DE102022115800B3 - Method and device for testing a tire, in particular using an interferometric measuring method - Google Patents

Abstract

Method and device for testing a tire (100) using a testing device (10) which has a test chamber (11), measuring heads (14, 16) and a positioning device (20). The procedure comprises the following procedural steps:
a) the tire (100) is placed in the testing device (10);
b) the tire (100) is tested in a first test run (P1) using an interferometric test method, without the measuring heads (14, 16) and the tire (100) making a relative movement about the roll axis (φ) of the tire (100) during experience a first test run (P1);
c) the tire (100) is placed in the positioning device (20) after the first test run (P1) and rotated about an axis of rotation (γ) perpendicular to the roll axis (φ) by 180° and about the roll axis (φ) by one rotated predetermined rotation angle (α);
d) the tire (100) is placed in the testing device (10);
e) the tire (10) is tested in a second test run (P2) using an interferometric test method, without the measuring heads (14, 16) and the tire (100) making a relative movement about the roll axis (φ) of the tire (100) during the second test run (P2).

Description

The invention relates to a method and a device for testing a tire, in particular by means of an interferometric measuring method or another non-destructive measuring method, such as an ultrasonic test or radiographic test using X-rays. The tire to be tested is in particular a tire for a vehicle.

Tires or other components subjected to stress during use are usually subjected to a materials test for quality control and to reduce safety risks, which makes it possible to identify faulty areas, so-called imperfections. Especially when it comes to used tires that are to be retreaded, non-destructive material testing is usually used, which ensures a comparatively quick serial examination. For this purpose, the tires are usually examined without the rim.

Optical measuring methods such as holography or shearography, also known as speckle pattern shearing interferometry, are often encountered in industrial practice. Shearography is a relative interferometric measurement method that delivers a result image that shows the difference between two states of the test object that are offset in time. Due to the increasing spread of electronic image sensors, such as CCD or CMOS sensors, in order to generate the result images, which are usually digital nowadays, it is therefore necessary to determine the condition of the test object between two measurements by the action of an expediently mechanical, thermal or to change pneumatic force. For this reason, known devices have a pressure chamber that is either evacuated or pressurized, so that the test object in the pressure chamber is deformed as a result of the pressure change and thus transitions from a first reference state to a second measurement state.

In contrast to holography, shearography does not determine the deformation on the surface of a test object, but rather measures the gradient of the deformation. This is due to the fact that shearography uses a so-called shearing element, which is a shearing optic such as an optical wedge, an optical biprism or a Michelson interferometer, which produces an image doubling. Due to the shearing element, two slightly spatially offset images of the test object are created, which are superimposed in order to generate an interferogram due to the interference that results in this way. The shearogram characterizing the gradient of the deformation is generated by subtracting the intensities of the interferograms obtained in the reference state and in the measurement state. The shearogram shows whether the position of a point has changed in relation to a neighboring point due to the deformation of the test object. If so, then this path difference leads to a local change in the intensity distribution, which provides information about a defect.

The devices used to test a test object using an interferometric measuring method are usually provided with at least one measuring head, which has an illumination unit and an image recording unit. The lighting unit is often formed by a laser or laser diodes emitting coherent light. The image recording unit is usually a camera that is provided with an image sensor, ie a light-sensitive semiconductor sensor, for example a CCD or CMOS sensor. In order to obtain a meaningful measurement result, it is necessary to coordinate the field of view of the camera and the section of the test object to be tested. Usually, such a tuning is done by positioning the measuring head in a measuring position and aligning it in a measuring direction that ensures that on the one hand the selected measurement section of the test object is completely covered by the angle of view of the camera and is therefore in the field of view of the camera and on the other hand consecutive sectors overlap sufficiently to allow for a gapless inspection. The test position and the alignment of the measuring head depend on the dimensions of the test object.

Such test methods are often provided in a production process alongside or in a production line. In order to integrate these as seamlessly as possible, it is necessary to keep the duration of the test for a tire as short as possible so that the cycle time of the production line can be maintained. A short test duration poses a challenge, since the test chamber has to be evacuated in order to carry out an interferometric measurement method in order to generate the different load conditions.

A well-known test method for tires using an interferometric measuring method is published in EP 1 959 227 A2 described. The device used in this case has a large number of measuring heads which, in sections, detect an area of a side wall of the tire. During the measurement, the tire stored in a pressure chamber on a base is rotated intermittently about an axis of rotation to generate an overall view of the tire.

In addition revealed EP 2 549 258 A1 a tire testing system for testing tires using an interferometric method. The tire testing system includes a tire testing device with several test heads. This tire testing device is characterized by the fact that twice as many probes are provided for testing the outer side surface of the tire as for testing the inner tread of the tire. During a test run, the tire is rotated 180° around the vertical axis to record the tread. The tire is then turned and recorded again in the tire testing system. When turning the tire, the focus is in particular on turning in the correct position, but it is not disclosed how such turning in the correct position is to be carried out. Turning the tire by hand is sufficient to meet the requirements for turning the tire in the correct position.

Further revealed EP 2 851 670 A2 a tire testing system for testing a tire using an interferometric measuring method. The tire testing system includes a tire testing device and a tire turner. The tire testing device has non-rotatably arranged measuring heads and a non-rotatably arranged contact surface for the tire to be tested. During the measurement of the tire, no rotation of the tire about a vertical axis relative to the measuring heads is provided. In order for the tire to be fully detected, the tire must be turned in the correct position. According to the disclosed teaching, turning in the correct position is to be understood as meaning that after the tire has been turned over, the previously upper sidewall of the tire is now the lower sidewall of the tire. However, the tire turner provided for this purpose is limited to only turning the tire around an axis orthogonal to the conveying direction of a conveyor belt.

Further disclosed DE 10 2008 037 356 A1 a test facility and a method for testing tires. The testing facility includes a conveyor system provided with a plurality of sensors that detect the presence of a tire in a conveyor section of the conveyor system. A control device is designed in such a way that the position of the tires is registered and the movement of the tires is tracked.

A test system or a test device for testing tires are also out DE 10 2020 116 915 A1 and DE 199 44 314 A1 known.

It is the object of the present invention to specify a method and a device for testing a tire, in particular by means of an interferometric measuring method, which is characterized by a relatively short duration of the testing process.

This object is achieved by a method according to claims 1, 28 and 29 and a device according to claim 17. Preferred embodiments of the invention are the subject of claims 2 to 16, 18 to 27 and 30 and 31.

The inventive method for testing a tire uses a testing device that can be integrated into a production line. The test device has a test chamber with a support surface for the tire and a large number of measuring heads as well as a positioning device for the tire. The tire has a first sidewall, a second sidewall, a tread each divided into a predetermined number of sectors, and an axially extending roll axis. The method according to the invention comprises in particular the following method steps: Step a): The tire is arranged in the testing device with the second side wall lying on the support surface. Step b): In a first test run, the tire is tested using an interferometric test method in such a way that the first sidewall located at the top in the test device is completely and at the same time a first selection of sectors of the tread, which cover at least half of the tread of the tire, using the measuring heads can be recorded without the measuring heads and the tire experiencing a relative movement around the rolling axis of the tire during the first test run. Step c): After the first test run, the tire is placed in the positioning device and rotated through 180° about an axis of rotation perpendicular to the roll axis and rotated about the roll axis by a predetermined angle of rotation. This method step is also referred to below as just positioning. Step d): The tire is placed in the testing device with the first sidewall lying on the support surface. Step e): In a second test run, the tire is tested using an interferometric test method in such a way that the second sidewall located at the top in the test device is completely covered and at the same time a second selection of sectors of the tread, which cover at least half of the tread of the tire, by means of the measuring heads can be recorded without the measuring heads and the tire experiencing a relative movement around the rolling axis of the tire during the second test run.

The method according to the invention enables the tire to be tested comparatively quickly, since the number of evacuations in the test chamber can be reduced to a minimum.

Furthermore, the method enables the tire to be aligned after rotating about the axis of rotation with respect to the position of the stationary measuring heads in such a way that the sectors not yet detected in the first test run are detected in the second test run. Here, in a particularly advantageous manner, the orientation of the axis of rotation can also not be orthogonal to a conveying direction of a conveyor belt. Turning and rotating can be done simultaneously or sequentially. Simultaneously can be understood to mean that the axis of rotation is preset and/or fixed. For example, the tire can be rotated about an axis of rotation, which is also at an angle to the conveying direction of a conveyor belt. Corresponding to the angle of alignment of the rotation axis to the conveying direction of the conveyor belt, the tire rotates about the rolling axis at the same time.

By roll axis is meant an axis running through the center of the tire and in the axial direction with respect to the tire. An axis of rotation perpendicular to the rolling axis is to be understood as meaning an axis running in the radial direction with respect to the tire. Furthermore, the terms testing and measuring are to be understood synonymously.

Another advantage is that the testing device can be integrated directly into a production line, which is preferably provided with a conveyor belt. This is also known as so-called "in-line testing". As an alternative to this, the production line can be integrated indirectly into a production line. In this case, the tire has to be transported separately, for example by a conveyor belt, to the device. Such a method is known as so-called “at-line testing”.

The tire is advantageously transported in a conveyor device which has an intermediate storage section, the tire being temporarily stored in the intermediate storage section according to method step c). The intermediate storage of the tire, which enables the tire to relax and thus ensures reliable testing in the second test run, can further increase the utilization of the testing device, in particular the testing chamber. In an advantageous development, the conveying device is a stacking module which has two conveying devices which are arranged one above the other and have conveying means which can be moved in the vertical direction. Here, a conveyor can pick up a tire from the positioning device, while another tire is temporarily stored on the other conveyor. The conveyor then serve as an intermediate storage section.

In a further advantageous embodiment, the tire is relaxed after step c), ie returned to its basic state. This makes it possible for the tire to relax after turning according to method step c) and before the second test run, that is to say to carry out a relaxation. In particular, this means that the tire can relax and vibrate and therefore exhibit less creeping and whole-body movements during the second test run. It has been shown that particularly good measurements in the second test run are obtained with a relaxation time of more than 30 seconds, more preferably more than 1 minute and most preferably more than 2 minutes. The tire is advantageously always relaxed in an intermediate storage section. This means that another tire can be tested in the test chamber at the same time, so that it is always busy and maximum throughput is achieved.

Advantageously, the second selection of tread sectors comprises different sectors than the first selection of tread sectors. The sectors are expediently of the same size in the circumferential direction of the tire.

Since the first selection of sectors of the tread differ from the sectors of the second selection, a double detection of a sector is avoided. Consequently, there is a reduced computational effort when creating an overall view as described below. Because the sectors are the same size, there are several options for positioning the tire around the roll axis.

Adjacent sectors of the running surface advantageously overlap in a partial area. It has been found that in an advantageous embodiment the partial area is at least 1% to 60% of the area of the affected sector. In further advantageous configurations, the partial area is 1% to 50%, 1% to 20% or 5% to 20% of the area of the affected sector. However, an overall view can be calculated most quickly when the partial area is between 5% and 10% of the area of the respective sector in a particularly preferred embodiment.

Overlapping of the detected sectors allows for a tolerance in the placement of the tire for the second test run. Thus, after rotating around the axis of rotation and rotating around the axis of roll, the tire may be allowed not to be perfectly aligned with the cameras in order to capture the tire continuously around the entire circumference of the tire.

In an advantageous embodiment of the method, in step c) the tire is rotated successively about the axis of rotation and rotated about the roll axis or, alternatively, successively rotated about the roll axis and rotated about the axis of rotation.

In step c), the tire is advantageously rotated about the axis of rotation and rotated about the roll axis at the same time. The simultaneous rotation about the rotation and roll axis can be done by separate rotary movements about the respective axes. Alternatively, as described above, it can result from a rotation about an axis of rotation at an angle to the conveying direction of the conveyor belt and the rotation of the tire about a specific angle of rotation about the rolling axis can be generated by the rotation about the axis of rotation. According to the invention, the angle of rotation about the roll axis is not equal to zero.

Advantageously, the first test run and/or the second test run each have the following steps: Step a): At least one, preferably at least two, more preferably at least three, more preferably at least four and more preferably at least five, internal measuring heads are moved into a test position in the Move inside the tire to check the sectors distributed on the inside of the tread and/or on the inside of the first sidewall and/or the second sidewall of the tyre. Step b): At least two, preferably at least three, more preferably at least four, more preferably at least five, more preferably at least six and more preferably at least seven external measuring heads are placed in a test position at a distance from the upper sidewall of the tire to test the Side wall distributed sectors procedure.

The number of external measuring heads is advantageously an odd and/or non-integer multiple of the number of internal measuring heads. Preferably, the non-integer multiple is 1.25, 1.33, 1.5, 1.66, 1.75, 2.25, 2.33, 2.5, 2.66, 3.33, 3.5, 3.66, 4.33, 4.5 or 4.66 and more preferably the odd multiple is 3, 5, 7 or 9.

In practice, it has been found that a testing device with twice as many external measuring heads is disadvantageous relative to the internal measuring heads, specifically because there is only an insufficient overlapping partial area of the sectors on the outside. For example, in a testing device with only one internal measuring head, only two external measuring heads are provided, so that there can be no overlapping area if a total sector of at least 180° is to be recorded in one test run. On the other hand, the ratio is advantageously 1.5, with six external measuring heads and four internal measuring heads being provided.

After the second test run, the tire is advantageously rotated again about the axis of rotation and/or rotated about the roll axis in accordance with method step c). This is particularly advantageous when the tire is still undergoing subsequent production steps. As a result, the tire is returned to its original position, i.e. the starting position.

The sectors detected by the measuring heads are advantageously transmitted to an evaluation unit in order in particular to create an overall view of the tire. An overall view within the meaning of the present invention is not understood to mean a juxtaposition of individual images of the sectors, but a conversion of the resulting images into a uniform representation, as is shown in EP 3 545 259 B1 is taught. To create the overall view, the recorded measurement results of the sectors of the side wall are accordingly scaled by area. For example, the radially inner portion of the sidewall is increased more than the radially outer portion of the tire. In 13 an overall view created in this way is shown as an example. The overall view represents a particularly simple and clear representation of the detected tire, with the tire being represented in a particularly intuitive manner and in a way that is comparable to the actual three-dimensional shape of the tire.

Advantageously, a sub-area is removed from a detected sector which, in the overall view, overlaps with a sub-area of an adjacent sector.

The overlapping partial areas of two sectors can also be called the overlap area. By removing a partial area or an overlapping area, the double display of partial areas is avoided in an advantageous manner.

The evaluation unit advantageously carries out an automated evaluation using image processing functions.

The test is advantageously carried out using an interferometric, preferably sherographic, measuring method. A spatial or temporal phase shift method is advantageously used for testing.

The measuring heads are advantageously in the first test position and/or the second test position additionally pivoted by means of a pivoting movement about a pivot axis running parallel to the bearing surface of the testing device. This allows the testing device to be adapted to different tire sizes. In particular, this makes it possible to detect tires with varying diameters in the same testing device. This is particularly advantageous in the case of a testing device integrated into a production line (“in-line testing”).

The device according to the invention is used to carry out the method described above. The device comprises a test chamber provided with a support surface. The contact surface is designed to arrange the tire according to steps a) and d). The support surface can be designed to be rotatable, for example in order to align the tire in a predetermined position in the test chamber. The device also includes a measuring device that is designed to test the tire according to steps b) and e). Furthermore, the device comprises at least one positioning device, which is designed to position the tire according to step c).

For example, the device can only have internal measuring heads. Such a device is used, for example, in a so-called split-crown test. Here, for example, the tread and a partial area of the sidewall on the inside of the tire are recorded with at least two internal measuring heads. It is not necessary to register the side wall on the outside.

The device advantageously has a conveyor device which is suitable for transporting and/or storing the tire between the testing device and the positioning device. For this purpose, in a preferred embodiment, the conveying device has a conveyor belt or a conveyor belt. These can also include a variety of steerable rollers to transport the tire.

In a preferred embodiment, the conveyor device has an intermediate storage section, the conveyor device and/or the intermediate storage section being designed to relax the tire, ie to subject it to relaxation.

The intermediate storage section can be a partial area of the conveying device. In a preferred embodiment, the intermediate storage area is a separate area of the conveying device. This intermediate storage area branches off from an area of the conveyor device, which is used to transport the tire between two adjacent devices, such as the positioning device or the test chamber. As a result, a tire can continue to be transported via the transport section of the conveyor device, while another tire is stored and/or relaxed in the intermediate storage area of the conveyor device. In a further preferred embodiment, the conveyor device can have two intermediate storage areas. The conveyor device with an intermediate storage area can also be designed as a stacking module. The stack module is described in more detail below.

In a preferred embodiment, the device has at least two positioning devices. A first positioning device is expediently arranged in the conveying direction before the test chamber and a second positioning device in the conveying direction after the test chamber. This makes it possible to test one tire in the test chamber while a second tire is rotating and turning. The total test duration is thus significantly reduced.

The conveyor device advantageously has a first intermediate storage section and/or a second intermediate storage section. The first intermediate storage section is arranged after the positioning device in the conveying direction and before the test chamber in the conveying direction. Alternatively or in combination, the second intermediate storage section is arranged after the test chamber in the conveying direction and before the positioning device and/or after the second positioning device in the conveying direction. This means that a tire that has already been turned and rotated can be temporarily stored for buffering, while another tire that has either been newly introduced or has already been temporarily stored is being tested in the test chamber. The test chamber can thus be optimally utilized without testing tires that have not relaxed. Furthermore, the second positioning device makes it possible in a particularly efficient manner to store and/or relax the tire on one of the two intermediate storage sections after step c) has been carried out, while at the same time another tire is tested in the test chamber according to step b) or e). becomes.

The number of external measuring heads is advantageously an odd and/or non-integer multiple of the number of internal measuring heads.

The odd multiple is advantageously 3, 5, 7 or 9. It has been found that providing an even multiple is disadvantageous, for example with twice the number of external measuring heads for testing the outside as internal measuring heads for testing the inside. Because especially the edge area of a detected sector is at a double Number of external measuring heads imprecise due to the flat recording angle.

The non-integer multiple is advantageously 1.25, 1.33, 1.5, 1.66, 1.75, 2.25, 2.33, 2.5, 2.66, 3.33, 3.5, 3.66, 4.33, 4.5 or 4.66. A device with six external and four internal measuring heads, which thus has a multiple of 1.5, is particularly advantageous.

At least one of the measuring heads, preferably at least two measuring heads, can advantageously be pivoted about a pivot axis running parallel to the bearing surface of the test chamber. This makes it possible to test tires with different diameters in the testing device. As a result, the otherwise necessary linear adjustment of the measuring heads in the radial direction can be omitted, which would be correspondingly complex, particularly given a large number of measuring heads.

The support surface is advantageously rotatable about an axis running perpendicular to the support surface. For this purpose, the device can have a turntable in a further advantageous embodiment. This makes it possible to adjust the angle of rotation of the tire before detection by means of the measuring device or to carry out the rotation of the tire around the roll axis on the contact surface when using other test methods.

The at least two internal measuring heads are advantageously designed to detect an area of the tread on the inside of the tire and an area of the sidewall on the inside of the tire. This is common in a so-called split-crown exam. In this case, the side wall is usually not covered on the outside.

Furthermore, a method for testing tires using a testing device that has a testing chamber, at least one positioning device and at least one intermediate storage section is proposed. The testing device is preferably the testing device described above. The procedure has the following steps. Step a): Insertion of a first tire into the test chamber. Step b): Testing part of the first tire in the test chamber. Step c): transporting the first tire to the positioning device and introducing a second tire into the test chamber. Step d): testing part of the second tire in the test chamber and positioning the first tire in the positioning device. Step e): transporting the first tire to the intermediate storage section and positioning the second tire in the positioning device. Step f): positioning the second tire in the positioning device and relaxing the first tire in the intermediate storage section. Step g): transporting the first tire to the test chamber and transporting the second tire to the intermediate storage section. Step h): testing another part of the first tire in the test chamber and relaxing the second tire in the intermediate storage section. Step i): Leading the first tire out of the test device and transporting the second tire to the test chamber. Step j): Testing another part of the second tire in the test chamber. Step k): Taking the second tire out of the testing device.

It is particularly preferred that the actions mentioned in one step take place at the same time or at least temporarily at the same time.

Insertion in the context of the present invention is to be understood as meaning that the tire is transferred to the testing device, for example via a conveyor belt of the production line. For the purposes of the present invention, removal is to be understood as meaning that the tire is transferred back, for example, from the testing device to the production line for further processing. Advantageously, after step h) and before step i), the first tire is transported into the positioning device and positioned before the tire is then fed out. More preferably, after step j), the second tire is also transported into the positioning device and positioned before the tire is then fed out. Testing a part of the tire means, for example, a first selection of sectors of the tire as previously described. Testing a further part of the tire means, for example, a second selection of sectors of the tire as previously described.

More preferably, in step k) a further tire according to step a) is introduced into the test chamber. The method according to step a) is repeated with the additional tire, it being possible for the tire to be temporarily stored before further steps are carried out with it. This method results in a high utilization of the test chamber and at the same time a comparatively long relaxation time or relaxation time for the tire before the second testing of another part of the tire.

In a further advantageous embodiment of the method for testing tires, the testing device comprises a testing chamber, a first positioning device, a second positioning device, a first intermediate storage section and a second intermediate storage section. In contrast to the method described above, the method has the following steps: Step a): Insertion of the first tire into the test chamber. Step b): Testing part of the first tire in the test chamber. Step c): transporting the first tire to the second positioning device and introducing the second tire into the test chamber. Step d): testing part of the second tire in the test chamber and positioning the first tire in the second positioning device. Step e): transporting the first tire to the second intermediate storage section, transporting the second tire to the second positioning device and introducing a third tire into the test chamber. Step f): Relaxing the first tire in the second intermediate storage section, positioning the second tire in the second positioning device and testing a part of the third tire in the test chamber. Step g): transporting the third tire to the first positioning device, transporting the second tire to the first intermediate storage section, and transporting the first tire to the test chamber. Step h): testing another part of the first tire in the test chamber, relaxing the second tire in the first intermediate storage section and positioning the third tire in the first positioning device. Step i): Leading out the first tire from the test device, transporting the second tire to the test chamber, and transporting the third tire to the first intermediate storage section. Step j): testing another part of the second tire in the test chamber and relaxing the third tire in the first intermediate storage section. Step k): Leading the second tire out of the test device and transporting the third tire to the test chamber. Step I): Testing another part of the third tire in the test chamber. Step m): Leading out the third tire from the testing device.

Such a method allows for an even longer relaxation time than the previously described method for the tire before the second test run. Furthermore, the utilization can be further increased.

Advantageously, after step h) and before step i), the first tire is transported into the positioning device and positioned before the first tire is then fed out. Further advantageously, the second tire is transported into the positioning device and positioned after step j) and before step k), before the second tire is then fed out. Further advantageously, after step i) and before step m), the third tire is transported into the positioning device and positioned before the tire is subsequently guided out. In step m), a further tire according to step a) is advantageously introduced into the test chamber.

• 1 eine schematische Darstellung der Prüfvorrichtung, die in einer Fertigungsstraße integriert ist;
• 2 einen Querschnitt durch eine Prüfkammer, in welcher ein Reifen zur Prüfung angeordnet ist;
• 3 ein schwenkbarer Messkopf zur Messung von Reifen mit unterschiedlichen Durchmessern;
• 4 zwei Messköpfe, die ausgebildet sind, eine Innenseite eines Reifens zu prüfen;
• 5 einen Reifen, dessen Seitenwand von fünf Messköpfen erfasst wird;
• 6 einen Reifen, dessen Innenseite der Lauffläche von drei Messköpfen erfasst wird;
• 7 Positionierung des Reifens um eine Rollachse;
• 8 Positionierung des Reifens um eine Rotationsachse und um eine Rollachse;
• 9 eine Draufsicht auf den erfassten Reifen;
• 10a einen Querschnitt durch eine erfindungsgemäße Ausgestaltung der Prüfvorrichtung;
• 10b einen Querschnitt durch eine weitere erfindungsgemäße Ausgestaltung der Prüfvorrichtung;
• 11a einen Querschnitt durch eine weitere erfindungsgemäße Ausgestaltung der Prüfvorrichtung;
• 11 b einen Querschnitt durch eine weitere erfindungsgemäße Ausgestaltung der Prüfvorrichtung;
• 12 einen Querschnitt durch eine weitere mögliche Ausgestaltung der Prüfvorrichtung;
• 13 eine Gesamtansicht des Reifens als Messergebnis; und
• 14 ein Ablaufdiagramm eines Prüfverfahrens zum Prüfen von drei Reifen.

Details and further advantages of the invention are explained in the following description and the schematic drawings of exemplary embodiments. The figures show in detail:

• 1 a schematic representation of the test device, which is integrated in a production line;
• 2 a cross section through a test chamber in which a tire is arranged for testing;
• 3 a swiveling measuring head for measuring tires with different diameters;
• 4 two probes configured to inspect an inside of a tire;
• 5 a tire whose sidewall is measured by five measuring heads;
• 6 a tire whose inside tread is detected by three measuring heads;
• 7 positioning the tire about a roll axis;
• 8th positioning the tire about a rotational axis and about a roll axis;
• 9 a plan view of the detected tire;
• 10a a cross section through an inventive embodiment of the test device;
• 10b a cross section through a further embodiment of the test device according to the invention;
• 11a a cross section through a further embodiment of the test device according to the invention;
• 11 b a cross section through a further embodiment of the test device according to the invention;
• 12 a cross section through a further possible embodiment of the test device;
• 13 an overall view of the tire as a measurement result; and
• 14 a flow chart of a test method for testing three tires.

1 shows a testing device 10 for testing tires, which includes a test chamber 11, two positioning devices 20.1, 20.2 and a conveyor 18.1, 18.2 for transporting the tires 100. The testing device 10 is integrated into a production line 30 with a conveyor belt 32 that is not shown in full. The tire 100 can be transported in both directions on the conveyor device 18.1, 18.2 between the positioning devices 20.1, 20.2 and the test chamber 11. the This section can also be used as an intermediate storage section 19.1, 19.2. For this purpose, in an advantageous embodiment as in 1 shown, an additional branching off area can be provided, which serves to temporarily store and/or relax the tire 100 . Alternatively, this can also be formed in a stacking module 17.1, 17.2, which is shown, for example, in 12 shown testing device 10 is shown. These two design variants are interchangeable between the individual configurations of the testing devices. The conveying direction FR is shown with a black arrow.

The tire to be tested 100 comprises a first sidewall 101, a second sidewall 102 opposite the first sidewall 101 and a tread 103. The tire 100 also has an inside 106 and an outside 108. A roll axis φ of tire 100 runs through the center point in an axial direction z.

2 shows a cross-section of the test chamber 11. The test chamber 11 comprises an airtight hood which is designed to be evacuated. A support surface 12 is arranged in the test chamber 11, on which the first side wall 101 or the second side wall 102 of the tire 100 can be supported during the test. In a preferred embodiment, this bearing surface 12 can comprise a turntable, which enables rotation of the tire 100 in the test chamber 11 about the roll axis φ. Furthermore, the test chamber 11 includes a measuring device 13. In 2 the measuring device 13 is shown in a test position PP. The measuring device 13 comprises internal measuring heads 14 and external measuring heads 16. In an advantageous embodiment, the measuring heads 14, 16 can be pivoted about a pivot axis SA. This makes it possible to align the measuring heads 14, 16 on tires 100 with different diameters D1, D2. This can be done, for example, using an external measuring head 16 in 3 shown. where in 3 only a cross-section up to the roll axis φ is shown. The first diameter D1 is smaller than the second diameter D2.

In 4 two internal measuring heads 14.1, 14.2 are shown. The first inner measuring head 14.1 is designed to detect an area of the inner second side wall 102 and the inner running surface 103. The second inner measuring head 14.2 is designed to detect an area of the inner first side wall 101 and the inner running surface 103. The arrangement shown is used in a split-crown test.

5 and 6 show a measuring device 13 with five external measuring heads 16.1 to 16.5 and three internal measuring heads 14.1 to 14.3, which can be arranged as shown in a first test run P1. For this purpose, the tire 100 is divided into a large number of sectors. The first side wall 101 is divided into five sectors S1.1 to S1.5. The tread 103 is divided into six sectors L1 to L6. The external measuring heads 16.1 to 16.5 are each assigned to a sector 16.1 to 16.5, so that they can each fully record the assigned sector. As in 5 can be seen, partial areas TB of the detected sectors of two adjacent measuring heads can overlap. The partial area TB can also be called the overlapping area. The internal measuring heads 14.1 to 14.3 are also assigned to a selection of sectors of the running surface L1, L3, L5.

Another embodiment of the measuring device 13 that is not shown comprises six external measuring heads and four internal measuring heads.

After the first test run P1, the tire 100 is transported into a positioning device 20 in order to position the tire 100 for the second test run P2 since the measuring device 13 is fixed in the test chamber 11. The positioning device 20 is designed to position the tire, as in 7 or 8th shown to position for the second test run P2.

7 Figure 12 shows the tire 100 rotated only about the roll axis φ through 180°. This positioning can take place in a positioning device 20 which has a turntable. This can also take place in the test chamber 11, with the positioning device 20 being at least partially integrated in the test chamber 11.

8th Figure 12 shows the tire 100 rotated through 180° about a rotational axis γ and rotated through an angle α about the roll axis φ. This makes it possible to adapt the tire to the relative distribution of the measuring heads.

9 12 shows a representation of the tire 100 in a plan view. The detected sectors 1 to 6 correspond to the sectors L1 to L6 of the tire 100. Unlike the 6 and 7 are in the 9 the measuring heads 14.1 to 14.3 arranged in a semicircle, which is an alternative embodiment of the invention. The sectors detected by the measuring heads 14 , 16 are transmitted to an evaluation unit 40 with a memory unit 42 . Based on these measurements, evaluation unit 40 creates an overall view GA of tire 100, as shown in 13 is shown as an example. For this purpose, the evaluation unit uses 40 image processing functions, by means of which the detected Sekto be put together in such a way that a seamless picture of the tire results. For this purpose, for example, a partial area TB is removed from one of two detected sectors, which has already been detected in the other sector. The detected sectors are also scaled such that, for example, a radially inner area of the side wall is enlarged relative to a radially outer area of the side wall or the pixels of the individual sectors are transferred to a polar coordinate system and displayed.

the 10 until 12 show different configurations of the test device 10, which can be integrated in the production line 30. Here, the tire 100 is transferred to the testing device 10 via the conveyor belt 32 in the conveying direction FR.

In the 10a The testing device 10 shown picks up the tire 100 using the first conveyor 18.1 and transports the tire 100 into the test chamber 11. In the test chamber 11, the tire 100 is tested using the sherographic measuring method in a first test run P1. The tire 100 is then transported to a positioning device 20 by means of the second conveyor device 18.2. The positioning device 20 rotates the tire 100 around the rotation axis γ and rotates the tire 100 around the roll axis φ. Then the tire must be relaxed. In a preferred embodiment, the tire is allowed to relax for two minutes. During this time, up to two more tires 100 can be tested in the test chamber 11, with the conveyor devices 18.1, 18.2 and the intermediate storage sections 19.1, 19.2 being able to be used to accommodate a tire 100. The tire 100 can relax for two minutes and oscillate before the tire 100 is then transported back into the test chamber 11 and tested again in a second test run P2 using the sherographic measurement method. The measurement results of the sectors recorded in the first and second test run P1, P2 are then combined by an evaluation unit 40 to form an overall image GA. The tire 100 in turn is guided out of the testing device 10 via the second conveyor device 18.2 and through the positioning device 20 and transferred to the conveyor belt 32 of the production line 30. In an advantageous variant, the tire 100 can be turned back and rotated in the positioning device 20 beforehand, so that the tire 100 is again in the starting position. It is further preferred that another tire 100 is already introduced into the testing device 10 and waits in the first intermediate storage section 19.1 of the first conveyor device 18.1 in front of the test chamber 11 until the test chamber 11 is available again for another test run P1.

10b showed a further embodiment of the test device 10, which also has only one positioning device 20. Here, however, in contrast to the in 10a shown embodiment, the second conveyor 18.2 with the second intermediate storage section 19.2. arranged after the positioning device 20.

In the 11a and 11b Testing devices 10 shown have two positioning devices 20.1, 20.2. These testing devices 10 allow multiple tires 100 to be turned and rotated at the same time. This further increases the utilization of the test chamber 11 . In particular, with this arrangement, the tire 100 can be turned back into its original position after the test has ended, without this leading to a delay in the loading of the test chamber 11 .

In the 11b The embodiment shown differs from that in FIG 11a shown embodiment characterized in that the second positioning device 20.2 is arranged after the second conveyor 18.2 with the second intermediate storage section 19.2. This makes it possible in a particularly efficient manner to store the tire 100 in one of the two storage positions after step c) has been carried out, while at the same time either step b) or e) is carried out with other tires 100 in the test chamber 11 .

In the 12 Testing device 10 shown also has a stacking module 171, 17.2, which includes the conveyor 18.1, 18.2 and the intermediate storage section 19.1, 19.2. For this purpose, the stacking module 17.1, 17.2 has two conveying means which are arranged one above the other and are adjustable in height and on which the tire 100 can be transported in each case. Since the conveyor can be adjusted in height, a tire 100 can be temporarily stored while another tire 100 can be transferred to the test chamber 11 or to the positioning device 20.1, 20.2. The conveyor connected to the positioning device 20.1, 20.2 and/or the test chamber 11 represents the conveyor 18.1, 18.2 and the other conveyor represents the intermediate storage section 19.1, 19.2. This arrangement allows the time for a tire 100 to relax after step c ) also extend without the test chamber 11 remaining temporarily unused.

14 shows, for example, a flow chart for a test method for testing three tires 100.1, 100.2, 100.3. However, it is particularly preferred if the method is carried out on a test device Device 10 is applied, which has arranged the second positioning device 20.2 in the conveying direction FR before the second intermediate storage section 19.2 and after the test chamber 11.

The procedure consists of 13 steps. Step a) (S1) Inserting the first tire 100.1 into the test chamber 11. Step b) (S2) Testing a part of the first tire 100.1 in the test chamber 11. Step c) (S3) Transporting the first tire 100.1 to the second positioning device 20.2 and introducing the second tire 100.2 into the test chamber 11. Step d) (S4) Testing a part of the second tire 100.2 in the test chamber 11 and positioning the first tire 100.1 in the second positioning device 20.2. Step e) (S5) Transporting the first tire 100.1 to the second intermediate storage section 19.2, transporting the second tire 100.2 to the second positioning device 20.2 and introducing the third tire 100.3 into the test chamber 11. Step f) (S6) Relaxing the first tire 100.1 in the second intermediate storage section 19.2, positioning the second tire 100.2 in the second positioning device 20.2 and testing part of the third tire 100.3 in the test chamber 11. Step g) (S7) transporting the third tire 100.3 to the first positioning device 20.1, transporting the second tire 100.2 to the first intermediate storage section 19.1 and transporting the first tire 100.1 to the test chamber 11. Step h) (S8) Testing another part of the first tire 100.1 in the test chamber 11, relaxing the second tire 100.2 in the first intermediate storage section 19.1 and positioning the third tire 100.3 in the first positioning device 20.1. Step i) (S9) Taking the first tire 100.1 out of the test device 10, transporting the second tire 100.2 to the test chamber 11 and transporting the third tire 100.3 to the first intermediate storage section 19.1. Step j) (S10) testing another part of the second tire 100.2 in the test chamber 11 and relaxing the third tire 100.3 in the first intermediate storage section 19.1. Step k) (S11) Taking the second tire 100.2 out of the testing device 10, transporting the third tire 100.3 to the testing chamber 11. Step I) (S12) Testing another part of the third tire 100.3 in the testing chamber 11. Step m) (S13 ) Removal of the third tire 100.3 from the testing device 10.

All of the features explained in connection with individual embodiments of the invention can be provided in different combinations in the subject matter according to the invention in order to simultaneously realize their advantageous effects, even if they have been described for different embodiments.

The scope of protection of the present invention is given by the patent claims and is not limited by the features explained in the description or shown in the figures.

reference list

10

testing device

11

test chamber

12

bearing surface

13

measuring device

14

internal measuring heads

16

external measuring heads

17

stacking module

17.1

stacking module

17.2

stacking module

18.1

conveyor

18.2

conveyor

19.1

intermediate storage section

19.2

intermediate storage section

SA

pivot axis

20

positioning device

20.1

positioning device

20.2

positioning device

30

production line

32

conveyor belt

FR

conveying direction

40

evaluation unit

42

storage unit

GA

overall view

100

tires

101

first side wall

102

second side wall

103

tread

106

inside of the tire

108

outside of the tire

u

circumferential direction

D1

first diameter

D2

second diameter

S1.1 to S1.5

Sectors of the first side wall

S2.1 to S2.5

Sectors of the second side wall

L1 to L6

sectors of the tread

TB

subarea

φ

roll axis

g

axis of rotation

a

angle of rotation

e.g

axial direction

P1

first test run

p2

second test run

pp

test position

MP

measurement position

Claims (31)

Method for testing a tire (100), in particular on a production line (30), using a testing device (10); wherein the testing device (10) has a test chamber (11) provided with a support surface (12) for the tire (100) and a plurality of measuring heads (14, 16) and a positioning device (20) for the tire (100), wherein the tire (100) has a first sidewall (101), a second sidewall (102) and a tread (103) each divided into a predetermined number of sectors (S1.1 to S1.5; L1 to L6; S2.1 to S2.5), and has a roll axis (φ) extending in the axial direction (z) and the method comprising the following steps: a) the tire (100) is arranged with the second side wall (102) lying on the support surface (12) in the testing device (10); b) the tire (100) is tested in a first test run (P1) using an interferometric test method in such a way that the first side wall (101) at the top in the test device (10) is complete and at the same time a first selection of sectors (L1, L3, L5 ) of the tread (103), which cover at least half of the tread (103) of the tire (100), are detected by the measuring heads (14, 16), without the measuring heads (14, 16) and the tire (100 ) experience a relative movement about the roll axis (φ) of the tire (100) during the first test run (P1); c) the tire (100) is placed in the positioning device (20) after the first test run (P1) and rotated about an axis of rotation (γ) perpendicular to the roll axis (φ) by 180° and about the roll axis (φ) by one rotated by a predetermined angle of rotation (α), the angle of rotation (α) being non-zero; d) the tire (100) is arranged with the first side wall (101) lying on the support surface (12) in the testing device (10); e) the tire (10) is tested in a second test run (P2) using an interferometric test method in such a way that the second side wall (102) located at the top in the test device (10) is complete and at the same time a second selection of sectors (L2, L4, L6 ) of the tread (103), which cover at least half of the tread (103) of the tire (100), are detected by the measuring heads (14, 16), without the measuring heads (14, 16) and the tire (100 ) experience a relative movement about the roll axis (φ) of the tire (100) during the second test run (P2). procedure after claim 1 , characterized in that the tire (100) is transported in a conveyor (18) which has an intermediate storage section (19.1, 19.2), wherein in the intermediate storage section (19.1, 19.2) the tire (100) after step c) of claim 1 is stored. procedure after claim 1 or 2 , characterized in that the tire (100) after step c) of claim 1 relaxed, preferably for more than 30 seconds, more preferably for more than 1 minute and most preferably for more than 2 minutes. Procedure according to one of Claims 1 until 3 , characterized in that the second selection of sectors (L2, L4, L6) of the running surface (103) comprises other sectors than the first selection of sectors (L1, L3, L5) of the running surface (103), the sectors (L1 , L2, L3, L4, L5, L6) are equal in a circumferential direction (U) of the tire (100). Procedure according to one of Claims 1 until 4 , characterized in that adjacent sectors (L1, L2, L3, L4, L5, L6) of the running surface (103) overlap in a partial area (TB); preferably the portion (TB) is at least 1% to 60%, more preferably 1% to 50%, more preferably 1% to 20%, more preferably 5% to 20%, most preferably 5% to 10% of the area of the affected sectors (L1, L2, L3, L4, L5, L6). Procedure according to one of Claims 1 until 5 , characterized in that the tire (100) in step c) of claim 1 sequentially rotated about the rotation axis (γ) and rotated about the roll axis (φ), or sequentially rotated about the roll axis (φ) and rotated about the rotation axis (γ). Procedure according to one of Claims 1 until 5 , characterized in that the tire (100) in step c) of claim 1 is rotated around the rotation axis (γ) and rotated around the roll axis (φ) at the same time. Procedure according to one of Claims 1 until 7 characterized in that the first test run (P1) and/or the second test run (P2) each have the following steps: a. at least one, preferably at least two, more preferably at least three, more preferably at least four and more preferably at least five, internal measuring heads (14.1, 14.2, 14.3, 14.4, 14.5) are placed in a test position (PP) inside the tire (100) for checking the sectors (S1.1 to) distributed on the inside (106) of the tread (103) and/or on the inside (106) of the first sidewall (101) and/or the second sidewall (102) of the tire (100). S1.5; S2.1 to S2.5) procedure; b. At least two, preferably at least three, more preferably at least four, more preferably at least five, more preferably at least six and more preferably at least seven, external measuring heads (16.1, 16.2, 16.3, 16.4, 16.5) are placed in a test position (PP) at a distance to the upper sidewall (101, 102) of the tire (100) to check the sectors (S1.1 to S1.5; S2.1 to S2.5) distributed on the sidewall (101, 102). procedure after claim 8 , characterized in that the number of external measuring heads (16) is an odd number or a non-integer multiple of the number of internal measuring heads (14); preferably the non-integer multiple is 1.25, 1.33, 1.5, 1.66, 1.75, 2.25, 2.33, 2.5, 2.66, 3.33, 3.5, 3.66, 4.33, 4.5 or 4.66 and more preferably the odd multiple is 3, 5, 7 or 9 . Procedure according to one of Claims 1 until 9 , characterized in that the tire (100) after the second test run (P2) according to step c) of claim 1 is rotated about the rotation axis (γ) and/or rotated about the roll axis (φ). Procedure according to one of Claims 1 until 10 , characterized in that the sectors (S1.1 to S1.5; L1 to L6; S2.1 to S2.5) detected by the measuring heads (14, 16) are transmitted to an evaluation unit (40) in order in particular to obtain an overall view (GA) of the tire (100) to create. procedure after claim 11 , characterized in that a sub-area (TB) is removed from a detected sector (S1.1 to S1.5; L1 to L6; S2.1 to S2.5), which in the overall view (GA) has a sub-area ( TB) of an adjacent sector (S1.1 to S1.5; L1 to L6; S2.1 to S2.5) overlaps. procedure after claim 11 or 12 , characterized in that the evaluation unit (40) carries out an automated evaluation by means of image processing functions. Procedure according to one of Claims 1 until 13 , characterized in that the test is carried out by means of an interferometric, preferably shearographic, measuring method. Procedure according to one of Claims 1 until 14 characterized in that a spatial or temporal phase shift method is used for testing. Procedure according to one of Claims 1 until 15 , characterized in that the measuring heads (14, 16) in the first test position (P1) and/or in the second test position (P2) are additionally pivoted about a pivot axis (SA ) can be panned. Device for carrying out a method according to one of Claims 1 until 16 , characterized by : a test chamber (11) provided with a support surface (12); wherein the contact surface (12) is formed, the tire (100) according to steps a) and d) of claim 1 to arrange; a measuring device (13) which is designed to measure the tire (100) according to steps b) and e) of claim 1 to consider; and at least one positioning device (20) which is designed to position the tire (100) according to step c) of claim 1 to position. device after Claim 17 , characterized by a conveyor device (18) which is suitable for transporting and/or storing the tire (100) between the testing device (10) and the positioning device (20). device after Claim 18 , characterized in that the conveyor device (18) has at least one intermediate storage section (19.1, 19.2), the conveyor device (18) and/or the intermediate storage section (19.1, 19.2) being designed to relax the tire (100). Device according to one of claims 17 until 19 , characterized by at least two positioning devices (20.1, 20.2); a first positioning device (20.1) being arranged upstream of the test chamber (11) in the conveying direction (FR) and a second positioning device (20.2) downstream of the test chamber (11) in the conveying direction (FR). device after claim 20 , characterized in that the conveyor (18) has a first intermediate storage section (19.1) between the first positioning device (20.1) and the test chamber (11) and that the conveying device (18) has a second intermediate storage section (19.2) between the test chamber (11) and the second positioning device (20.2) and/or after the second positioning device (20.2). Device according to one of claims 17 until 21 , characterized in that the number of external measuring heads (16) is an odd number or a non-integer multiple of the number of internal measuring heads (14, 16). device after Claim 22 , characterized in that the odd multiple is 3, 5, 7 or 9. device after Claim 22 or 23 , characterized in that the non-integer multiple is 1.25, 1.33, 1.5, 1.66, 1.75, 2.25, 2.33, 2.5, 2.66, 3.33, 3.5, 3.66, 4.33, 4.5 or 4.66. Device according to one of claims 17 until 24 , characterized in that at least one of the measuring heads (14, 16), preferably at least two measuring heads (14, 16), can be pivoted about a pivot axis (SA) running parallel to the bearing surface (12) of the test chamber (11). Device according to one of claims 17 until 25 , characterized in that the bearing surface (12) is rotatable about an axis running perpendicularly to the bearing surface (12), in particular about the roll axis (φ) of the tire (100). Device according to one of claims 17 until 26 , characterized by at least two internal measuring heads (14.1, 14.2) which are designed, an area of the tread (103) on the inside (106) of the tire (100) and an area of the side wall (101, 102) on the inside (106 ) of the tire (100). Method for testing tires (100.1, 100.2) using a testing device (10) according to one of claims 19 until 27 , the method comprising the following steps: a. introducing a first tire (100.1) into the test chamber (11); b. Testing a part of the first tire (100.1) in the test chamber (11); c. Transporting the first tire (100.1) to the positioning device (20) and introducing a second tire (100.2) into the test chamber (11); i.e. Testing part of the second tire (100.2) in the test chamber (11) and positioning the first tire (100.1) in the positioning device (20); e. transporting the first tire (100.1) to the intermediate storage section (19.1, 19.2) and transporting the second tire (100.2) to the positioning device (20); f. positioning the second tire (100.2) in the positioning device (20) and relaxing the first tire (100.1) in the intermediate storage section (19.1, 19.2); G. transporting the first tire (100.1) to the test chamber (11) and transporting the second tire (100.2) to the intermediate storage section (19.1, 19.2); H. Testing another part of the first tire (100.1) in the test chamber (11) and relaxing the second tire (100.2) in the intermediate storage section (19.1, 19.2); i. Leading out the first tire (100.1) from the test device (10) and transporting the second tire (100.2) to the test chamber (11); j. Testing another part of the second tire (100.2) in the test chamber (11); and k. Removing the second tire (100.2) from the testing device (10). Method for testing tires (100.1, 100.2) using a testing device (10) according to one of claims 19 until 27 , wherein the testing device (10) comprises a first positioning device (20.1), a second positioning device (20.2), a first intermediate storage section (19.1) and a second intermediate storage section (19.2) and the method comprises the following steps: a. introducing the first tire (100.1) into the test chamber (11); b. Testing a part of the first tire (100.1) in the test chamber (11); c. Transporting the first tire (100.1) to the second positioning device (20.2) and introducing the second tire (100.2) into the test chamber (11); i.e. Testing part of the second tire (100.2) in the test chamber (11) and positioning the first tire (100.1) in the second positioning device (20.2); e. Transporting the first tire (100.1) to the second intermediate storage section (19.2), transporting the second tire (100.2) to the second positioning device (20.2) and introducing a third tire (100.3) into the test chamber (11); f. Relaxing the first tire (100.1) in the second intermediate storage section (19.2), positioning the second tire (100.2) in the second positioning device (20.2) and testing a part of the third tire (100.3) in the test chamber (11); G. transporting the third tire (100.3) to the first positioning device (20.1), transporting the second tire (100.2) to the first intermediate storage section (19.1) and transporting the first tire (100.1) to the test chamber (11); H. Check another part of the first tire (100.1) in the test chamber (11), relaxing the second tire (100.2) in the first intermediate storage section (19.1) and positioning the third tire (100.3) in the first positioning device (20.1); i. Leading out the first tire (100.1) from the testing device (10), transporting the second tire (100.2) to the test chamber (11) and transporting the third tire (100.3) to the first intermediate storage section (19.1); j. Testing a further part of the second tire (100.2) in the test chamber (11) and relaxing the third tire (100.3) in the first intermediate storage section (19.1); k. Leading out the second tire (100.2) from the test device (10) and transporting the third tire (100.3) to the test chamber (11); I. Testing another part of the third tire 100.3) in the test chamber (11); and m. removing the third tire (100.3) from the testing device (10). procedure after claim 28 , characterized in that in step no further tire (100.1, 100.2) according to step a is introduced into the test chamber (11). procedure after claim 29 , characterized in that in step m a further tire (100.1, 100.2, 100.3) according to step a is introduced into the test chamber (11).

Images