JPH05346325A - Evenness measuring device - Google Patents

Abstract

PURPOSE:To reduce effect of deflection deformation caused by dead-load of a steel plate to be measured. CONSTITUTION:The outputs of distance detection sensors for vertical direction assigned in two rows, front and rear, are simultaneously sampled with intervals corresponding to the pitches, and their difference is integrated for obtaining evenness profile. The evenness profile of the steel plate whose evenness is good is stored in advance as a virtual carrier line profile, and the difference between the evenness profile and the virtual carrier line profile is obtained. The difference obtained can be seen as a profile of true evenness, with the effect of deflection deformation caused by dead-load of a steel plate to be measured having been removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flatness measuring device for measuring flatness of a steel sheet or the like flowing on a conveyor line in a running state.

[0002]

2. Description of the Related Art Flatness is a particular problem in controlling the manufacturing quality of steel sheets and the like. JIS stipulates that when measuring the flatness of a steel sheet, it should be placed on a surface plate in a tension-free state for measurement, but in actual production, the measurement should be performed while the steel sheet is being conveyed on a conveyor line. Is going. This is to ensure production efficiency.

When the flatness is measured while being carried by the carrying line, particular attention should be paid to how to improve the measurement accuracy and how to achieve automation. The most commonly practiced method is a method of observing a defective flatness product by observing with the naked eye, temporarily stopping the line, and measuring the height of the uneven portion with a torus or the like. However, it is difficult to obtain good accuracy with this method, work efficiency is not good, and 100% inspection is practically impossible.

Therefore, as a more automatic and accurate method of measuring flatness, a method of measuring the flatness of a steel sheet being conveyed by a conveying line as a change in the distance in the direction perpendicular to the steel sheet (vertical distance change) Difference method) is being developed. This method can be performed online, and is preferable for automation.

A point to be noted in automating the flatness measurement by the vertical distance variation method is how to eliminate the vertical error component due to the vibration associated with the conveyance and the eccentricity of the conveyance roller. Conventionally, as a method therefor, a method for detecting the flatness by installing a plurality of sensors in the width and longitudinal directions and obtaining a relative difference (Japanese Patent Laid-Open No. 61-
4913), the moving average method (Japanese Patent Laid-Open No. 2-16130).
No. 7), a regression function method (see Japanese Unexamined Patent Publication No. 3-111711), a method of removing a carrier line fluctuation amount by frequency analysis (see Japanese Unexamined Patent Publication No. 3-81605), and arc length using a twin-beam displacement gauge. And a method of calculating the flatness from the elongation rate (see JP-A-3-249514) and the like have been proposed.

[0006]

However, in these methods, there is a problem that the influence of bending deformation due to the weight of the steel sheet cannot be eliminated, and the flatness measurement error is large especially for a thin steel sheet.

The present invention has been made to solve the above problems, and the accuracy of the flatness of the object to be measured during transportation is not affected by the bending deformation of the steel sheet due to its own weight. The purpose is to enable stable measurement with good stability.

[0008]

In order to achieve such an object, the present invention detects a vertical distance to an object to be measured on a conveying line and detects the vertical distance component of the object to be measured while removing it. In the flatness measuring device for obtaining the flatness profile of the surface of the object to be measured based on the result, by storing the virtual transport line profile including the bending deformation component due to its own weight, by correcting the flatness profile based on the virtual transport line profile, It is characterized in that the influence of flexural deformation due to the weight of the object to be measured is eliminated.

Further, a second aspect of the present invention is characterized in that a moving average of the flatness profile before correction and the virtual conveying line profile is obtained, and the virtual conveying line profile is updated by the obtained moving average.

[0010]

In the present invention, first, the vertical distance to the object to be measured on the transport line is detected, and the vertical vibration component of the object to be measured is removed while the flatness profile of the surface of the object is measured based on the detection result. Desired. The apparatus of the present invention corrects the flatness profile thus obtained based on the virtual transport line profile. That is, the apparatus of the present invention stores a virtual transport line profile including a flexural deformation component due to its own weight, and based on this virtual transport line profile, the flexural deformation component in the flatness profile obtained as described above is removed. Find the true flatness profile. Therefore, in the present invention, the flatness can be accurately and stably measured without being affected by the bending deformation of the measured object due to its own weight.

According to the second aspect of the present invention, the virtual transport line profile is sequentially updated, and more accurate flatness measurement is realized. That is, the moving average of the virtual transport line profile that has been used up to that time and the flatness profile before correction is obtained, and as a result, the virtual transport line profile is updated. As a result, the accuracy is further improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

1 and 2 show the structure of a flatness measuring apparatus according to an embodiment of the present invention. In particular, FIG. 1 is a side view and FIG. 2 is a front view.

The apparatus of this embodiment is an apparatus for measuring the flatness of the steel plate 10 to be measured while conveying the steel plate 10 to be measured from the right side to the left side in FIG. The vertical distance can be detected on the lower side of the conveyor line in the front and rear 2
This is performed by the distance detection sensors 14 provided in the left and right five rows. Further, the distance detection sensor 14 is provided below the conveying line so as to avoid the influence of the thickness of the steel plate 10 to be measured, and there is no problem even when the steel plate 10 to be measured is suspended by a piler or the like. Distance detection sensor 14
Has a longitudinal pitch P _L and a widthwise pitch P _W ,
These are set sufficiently smaller than the minimum significant flatness pitch in each direction.

The outputs of the distance detection sensors 14 are input to the corresponding displacement gauges 16. The output of the displacement gauge 16 is
As shown in FIG. 3A, the back surface 10 of the steel plate 10 to be measured
The vertical distance from 0 is shown. A displacement gauge 16 in the front row and an A / D converter 18 for converting the output of the displacement gauge 16 in the rear row into digital data are provided in the subsequent stage of the displacement gauge 16.

The A / D converter 18 includes the front and rear end detection sensor 2
It operates according to the output of 0. The front and rear end detection sensor 20 detects the front and rear ends of the steel plate 10 to be measured by transmitting / blocking light, and when the forward end of the steel plate 10 to be measured is detected, the A / D converter 18 operates.

The A / D converter 18 includes a counter 22.
Sampling is executed when the output of P has a value representing the pitch P _L. The counter 22 counts the output of a speed distance detector 24 that is provided on the conveyor roller 12 and detects the moving speed (conveying speed) of the steel plate 10 to be measured. Therefore, the output of the displacement meter 16 related to the distance detection sensor 14 in the rear row is the output related to the same point as the distance detection target of the distance detection sensor 14 in the front row at the previous sampling time. The processing device 26 obtains the difference between the digital data output from the A / D converter 18, and further executes a calculation such as a flatness profile described later. The processing device 26, if necessary,
Communication with the host computer via the communication control unit 28 allows the printer 30 to plot and print the flatness shape,
The screen is displayed on the display 32.

By the way, the steel plate 10 to be measured conveyed by the conveying line is accompanied by vertical vibration. This vertical vibration is substantially parallel vertical movement, and the output of the distance detection sensor 14 at the same point has substantially the same change between the front row and the rear row. Therefore, when the difference between the output of the distance detection sensor 14 in the front row and the output of the distance detection sensor 14 in the rear row is calculated, this difference is considered to represent the flatness of the steel plate 10 to be measured.

From the above, it is understood that the flatness shape in the width direction and the flatness shape in the longitudinal direction of the steel plate 10 to be measured can be obtained by the apparatus shown in FIGS. 1 and 2.

For example, when the distance detection sensor 14 at the left end of the front row is used as a reference and the difference between the output of the distance detection sensor 14 in the same row and this reference output is plotted, a flatness shape in the width direction can be obtained. That is, at a certain point of time, the output of the displacement meter 16 relating to the distance detection sensor 14 in each row is converted into digital data by the A / D converter 18, and the processing device 2
6 processes this digital data. Processor 2
6 uses the data relating to the distance detection sensor 14 at the left end of each column as a reference, and obtains the difference between this reference output and the data relating to the other distance detection sensors 14 belonging to the same column and arranged at the pitch P _W. By plotting the obtained difference, the flatness profile in the width direction of the steel plate 10 to be measured can be obtained.

Further, if the difference between the output of the distance detection sensor 14 in the rear row and the output of the distance detection sensor 14 in the front row is obtained for each pitch P _L and integrated over the entire length, the flatness profile in the longitudinal direction can be obtained. Obtainable. 3 and 4 show the principle of flatness measurement, particularly in the longitudinal direction, of the flatness measurements in this embodiment.

As shown in FIG. 3 (a), the distance detection sensors 14 arranged in two rows in the front and rear respectively detect the vertical distances to the back surface 100 of the steel plate 10 to be measured. At a certain point, the distance detection sensor 14 in the front row detects the vertical distance h _A to the point _A
And the distance detection sensor 14 in the rear row detects the vertical distance h _B to the point _B , the difference ΔA = as shown in FIG. 3B from the difference between the outputs of both sensors 14 at that time.
h _B −h _A is obtained. Specifically, the output of the displacement gauge 16 corresponding to the distance detection sensor 14 in the front row is sampled by the corresponding A / D converter 18 at every pitch P _L equivalent time, and in synchronization with this, the distance detection sensor 14 in the rear row is sampled. The output of the displacement meter 16 corresponding to is sampled by the corresponding A / D converter 18. The processing device 26 obtains these differences and generates data relating to the flatness in the longitudinal direction of the measured steel plate 10.

By repeating such an operation, the difference at each measurement point can be obtained. That is, the distance detection sensor 14 in the front row has A and B shown in FIG.
Vertical distances h _A , h _B ′, h for each point of ′, C ′, ...
_C ′, ... Is detected, and the distance detection sensor 14 in the rear row detects the vertical distances h _B , h _C , h for each point B, C, D ,.
_D , ... Is further detected, and the difference between the two detection results is obtained by the processing device 26. Difference ΔA = h _B −h _A , ΔB = h
_{C -h B ', h D -h} C', ... can be obtained. However, B
The points ', C', ... Are the same points on the steel plate 10 to be measured, but are drawn at different positions in FIG. 3B because of the vertical movement described above. If the obtained difference is smaller than a predetermined significant flatness variation (determined by the minimum flatness pitch / height), the difference is treated as 0.

After the difference is obtained in this way, the processing device 26 performs integration processing. That is, as shown in FIG. 4A, the flatness profile is obtained from the differences ΔA, ΔB, ΔC, .... Further, the processor 26 subtracts the profile of the virtual transport line from the flatness profile obtained by the integration process to obtain the true flatness profile. The content of this processing is shown in FIG. 4, and is the processing according to the feature of this embodiment.

In carrying out this processing, a virtual transport line profile as shown in FIG. 4B is stored in advance inside the processing device 26. This profile is
It is a flatness profile obtained for a steel sheet having a good flatness, for example, a profile obtained as a result of performing a plurality of measurements on a steel sheet having a good flatness prepared for each type. This profile includes a linear gradient due to the cumulative value of the measurement error at each point (cumulative error) and a component of flexural deformation due to the weight of the steel sheet used for the measurement.

The processing unit 26 subtracts such a virtual carrier line profile from the flatness profile (FIG. 4A) obtained by the process of FIG. 3 to obtain the difference. Here, it can be considered that the flatness profile of FIG. 4A includes almost the same linear gradient and bending deformation component as the virtual transport line of FIG. 4B. Therefore, it can be said that the obtained difference indicates the true flatness profile of the steel plate 10 to be measured which is currently being measured. If the resulting true flatness profile has a linear slope,
The processing device 26 uses this as a virtual surface plate to obtain the flatness index.

The true flatness profile obtained by such a treatment is, therefore, one in which the influence of the bending deformation due to the own weight of the steel plate 10 to be measured is significantly reduced. As described above, according to this embodiment, it is possible to measure the flatness more stably and accurately. Further, according to the present embodiment, the flatness of the steel plate 10 to be measured during transportation is simultaneously sampled in the longitudinal direction and the difference is integrated, and the sampling timing is set by the output of the velocity distance detector 18. Therefore, it is possible to cope with a sudden change in the transport speed and a change in the surface temperature.

The process of obtaining the flatness profile in the longitudinal direction is executed for each survey line (that is, for each front and rear pair of the distance detection sensors 14 arranged at the pitch P _W as shown in FIG. 2). The flatness in the width direction is obtained by the distance detecting sensors 14 arranged in the width direction.

Further, the accuracy can be further improved by successively updating the virtual carrier line profile. That is, the flatness profile obtained by the measurement (see FIG.
(A)) and the moving average between the measurement points of the profile that has been used as the virtual transport line profile (FIG. 4 (b)) until then, and this moving average is stored in the processing device 26 as a new virtual transport line profile. By storing the profile, the true flatness profile can be accurately obtained using the updated virtual transport line profile.

[0030]

As described above, according to the present invention,
Since the flatness profile of the surface of the measured object obtained while removing the vertical vibration component of the measured object was corrected by the virtual transport line profile including the bending deformation component due to its own weight, the bending deformation component in the flatness profile was calculated. The true flatness profile can be obtained by removing the flatness, and as a result, the flatness can be measured accurately and stably without being affected by the bending deformation of the object to be measured, for example, the steel plate due to its own weight.

Further, according to the second aspect, since the virtual transport line profile is successively updated by the moving average of the flatness profile before correction, more accurate flatness measurement can be realized.

[Brief description of drawings]

FIG. 1 is a diagram showing a side surface configuration and a circuit configuration of a flatness measuring apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a front structure of this embodiment.

FIG. 3 is a diagram showing the principle of measuring the flatness in the longitudinal direction in this example.

FIG. 4 is a diagram showing the principle of flatness measurement in the longitudinal direction in this example.

[Explanation of symbols]

 10 Measured Steel Plate 12 Conveying Roller 14 Distance Detection Sensor 16 Displacement Meter 18 A / D Converter 22 Counter 24 Speed Distance Detector 26 Processing Device

Front Page Continuation (72) Inventor Hiroki Murakami 1 Kanazawa-machi, Kakogawa-shi, Hyogo Inside Kadogawa Works, Kakogawa Works (72) Inventor Tomohiko Ono 5-1-1 Shimorenjaku, Mitaka-shi, Tokyo Japan Radio Co., Ltd. (72) Inventor Shinji Watanabe 5-1-1 Shimorenjaku, Mitaka-shi, Tokyo Japan Radio Co., Ltd. (72) Inventor Takashi Ichikawa 5-1-1 Shimorenjaku, Mitaka-shi, Tokyo Within Japan Radio Co., Ltd. (72 ) Inventor Zenjiro Kuroda, 1-1, Shimorenjaku, Mitaka-shi, Tokyo Japan Radio Co., Ltd. (72) Inventor, Kazuhiko Iwata 5-1-1, Shimorenjaku, Mitaka-shi, Tokyo Japan

Claims (2)

[Claims] 1. A distance detecting means for detecting a vertical distance to a measured object on a transfer line, and a process for removing a vertical vibration component of the measured object and obtaining a flatness profile of the measured object surface based on the detection result. In the flatness measuring device including means, the processing means stores a virtual transport line profile including a flexural deformation component due to its own weight, and corrects the flatness profile based on the virtual transport line profile, thereby measuring the object to be measured. A flatness measuring device characterized by removing the influence of flexural deformation due to its own weight. 2. The flatness measuring apparatus according to claim 1, wherein the processing means obtains a moving average of the flatness profile before correction and the virtual transport line profile, and updates the virtual transport line profile with the obtained moving average. A flatness measuring device characterized by the above.