 thus obtained and the total length 2L of the ionizing box 5, the dead band disappears in the flow direction of the object 4 to be measured. The rotation angle α can be obtained by setting α = tan ⁻¹ (T / L). In addition, the gas filling coefficient c 'may be any integer (for example, a value of about 0.7 to 0.8).

(7th Embodiment)

It is a figure explaining the 7th Embodiment of this invention. As in the first to sixth embodiments, when the plurality of ionizing boxes 5 are arranged adjacent to each other, the ionizing boxes 5 are provided from adjacent ionizing boxes 5 in addition to the radiation 14 radiated from the generator 3. Since the scattering line 13 is incident, the measurement result may be adversely affected, such as a decrease in accuracy of the edge portion and a decrease in resolution.

Therefore, in the said embodiment, in order to reduce the influence of such scattering lines 13, the separating plate 12 is arrange | positioned between the adjacent ionizing boxes 5.

The thickness of the separating plate 12 is a thickness capable of sufficiently absorbing scattering lines, and the length and height of the separating plate 12 are equal to or greater than the length and height of the ionizing box 5, respectively.

In addition, although the material of the separator 12 can use stainless steel (for example, SUS304), it will not be limited if it is a material which can absorb a scattering line. For example, tungsten, zinc or the like can be used.

In addition, the plate thickness can be made thinner as the material having a larger linear absorption coefficient.

In addition, when the separator 12 is used in this manner, the rotation angle α 'of the ionizing box 5 which eliminates the dead zone with respect to the flow direction of the object 4 is determined by the plate thickness of the separator 12. When it is set to t ₂ , instead of T in the sixth embodiment, (T + 0.5t ₂ ) can be used to obtain α ′ = tan ⁻¹ {(T + 0.5t ₂ ) / L}.

As described above, according to the present invention, by rotating the ionizing box in a clockwise or counterclockwise direction with respect to the flow direction of the object to be measured, the area having low radiation sensitivity is reduced, and the change in sensitivity is small throughout the measurement area. A measurement thickness measuring system can be obtained, and this can be easily detected when there is a high spot (defect) locally in the object to be measured.

Furthermore, by calculating the meandering amount from the input signal and applying it to a function interpolated between the respective measuring positions, it is possible to cope with the deviation of the target measuring position due to the meandering of the measured object, and to continuously measure the vicinity of the target measuring position. have.

1 is a front view showing the configuration of a multi-point measurement thickness measuring system according to a first embodiment of the present invention;

FIG. 2 is a perspective view showing the arrangement of the ionizing box in the first embodiment; FIG.

Figure 3 is a view by the AA 'arrow showing a state seen from directly above the iono box in FIG.

FIG. 4 is a diagram showing a sensitivity distribution with respect to the width direction of the ionizing box in the first embodiment; FIG.

5 is a diagram showing the configuration of a multi-point measurement thickness measuring system according to a second embodiment of the present invention;

6 is a diagram showing the configuration of a multi-point measurement thickness measuring system according to a third embodiment of the present invention;

7 is a diagram showing the configuration of a multi-point measurement thickness measuring system according to a fourth embodiment of the present invention;

8 is a diagram showing the configuration of a multi-point measurement thickness measuring system according to a fifth embodiment of the present invention;

9 is a graph showing a graph obtained by interpolating a plate thickness value of a target measurement position when the target measurement position in the fifth embodiment is between the actual measurement positions;

FIG. 10 is a graph showing a graph obtained by interpolating a plate thickness value of a target measurement position when the measured object meanders in the fifth embodiment;

FIG. 11 is a view for explaining a method for determining the rotation angle of an ionizing box in a sixth embodiment of the present invention; FIG.

12 is a view for explaining a method of determining the rotation angle of an ionizing box by using the inside diameter of the ionizing box, the gas amount ratio with respect to the center of the ionizing box, and the like in the sixth embodiment of the present invention;

FIG. 13 is a view for explaining a method of determining the rotation angle of an ionizing box by using an ionizing box outer diameter, a gas filling factor, and the like in a sixth embodiment of the present invention; FIG.

14 is a diagram showing the configuration of main parts of a multi-point measurement thickness measuring system according to a seventh embodiment of the present invention;

15 is a front view showing the structure of a conventional example;

16 is a perspective view showing the arrangement of the ionolysis box in the conventional example;

FIG. 17 is an AA ′ perspective view showing a state seen directly from above the ionolysis box in FIG. 16;

Fig. 18 is a diagram showing a sensitivity distribution in the width direction of the ionizing box in the conventional example.

* Explanation of symbols for the main parts of the drawings

1: inverted U-shaped frame 2: detector

3: Generator 4: Measured Object

5: ionizing box 6: multi-point thickness gauge moving device

7: thickness calculator 8: width measuring system

9: Edge sensor 10: Plate center misalignment measuring device

11: deadband 12: separator

13: scatter line 14: radiation

Claims (9)

Detecting means having a radiation source, an ionizing box, which is radiated from the radiation source, passes through the object under test, and obtains an output signal relating to the level of incident radiation; and calculating means for calculating the thickness of the object under measurement from the output signal of the detecting means. And the ionization box is arranged by rotating at an angular angle with respect to the flow direction of the object to be measured. The method of claim 1, The calculating means inputs the width value measured by the means for measuring the width of the object to be measured, calculates an edge position or a center position of the object to be measured, and calculates the thickness of the object to be measured from the output signal of the detecting means. A multi-point measurement thickness measurement system, which can specify a position from an edge position or a center position. The method of claim 1, The calculating means receives an output signal from the means for detecting the edge of the object to be measured, calculates the position of the edge of the object to be measured, and positions from the edge position of the object to the thickness calculated from the output signal of the detecting means. Multi-point measurement thickness measurement system, characterized in that can be specified. delete delete delete delete delete delete