JPH09229873A - Method and apparatus for detecting abnormality of bite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely detect an abnormal missing or abrasion state of chips in any case. SOLUTION: A CCD camera 5 for photographing a bevel-worked face 1a of a steel pipe 1 and a controller 7 for processing an image obtained by the CCD camera 5 are provided. After the state of a good face and a state of a defective face are converted to be at, for instance, a white level and a black level respectively, an instrumentation window is set, e.g. at the central part within a detected instrumentation screen, ad an area ration of the white level reduced by influences of the black level is calculated. The area ratio is compared with a reference area ratio preliminarily set for the state of the good face. When the deviation is not smaller than a predetermined value, the face is judged to be abnormal by the controller 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a method for indirectly detecting abnormalities such as chipping or wear of a chip attached to a cutting tool which is a cutting tool in a pipe cutting machine for cutting a steel pipe and the like. It relates to the device.

[0002]

2. Description of the Related Art For example, in the process of manufacturing a steel pipe, a cutting device for finishing the steel pipe to a predetermined length, or a steel pipe rotated in the circumferential direction for cutting a beveled surface at the pipe end is provided with a cutting tool. There is a device for pressing, cutting and surface-treating a chip part. In such a device, since automatic operation is performed, when the chip is damaged or worn, it is necessary to immediately detect the state and stop cutting or surface processing.

Therefore, at present, as a method of detecting chipping or wear of a chip, a method of detecting an elastic wave (ultrasonic wave) generated when the chip is broken by an echo stick emission (AE) sensor, or a vibration generated when the chip is broken. The vibration sensor, the load cell to detect an increase in cutting resistance,
A method of detecting an increase in the rate of change of the back pressure of a hydraulic cylinder for feeding the bite has been implemented.

[0004]

However, in the above-mentioned method, the output difference between the signal generated from the plastic deformation area of the object to be cut at the time of normal cutting and the signal generated at the time of chip loss is small, There is a problem that a comparison reference value for determining the presence or absence of a defect cannot be set accurately.

In addition, the method (1) has a problem that the device configuration becomes complicated because it is necessary to incorporate the load cell in the bite feeding mechanism. Furthermore, the method is effective when applied to the processing such as the pilot hole drilling for seamless steel pipe manufacturing, in which the cutting area during cutting increases the cutting resistance and the back pressure decreases. However, when the cutting area during cutting is constant and there is no change in back pressure as in the case of cutting steel pipes, it is difficult to detect chipping of the chip.

The present invention has been made in view of the above-mentioned conventional problems, and is applied to a bite abnormality detecting method and a method for surely detecting a chip defect or wear state abnormality in any case. The purpose of the present invention is to provide a device.

[0007]

In order to achieve the above-mentioned object, according to the present invention, after a cutting end portion by a cutting tool is imaged by a camera, the image is processed by a controller and binarized and converted, A measurement window is provided in the measurement screen after the binarization conversion, and points with low or high brightness in the measurement window are aggregated as an area, and this aggregated value is compared with a normal value that is a reference in advance. And
If the deviation exceeds a certain amount by this comparison,
Judge that it is a byte error.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION
After irradiating, for example, a halogen light on the cutting end portion by the cutting tool and imaging the irradiated portion with, for example, a CCD camera,
A measurement window is provided in the measurement screen after binarizing the image by image processing and binarizing the image, and then, for example, a point having a low brightness in the measurement window is aggregated as an area, and the aggregated value, The normal value which is the reference in advance is compared.

Further, the bite abnormality detecting device of the present invention, for example, a halogen light source for irradiating a cutting end portion by a bite, a CCD camera for imaging the irradiation portion by the halogen light source, and an image processing of an image by this CCD camera. After binarizing and converting it, the controller is equipped with a controller that totalizes, for example, points with low brightness in the measurement window provided in the measurement screen as an area, and compares the aggregated value with a normal value that is a reference in advance. Of.

In the bite anomaly detecting apparatus having the above-mentioned structure, the cutting end portion of the bite imaged by the CCD camera is image-processed, and for example, the good product surface texture is binarized into the white level and the defective product surface texture into the black level. After that, a measurement window is set in, for example, the central portion of the detected measurement screen, and the area or area ratio occupied by the white level that is reduced by the influence of the black level (hereinafter, this value is referred to as "feature amount") is calculated. To do. Then, this feature amount is compared with the feature amount of the good quality surface property set as a reference in advance, and when the deviation is equal to or more than a predetermined amount, it is determined to be abnormal, and for example, an alarm is output to prompt the exchange of the tool. To do.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A bite abnormality detecting device of the present invention will be described below with reference to an embodiment shown in the accompanying drawings, and covers a method of detecting an abnormality of a bite using the bite abnormality detecting device of the present invention. FIG. 1 is a control block diagram of the bite abnormality detection device of the present invention when applied to a steel pipe bevel cutting device, FIG.
Is a schematic plan view of a steel pipe bevel cutting device, (b) is an explanatory view of a measurement field of view on a steel pipe bevel processing surface, and FIG. 3 (a) is an explanatory view of a measurement raw image of a non-defective bevel processing surface to be a reference according to the method of the present invention. , (B) are explanatory views of a binarized image, FIG.
Is an explanatory view of a setting display screen, FIG. 5 is an explanatory view of a measurement screen by the method of the present invention, and (a) is a normal beveled surface,
6B is a diagram showing a case of an abnormally beveled surface, FIG. 6 is an explanatory view of a beveled surface property of a steel pipe, and FIG. 6A is a scratch caused by chips being caught in a chip during cutting of the beveled surface. (B) Defects caused by defective operating conditions such as defective bit setting and defective rotation speed of the steel pipe. (C) Chips were missing during cutting of the beveled surface, resulting in uncut parts. In this case, FIGS. 7 to 9 show images when detecting (a) to (c) of FIG. 6, respectively, where (a) is a raw image,
1B is a binarized image, FIG. 1C is a diagram showing a measurement screen, and FIG.
0 (a) to (c) are the results shown in FIG.
It is a figure similar to (a)-(c) of FIG.

In FIGS. 1 and 2, reference numeral 1 is a tip 2 attached to a beveling tool of a steel pipe bevel cutting device.
The present invention is a steel pipe whose end surface is beveled by the present invention. The present invention is a device for detecting abnormality such as chipping or wear of the tip 2 of such a steel pipe bevel cutting device, and has the following configuration. In addition, 10 in FIGS. 1 and 2 indicates a parting tool for cutting the steel pipe.

Reference numeral 3 denotes a beveled surface 1 at the end of the steel pipe, for example, to irradiate the end portion of the beveling by the tip 2 of the steel pipe 1.
A halogen lamp 4 arranged in the upper front of a is a light source device for irradiating the halogen lamp 3. Also, 5
Is an image of the beveled surface 1a of the steel pipe end illuminated by the halogen lamp 3 [the portion surrounded by a rectangle in FIG. 2 (b)]. It is a CCD camera arranged.

The image captured by the CCD camera 5 is transmitted to the controller 7 via the image memory 6, for example. In the controller 7, the image transmitted through the image memory 6 is subjected to image processing to binarize the good product surface quality to a white level and the bad product surface property to a black level, and perform this binarization conversion. Abnormalities such as wear of the tip 2 are detected based on the image as described below.

First, as shown in FIG. 3, a bevel processed surface 1a of a non-defective level to be used as a reference is imaged by a CCD camera 5, and the obtained raw image [see FIG. It is converted into a binarized image [see FIG. 3 (b)].
Then, a measurement window 8 is drawn on the converted binarized image as shown in FIG. 4, and for example, an area ratio (feature amount) occupied by the white level in the measurement window 8 is obtained by software processing, and this feature amount is calculated. The reference feature amount AS is registered in the arithmetic comparison unit in the controller 7.

Further, the reference characteristic amount AS is set to 100%, and the lower limit coefficient is set and registered in the unit of% with respect to the value in the arithmetic comparison unit in the controller 7.
Then, under such a state, the actual bevel processed surface 1a is imaged by the CCD camera 5, the obtained raw image is converted into a binary image by the controller 7, and then the converted binary image is measured. The window 8 is drawn, the characteristic amount AR is obtained in the same manner as described above, and the characteristic amount AR is compared with the reference characteristic amount AS. The comparison result is displayed as “OK” or “NG” on the screen of the monitor 9,
In case of NG, an alarm is output. FIG. 5 shows a display example on the measurement screen when the beveled surface 1a is normal [(a) figure] and when it is abnormal [(b) figure].

According to the present invention, as described above, for example, the beveled surface 1a of the steel pipe 1 is imaged by the CCD camera 5, and the image is processed by the controller 7 to be converted into the binarization of the white level and the black level. The measurement window 8 is provided in the measurement screen after the binarization conversion, the feature amount AR in the measurement window 8 is compared with the reference feature amount AS that is a reference in advance, and when the deviation is a certain amount or more, It is determined that the bite is abnormal.

Next, FIGS. 7 to 10 show the results of measuring the actual beveled surface according to the present invention. FIG. 7 shows FIG. 6 (a).
As shown in FIG. 8, a chip in which chips are caught in the chip during cutting to cause a scratch 1b ′ on the beveled surface 1a is shown in FIG.
As shown in FIG. 6 (b), the beveled surface 1 is caused by defective operating conditions such as defective setting of the bite and defective rotation speed of the steel pipe.
As shown in FIG. 6 (c), when the flaw 1b is generated in a, the chip 2 is damaged during cutting and the beveled surface 1a is cut.
FIG. 10 shows a normal beveled surface, in which the uncut portion 1c has occurred, in which (a) is a raw screen, (b) is a binarization screen, and (c) is a measurement screen. .

When the beveled surface 1a has scratches 1b ', flaws 1b and uncut portions 1c as shown in FIGS. 6 (a) to 6 (c), the normal bevel shown in FIG. 10 (c) is obtained. Compared with the measurement screen on the processed surface 1a, (c) of FIGS.
As shown in FIG. 7, it is understood that the area ratio occupied by the black level (defective portion) in the measurement window 8 increases and the area ratio occupied by the white level (normal portion), that is, the feature amount decreases [FIGS. Reference photographs corresponding to (a) to (c) of No. 1 are attached as (a) to (c) of reference photographs 1 to 4].

Although the beveled surface 1a is irradiated with halogen light and imaged by the CCD camera 5 in the present embodiment, no particular illumination is required as long as the image can be captured well by the camera. Also, the camera is not limited to the CCD camera.

[0021]

As described above, according to the present invention,
Abnormalities of the bite due to chip loss or wear can be detected early and with high accuracy. Therefore, the reuse rate of the tip can be improved, and the occurrence of defects in the beveled surface property of the steel pipe end can be prevented as much as possible, and the quality can be improved.

[Brief description of drawings]

FIG. 1 is a control block diagram of a bite abnormality detection device of the present invention when applied to a steel pipe bevel cutting device.

2A is a schematic plan view of a steel pipe bevel cutting device, FIG.
(B) is explanatory drawing of the measurement visual field in the beveling surface of a steel pipe.

3A is an explanatory diagram of a measurement raw image of a non-defective bevel processed surface to be used as a reference according to the method of the present invention, and FIG. 3B is an explanatory diagram of a binarized image of the same.

FIG. 4 is an explanatory diagram of a setting display screen.

FIG. 5 is an explanatory diagram of a measurement screen according to the method of the present invention, (a)
FIG. 3B is a diagram showing a normal bevel processed surface, and FIG. 7B is a diagram showing an abnormal bevel processed surface.

FIG. 6 is an explanatory view of the beveled surface properties of a steel pipe, where (a) shows chips that were caught in the chip during cutting of the beveled surface and caused scratches, and (b) shows a bite setting failure and Defects caused by poor operating conditions such as poor rotation speed of steel pipes,
(C) shows a case where a chip is missing and an uncut portion is generated during cutting of a beveled surface.

7A and 7B show images when the flaw shown in FIG. 6A is detected, where FIG. 7A is a raw image and FIG. 6B is a binarized image.
(C) shows a measurement screen.

8A and 8B show images when the flaw shown in FIG. 6B is detected, where FIG. 8A is a raw image and FIG. 8B is a binarized image.
(C) shows a measurement screen.

9A and 9B show images when the flaw shown in FIG. 6C is detected, where FIG. 9A is a raw image, and FIG. 9B is a binarized image.
(C) shows a measurement screen.

10A and 10B show images of a normal beveled surface, FIG. 10A shows a raw image, FIG. 10B shows a binarized image, and FIG. 10C shows a measurement screen.

[Explanation of symbols]

 1 Steel pipe 1a Beveled surface 2 Chip 5 CCD camera 7 Controller 8 Measurement window

Claims (2)

[Claims] 1. A method for detecting an abnormality in a bite, comprising:
After imaging the cutting end part with the bite, image processing the image and binarizing and converting it to provide a measurement window in the measurement screen after the binarization, and then the point of low brightness or high brightness in this measurement window A method for detecting a bite abnormality, which is characterized by totalizing points as an area and comparing the total value with a normal value that is a reference in advance. 2. An apparatus applied to the bite abnormality detection method according to claim 1, wherein a camera for picking up a cutting end portion by a bite, and an image processed by the camera are binarized and converted. Byte anomaly detection characterized by including a controller that aggregates low or high brightness points in a measurement window provided in the measurement screen as an area and compares this total value with a normal value that is a reference in advance. apparatus.