Device for detecting peripheral surface defects of long metal material guided through device

Abstract

The utility model relates to a device for detecting defects on the peripheral surface of a long metal material guided through a device, the long metal material having a longitudinal axis, and the device for detecting defects on the peripheral surface of the long metal material having the longitudinal axis guided through the device. The device comprises a ring lamp for peripherally illuminating a section of the surface, where the ring lamp has a central opening through which the long material can pass in the direction of the process flow along its longitudinal axis. Furthermore, the device comprises at least one camera, preferably a mirror unit, for capturing an image of the surface section, the mirror unit comprising at least one mirror, which is arranged in such a way that an image of at least a part of the surface section can be captured by the at least one camera via the at least one mirror, and the device comprises a calculation unit which is suitable for receiving the image data generated by the at least one camera and determining the surface defects of the long material according to the image data.

Description

Technical Field

[0001] The present application relates to a device for identifying defects on the peripheral surface of a metal product guided through the device, wherein the metal product is, for example, a rotationally symmetrical long product, such as a rod or tube that has been subjected to surface treatment such as grinding, stretching, rolling, scraping, or threading. Background Art

[0002] After the forming and heat treatment processes, the long product undergoes further processing steps in order to maintain high tolerances and quality standards and to ensure a defect-free surface. In addition, a scraping process can be carried out within the scope of these post-processing steps. Here, a large amount of surface removal is ensured by means of a scraper, in particular the removal of flaking areas caused by the heat treatment. In this case, the scraping tool can rotate around the workpiece, the workpiece can also rotate in the scraping tool, or both.

[0003] For the purpose of this publication, long products (also referred to as long strips) are semi-finished metal products that have a constant cross-section over the length range produced by rolling, drawing or forging, and these semi-finished metal products are not flat products because their length is much greater than their thickness and width. In particular, they include round steel, bars, wires, tubes and profiles.

[0004] In the manufacturing process of bright steel products, the detection of surface defects is an important component, so continuous defect detection is required. Defects on the surface of long products may already exist before the scraping process, such as point-shaped residual stains and husk, but may also be generated during the scraping process, such as chatter marks, scraping marks, two-dimensional residual stains and mechanical damage. The following is a brief description of the main common defect types. Various point defects and surface defects may occur during the manufacturing and processing process and during the scraping process. For this type of defect, different point defects or surface defects will remain on the scraped test object after the scraping process. For husk, the root cause is raw material defects or local over-rolling during the forming process. When the surface is removed, these defects are visible during the scraping process, so these defects can be identified on the surface during defect detection. Mechanical damage is, for example, scratches or recurring scratches, so for example, surface damage of different depths generated when handling raw materials or during scraping. Scraping marks are only generated during the scraping process and can extend continuously or appear scattered. These scrape marks must be distinguished from common scrape marks, which are not surface defects but only describe the appearance of strongly illuminated surfaces. The main feature that distinguishes scrape marks from scrape marks is the defect depth or brightness intensity. Scrape marks and scrape marks also differ in appearance. Scrape marks appear continuously but cannot be seen with the naked eye. Scrape marks, on the other hand, can be seen with the naked eye and the surface unevenness can be felt by hand. Chatter marks also only occur during the scraping process due to a mismatch in the ratio of the rotation speed of the test object or scraper to the feed speed. These chatter marks can be observed especially during the run-in period of the scraping process.

[0005] Despite the often automated manufacturing methods and stable process chains, if defective workpieces are not identified and are delivered, this can have serious consequences, especially in terms of recycling costs and possible repair costs.

[0006] In the bright steel process, the formation of scraping marks can be almost avoided by timely tool changes. However, in the bright steel process, the formation of point defect images cannot be influenced due to raw material and random metallurgical issues. Therefore, these defective bars can only be detected as surface defects during manipulation and in continuous quality control.

[0007] Currently, in the case of bright steel manufacturing, quality control is usually performed visually behind the scraper by the corresponding equipment operator. Further test procedures are then carried out to maintain dimensional accuracy, and eddy current tests are often required to find internal defects. However, the above-mentioned surface defects are only subject to visual inspection of random samples. Therefore, intelligent optical recognition systems have great potential for online inspection of surface defects in bright steel. Classifying the defect type ultimately also helps to sort defective materials.

[0008] As is known, automatic continuous defect detection in steel production processes is particularly applicable to flat products, but also to other shaped products. For example, the patent document with publication number EP1582068B1 describes a recording system with three or more cameras, wherein a line light source is respectively assigned to a camera. This system is used in rolling processes and accordingly evaluates the peeling surface of long products.

[0009] The patent document with publication number EP0574336B1 describes a test structure, in which the lighting fixture is a circular fluorescent tube. Two camera units are used. The first group consists of four linear array cameras, and the second group consists of six linear array cameras, which are arranged in a circle around the product.

[0010] Different methods for detecting surface defects are known. Patent document with publication number CN112601007A, for example, describes an image recording method and a corresponding device, wherein a global image of a specified object is acquired by a first image acquisition device and a first feature recognition is performed on this global image, so as to determine a feature area based on this global image. Subsequently, a characteristic position of the specified object is determined and a regional image of the characteristic position is acquired by a second image acquisition device, wherein this regional image is used for a second feature recognition, so as to obtain a feature recognition result corresponding to the specified object.

[0011] The patent document with publication number CN114463285A describes a device including a bracket, a linear array camera and a ring-shaped green LED light source. After acquiring the image, defect recognition is performed. To this end, the image dataset of the acquired round steel surface is compared with the defect-free dataset with the help of an effective online classification priority network and a YOLOv5 network. The network model is then trained. This method can detect dents, scratches, rolling marks, warped skins, flanges, iron oxide bands and cracks. Utility Model Content

[0012] The utility model aims to provide an on-line testing device for defects on the bright metal surface of a long material after undergoing a processing process after forming and / or heat treatment, by which the surface defects can be reliably identified and classified.

[0013] The device according to the invention in the above-mentioned technical field is designed in such a way that a rotationally symmetrical metal long material (such as a tube or a bar) can be conveyed through the device along its longitudinal axis, so that the device can be used to test the surface of the long material and identify undesired processing defects on the surface. In some embodiments, long materials with non-rotationally symmetrical cross-sections can also be tested.

[0014] The device comprises at least one camera for capturing images of a surface section. In this case, the camera is oriented in a certain way relative to the long material passing through the device so that the camera can capture images of the long material. The camera can directly capture images of a partial area of ​​the surface facing the camera, i.e., the surface area facing the camera is located within the field of view of the camera. As an alternative, the camera can also capture images of this area via a deflector or the like.

[0015] Furthermore, the device comprises a mirror unit, which comprises at least one mirror, which is arranged in such a way that an image of at least a part of the surface section can be captured by at least one camera via the at least one mirror. The camera preferably captures an image of a region of the surface section via the at least one mirror, which region is located on the side of the long material facing away from the camera, so that the camera cannot capture an image directly because this region of the surface section is not within the field of view of the camera. By means of an advantageous arrangement and orientation of the camera and the mirror, an image of the surface section of the long material can be captured by means of the camera over its entire circumference.

[0016] Furthermore, the device according to the invention has at least one ring light which is suitable for circumferentially illuminating a section of the surface, wherein the ring light has a central opening through which the long material can pass along its longitudinal axis in the process flow direction. This ring light produces a uniform illumination of the surface, preferably over the entire circumference of the long material, which facilitates the acquisition of images. The ring light according to the invention is particularly suitable for ensuring good illumination for the optical inspection of mostly shiny, reflective surfaces of the long material to be tested.

[0017] The device preferably comprises a housing for accommodating at least one camera, the mirror unit and the ring light. The at least one camera, the mirror unit and the ring light can be fixed to the housing and covered by the housing to protect them from contamination or damage. In addition, the housing can also be fixed to a processing device by suitable fixing means and thus flexibly integrated into a processing device in which the long material is processed, for example scraped. The housing has an opening through which the long metal material can pass.

[0018] The computing unit of the device is suitable for receiving the image data generated by the camera and determining the defects of the surface of the long material based on the image data. In this case, the camera captures the image at least partially through the mirror unit. Preferably, the image of the surface area facing away from the camera is captured by the mirror unit. The image data received by the computing unit forms the entire periphery of the long material. This means that the image data of the surface are processed in a certain way so that a full image of the surface is generated based on these image data within the entire periphery of the long material to be tested. Therefore, it can be reliably ensured that the surface is tested within the entire periphery of the long material by the advantageous layout of the mirror and the camera. It is also possible to detect a part of the periphery of the long material directly by the camera.

[0019] This device is preferably suitable for identifying surface defects produced by scraping of long materials. To this end, the computing unit of the device uses a special algorithm suitable for identifying special defect patterns that occur during scraping.

[0020] These defects are especially 2mm 2 or larger surface defects. These surface defects can be traced back in particular to the scraping of the long material, wherein these surface defects are, for example, residual stains, scratches, deposits, indentations or scratches, scraping marks, chatter marks, grinding defects, stretching defects or voids.

[0021] In a preferred embodiment, the continuous metal long material is a solid material or a hollow material with a rotationally symmetrical cross section. In conventional scraping processes, the workpiece (here the continuous metal long material) rotates in the tool, or the tool rotates around the workpiece. The device is preferably suitable for identifying surface defects when the continuous metal long material passes through the device in a rotating and non-rotating manner. Therefore, the device can be used flexibly independently of the type of scraping device (i.e., regardless of whether the workpiece or the tool rotates).

[0022] The mirror unit preferably comprises a mirror support and further preferably comprises four mirrors, wherein the mirrors are fixed to the mirror support and arranged on the mirror support in such a way that at least one camera can capture an image of the portion of the surface section corresponding to the respective mirror through each of the mirrors. The four mirrors are preferably arranged in five substantially identical arches relative to each other in a manner connected to the camera with respect to the longitudinal axis of the long material. The mirrors are advantageously arranged and oriented in such a way that they image the corresponding area of ​​the surface for the camera. Therefore, a single camera can be used to capture images of the entire perimeter of the long material by means of the mirror unit.

[0023] In a preferred embodiment, the mirror unit is arranged above the continuous metal long material. This reduces the risk that debris, process media, etc. generated during the scraping process fall onto the mirror, deposit there and affect the quality of the acquired image data. In this case, the camera is arranged below the continuous metal long material, wherein an easy-to-clean protective screen is preferably arranged between the camera and the long material, which protects the camera from debris, process media, etc. generated during the scraping process. The resulting easy cleanability ensures short maintenance times, so that the quality of the acquired images and the effectiveness of the device can be restored again after contamination.

[0024] In a preferred embodiment of the device, the ring light is dimmable. Therefore, the brightness of the illumination can be optimally adjusted according to the characteristics of the long material to be tested, the expected surface defects and other factors. The ring light preferably has a luminance, i.e. a luminous flux, of at least 10,000 lm, more preferably at least 20,000 lm. In many application examples, bright illumination is conducive to the reliable identification of surface defects. In addition, the wavelength of the light emitted by the ring light is preferably between 600 nm and 700 nm, which is conducive to the identification of surface defects after the scraping process.

[0025] In a preferred embodiment of the invention, the camera is a line scan camera or a matrix camera that records in a line scan mode. Line scan cameras or line scan modes enable a high image recording frequency with a relatively small amount of data to be transmitted and do not require uniform illumination of large areas. This high recording frequency is advantageous because when processing long materials, the processing speed is often very high in some cases, for example up to 40 m / min.

[0026] The camera is preferably arranged on a movable slide so that the clarity of the recorded image can be controlled or adjusted by changing the distance of the camera from the continuous metal long material, so that the image captured by the camera is suitable for identifying defects on the shiny surface of the continuous metal long material. In particular, an optimal distance between the long material and the camera for image recording is set. In this way, the clarity of the recorded image can be adjusted in a certain way, for example, depending on the diameter of the continuous long material, so that this image has a sufficient quality. Therefore, long materials within a predefined diameter range, for example from 18 mm to 180 mm, can be tested with the aid of this device.

[0027] In some embodiments, the device further comprises at least one deflector for increasing the distance between the camera and the continuous metal long product. Thus, the camera is directed towards the deflector, which images the continuous metal long product and the mirror unit having at least one mirror. The deflector can be used to increase the optical path between the camera and the test object in a space-saving manner. This improves the depth of field, which facilitates lossless imaging of all views of the test object, i.e., in particular the direct view and one or more mirror views.

[0028] An alternative embodiment of the device is to use a plurality of cameras to collect image data of a surface segment of a continuous metal long material instead of using a mirror unit for the entire circumference. In this embodiment, the device preferably comprises three or more cameras for collecting images of the surface, which are arranged in such a way that the portions of the segment image that can be collected by the respective cameras or that can be collected by the respective cameras complement each other in the circumferential direction. In this case, the cameras are preferably arranged substantially uniformly around the circumference of the long material in a plane perpendicular to the longitudinal axis of the long material, so that the surface is imaged uniformly over the entire circumference.

[0029] The cameras are preferably arranged on movable slides, respectively, so that the definition can be adjusted by changing the distance of the at least three cameras from the continuous metal long product, so that the image data collected by the at least three cameras are suitable for identifying defects on the bright surface of the continuous metal long product. Except for the features related to the mirror unit, all the above features can be combined with alternative embodiments without mirrors.

[0030] Specifically, the utility model provides the following technical solutions:

[0031] The utility model provides a device for identifying circumferential surface defects of a metal long material guided through the device, wherein the metal long material has a longitudinal axis, wherein the device comprises: an annular light for circumferentially illuminating a section of the surface, wherein the annular light has a central opening, and the long material can pass through the central opening along its longitudinal axis in the process flow direction; at least one camera for capturing an image of the surface section; a mirror unit, wherein the mirror unit comprises at least one mirror, and the at least one mirror is arranged in a certain manner so that the at least one camera can capture an image of at least a part of the surface section through the at least one mirror; and a computing unit, which is suitable for receiving image data generated by the at least one camera and determining the surface defects of the long material based on the image data.

[0032] Optionally, the device further comprises a shell, wherein the ring light, the at least one camera and the mirror unit are accommodated in the shell, and the shell is suitable for allowing the long material to pass through along its longitudinal axis in the process direction.

[0033] Optionally, the defect is 2 mm 2 Or larger area of ​​point or surface defects.

[0034] Optionally, the surface defects can be traced back to the scraping or steelmaking process or steel processing process of the long product.

[0035] Optionally, the surface defects are residual stains, scratches, deposits, indentations or scratches, scraping marks, vibration marks, grinding defects, tensile defects, cracks, inclusions, bubbles, pores, burrs or voids.

[0036] Optionally, the long material is a solid material or a hollow material having a cross-section that is rotationally symmetrical about its longitudinal axis, and the device is suitable for identifying the defect when the long material passes through in a rotating and non-rotating manner.

[0037] Optionally, the mirror unit comprises a plurality of first mirrors, wherein the first mirrors are arranged in such a way that an image of a portion of the surface segment corresponding to the corresponding mirror can be captured by the at least one camera through each of the first mirrors.

[0038] Optionally, the mirror unit includes four first mirrors.

[0039] Optionally, the first mirrors are mounted on a common mirror support.

[0040] Optionally, the mirror unit is designed and arranged to image the entire section of the surface via the at least one camera directly or simultaneously via the mirror unit on the circumference.

[0041] Optionally, the mirror unit is arranged above the opening of the ring light when viewed along the process flow direction, and the at least one camera is arranged below the opening of the ring light when viewed along the process flow direction.

[0042] Optionally, a protective screen is arranged between the at least one camera and the opening of the ring light in the process direction.

[0043] Optionally, the ring light is dimmable.

[0044] Optionally, the ring light has a light power of at least 10000 lm.

[0045] Optionally, the ring light has a light power of at least 20000 lm.

[0046] Optionally, the ring light is suitable for emitting light with a wavelength between 600nm and 700nm.

[0047] Optionally, the at least one camera is a line array camera or a matrix camera adopting a line array mode.

[0048] Optionally, the at least one camera has an optical axis and a recording focus located on the optical axis, wherein the at least one camera is arranged on a slider movable along the optical axis so that the relative position of the camera can be adjusted along the optical axis.

[0049] Optionally, the device further comprises at least one second mirror designed and arranged to deflect the optical path between the at least one camera and the segment of the surface.

[0050] Optionally, the computing unit is adapted to receive image data generated by the at least one camera within an adjustable system cycle and to determine surface defects of the long material based on the image data.

[0051] The utility model also provides a device for identifying circumferential surface defects of a long metal product guided through the device, the long metal product having a longitudinal axis, wherein the device comprises: a ring light for circumferentially illuminating a section of the surface, wherein the ring light has a central opening, and the long product can pass through the central opening along its longitudinal axis in the process flow direction; a plurality of cameras for capturing images of the surface section, wherein the cameras are arranged in a certain manner so that portions of the images of the surface section can be captured by the cameras over the entire circumference of the long product, wherein the portions of the images of the section that can be captured by the corresponding cameras complement each other along the circumferential direction; and a computing unit, which is suitable for receiving image data generated by the plurality of cameras and determining surface defects of the long product based on the image data.

[0052] Optionally, the device further comprises a shell, wherein the ring light and the camera are accommodated in the shell, and the shell is suitable for allowing the long material to pass through along its longitudinal axis in the process direction.

[0053] Optionally, the defect is 2 mm 2 Or larger area of ​​point or surface defects.

[0054] Optionally, the surface defects can be traced back to the scraping or steelmaking process or steel processing process of the long product.

[0055] Optionally, the surface defects are residual stains, scratches, deposits, indentations or scratches, scraping marks, vibration marks, grinding defects, tensile defects, cracks, inclusions, bubbles, pores, burrs or voids.

[0056] Optionally, the long material is a solid material or a hollow material having a cross-section that is rotationally symmetrical about its longitudinal axis, and the device is suitable for identifying the defect when the long material passes through in a rotating and non-rotating manner.

[0057] Optionally, the plurality of cameras are at least three cameras, which are arranged in a certain manner so that a portion of the surface segment that is completely complementary to the surface segment can be detected simultaneously by the at least three cameras.

[0058] Optionally, in the process direction, a protective screen is arranged between each of the plurality of cameras and the opening of the ring light.

[0059] Optionally, the ring light is dimmable.

[0060] Optionally, the ring light has a light power of at least 10000 lm.

[0061] Optionally, the ring light has a light power of at least 20000 lm.

[0062] Optionally, the ring light is suitable for emitting light with a wavelength between 600nm and 700nm.

[0063] Optionally, each of the multiple cameras is a line array camera or a matrix camera in a line array mode.

[0064] Optionally, each of the multiple cameras has an optical axis and a recording focus located on the optical axis, wherein the respective cameras are arranged on a slider movable along the optical axis so that the relative positions of the corresponding cameras can be adjusted along the optical axis.

[0065] Optionally, the computing unit is adapted to receive image data generated by the plurality of cameras within an adjustable system cycle and to determine surface defects of the long material based on the image data. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Several embodiments are shown in the drawings which are purely exemplary and do not limit the scope of the present invention. Among them:

[0067] Figure 1 A schematic diagram of an embodiment of a device for detecting defects on a shiny surface of a long metal product;

[0068] Figure 2A A schematic diagram of an embodiment of a device for defect detection, the device having a mirror unit including four mirrors;

[0069] Figure 2Bis a schematic side view of an embodiment of a device for defect detection, the device having a mirror unit with four mirrors; and

[0070] Figure 3 Schematic diagram of an alternative specific embodiment of a device for defect detection, which has a mirror unit with five mirrors. DETAILED DESCRIPTION

[0071] Figure 1 The figure is a schematic diagram of an embodiment of a device 1 for detecting defects on a shiny surface of a metal long product. The device 1 is used to test a metal long product 10 passing through the device 1 and to detect defects on the surface of the long product 10 .

[0072] One advantage to be noted is the independent integration of the test system into a continuous processing line. For example, the device 1 can be installed after a scraper in order to detect the surface of a bright metal long product 10 during the processing cycle and evaluate it during the processing cycle. Defective material can then be marked accordingly and, if necessary, a signal can also be sent to a downstream machine control device in order to, for example, prompt its removal.

[0073] Figure 1 The cross section of a long product 10 is shown, which has a circular cross section and is perpendicular to Figure 1 The direction of the image plane shown passes through the device 1. In some embodiments, the long material 10 can also have a cross-section of another shape. In a preferred embodiment, the long material 10 has been shaved in a shaving process (not shown) upstream of the device 1, and after the above-mentioned processing, this long material is conveyed through the device 1. In a common shaving process, the shaving tool can rotate around the workpiece (here: the long material 10), or the shaving tool can be arranged essentially fixedly and the workpiece rotates. According to Figure 1 In the embodiment in FIG. 1 , the long material 10 rotates in the direction of the arrow shown when passing through the device 1. The long material 10 can also pass through the device 1 without rotation. In addition to the upstream scraping process, in some embodiments, other pretreatment steps can also be provided upstream of the device 1.

[0074] The illustrated embodiment of the device 1 comprises a housing 20, in which the other components of the device 1 are arranged and fixed, which components will be described in detail below. The housing 20 is designed in such a way that it has an opening in a direction perpendicular to the image plane, through which the metal long material 10 to be tested by the device 1 is passed. In addition to protecting and positioning the components, the housing 20 also allows the device to be flexibly integrated into existing processing equipment. The housing 20 and the entire device 1 can be integrated into the equipment in such a way that the long material 10 is automatically conveyed through the device 1 after leaving the upstream processing step for the surface testing. The housing 20 can be made of different materials, for example of steel or other metals, but also of plastic.

[0075] Device 1 Figure 1 The embodiment shown comprises a camera 30. The camera 30 is arranged substantially centrally below the passing long material 10 and the field of view is oriented vertically upwards in the direction of the long material 10. Thus, at least one section of the long material 10 and in particular the part of the surface section of the long material 10 facing the camera 30 is temporarily in the field of view of the camera 30 and can be optically detected by the camera 30 and further processed for analysis and defect detection. In a preferred embodiment, the camera 30 is a line array camera or a matrix camera in a line array mode. The camera 30 is preferably connected to a power supply not shown and can also be operated by batteries or accumulators.

[0076] As shown, the camera 30 is arranged and fixed on a slider 36. The fixation can be achieved by an applicable fixing member (e.g., screw connection). The slider 36 is preferably supported on a guide rail 38 in a translational manner. The guide rail 38 can be installed in the housing 20. The guide rail 38 and the slider 36 are preferably oriented in a certain way so that the movement of the slider is oriented in a direction that intersects the cross section of the long material and is substantially perpendicular to the process flow direction of the long material. Therefore, the slider 36 and the camera 30 arranged thereon can be moved in a certain way so that the distance from the long material 10 can be adjusted by movement, thereby adjusting the clarity of the surface image of the long material 10. The slider 36 is connected to the guide rail, for example, by a guide shoe. The slider 36 is driven, for example, by means of an electric cylinder (not shown) that can be positioned very accurately. For this purpose, this electric cylinder is provided with precise positioning, so that it can be quickly and accurately moved to a position known for a specific setting under specific conditions.

[0077] according to Figure 1In the embodiment shown, the device 1 comprises a mirror unit 40. The mirror unit 40 comprises a mirror support 44 mounted in the housing 20. Four mirrors 42 are fixed to the mirror support 44 and are positioned in the device 1. In this case, these mirrors are arranged substantially in a plane corresponding to the drawing plane in the figure. The mirrors 42 are tilted and arranged around the long material 10 in a certain way so that each mirror 42 images a mirror view of the surface area of ​​the long material 10 to which it corresponds, which mirror view can be captured by the camera 30. Therefore, in the embodiment shown, the camera 30 captures a direct view of a surface area of ​​the long material 10 and four mirror views of other surface areas of the long material 10. The above-mentioned one direct view and the four mirror views together form a full image of the surface of a section of the long material 10 over the entire periphery.

[0078] The mirror 42 may be accommodated in a mirror holder 44 at an angle so that the orientation may be adjusted to achieve optimal detection of the surface. The adjustment may be made manually by a suitable actuation mechanism and / or may be made automatically. In some embodiments, instead of four mirrors 42, another number of mirrors 42 may be used, and the mirrors 42 may be curved (particularly concave).

[0079] In the embodiment shown, the ring light 50 is arranged in such a way that the long material 10 passes through its central opening. In this case, this ring light is arranged in a staggered manner with respect to the camera and mirror unit 40 in the process flow direction of the long material 10, so that this ring light does not interfere with the detection of the surface of the long material 10, for example in that the incident angle of the generated light causes undesired mirror effects on the shiny reflective surface of the long material 10. The ring light 50 is accommodated and fixed in the housing 20 and has a very high luminous intensity of at least 10000 lm.

[0080] The device 1 also comprises a computing unit 60 for evaluating the image data acquired by the camera 30 and for detecting defects based on these image data. The computing unit 60 is arranged externally and is communicatively connected to the camera 30. Due to the special requirements of very high processing speeds placed on the camera 30, which include, for example, high data rates during recording, the connection between the camera 30 and the computing unit 60 must also be designed for correspondingly high data rate transmission, for example, via a fast USB connection.

[0081] A heater 70 is installed in the housing 20 in order to prevent the mirror 42 from fogging up by thermostating the device 1 at lower ambient temperatures. A filter fan 80 generates an air flow in the housing 20 which prevents impurities from being deposited in the housing and on the system components. In addition, the filter fan 80 can dissipate excess heat generated by the components. In addition, a cooler 90 is provided for recooling the heat generated by the ring light 50. This cooler can include a recooling device and a heat exchanger (not shown).

[0082] Figure 2A 2 is a schematic diagram of an embodiment of a device 1 for defect detection, which has a mirror unit 40 with four mirrors 42. FIG. 2 shows in particular the arrangement of the camera 30 and the mirror 42 in FIG. Figure 1 The long material 10 and all mirrors 42 are located in the field of view of the camera 30, so that this camera can capture mirror images of surface areas of the long material 10 via the mirrors 42, which at least partially cannot be captured directly by the camera 30 or can only be captured directly at a very narrow and therefore less favorable angle.

[0083] Figure 2B Embodiment of a device 1 for defect detection having a mirror unit 40 with four mirrors 42 Figure 2A Schematic diagram that is rotated compared to the previous one.

[0084] Figure 3 FIG. 4 is a schematic diagram of an alternative embodiment of a device 1 for defect detection, which has a mirror unit 40 comprising five mirrors 42 , 43 . Figure 2A and Figure 2B The fifth additional mirror of the embodiment shown serves as a deflector 43 and allows the camera 30 to be positioned in different ways. In this arrangement, the camera 30 no longer has to be aimed directly at the long material 10. The deflector 43 can be fixed to a mirror support 44 and can be tilted and adjusted like the other mirrors 42. In particular, the camera 30 can be positioned further away from the long material 10 to be tested, so that the depth of field and thus the image quality of all views of the surface of the long material 10 can be improved. In this embodiment, the camera 30 can also be arranged on a movable slide 36 in order to achieve an optimal detection of the surface. As an alternative and supplementary solution, the deflector 43 can be designed in a movable manner so that the length of the optical path can be adjusted, thereby achieving the same effect.

[0085] Reference numerals

[0086] 1 Device for defect identification

[0087] 10 Metal long products

[0088] 20 Shell

[0089] 30 Cameras

[0090] 36 Sliders

[0091] 38 Rails

[0092] 40 mirror units

[0093] 42 Mirror

[0094] 43 Polarizing Mirror

[0095] 44 Mirror bracket

[0096] 50 Ring Light

[0097] 60 computing units

[0098] 70 Heater

[0099] 80 filter fan

[0100] 90 Cooler.

Claims

1. A device for detecting defects on the peripheral surface of a long metal product guided through the device, the long metal product having a longitudinal axis, characterized in that The device comprises: a ring light for lateral illumination of a section of the surface, wherein the ring light has a central opening through which the long material can be passed along its longitudinal axis in the process direction; at least one camera for acquiring an image of the surface section; a mirror unit, the mirror unit comprising at least one mirror, the at least one mirror being arranged in such a way that an image of at least a part of the surface section can be captured by the at least one camera via the at least one mirror; and A computing unit is adapted to receive the image data generated by the at least one camera and to determine surface defects of the long product based on the image data.

2. The device according to claim 1, characterized in that: The device further comprises a housing, in which the ring light, the at least one camera and the mirror unit are accommodated, and the housing is suitable for allowing the long material to pass through along its longitudinal axis in the process flow direction.

3. The device according to claim 1 or 2, characterized in that: The defect is 2 mm 2 Or larger area of ​​point or surface defects.

4. The device according to claim 3, characterized in that: The surface defects can be traced back to the scraping or steelmaking process or steel processing process of the long product.

5. The device according to claim 3, characterized in that: The surface defects are residual stains, scratches, deposits, indentations or scratches, scraping marks, chatter marks, grinding defects, tensile defects, cracks, inclusions, bubbles, pores, burrs or voids.

6. The device according to claim 1 or 2, characterized in that: The long material is a solid or hollow material having a cross section which is rotationally symmetrical about its longitudinal axis, and the device is adapted to identify the defect when the long material passes through in a rotating and non-rotating manner.

7. The device according to claim 1 or 2, characterized in that: The mirror unit comprises a plurality of first mirrors, wherein the first mirrors are arranged in such a way that an image of the portion of the surface section which is associated with the respective mirror can be captured by the at least one camera via each of the first mirrors.

8. The device according to claim 7, characterized in that: The mirror unit includes four first mirrors.

9. The device according to claim 7, characterized in that: The first mirrors are mounted on a common mirror support.

10. The device according to claim 1 or 2, characterized in that: The mirror unit is designed and arranged to image the entire section of the surface via the at least one camera directly or simultaneously via the mirror unit on the circumference.

11. The device according to claim 1 or 2, characterized in that: The mirror unit is arranged above the opening of the ring light when viewed along the process direction, and the at least one camera is arranged below the opening of the ring light when viewed along the process direction.

12. The device according to claim 1 or 2, characterized in that: A protective screen is arranged between the at least one camera and the opening of the ring light in the process direction.

13. The device according to claim 1 or 2, characterized in that: The ring light is dimmable.

14. The device according to claim 1 or 2, characterized in that: The ring light has a light power of at least 10000 lm.

15. The device according to claim 1 or 2, characterized in that: The ring light has a light power of at least 20,000 lm.

16. The device according to claim 1 or 2, characterized in that: The ring light is adapted to emit light having a wavelength between 600 nm and 700 nm.

17. The device according to claim 1 or 2, characterized in that: The at least one camera is a line array camera or a matrix camera in a line array mode.

18. The device according to claim 1 or 2, characterized in that: The at least one camera has an optical axis and a recording focus located on the optical axis, wherein the at least one camera is arranged on a slide movable along the optical axis so that the relative position of the camera can be adjusted along the optical axis.

19. The device according to claim 1 or 2, characterized in that: The device further comprises at least one second mirror designed and arranged to deflect a light path between the at least one camera and the section of the surface.

20. The device according to claim 1 or 2, characterized in that: The computing unit is adapted to receive image data generated by the at least one camera within an adjustable system cycle and to determine surface defects of the long material based on the image data.

21. A device for detecting lateral surface defects of a metal length guided through the device, the metal length having a longitudinal axis, characterized in that: The device comprises: a ring light for lateral illumination of a section of the surface, wherein the ring light has a central opening through which the long material can be passed along its longitudinal axis in the process direction; a plurality of cameras for capturing images of the surface section, wherein the cameras are arranged in such a way that portions of the image of the surface section can be captured by the cameras over the entire circumference of the long material, wherein the portions of the image of the section that can be captured by the respective cameras complement each other in the circumferential direction; and A computing unit is adapted to receive the image data generated by the plurality of cameras and to determine surface defects of the long product based on the image data.

22. The device according to claim 21, characterized in that: The device further comprises a housing, in which the ring light and the camera are accommodated, and the housing is suitable for allowing the long material to pass through along its longitudinal axis in the process direction.

23. The device according to claim 21 or 22, characterized in that: The defect is 2 mm 2 Or larger area of ​​point or surface defects.

24. The device according to claim 23, characterized in that: The surface defects can be traced back to the scraping or steelmaking process or steel processing process of the long product.

25. The device according to claim 23, characterized in that: The surface defects are residual stains, scratches, deposits, indentations or scratches, scraping marks, chatter marks, grinding defects, tensile defects, cracks, inclusions, bubbles, pores, burrs or voids.

26. The device according to claim 21 or 22, characterized in that: The long material is a solid or hollow material having a cross section which is rotationally symmetrical about its longitudinal axis, and the device is adapted to identify the defect when the long material passes through in a rotating and non-rotating manner.

27. The device according to claim 21 or 22, characterized in that: The plurality of cameras is at least three cameras which are arranged in such a way that a part of the surface section which is completely complementary to the surface section can be detected simultaneously by the at least three cameras.

28. The device according to claim 21 or 22, characterized in that: In the process direction, a protective screen is arranged between each of the plurality of cameras and the opening of the ring light.

29. The device according to claim 21 or 22, characterized in that: The ring light is dimmable.

30. The device according to claim 21 or 22, characterized in that: The ring light has a light power of at least 10000 lm.

31. The device according to claim 21 or 22, characterized in that: The ring light has a light power of at least 20,000 lm.

32. The device according to claim 21 or 22, characterized in that: The ring light is adapted to emit light having a wavelength between 600 nm and 700 nm.

33. The device according to claim 21 or 22, characterized in that: Each of the plurality of cameras is a line array camera or a matrix camera in a line array mode.

34. The device according to claim 21 or 22, characterized in that: Each of the plurality of cameras has an optical axis and a recording focus located on the optical axis, wherein the respective cameras are arranged on a slider movable along the optical axis so that the relative positions of the respective cameras can be adjusted along the optical axis.

35. The device according to claim 21 or 22, characterized in that: The computing unit is adapted to receive the image data generated by the plurality of cameras within an adjustable system cycle and to determine surface defects of the long material based on the image data.

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