JP2004233287A - Calibration method of deflection measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a calibration method of a deflection measuring device capable of calibration without using a calibration rod having high straightness. <P>SOLUTION: This measuring device has a constitution wherein at least three displacement measuring means are arranged at intervals in the conveyance direction of a rod member conveyed in the longitudinal direction, in the directions mutually crossing in a plane vertical to the conveyance direction. The rod member is allowed to pass the measuring device, and deflections at a plurality of points are measured in the longitudinal direction, and the standard position of displacement is corrected based on the plurality of deflection measured values. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for calibrating a bending amount measuring device for measuring a bending amount of a rod.
[0002]
[Prior art]
Conventionally, a method disclosed in Patent Document 1 or Patent Document 2 is known as a method for measuring the amount of bending of a rod-shaped body such as a steel bar, but the method disclosed in Patent Document 1 is orthogonal to the longitudinal direction. In order to measure the amount of bending when the bar to be measured that moves in the direction reaches a predetermined position, the amount of bending can be measured at the part where the detector is installed, but it bends while transporting the bar to be measured in the longitudinal direction. The problem is that the amount cannot be measured and the bending per unit length in the longitudinal direction of the measured bar cannot be measured at a predetermined pitch (for example, 100 mm pitch) over the entire length of the measured bar. There is. On the other hand, the method disclosed in Patent Literature 2 is a method of measuring the amount of bending of a tip portion of a tube supported in a cantilever state, and therefore, when bending occurs continuously at the same curvature like a tube. Although there is no problem, the amount of bending cannot be measured in the case where the curvature is not always the same, such as a steel bar.
[0003]
Therefore, in order to solve such a problem, at least three displacement amount detectors arranged at substantially equal intervals in the transport direction of the rod conveyed while being guided in the longitudinal direction by the guide roll are perpendicular to the transport direction of the rod. Patent Document 3 discloses a bending amount measuring device that detects the amount of displacement of a rod in two directions crossing each other in a simple plane and measures the amount of bending of the rod based on these amounts of displacement. ing.
[0004]
When measuring the amount of bending of the rod with such a bending measuring device, if the rod is bent between the guide rolls or is deformed due to wear of the guide roll, a measurement error exceeding an allowable range occurs. However, it is difficult to accurately measure the amount of bending of the rod. Therefore, conventionally, before measuring the amount of bending of the rod-shaped body, the bending amount measuring device is calibrated using a straight calibration rod having no bending according to the material, diameter, and length of the material to be measured. ing.
[0005]
[Patent Document 1]
JP-A-51-132856 [Patent Document 2]
JP-A-8-94348 [Patent Document 3]
JP 2000-161944 A
[Problems to be solved by the invention]
However, in the above-mentioned calibration method, since a straight calibration rod without bending must be used according to the material, diameter, and length of the material to be measured, there is a problem that a large cost is required for manufacturing and managing the calibration rod. was there.
SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to calibrate a bending amount measuring device without using a straight calibration rod without bending for each material, diameter and length of a material to be measured. It is an object of the present invention to provide a method for calibrating a bending amount measuring device capable of performing the following.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is characterized in that at least three displacement amount detecting means arranged at intervals in the conveying direction of the bar conveyed in the longitudinal direction and the direction of conveyance of the bar are conveyed. A method of calibrating a bending amount measuring device that detects the amount of displacement of the rod in two directions intersecting each other in a vertical plane and measures the amount of bending of the rod based on the amount of displacement. While passing the rod-like body through the bending amount measuring device, measuring the bending amount of a plurality of points over the longitudinal direction of the rod-like body, correcting the reference position of the displacement amount based on the plurality of bending amount measurement values, The bending amount measuring device is calibrated.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of a bending amount measuring device to which the method of the present invention is applied. As shown in FIG. 1, the bending amount measuring device 10 includes three guide rolls 11, 12, and 13 that transport a rod-shaped body a such as a steel bar while guiding the rod-shaped body a in the longitudinal direction (the direction of arrow Z in the figure). In the vicinity of these guide rolls 11 to 13, the displacement of the rod-shaped body a in two directions (arrows X and Y directions in the drawing) orthogonal to each other in a plane perpendicular to the longitudinal direction of the rod-shaped body a, that is, from the reference point. Displacement detectors 21, 22, and 23 for detecting the amount of displacement are arranged at substantially equal intervals in the longitudinal direction of the rod-shaped body a.
[0009]
The displacement detectors 21 to 23 are a first position detector 21a for detecting a position xm in the X direction of the rod a (see FIG. 2) and a second position detection for detecting a position ym in the Y direction of the rod a. The signals output from the position detectors 21a and 21b are supplied to an arithmetic unit 30 that calculates the amount of bending S1 of the rod-shaped body a. As shown in FIG. 3, the position detectors 21a and 21b are composed of a laser projector 211 and a laser receiver 212 which face each other with the rod-shaped member a interposed therebetween.
[0010]
The arithmetic unit 30 is configured to calculate the bending amount S1 of the rod-shaped body a according to the flowchart shown in FIG. That is, when the rod-shaped body a is transported in the longitudinal direction by the guide rolls 11 to 13, the arithmetic unit 30 takes in the position signals output from the position detectors 21a and 21b of the displacement detectors 21 to 23 at predetermined time intervals. (Step S21). Then, based on the X-direction position xm of the bar-shaped object a detected by the position detector 21a and the X-direction reference position x0 (see FIG. 2) set prior to the measurement, the X-direction displacement amount X1, X2 and X3 are calculated, and based on the Y direction position ym of the bar a detected by the position detector 21b and the Y direction reference position y0 (see FIG. 2) set prior to the measurement, The Y-direction displacement amounts Y1, Y2, and Y3 are calculated (step S22).
[0011]
When the X-direction displacement amounts X1, X2, X3 and the Y-direction displacement amounts Y1, Y2, Y3 of the rod a are calculated in this way, the arithmetic unit 30 calculates the X-direction bending dx and the Y-direction bending dy of the rod a. Is obtained from the following equations (1) and (2) (steps S23 and S24). Then, the bending amount S1 of the rod-shaped body a is calculated from the following equation (3) based on the X-direction bending amount dx and the Y-direction bending amount dy of the rod-shaped body a obtained in steps S23 and S24 (step S25).
[0012]
dx = ((X1 + X3) / 2) -X2 (1)
dy = ((Y1 + Y3) / 2) -Y2 (2)
S1 = √dx2 + dy2 (3)
At this time, in order to set the X-direction reference position and the Y-direction reference position, a rod having high straightness and substantially no bending is set as a calibration rod at the position of the displacement detector, and in this state, the X-direction bending is performed. The X-direction reference position x0 and the Y-direction reference position y0 may be set so that the amount dx and the Y-direction bending base dy are measured, and the measured X-direction bending amount dx and Y-direction bending amount dy become zero. However, according to this method, the distortion of the calibration rod due to abrasion of the guide rolls 11 to 13 also changes depending on the material, diameter, and length of the rod, so that the material, diameter, It is necessary to prepare a calibration rod with no bending for each length and reset the reference point.However, it is practically difficult to manufacture and manage a calibration rod with high straightness, and the reference point is limited in setting accuracy. There is.
[0013]
In the present embodiment, the straightness of the calibration rod is not required as much as in the case of the above-described calibration method, and further, the accuracy of setting the reference point is improved as compared with the conventional method using a calibration rod having a high straightness. For this purpose, a reference point is set by the method described below. FIG. 5 is a flowchart illustrating the calibration method according to the present embodiment.
[0014]
First, a rod-like body used for calibration (a certain degree of straightness is required, but not as straight as that used in the above-described calibration method) is passed through a displacement detector (step S32). Then, the measurement of the X-direction bending amount dx and the Y-direction bending amount dy is repeated at predetermined time intervals while moving the rod-shaped body. (Steps S33 to S37) Specifically, as the first measurement, the displacement amounts X1, X2, X3, Y1, Y2, and Y3 are measured by the three displacement amount detectors (steps 33 to 35). From these displacement amount detection values, the bending amounts dx and dy are calculated by the above equations (1) and (2) (step S36), and are calculated as the first bending amounts dxn (n = 1) and dyn. (N = 1) is recorded (step S37). If the rod is still passing through the displacement detector, the process returns to step S34, and the second measurement is performed according to steps S35 to S37, and the bending amount dxn (n = 2), Record dyn (n = 2).
The measurement of dxn and dyn is repeated until the rod-shaped object has passed the displacement detector, and a plurality of measured bending amounts dxn (n = 1, 2, 3,...) And dyn (n = 1, 2, 3) ...) are recorded. When the rod has passed through the displacement detector, measurement and recording of a plurality of bends are completed (step S38), and the process proceeds to step S39. In step S39, dxn '= dxn-x0
dyn '= dyn-y0
As
Σ | dxn '(n = 1, 2, 3,...) |
Σ | dyn '(n = 1, 2, 3 ...) |
Are calculated as x0 and y0, respectively. Then, in step S39, the calculated values x0 and y0 are set as an X-direction reference position and a Y-direction reference position, respectively (step S40). More specifically, the displacement measurement values X2 and Y2 may be corrected to be reduced by x0 and y0, respectively.
[0015]
According to the above-described method of determining the reference position, the rod-shaped body used for calibration can be set so that the average value of the measured values of the bending amounts at a plurality of points becomes zero while passing the rod-shaped body through the displacement detector. Even if there is a partial bend, even if there is a measured value at a bent point, the finally obtained reference position is uniformed with the measured values at other non-bent points, Therefore, there is an effect that management of the straightness of the calibration rod is eased. Further, without using the calibration rod, after measuring the amount of bending of the rod-shaped body to be measured over the entire length, an average value of the obtained plurality of measured bending amounts dx and dy is obtained, and the average value is used as a base groove point. As x0 and y0, all the measured values may be corrected using this reference position.
[0016]
FIG. 6 shows the amount of bending in the X direction and the amount of bending in the Y direction at a plurality of points in the longitudinal direction of the rod-shaped body (steel type: S40C, outer diameter 27.1 mm × length 6000 mm) while passing through a displacement detector. It is the figure which plotted the result of having measured. (A) shows the case where the reference position is set according to the conventional method, and (b) shows the case where the reference position is set according to the method of the present invention. That is, in the case of (a), a conventionally used calibration rod having a high straightness is installed in a state where it is stopped at the position of the displacement detector, and the bending amount measured at this time is zero (dx = 0 in the figure). , Dy = 0). On the other hand, in (b), the bending amount dx in the X direction and the bending amount dy in the Y direction are measured at a plurality of points in the longitudinal direction of the rod-like body, and a reference is obtained from the measured values of dx and dy at the plurality of points according to the flow shown in FIG. This is the case where the position is set. A comparison between (a) and (b) shows that the distribution of the measurement points with respect to the origin of dx and dy is shifted. FIG. 7 shows the case where the reference point is determined as described above, using a rod-shaped body (steel type: S40C, outer diameter 27.1 mm × length 6000 mm) having a maximum bending amount of 0.52 mm / M. FIG. 6A shows the measurement results of the bending amount dx in the X direction and the bending amount dy in the Y direction at a plurality of points in the longitudinal direction of the rod-like body. FIG. 6A shows the setting of the reference position by the conventional method as in FIG. (B) shows the case where the reference position is set by the method described with reference to FIG. 6 (a). In the measurement, the same rod was passed through the displacement detector three times in each of the conventional method and the method of the present invention. In the figure, the first measurement result is plotted as ■, the second measurement result as ○, and the third measurement result as ▽. As shown in the figure, when the reference point is set according to the conventional method, the maximum value of the amount of bending is 0.63 mm for the first measurement and 0.2 mm for the second measurement in each of the first to third measurement results. 63 mm, third time: 0.42 mm, and the variation was large. On the other hand, according to the present invention, the maximum value of the bending amount is 0.55 mm for the first time, 0.55 mm for the second time, and 0.48 mm for the third time, and the variation is small. I understand.
[0017]
FIG. 8 is a diagram showing the result of measuring the bending of the rod using a dial gauge, and FIG. 9 is a diagram showing the result of measuring the bending of the rod after calibrating the bending measuring device 10 by the method of the present invention. As is apparent from these figures, the calibration of the bending amount measuring device 10 by the method of the present invention makes it possible to accurately measure the bending of the rod-like body over the entire length.
[0018]
FIG. 10 is a diagram showing a result of measuring a rod having a maximum bending amount of 0.55 mm / M with the bending amount measuring device 10 after the bending amount measuring device 10 is calibrated by the method of the present invention. As shown in the figure, it is understood that the bending of the rod-shaped body can be accurately measured over the entire length by calibrating the bending amount measuring device 10 by the method of the present invention.
[0019]
【The invention's effect】
As described above, according to the present invention, while passing the rod-shaped object through the bending amount measuring device, the bending amount at a plurality of points is measured, and the reference position of the displacement amount is determined based on the plurality of bending amount measurement values. Since the correction is performed, the bending amount measuring device can be accurately calibrated even if the calibration rod has some bending.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of an apparatus for measuring a bending amount of a rod-shaped body.
FIG. 2 is an explanatory diagram for explaining a method of calculating an X-direction displacement amount and a Y-direction displacement amount of a rod-shaped body from an output of a displacement amount detector shown in FIG.
FIG. 3 is a diagram showing a configuration of a position detector shown in FIG.
FIG. 4 is a flowchart for explaining a method for calculating the amount of bending of a rod-like body using the arithmetic device shown in FIG. 1;
FIG. 5 is a flowchart illustrating a calibration method according to an embodiment of the present invention.
6A and 6B are diagrams showing the results of measuring the X-direction displacement amount and the Y-direction displacement amount of the rod-like body, and FIG. 6A shows the X-direction displacement amount of the rod-like body when the bending amount measuring device is calibrated by a conventional calibration method. And (b) shows the results of measuring the X-direction displacement and the Y-direction displacement of the rod when the bending amount measuring device is calibrated by the calibration method of the present invention. FIG.
FIG. 7 is a diagram showing the results of measuring the X-direction displacement and the Y-direction displacement of a rod using a rod having a maximum bending amount of 0.52 mm / m. FIG. 7A shows a bending amount measuring apparatus. FIG. 7B is a diagram showing the results of measuring the X-direction displacement amount and the Y-direction displacement amount of the rod-like body when calibrated by the conventional calibration method. FIG. 6B shows the rod-like body when the bending amount measuring device is calibrated by the calibration method of the present invention. It is a figure showing the result of having measured the X direction displacement amount and the Y direction displacement amount of the body.
FIG. 8 is a diagram showing the result of measuring the amount of bending of a rod-like body using a dial gauge.
FIG. 9 is a view showing the result of measuring the amount of bending of a rod-like body by using the bending amount measuring device after calibrating the bending amount measuring device by the method of the present invention.
FIG. 10 is a view showing a result of measuring a rod having a maximum bending amount of 0.55 mm / M with the bending amount measuring device after calibrating the bending amount measuring device by the method of the present invention.
[Explanation of symbols]
10 Bending amount measuring devices 11, 12, 13 Guide rolls 21, 22, 23 Displacement amount detectors 21a, 21b Position detector 30 Arithmetic unit

Claims (1)

The rod-like body in two directions crossing each other in a plane perpendicular to the transport direction of the rod-like body by at least three displacement amount detecting means arranged at intervals in the transport direction of the rod-like body transported in the longitudinal direction. A method of calibrating a bending amount measuring device that detects the amount of displacement and measures the amount of bending of the rod based on these amounts of displacement, wherein the rod is passed through the bending amount measuring device, The amount of bending at a plurality of points is measured in the longitudinal direction, and the reference position of the displacement is corrected based on the plurality of measured values of the amount of bending to calibrate the bending amount measuring device. How to calibrate a quantity measuring device.

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