DE4130217A1 - Method and device for testing surfaces - Google Patents

Method and device for testing surfaces

Info

Publication number
DE4130217A1
DE4130217A1 DE19914130217 DE4130217A DE4130217A1 DE 4130217 A1 DE4130217 A1 DE 4130217A1 DE 19914130217 DE19914130217 DE 19914130217 DE 4130217 A DE4130217 A DE 4130217A DE 4130217 A1 DE4130217 A1 DE 4130217A1
Authority
DE
Germany
Prior art keywords
round
irradiated
radiation
light
radiation source
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
DE19914130217
Other languages
German (de)
Inventor
Shigetoshi Hyodo
Koji Okamura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hajime Industries Ltd
Original Assignee
Hajime Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to JP24466290A priority Critical patent/JPH04122839A/en
Application filed by Hajime Industries Ltd filed Critical Hajime Industries Ltd
Publication of DE4130217A1 publication Critical patent/DE4130217A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00Investigating or analysing materials by the use of optical means, i.e. using infra-red, visible or ultra-violet light
    • G01N21/84Systems specially adapted for particular applications
    • G01N21/88Investigating the presence of flaws or contamination
    • G01N21/95Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
    • G01N21/952Inspecting the exterior surface of cylindrical bodies or wires
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00Investigating or analysing materials by the use of optical means, i.e. using infra-red, visible or ultra-violet light
    • G01N21/17Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/47Scattering, i.e. diffuse reflection
    • G01N21/4738Diffuse reflection, e.g. also for testing fluids, fibrous materials
    • G01N21/474Details of optical heads therefor, e.g. using optical fibres
    • G01N2021/4752Geometry
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00Investigating or analysing materials by the use of optical means, i.e. using infra-red, visible or ultra-violet light
    • G01N21/84Systems specially adapted for particular applications
    • G01N21/88Investigating the presence of flaws or contamination
    • G01N21/8851Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges
    • G01N2021/8887Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges based on image processing techniques
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2201/00Features of devices classified in G01N21/00
    • G01N2201/10Scanning
    • G01N2201/102Video camera

Description

The invention relates to a method and a Vorrich device for testing surfaces, especially towards visually the polished surface of steel tubes, Steel rods or the like, which on the outer, round surface surface in the circumferential direction.

There are methods for automatic optical detection flaws on the outer surface of steel known. This is done, for example, with high precision sion when testing surfaces with a laser beam scanned the surface of the steel. Although many suggestions for automatic optical inspection the outer, round surface of steel tubes, steel rods etc. known with a circular cross-section there is hardly a method in practice Use. The reason is that when testing of such surfaces through optical devices the automatic inspection by grinding marks in the Steel tube, steel rod or the like or by their vibration is disturbed during transport.

The outer, round surface of steel tubes, steel rods or the like, which he a precise surface inspection demand, are usually completed during production has been ground in the circumferential direction. At Versu small flaws on the outer, round surface to determine by optical methods, therefore very fine grinding marks in the circumferential direction on the outer round surface of the steel tube or the like together determined with the surface defects. Such  Grinding marks are all the more recognizable malfunctions swell the more precisely the test system works. For this The reason was previously not possible with optical processes Lich, an extremely precise surface inspection from the outside round surfaces of steel tubes, rods or similar perform.

When checking the entire outer, round surface of steel tubes, rods or the like, these become more common transported in a spiral. By eccentric However, construction or deformations will vibrate those under test Materials during spiral conveyance, so that erroneous investigation or overlooked the automatic optical surface the steel test of steel pipes or the like considerably disrupt.

For testing the surface of metallic, external, round surfaces by using scattered light Japanese Patent Publication 58-53 861 is known, after which the reflected from an irradiated part Light an optical sensor over a frosted glass as a pro injection plate and a slot is fed. There by this method the reflec from the irradiated part light onto a frosted glass Projection plate and then from the optical sensor the extremely small mistakes are not included detectable with high precision.

The object of the invention is therefore a method and to provide a device for testing surfaces which allows an op table surface inspection of steel tubes and rods o. Ä. To perform, whose outer, round surfaces in Circumferential direction were ground without grinding  traces or due to irregularities in the steel tube or similar vibrations influenced or disturbed will.

This task is accomplished by a process containing the method steps mentioned in claim 1, and a Device comprising those mentioned in claim 4 Characteristics, solved.

For a better understanding of the characteristics, characteristics and Advantages of the invention will be preferred below Exemplary embodiment explained with reference to the drawing.

Fig. 1 shows a schematic representation of an embodiment of the invention.

For a more detailed representation of exemplary embodiments of the Invention will become a major consideration below Invention explained.

For checking the surface of a counter to be checked usually the surface of the material irradiated with light, the reflected light through the Use of an optical photosensor, such as as a television camera, photoelectrically converted and the signal thus obtained for the determination of errors learn further developed. Unless one is caused by foreign bodies errors due to the material surface to be tested or if there is a slight defect, this will be met scattered light. Because this creates strong, direct reflecting radiation in the surrounding error prevented the part and only detected scattered light minor errors caused by foreign bodies and shortcomings in a high useful / interference signal ratio  be determined. However, if the mate to be tested rial is metallic, is basically strong, direct reflective radiation is generated as soon as light is on the material surface to be tested hits. By Use of light with high scattering quality and indi Direct exposure to the metal can cause direct reflection radiation are prevented, so that the proportion stray light can be easily determined.

In the present case, the radiation source outgoing radiation on a radiation scatter plate, for example a milky white radiation scattering plate, directed to scatter the radiation and the beam passing through the radiation scattering plate to the object surface to be tested The milky white radiation scattering plate also scatters within the plate the radiation so that the whole Surface of the wispy-white radiation scattering plate shines brightly as flat plate radiation source to serve. In this way, a strong ge scattered light radiation generated. By irradiating the It is the object to be tested with this radiation possible to do both on the surface of the test Object refracting light as well as that of Directly reflecting beam from grinding marks to suppress lung.

What grinding marks on the surface of the test As far as the object is concerned, there is no risk that the optical sensor shows the grinding marks as shadows conceives because the light on the surface of the test the object in the direction of the grinding marks falls.  

The present invention also finds in the sub Search for objects with a round, columnar shape turn. Even if the object to be checked during the test should vibrate a little, so can by the vibration of the central axis of the object caused Fluctuations are suppressed because of the subject by stray light of great width from the entire mil chi-white radiation scattering plate is irradiated.

Since the material surface to be tested with white light is irradiated, the optical sensor detects this mate rial surface as a white, light surface. Generally mine is white light from a continuous Spectrum without any amplification or attenuation of Light components of a certain wavelength, so that white light the appropriate radiation source to use in tests to determine defects on metalli surfaces. If a faulty part is on the surface of the metallic material, the light on this defective part is ge scatters that the proportion of white light up to one Shadow is reduced so that the optical sensor this part clearly as a black, flawed Part recorded.

As for the milky white radiation scattering plate, those in the device according to the invention and in the process used for testing surfaces, so a milky white plastic plate, the opal glass, is sufficient or similar as a construction material. While the light scatter from milky white glass the of plastic sheets, appears in the present a plastic plate against glass breakage safer and cheaper to use. This kind of  Milky white plate contains extremely small white bodies ner to the radiation direction of the radiating Splitting light spatially and a high scatter degree to achieve. White light of continuous Spectrum as light radiation represents a suitable one Radiation to metallic surfaces.

An embodiment of the invention is explained below. Fig. 1 shows a schematic representation of an embodiment of the invention.

In this exemplary embodiment, a steel tube 1 to be tested is transported spirally in the horizontal direction or in the direction of its central axis O.

A radiation source 2 designed as a stroboscope uses, for example, a xenon lamp which radiates an upper, outer, round surface of the steel tube 1 from above the steel tube 1 in an inclined direction. An optical axis 2 A of the radiation source 2 is at right angles to the central axis O of the steel tube 1 , while an angle (cutting angle α) between the optical axis 2 A and a perpendicular N at an intersection I at which the radiation source 2 originates Radiation hits the outer round surface 1 A of the steel tube 1 , is selected in the order of about 45 °. In front of the radiation source 2 , a radiation scattering plate, for example a mil-white radiation scattering plate, is arranged at a right angle to the optical axis 2 A of the radiation source 2 .

A current source 3 of the radiation source 2 is switched on and off by a switching signal, the switching signal being supplied by a signal processor 4 in order to actuate the radiation source 2 in a flash.

A hereinafter briefly referred to as an optical sensor optical sensor device 6, such as a remote vision camera (CCD-camera) is on a Reflektionsstrah beam path OP arranged to an upper part of the be radiated, external to detect 1 A steel tube 1 is round surface. A video signal from the optical sensor 6 is sent to the signal processor 4 , where it is stored in coordination with the flash sequence of the radiation source 2 . The stored video signal is fed to a monitor 7 for imaging. The signal in the signal processor 4 is immediately digitized in binary form or it is digitized in binary form after it has been analyzed by differentiation in order to amplify the brightness differences. On the other hand, based on such a difference in brightness, the surface error signal is fed to an output terminal 8 .

The method according to the invention for testing surfaces is carried out as follows using the device described above:
While the steel tube 1 is transported spirally, the upper part of its outer round upper surface 1 A is irradiated by the radiation source 2 . The upper part of the outer round surface 1 A of the steel tube 1 irradiating light has already radiated through the mil chigwhite radiation scattering plate 5 , while it radiates at right angles to the central axis O of the steel tube 1 , so that in the irradiated part of the steel tube 1 the in the outer surface 1 A of the steel tube in the circumferential direction, that is to say perpendicular to the central axis O of the steel tube 1, traces of grinding disappear in order to show the defect-free part in white color, but errors as black shadows. By scanning the irradiated part in an enlarged view by the optical sensor 6 , by imaging the image obtained by the monitor 7 and by processing the video signal obtained in the signal processor 4 , errors can be reliably determined without detecting the grinding tracks as external sources of interference. At the same time, the influence is switched off, which is due to vibrations due to irregularities, etc. of the steel tube 1 . By repeatedly scanning the spirally transpor ted steel tube 1 , the entire outer round surface of the steel tube 1 is searched with high precision.

For steel tubes with an outer diameter of 6.5 mm and a wall thickness of 0.5 mm, the outer round surface of which was finished using the PVA grinding method, surface defects of the order of 50 microns and 20 microns depth could be detected using the method described above be determined. If the milky white radiation scattering plate 5 was removed and the light radiation was scattered onto the grinding tracks, many signals were determined which corresponded to the above surface defects.

Although the milky white radiation diffusing plate 5 was used, in the case where the outer circular surface of the steel tube 1 was irradiated in the direction inclined toward the center salmon O of the steel tube 1 , many shadows from grinding marks were found.

The optical sensor 6 used on this occasion was a CCD camera with a selected 50x magnification. A xenon stroboscope was used as the light source 2 and an opal glass similar to the construction material was used as the milky white radiation scattering plate 5 .

It follows from the above description of the device according to the invention and of the invention Procedure that by grinding marks and other irregularities to be ignored etc. related disturbances of the material to be tested be eliminated so that it is possible to pass the test the polished outer round surface with high Perform precision. In contrast to the examination method The state of the art is thus achieved, au tomatically with considerable simplification the signal processing to determine errors.

Claims (8)

1. A method for testing surfaces, comprising the following process steps:
  • a) a part of an outer, round, circumferentially ground surface of an object to be tested is irradiated with scattered light perpendicular to the central axis of the object;
  • b) the irradiated part of the surface of the object is scanned abge by an optical sensor which is arranged in the beam path of the light reflected by the surface part be irradiated; and
  • c) a video signal of the optical sensor is processed for the purpose of determining a defective area on the outer surface.
2. The method according to claim 1, wherein as scattered light white light is selected.
3. The method of claim 1, wherein the angle of incidence of the scattered light on the outer, round surface is about 45 °.
4. Device for testing surfaces, comprising:
  • a) a radiation source for emitting light, so that part of an outer, round, in the circumferential direction ground surface of an object to be tested is irradiated obliquely in a direction perpendicular to the central axis of the object;
  • b) a radiation scattering device, which is arranged in front of the radiation source and scatters the light emitted by the radiation source and uniformly irradiates the part of the outer, round surface of the object;
  • c) an optical sensor which is arranged in the beam path of the light reflected from the irradiated surface part and which scans the irradiated part of the surface of the object to generate a video signal.
  • d) a signal processor which processes the video signal to determine a faulty location on the outer, round surface of the object.
5. The device of claim 4, further comprising a current source feeding the radiation source, the is controlled by the signal processor.
6. The device of claim 5, further comprising a monitor that the video signal the signal processor device for reproducing an image of the Object.
7. The device according to claim 4, wherein as radiation scattering device a milky white radiation scatter plate serves.  
8. The device of claim 7, wherein the milky white Radiation scattering plate made of art similar to opal glass fabric is made.
DE19914130217 1990-09-14 1991-09-11 Method and device for testing surfaces Withdrawn DE4130217A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP24466290A JPH04122839A (en) 1990-09-14 1990-09-14 Inspecting method of surface

Publications (1)

Publication Number Publication Date
DE4130217A1 true DE4130217A1 (en) 1992-03-19

Family

ID=17122088

Family Applications (1)

Application Number Title Priority Date Filing Date
DE19914130217 Withdrawn DE4130217A1 (en) 1990-09-14 1991-09-11 Method and device for testing surfaces

Country Status (6)

Country Link
JP (1) JPH04122839A (en)
AU (1) AU8380591A (en)
CA (1) CA2051032A1 (en)
DE (1) DE4130217A1 (en)
FR (1) FR2666884A1 (en)
GB (1) GB2249169A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4415004A1 (en) * 1993-04-30 1994-11-03 Univ Schiller Jena Arrangement and method for characterising surfaces and for characterising and classifying surface defects and near-surface defects as well as inhomogeneities in the volume of transparent media
DE4325921A1 (en) * 1993-08-02 1995-02-09 Schlafhorst & Co W Cross-wound bobbin quality test
DE19809790A1 (en) * 1998-03-09 1999-09-30 Daimler Chrysler Ag Method and device for determining a swirl structure in the surface of a finely machined cylindrical workpiece
WO2003008951A1 (en) * 2001-07-17 2003-01-30 Centre De Recherches Metallurgiques, A.S.B.L. Method for inspecting the surface of a roll cylinder and device therefor

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06129995A (en) * 1992-10-16 1994-05-13 Nippon Steel Corp Optical inspection device for surface defect
DE69530007D1 (en) * 1995-06-15 2003-04-24 British Nuclear Fuels Plc Check the surface of an object
BE1014222A3 (en) * 2001-06-13 2003-06-03 Ct Rech Metallurgiques Asbl Characterization ONLINE PROCESS OF MOVING SURFACE AND DEVICE FOR ITS IMPLEMENTATION.
FR2829572B1 (en) * 2001-09-10 2005-03-25 Giat Ind Sa Device and method for determining the wear of a tube, such as a tube of an arm
US7792419B2 (en) 2005-11-02 2010-09-07 Microscan Systems, Inc. Illuminator-especially for cylindrical curved surfaces
DE602006016836D1 (en) * 2005-11-02 2010-10-21 Microscan Systems Inc Lighting device for curved cylinder surfaces
KR100891842B1 (en) 2007-08-28 2009-04-07 주식회사 포스코 Device for detecting the optic bug of archetypal rod and method thereof
FR2965616B1 (en) * 2010-10-01 2012-10-05 Total Sa Method of imaging a longitudinal drive
CN106353340B (en) * 2016-10-18 2019-07-16 厦门威芯泰科技有限公司 A kind of rodlike high reflectance surface defects of parts detection method

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3320939C2 (en) * 1982-06-15 1985-04-18 Hajime Industries, Ltd., Tokio/Tokyo, Jp
DE3641816A1 (en) * 1986-12-06 1988-06-16 Robert Prof Dr Ing Massen Method and arrangement for measuring and / or monitoring properties of yarns and ropes
DE3402855C2 (en) * 1983-01-31 1989-08-10 Nippon Kokan K.K., Tokio/Tokyo, Jp

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JPS597937A (en) * 1982-07-06 1984-01-17 Minolta Camera Co Ltd Electronic flashing device with plural flash discharge tubes
JPS6113142A (en) * 1984-06-29 1986-01-21 Nuclear Fuel Co Ltd Lighting device for small pinhole inspection apparatus
JPH01165940A (en) * 1987-12-23 1989-06-29 Nissan Motor Co Ltd Inspecting apparatus of surface defect
JPH0682104B2 (en) * 1988-09-19 1994-10-19 松下電工株式会社 Printed circuit board appearance inspection method

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3320939C2 (en) * 1982-06-15 1985-04-18 Hajime Industries, Ltd., Tokio/Tokyo, Jp
DE3402855C2 (en) * 1983-01-31 1989-08-10 Nippon Kokan K.K., Tokio/Tokyo, Jp
DE3641816A1 (en) * 1986-12-06 1988-06-16 Robert Prof Dr Ing Massen Method and arrangement for measuring and / or monitoring properties of yarns and ropes

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
The Engineering, August 1966, S. 203 *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4415004A1 (en) * 1993-04-30 1994-11-03 Univ Schiller Jena Arrangement and method for characterising surfaces and for characterising and classifying surface defects and near-surface defects as well as inhomogeneities in the volume of transparent media
DE4325921A1 (en) * 1993-08-02 1995-02-09 Schlafhorst & Co W Cross-wound bobbin quality test
DE19809790A1 (en) * 1998-03-09 1999-09-30 Daimler Chrysler Ag Method and device for determining a swirl structure in the surface of a finely machined cylindrical workpiece
DE19809790B4 (en) * 1998-03-09 2005-12-22 Daimlerchrysler Ag Method for determining a twist structure in the surface of a precision-machined cylindrical workpiece
WO2003008951A1 (en) * 2001-07-17 2003-01-30 Centre De Recherches Metallurgiques, A.S.B.L. Method for inspecting the surface of a roll cylinder and device therefor
BE1014299A3 (en) * 2001-07-17 2003-08-05 Centre Rech Metallurgique Method for inspection of the surface of a rolling cylinder and device for its implementation.
US7006213B2 (en) 2001-07-17 2006-02-28 Centre De Recherches Metallurgiques, A.S.B.L. Method for inspecting the surface of a roll cylinder and device therefor

Also Published As

Publication number Publication date
CA2051032A1 (en) 1992-03-15
GB9119372D0 (en) 1991-10-23
AU8380591A (en) 1992-03-19
JPH04122839A (en) 1992-04-23
FR2666884A1 (en) 1992-03-20
GB2249169A (en) 1992-04-29

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