JPH06331553A - Detection apparatus of outward-appearance defect of long material - Google Patents

Abstract

PURPOSE:To simplify the structure of the title apparatus by a method wherein a cleaning part and a detection part are arranged in series on the path line of a material to be inspected, the material to be inspected is fed to the detection part immediately after its cleaning operation, a defect is detected at high speed and surely and the material to be inspected is fed only rectlinearly. CONSTITUTION:A cleaning part and a detection part are arranged in series. While the outer circumference of a material 3 to be inspected is being cleaned, an outward-appearance defect can be inspected, and a treatment sped of two to three times can be obtained. In addition, a rectlinear feed operation omits a complicated mechanism for a rotary feed operation, an apparatus can be simplified and made lightweight, and the vibration of the material 3 to be inspected is reduced. In addition, the outward-appearance defect is detected in two zones in the upper half and the lower half on the surface of the material 3 to be inspected. As a result, three each of television cameras 4a to 4f equipped with an electronic shutter are arranged at angle intervals of 60 deg. radially around the axis of the material 3 to be inspected, and even the material 3, to be inspected, which is fed rectlinearly and at high speed can be imaged without a shake. In addition, even when the material 3 to be inspected is vibrated, its detection is not affected as long as it is situated within the field of view of the television cameras 4a to 4f.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus which has a circular or polygonal cross section and mainly detects the appearance defect while cleaning the outer periphery of a long metal material or non-metal material.

[0002]

2. Description of the Related Art Mainly, long metal materials are manufactured mainly through a rolling process, a forging process, a machining process, etc., and an appearance inspection is performed immediately before sending them to the next process or immediately before shipping to remove appearance defects. I have to keep it. However, when performing a visual inspection, if dirt or foreign matter is attached to the outer periphery of the material to be inspected, it will be detected as a defect, and therefore it is necessary to clean the material to remove it as much as possible. As a conventional cleaning method, generally, an immersion method using an organic solvent, a running shower method, a brushing method, etc. are used. On the other hand, a method shown in FIG. 9 is known as a visual inspection method. 3 is a material to be inspected, 35 is a laser light source, and 36
Is a scanning mirror and 37 is a detector. In this inspection method, the material 3 to be inspected is rotatably fed in the direction of the arrow, and the surface of the material to be inspected is irradiated with the laser beam 38 emitted from the laser light source 35 while being linearly scanned by the scanning mirror 36. The detector 37 receives specularly reflected light from the surface to detect defects, and is disclosed in Japanese Patent Application Laid-Open No. 57-6305.

A method similar to this is disclosed in JP-A-61-161.
There is also a laser light source as disclosed in Japanese Patent No. 95205, which uses a light source in which a large number of semiconductor lasers are arranged in a line. Further, as a method of using a television camera as a detector, there is a surface open defect detection device disclosed in Japanese Patent Laid-Open No. 01-201140. In all of these, the material to be inspected is a flat surface or the one having a round bar shape is detected as a rotary feed. Conventionally, the cleaning device and the defect detecting device are separately installed, and after the cleaning is completed, the material to be inspected is conveyed to the defect detecting device to detect the appearance defect.

[0004]

In the conventional cleaning method, for example, when an organic solvent is used, since the solvent is quick-drying, unevenness in dryness is likely to occur on the surface of the material to be inspected. It is easy to misunderstand and it becomes inconvenient. Therefore, it is necessary to completely remove the organic solvent and perform a drying process immediately after the cleaning process to eliminate unevenness in dryness.However, when performing the drying process while the test material is running, a large drying rate is generated in proportion to the running speed. Ability is demanded and enormous energy and space are required. For this reason, the cleaning device and the detection device tend to be arranged apart from each other, and even if the material to be inspected is cleaned, stains and foreign substances are reattached to the detection device during transportation.

As described above, it is necessary for the cleaning device to be as compact as possible during transportation of the material to be inspected and from the installation space, and to increase the degree of surface cleaning of the material to be inspected. In order to increase the cleaning degree, for example, the injection pressure of the cleaning liquid is increased, the flow rate is increased, or the temperature of the cleaning liquid is raised, but it is necessary to take measures to prevent the cleaning liquid from flowing out of the cleaning tank. Further, it is also necessary to remove the cleaning liquid adhering to the surface of the test material so as not to affect the defect detection. In addition, since the organic solvent dries quickly but adversely affects the environment and the human body, it is necessary to refrain from using the organic solvent as much as possible, and thus a washing device that dries quickly is required.

Further, as one of the detection methods, in the conventional technique, it is necessary to rotate the material to be inspected around the axis, so that there is a drawback that the conveying mechanism becomes complicated, and moreover, by rotating the material to be inspected. There is a high possibility that the inspection material will vibrate. Figure 9
In the case of the detection device as shown in FIG. 3, the change in the position of the material 3 to be inspected means the change in the incident angle of the laser beam 38 with respect to the irradiation surface. Laser light source 35 and detector 3
Since the position of 7 is fixed, if the incident angle changes, the laser beam 38 that is specularly reflected on the surface of the material to be inspected will not enter the detector 37. As a result, the detection accuracy is greatly affected. For example, if the material 3 to be inspected has a length of more than 2 m and a small diameter metal round bar having an outer diameter of 6 mm or less, a vibration of about 0.5 mm is an unavoidable value, so that an erroneous determination is likely to occur.

Further, the processing capacity of the material to be inspected is disadvantageous in that it cannot be processed at high speed because the material to be inspected must be rotationally moved in the longitudinal direction. From the above, the present invention is
It is equipped with a compact cleaning device that removes dirt on the surface of the material to be tested without using an organic solvent and has a high drying capacity. It is an object of the present invention to provide an appearance defect detection device which has a simple structure and can detect defects at a high speed and reliably by only performing straight-line feed. Then, after cleaning the test material, an appearance defect detecting device for a long material is provided, which can be promptly sent to the detection unit so that the surface is not soiled again.

[0008]

As a result of various studies to solve the above-mentioned problems of the prior art, the inventor of the present application succeeded in downsizing the cleaning device for the test material and the defect detection device. It is based on the fact that even if they are arranged in series, a large space is no longer required. That is, according to the present invention, in an appearance defect detection device for a long material, a cleaning unit that removes foreign matter adhering to the outer peripheral surface of the test material and a detection unit that detects a defect on the outer peripheral surface of the test material are It is an appearance defect detection device for a long material, which is arranged in series on a material pass line.

The cleaning unit for cleaning the surface of the material to be tested while moving the material to be tested at high speed in the longitudinal direction is provided with a cleaning tank through which the material to be tested passes and the inlet side of the material to be tested of the cleaning tank. And air nozzles provided at both ends on the outlet side to prevent the outflow of the cleaning liquid and remove the cleaning liquid adhering to the surface of the material to be inspected, and one or more forward nozzles installed inside the cleaning tank to inject the cleaning liquid. It consists of a washing nozzle or a reverse washing nozzle. Another feature is that a cleaning unit provided with a device for heating the cleaning liquid as needed is provided. Further, the detection unit for inspecting the outer peripheral surface of the long material to be inspected at a high speed irradiates the outer peripheral surface of the material to be inspected uniformly and widely, and a plurality of ring light sources facing each other, and the light source of the light source. A reflection cover that removes the influence and reflects the light of the light source radiated to the outside to irradiate the test material with light, and a plurality of imaging means that is located on the outer peripheral surface of the test material and images the outer peripheral surface, It is characterized in that appearance defects on the outer peripheral surface of the test material are detected.

[0010]

In the cleaning section, the material to be tested is purified in the cleaning tank by the cleaning liquid sprayed from the forward nozzle or the backward nozzle. The cleaning liquid may be heated if necessary. Furthermore, the cleaning liquid adhering to the surface of the material to be inspected is removed by injecting air on the outlet side of the cleaning tank, the surface of the material to be inspected is sufficiently purified, and it does not affect the visual inspection. Further, since no special drying process is required, high speed cleaning of the test material is possible. By arranging the nozzles for injecting the cleaning liquid so as to face each other in the forward and reverse directions and providing the nozzles for injecting air at the inlet side and the outlet side of the cleaning tank, the outflow of the cleaning liquid can be prevented and the cleaning device can be made compact. . Further, since the cleaning nozzle for injecting the cleaning liquid and the nozzle for injecting the air can have the same shape, it is advantageous in downsizing and cost reduction.

As shown in FIG. 5, the appearance defects are detected by arranging ring light sources as illuminations in parallel at positions opposed to each other and allowing the test material to pass through the center of the ring light source. The basic idea is to image the material to be inspected by the imaging means. Further, a reflection cover is provided on the outer circumference of the ring light source, and a pinhole for taking an image with the image pickup means is opened. With such a structure, it is possible to uniformly irradiate the surface of the test material without the appearance of ambient light or other images on the outer peripheral surface of the test material. As a method of illuminating the surface of the material to be inspected, there are an optical fiber, a straight tube type light source, etc., but as a result of the experiment, it was found that the ring light source can illuminate the widest area as shown in FIG. 8 and is optimal for defect detection. It was

The area where the imaging means can receive light when irradiating the material to be inspected is 180 ° in terms of the angle from the center of the material to be inspected as shown by 31 in FIG. When the image is taken from directly above, the defect 29 on the edge of the material to be inspected looks flat on the TV screen 30, so that the practical area 32 per imaging unit is about 90 ° from the center of the material to be inspected.
Becomes narrower. Therefore, in the present invention as described above, the examination of the illumination method and the installation of the imaging means, which is a detector, on the entire circumference of the test material allows the outer peripheral surface of the test material to be fed in a straight line without rotating the test material. It is made possible to perform a full-circle inspection. Further, in the present invention, by arranging the cleaning unit and the defect detection unit in series, the test material can be sent to the defect detection unit immediately after cleaning. It is possible to substantially eliminate the unnecessary time until, the efficiency is high, and only the defect can be surely detected.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a side sectional view showing an embodiment of the appearance defect detecting apparatus of the present invention. The cleaning unit 1 and the detection unit 2 are arranged in this order in series along the feeding direction 12 of the material 3 to be inspected, so that the defect can be detected immediately after cleaning. Then, first, the structure of the cleaning unit will be described in detail. 2 is a sectional view of a side surface of the cleaning unit, and FIG. 3 is a sectional view showing a structure of the nozzle. Inside the cleaning tank 13 through which the material 3 to be tested passes, an inlet-side cylindrical guide 14 having a hole through which the material 3 to be tested, an outlet-side cylindrical guide 15, and a chamber block 16 having a cleaning liquid inlet 26 Then, four cleaning nozzles 17 to 20 provided with annular gaps through which the cleaning liquid is ejected are arranged. The cleaning nozzle is a forward cleaning nozzle 17 having a nozzle angle of 60 ° from the left in the drawing, and a nozzle angle of 1
A 40 ° forward cleaning nozzle 18, a backward cleaning nozzle 19 with a nozzle angle of 140 °, and a reverse cleaning nozzle 20 with a nozzle angle of 60 ° are provided to face the forward and reverse directions to cancel the flow, and the cleaning liquid is a cleaning tank. It was placed so that it would not leak out.

Further, a forward air nozzle 21 having a nozzle angle of 60 ° and a forward air nozzle 22 having a nozzle angle of 140 °, which have the same structure as the cleaning liquid nozzle for preventing the outflow of the cleaning liquid, are provided on the inlet side of the cleaning tank 13. A reverse air nozzle 23 having a nozzle angle of 140 ° and a reverse air nozzle 2 having a nozzle angle of 60 ° and having the same structure as the cleaning liquid nozzle for preventing the outflow on the outlet side of the cleaning tank 13 and removing the cleaning liquid adhering to the test material 3.
4 is provided. The cleaning liquid removed by air and the air are returned to the tank for the cleaning liquid (not shown) through the return pipe 25, and the cleaning liquid is heated to about 60 ° C. in the tank by a heating device (not shown) if necessary. . The cleaning liquid flowing from the cleaning liquid inlet 26 flows into the annular flow path formed by the gap between the inlet side cylindrical guide 14 and the outlet side cylindrical guide 15 and is ejected from the annular gap.

By the above-described cleaning device, the material 3 to be tested passing through the cleaning tank 13 is purified by the cleaning liquid sprayed from the forward cleaning nozzles 17 and 18 and the backward cleaning nozzles 19 and 20 in the cleaning tank 13. . Then, the cleaning liquid and the adhering substances adhered to the material 3 to be inspected can be removed by the air jetted from the air nozzle provided on the outlet side of the cleaning tank 13. Although the case where four cleaning liquid jet nozzles and nozzle angles of 60 ° and 140 ° are used has been described above, the combination of the number of nozzles, the nozzle angle, the nozzle interval, and the like can be appropriately selected according to the situation of the test material. Good. For example, if the material to be inspected has a small degree of dirt or foreign matter adhesion, the cleaning device can be made more compact, and the cleaning power can be increased by increasing the number of nozzles. Will also be possible.

Next, the detection section will be described in detail.
FIG. 4 is a front view and a side view showing the detection unit 2. The appearance defect is detected by dividing the surface of the material to be inspected 3 into two zones, an upper half and a lower half, so that three television cameras with electronic shutters 4a to 4f are radially arranged around the axis of the material to be inspected 3 respectively. At 60 ° angular intervals. Each of the television cameras 4a to 4f is controlled by the camera controller 7, is sent to the video processing device 8 to detect a defect, and outputs the determination result outputs 9a to 9f to the central processing unit 10.
For illumination, two ring fluorescent lamps 6 are arranged in parallel for each zone so that the material 3 to be tested passes through the center thereof. Further, a reflection cover 5 is provided on the outer circumference of the ring fluorescent lamp 6 and a pinhole 5a for taking an image with the television camera 4 is opened.
Further, a reflection cover 5b having a hole through which the material to be inspected passes is provided at the edge of each zone to block the influence of light from the other zone. With such a structure, the outer peripheral surface of the test material 3 can be uniformly irradiated without the appearance of ambient light or other images on the outer peripheral surface of the test material 3.

The non-flicker power source 11 is used as the power source of the fluorescent lamp so as to eliminate the influence of flicker. The detector 2 is provided with a lifting function so that the position of the test material 3 can be adjusted. Since the television camera 4 with an electronic shutter is used in this appearance defect detection apparatus, it is possible to pick up an image of a test material that moves at high speed without blurring. It was also found that even if the material to be inspected 3 vibrates, it does not affect the detection as long as it is within the field of view of the television camera 4. Figure 6
It is a conceptual diagram of a camera visual field when inspecting the bar steel 27. The camera visual field was set to 15 × 20 mm, and the overlap amount for each screen was set to 2 mm. Moreover, since the captured screen is processed in real time, the cycle of the video signal is 1/60
Since it will be seconds (20 mm-2 mm) / (1/60 seconds) = 1080 mm
/Sec=64.8 m / min. This value is the maximum line speed for straight feed under these conditions.

At this line speed, a water-soluble cleaning liquid was used to perform cleaning and a defect detection test. Although the case where six TV cameras are used has been described above, the permissible vibration can be increased by increasing the number of cameras at 60 ° intervals so that the vibration can be increased. The maximum line speed can be increased by adding more cameras. By arranging the cleaning unit and the detection unit in series as in the present invention, the appearance defect can be detected while cleaning the outer periphery of the material to be inspected, and the straight-line feed speed of the conventional machine is 20 to 30 m / min. The processing speed is 2 to 3 times that of the conventional machine.

[0019]

As described above, since the cleaning is performed by the forward nozzle and the reverse nozzle and the cleaning liquid adhering to the surface of the material to be tested is removed by the air nozzle on the outlet side, even if the water-soluble cleaning liquid is used, It is possible to obtain a sufficient degree of surface cleaning that does not affect the appearance inspection, which is equivalent to that of a cleaning device using a solvent. Further, by facing the cleaning nozzles and providing air nozzles on the inlet side and the outlet side, the cleaning liquid can be prevented from flowing out, and the cleaning device can be made much more compact than the conventional one. Further, the appearance defect detecting device that conventionally required to rotate and feed the material to be inspected, but in the present invention, since only the straight advance feed is required, the rotation mechanism for conveyance is unnecessary, and the simplification and weight reduction of the entire device can be achieved. It is possible and there is little vibration. Even if there is vibration or fluctuations in the pass line,
Since the detector is an area sensor, it can sufficiently tolerate vibrations and fluctuations in the area, and therefore appearance defects can be detected without degrading detection accuracy. Further, according to the present invention, it is possible to arrange the cleaning unit and the detection unit in series, so that the defect inspection can be performed immediately after cleaning, and the efficiency can be greatly improved. Therefore, the present invention is an apparatus that mainly detects the appearance defect while cleaning the outer periphery of a long metallic material or non-metallic material, and is an invention that is very effective in the inspection process industrially.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an embodiment of an appearance defect detection device for a long material of the present invention.

FIG. 2 is a cross-sectional view showing an example of a cleaning unit according to the appearance defect detection device for a long material of the present invention.

FIG. 3 is a cross-sectional view showing an example of a cleaning nozzle and an air nozzle according to the apparatus for detecting an appearance defect of a long material according to the present invention.

4A and 4B are a front view and a side view showing an embodiment of a detection unit according to the appearance defect detection device for a long material of the present invention.

FIG. 5 is a conceptual diagram showing a basic structure of a detection unit in the appearance defect detection device for a long material of the present invention.

FIG. 6 is a conceptual diagram for studying the inspection speed when the appearance defect detection device for a long material of the present invention is applied to the appearance inspection of a bar steel.

FIG. 7 relates to an appearance defect detection device for a long material according to the present invention,
It is a figure of the monitor screen which the television camera in FIG. 6 imaged.

FIG. 8 relates to a device for detecting an appearance defect of a long material according to the present invention,
It is a perspective view which shows the experimental result when examining a lighting method.

FIG. 9 is a conceptual diagram showing an example of a conventional inspection apparatus for appearance defects of a long material.

[Explanation of symbols]

 1 Cleaning Section 2 Detecting Section 3 Test Material 4 Television Camera with Electronic Shutter 5 Reflective Cover 5a Pinhole 5b Reflective Cover 6 Ring Fluorescent Lamp 7 Camera Controller 8 Image Processing Device 9a Judgment Output 9b Judgment Output 9c Judgment Output 9d Judgment Output 9e Judgment Output 9f Judgment output 10 Central processing unit 11 Non-flicker power supply 12 Test material feed direction 13 Cleaning tank 14 Inlet side cylindrical guide 15 Outlet side cylindrical guide 16 Chamber block 17 Nozzle angle 60 ° forward nozzle 18 Nozzle angle 140 ° forward Nozzle 19 Reverse cleaning nozzle with 140 ° nozzle angle 20 Reverse cleaning nozzle with 60 ° nozzle angle 21 Reverse air nozzle with 60 ° nozzle angle 22 Reverse air nozzle with 140 ° nozzle angle 23 Forward air nozzle with 140 ° nozzle angle 24 Nozzle angle 60 ° forward air nozzle 25 Return pipe 26 Cleaning liquid inlet 27 Polished steel bar 28 Defect 29 Defect 30 TV screen 31 Light receiving area 32 Actual Pass 33 Optical fiber 34 straight tube type fluorescent lamp 35 laser light source 36 scanning mirror 37 the detector 38 the laser beam

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[Procedure amendment]

[Submission date] July 9, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 2

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

Further, a forward air nozzle 21 having a nozzle angle of 60 ° and a forward air nozzle 22 having a nozzle angle of 140 °, which have the same structure as the cleaning liquid nozzle for preventing the outflow of the cleaning liquid, are provided on the inlet side of the cleaning tank 13. A reverse air nozzle 23 having a nozzle angle of 140 ° and a reverse air nozzle 2 having a nozzle angle of 60 ° and having the same structure as the cleaning liquid nozzle for preventing the outflow on the outlet side of the cleaning tank 13 and removing the cleaning liquid adhering to the test material 3.
4 is provided. The cleaning liquid and the air removed by the air pass through the return pipe 25 and return to the cleaning liquid tank (not shown). If necessary, the cleaning liquid is heated in the tank to about 65 ° C. by a heating device (not shown). . The cleaning liquid flowing from the cleaning liquid inlet 26 flows into the annular flow path formed by the gap between the inlet side cylindrical guide 14 and the outlet side cylindrical guide 15 and is ejected from the annular gap.

Claims (4)

[Claims] 1. An apparatus for detecting an appearance defect of a long material, comprising: a cleaning unit that removes foreign matter adhering to the outer peripheral surface of the test material, and a detection unit that detects a defect on the outer peripheral surface of the test material. An appearance defect detection device for a long material, which is arranged in series on a pass line of the material to be inspected. 2. A cleaning unit mounted on an appearance defect detection apparatus for a long material is provided with a cleaning tank through which a material to be tested passes, and both end portions of the cleaning tank on the inlet side and the outlet side of the material to be tested, It is composed of an air nozzle for preventing the outflow of the cleaning liquid or for removing the cleaning liquid adhering to the material to be tested, and a single or plural forward cleaning nozzles and reverse cleaning nozzles which are attached inside the cleaning tank and inject the cleaning liquid. The appearance defect detection device for a long material according to claim 1, wherein. 3. A detection unit mounted on an appearance defect detection device for a long material irradiates an outer peripheral surface of a material to be inspected and reflects a plurality of ring-shaped light sources facing each other and light emitted to the outside of the light source. And a plurality of image pickup means located on the outer peripheral surface of the test material for detecting outer peripheral surface defects of the test material. 1
The appearance defect detection device for a long material according to. 4. The appearance defect detecting device for a long material according to claim 1, wherein the cleaning unit mounted on the appearance defect detecting device for a long material has a heating device for heating the cleaning liquid.