DE102010017531A1 - Method for automatic detection of defects in material layer with reinforcements for manufacture of vehicle tires, involves providing material layer of elastomer material with embedded parallel and consecutive arranged reinforcements - Google Patents

Abstract

The method involves providing a material layer (1) of elastomer material with embedded parallel and consecutive arranged reinforcements. A high-speed camera (3) is arranged to a side edge of the material (13) of the material layer, where the high-speed cameras are essentially perpendicular to the edge of the material of the material layer.

Description

The invention relates to a method for the automated detection of defects in a material layer with reinforcements for the production of vehicle tires.

In the conventional production of new tires, materials or certain tire components are prefabricated. In particular, the carcass ply for producing the tire carcass belongs to these prefabricated components. The carcass ply is a material layer of an elastomeric material with reinforcements arranged parallel to one another. The strength members are generally aligned in a radial passenger car tire in the radial direction. In one of the manufacturing steps for producing the carcass ply, an endless strip of material is passed over a conveyor belt and then cut accordingly. The carcass ply receives the length needed to make the green tire on the tire building drum. The preparation of the materials for the carcass ply is generally carried out via a calendering process. This calendering process can lead to defects in the material layer. These imperfections can lead to the fact that manufactured green tires must be sorted out later as rejects. It is therefore desirable to detect corresponding defects in the materials as early as possible in order to then be able to take the appropriate countermeasures.

The invention has for its object to provide a method by which defects in a material layer with reinforcements can be detected automatically in a simple way.

• a) Bereitstellen einer Materiallage aus Elastomermaterial mit eingebetteten und parallel hintereinander angeordneten Festigkeitsträgern
• b) Verfahren der Materiallage auf einer Fördervorrichtung, wobei die Festigkeitsträger in der Materiallage im Wesentlichen senkrecht zur Förderrichtung der Materiallage ausgerichtet sind,
• c) Anordnung einer Hochgeschwindigkeits-Kamera seitlich zu einer Materialkante des Materialstreifens mit einer verfahrbaren Halterung, wobei die Hochgeschwindigkeits-Kamera im Wesentlichen senkrecht zur Materialkante des Materialstreifens ausgerichtet ist,
• d) kontinuierliche Beobachtung der Materialkante mit den sichtbaren Festigkeitsträgerenden mit der Hochgeschwindigkeits-Kamera, wobei der Materialstreifen kontinuierlich mit einer hohen Fördergeschwindigkeit auf der Fördervorrichtung weiterbefördert wird und die Hochgeschwindigkeits-Kamera jeweils einzelne Bildausschnitte der Materialkante des Materialstreifens aufnimmt,
• e) Ausleuchtung der Materialkante des Materialstreifens mit einer Beleuchtung mit einer hohen Lichtintensität,
• f) kontinuierliche Auswertung der einzelnen Bilder der Hochgeschwindigkeits-Kamera mit einer Bildverarbeitungssoftware,
• g) Automatisiertes Detektieren von Festigkeitsträger-Fehlstellen in der Materiallage mit der Bildverarbeitungssoftware,
• h) Automatisiertes Anhalten der Fördervorrichtung zum Überprüfen der Fehlstelle in der Materiallage.

The object is achieved according to claim 1 with a method comprising the following steps:

• a) providing a material layer of elastomeric material with embedded and parallel successively arranged reinforcements
• b) moving the material layer on a conveying device, wherein the reinforcing elements in the material layer are aligned substantially perpendicular to the conveying direction of the material layer,
• c) arranging a high-speed camera laterally to a material edge of the material strip with a movable holder, the high-speed camera being oriented essentially perpendicular to the material edge of the material strip,
• d) continuous observation of the material edge with the visible strength member ends with the high-speed camera, wherein the material strip is continuously conveyed on the conveying device at a high conveying speed and the high-speed camera receives individual image sections of the material edge of the material strip,
• e) illumination of the material edge of the strip of material with illumination with a high light intensity,
• f) continuous evaluation of the individual images of the high-speed camera with image processing software,
• g) Automated detection of strength carrier defects in the material layer with the image processing software,
• h) Automated stopping of the conveyor for checking the defect in the material layer.

An advantage of the invention is to be seen in particular in that the method ensures a high production quality of the vehicle tires to be produced. Defects in the material layer, for example, a lack of reinforcement, are detected automatically and safely in a simple manner. Subsequently, the conveyor belt for conveying the material layer is stopped immediately and the material layer is examined in more detail at the appropriate location. As a result, the quality defect would be detected very early and not only when the corresponding green tire is detected. In this way, at the same time productivity in the production of new tires is significantly increased.

In an advantageous development of the invention, it is provided that the material strip is scanned at least in step d) by a laser with a linear light beam, whereby material overlaps of the prefabricated material layer are detected. These material overlaps of the prefabricated material layer are due to corresponding overlap splice required in the prefabrication of the material layer. The material overlaps must be taken into account when evaluating the excluded images by the camera in order to avoid misinterpretations in the image evaluation.

In a further advantageous embodiment of the invention, it is provided that the laser continuously scans the material layer in an oblique orientation from above the surface of the material strip.

This orientation allows the surface of the material layer to be scanned in a simple manner.

In a further advantageous embodiment of the invention it is provided that the high-speed camera, the lighting and the laser are arranged on a movable frame.

In this way, in particular the Hochgeschwindigkeitskammera can be easily moved to the optimum position for observation of the material edge.

The alignment of the high-speed camera is crucial to be able to observe the material edge optimally.

In a further advantageous embodiment of the invention, it is provided that the movable frame is moved transversely to the conveying direction of the strip of material via a linear actuator.

Thereby, the frame and the components attached thereto can be moved with a high accuracy in a corresponding position.

In a further advantageous embodiment of the invention it is provided that the lighting is an LED lamp with a high light intensity.

The LED has the advantage that it has a high luminous intensity in order to evaluate the recorded images optimally.

In a further advantageous development of the invention, it is provided that the image processing software automatically recognizes missing strength carriers and / or misplaced strength carriers.

Missing reinforcements in the material layer always lead to a Mateiralausschuss of the produced material tire. Therefore, such imperfections must always be recognized early in the prefabrication in order to increase the productivity in the material pre-assembly.

In a further advantageous development of the invention, it is provided that the image processing software visually simplifies the arrangement of the reinforcing elements in the material layer and at the same time carries out an automatic evaluation of reinforcing element flaws.

As a result, defects in the material layer can be detected safely and easily.

In a further advantageous embodiment of the invention, it is provided that the image processing software automatically determines the number of reinforcement carriers per image section.

The number of reinforcements per image section can also be used to perform a plausibility check, which makes it easier to detect defects in the material layer.

In a further advantageous embodiment of the invention it is provided that the conveyor moves the strip of material at a conveying speed of 60 meters per second.

Such a conveying speed is very high. Therefore, a manual control of the strip of material is no longer possible.

In a further advantageous embodiment of the invention, it is provided that the high-speed camera takes at least 120 images per second.

As a result, the strip of material is continuously monitored over its entire length. An intermediate stop of the conveyor belt is therefore no longer necessary.

Reference to an embodiment of the invention will be explained in more detail. Show it:

1 the method according to the invention,

2 : the strip of material in a side view,

3 : A screen view with the schematic arrangement of the strength member ends.

The 1 shows a perspective view of the method according to the invention. The material strip 1 is on a conveyor, not shown, in the conveying direction 2 transported. With these strips of material 1 it is essentially an endless strip of material which is fed to a corresponding cutting device. In this cutter, the endless strip of material 1 cut to an appropriate length, which is required for the production of the green tire.

In the strip of material 1 are arranged parallel to each other strength carrier. The strength members are substantially perpendicular to the conveying direction 2 in the material situation 1 embedded. At the material edge 13 of the material strip 1 are the visible ends 8th to see the strength carrier. The material strip 1 is usually produced by a corresponding calendering process.

The high speed camera 3 , the LED light 4 and the laser 5 with the linear light beam are on the movable frame 6 arranged. The movable frame 6 is transversely to the conveying direction via the linear actuator 2 emotional. In a first process step, the high-speed camera 3 with the linear actuator 7 Move to a corresponding position with the camera 3 the material edge 13 of the material strip 1 can observe optimally. The LED light 4 illuminates the corresponding material edge from above. In the following process steps takes the high-speed camera 3 continuously individual image sections of the material edge 13 on. The images are automatically evaluated with the appropriate image processing software, for example, to automatically detect missing reinforcements. The image processing software is installed on a connected computer, which automatically evaluates the images accordingly. The image processing also processes the information that is transmitted via the laser 5 to be obtained, which is the surface of the material strip 1 scans and thereby detect material overlaps. In the event that a defect in the material layer has been automatically detected, the corresponding conveyor is stopped immediately and then examined the defect in the material layer.

The 2 shows the strip of material 1 in a side view, as observed by the high speed camera. The strength carriers 8th are arranged parallel to each other and in an elastomeric material 10 embedded. The strength carriers 8th may for example consist of metal or a textile material. In the figure is also a lack of strength support in place 9 to see. This defect would be automatically detected by the image processing software.

The 3 shows a screen shot created in conjunction with the image processing software. The points 11 represent the detected reinforcement ends. Over a curve 12 , which was created with the image processing software, it can be determined whether a strength element is missing at one point in the material layer. The irregular curve 12 at the point 9 indicates a missing strength element in the material layer. In such a case, automatically the conveying device for conveying the material layer would be automatically stopped. The defect in the corresponding material layer would then be removed and then the process continued. The main advantage of this method is that defects in the material layer are detected early.

LIST OF REFERENCE NUMBERS

1

Material strips of elastomeric material with reinforcements

2

Conveying direction of the material strip

3

High Speed Camera

4

LED light

5

Laser with linear light beam

6

Mobile frame or holder

7

Linear actuator

8th

Visible ends of the strength members embedded in elastomeric material

9

Missing strength element in the material layer

10

elastomeric material

11

Reinforcement ends in the representation with the image processing software

12

Curve course for the automatic evaluation of the defects of reinforcements

13

material edge

Claims (11)

Method for the automated detection of defects in a material layer ( 1 ) with reinforcements for the production of vehicle tires: a) providing a material layer ( 1 ) made of elastomeric material ( 10 ) with embedded reinforcing elements arranged parallel to one another b) method of the material layer ( 1 ) on a conveyor device, wherein the strength carriers in the material layer substantially perpendicular to the conveying direction ( 2 ) the material layer ( 1 c) arrangement of a high-speed camera ( 3 ) laterally to a material edge ( 13 ) of the material strip ( 1 ) with a movable holder 6 where the high-speed camera ( 3 ) substantially perpendicular to the material edge ( 13 ) of the material strip ( 1 ), d) continuous observation of the material edge ( 13 ) with the visible reinforcing member ends ( 8th ) with the high-speed camera 3 where the strip of material ( 1 ) is conveyed continuously at a high conveying speed on the conveying device and the high-speed camera ( 3 ) individual image sections of the material edge ( 13 ) of the material strip ( 1 ), e) illumination of the material edge ( 13 ) of the material strip ( 1 ) with a lighting ( 4 ) with a high light intensity, f) continuous evaluation of the individual images of the high-speed camera ( 3 ) with image processing software, g) Automated detection of strength carrier defects ( 9 ) in the material layer ( 1 ) with the image processing software, h) Automated stopping of the conveyor device for checking the defect ( 9 ) in the material layer 1 , Method according to claim 1, characterized in that the strip of material ( 1 ) at least at step d) by a laser ( 5 ) is scanned with a line-shaped light beam, whereby material overlaps of the prefabricated material layer ( 1 ) are detected. Method according to one of the preceding claims, characterized in that the laser ( 5 ) the material layer ( 1 ) in an oblique orientation from above the surface of the strip of material ( 1 ) continuously scans. Method according to one of the preceding claims, characterized in that the High Speed Camera 3 , the lighting ( 4 ) and the laser ( 5 ) on a movable frame ( 6 ) are arranged. Method according to one of the preceding claims, characterized in that the movable frame ( 6 ) via a linear actuator ( 7 ) transverse to the conveying direction ( 2 ) of the material strip ( 1 ). Method according to one of the preceding claims, characterized in that the illumination ( 4 ) is an LED lamp with a high light intensity. Method according to one of the preceding claims, characterized in that the image processing software automatically missing reinforcement ( 9 ) and / or misplaced reinforcements. Method according to one of the preceding claims, characterized in that the image processing software, the arrangement of the strength carrier ( 11 ) in the material layer ( 1 ) represents optically simplified and at the same time an automatic evaluation of strength carrier defects ( 9 ). Method according to one of the preceding claims, characterized in that the image processing software automatically determines the number of strength members ( 11 ) per image section. Method according to one of the preceding claims, characterized in that the conveyor device the strip of material ( 1 ) is moved at a conveying speed of 60 meters per second. Method according to one of the preceding claims, characterized in that the high-speed camera ( 3 ) takes at least 120 frames per second.

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