MXPA98004613A - A method and apparatus to test plains - Google Patents

Abstract

In the tire examination method, before and after an alteration in tire pressure, a respective interferogram of the rim surface is produced, using coherent radiation, and the interferogram becomes a 2ô module image, which on the other hand, it is processed to obtain an image in gray value, and in which case, from a comparison of the images in gray value, the information is obtained with respect to any defects present in the rim. To test a rim, the wheel, which carries the rim to be tested, is configured on a set of driven rollers, by driving the vehicle with the wheel, a test head is moved towards the rim to be at a distance test previously determined from it to produce the interferograms, in a first test segment, the tire is examined to determine defects, the tire is rotated increasingly by the set of rollers with an amount equal to the size of a segment of test, and in this way many test segments are examined, until the complete tire is tested. The tire test apparatus has an air pressure element to alter the pressure of the tire, a test head, and a computer. In addition, the apparatus comprises at least one set of driving rollers on which the vehicle tire to be tested can be configured to drive the vehicle, a setting element for the test head, with which the head is to be advanced of test to produce the interferograms towards the rim, as far as a predetermined test distance from the rim, and a control element for the set of rollers, in order to rotate the wheel increasingly by an amount corresponding to a segment test, when the previous test segment test is concluded

Description

A METHOD AND APPARATUS FOR TESTING TIRES The invention relates to a method for testing tires, wherein, before and after an alteration in tire pressure, a respective interferogram of the rim surface is produced using coherent radiation, and the interferogram becomes an image. of module 2tr, which in turn is processed to obtain an image in gray value, and in which case, from the images in gray value, information is obtained with respect to any defects present in the rim and in addition to an apparatus for the realization of the method. German Patent Publication Number 4231 578 discloses a method for determining the structural strength of the rims, wherein the rim is illuminated with coherent light, the diffusely reflected radiation back from the rim is divided into an interferometer of two beams, in two beam parts, in the double beam interferometer one of the two beam parts is tilted relative to the other beam part as a tear operation, in the double beam interferometer one of the two parts of beam is phase changed in steps, the radiation is reflected diffusely by the object being tested, and it is divided into two beam parts, and then they are joined again and returned through the components, presenting an image of the surface of the rim with a large opening to an electronic image sensor system, and the signals produced by the image sensor system are digitized and further processed to give an image of the module 2tr, and the 2tt module image is confirmed with an output gray value image. In accordance with German Patent Publication No. 195 02 073 A1, the aforementioned method is further developed to the extent that the image is partially differentiated in output gray value, a second image in gray value identical to the output gray value image, and it moves geometrically in the direction of tearing in relation to the gray output value image, and is altered by a gray value that is constant over the entire image area, and the second image in gray value manipulated in this way is subtracted from the image in output gray value, and in this way an image in resulting gray value is produced, from which any defects in the rim can be seen. When it is considered that the structural damage in the tires, and more particularly in the carcass that includes the band, this, in the case of car tires, can damage the safety of the vehicle, and it will be seen that it is desirable that a device be available. that can perform the tire test. An object of the invention is to create a tire testing method, and an apparatus that makes it possible to test large-scale tires in a motor vehicle, more especially as part of a general technical examination of the vehicle. For this purpose, in the method according to the invention for the examination on a rim in a motor vehicle, the motor vehicle with the wheel that assembles the rim to be tested, is driven on a set of rollers, moves a test head to produce the interferograms towards the rim, to be at a predetermined distance from it, the test is performed to determine defects on a first test segment of the rim, the wheel is rotated increasingly by the assembly of rollers by an amount equal to the size of a test segment, and the last two mentioned steps are repeated until the entire tire has been tested. The costs of the test head depend substantially on the area that can be covered in a single measurement step. Accordingly, the expense due to the test head can be substantially reduced to the extent that measurement is provided by segments of the rim, wherein a plurality of rim test segments are placed in a field of view of the tire. Test head one after the other. Therefore, it is desirable to rotate the rim increasingly to expose the test segments of the rim one after the other. In the case of the German Patent Publication Number 42 31 578 Al, the wheel is mounted on a rotating shaft of a machine, which is designed exclusively for the tire testing procedure, and the rim is not forced or influenced by a external force during its rotation and test. Since, according to the German Patent Publication Number 42 31 578 Al, the desired deformation of the rim for the test procedure can also be carried out by pressing the rim, it would be thought that, when the rim is pressed during rotation on a set of rollers, the effect of tightening the rim and the effect of the alteration in the pressure of the rim during the test procedure of the rim, would influence one on the other, with the effect that the test results are not reliable. However, in a surprising way, the test results are good and reproducible, despite the fact that the rim is rotated on a set of rollers, while still mounted on the vehicle. Additionally, it could be verified, surprisingly, that the forces applied to the tire by the vehicle do not have an adverse influence on the results of the test. A convenient development of the invention is characterized in that, between the increasing rotation of the wheel and the activation of the test head for the examination of a test segment, a quiet recovery time interval of a predetermined duration is allowed to elapse. . This ensures that the tire can come to rest before another rotation, which improves the accuracy of the measurement. In the case of a further convenient embodiment of the invention, the drive motor of the roller assembly is operated by a computer by means of a frequency converter, and more especially, the increasing rotation of the wheel is measured, and a input signal corresponding to the computer. This ensures that the wheel can be reliably rotated in an increasing manner exactly by the required amount, without unnecessarily increasing the structural complexity. In accordance with a further convenient development of the method, the size data necessary for the additional rotation of the wheel, such as the size of the tire to the computer, are supplied or obtained from a computer table. If the size data is saved in the form of a table, it is possible that this table is continuously supplemented by manual entries, so that there is the advantage that the adjustment of the apparatus for the test is made continuously simpler. A further convenient development of the method of the invention is characterized in that the test head moves in the X, Y and Z direction, in order to put it in the test position for different tires. This makes the method adaptable with respect to the types of tires that may be presented. A further convenient development of the method according to the invention is characterized in that, during the approach movement of the test head, its distance from the rim is monitored, and an indication is displayed, when the test head has reached its intended position, and then the test head is stopped. This means that a safe, fast, and accurate adjustment of the test head relative to the rim is possible. A further convenient development of the method according to the invention is characterized in that the pressure of the rim is reduced by a pressure passage for each test step, and after the test has been completed, it is returned to the nominal pressure. Following this method, it is possible to change the pressure of the tire during a whole test cycle, where the test sectors are measured one after the other, with a minimum loss of time, as the pressure change begins from a first test step to a second test step, from the final pressure present at the end of the first test step. Additionally, after each tightening action during the rotation, and after each pressure change, the tire has to rest for a certain period of time, so that the test results are not influenced by the continuous movements due to the change of pressure. Therefore, the time consumed for these recovery time periods is minimized if the number of pressure changes made during a test cycle is minimized. The number of recovery time periods would be increased if the tire pressure were brought up to the nominal pressure after each test step of the rim with respect to a particular section of the rim. Finally, it is an advantage that the two sets of rollers are provided for the simultaneous testing of the tires on the front wheels, and, respectively, on the rear wheels of a motor vehicle, and it is more especially convenient that the sets of wheels are used. rollers of a brake test station, and the impulse control of the roller assemblies of the brake test station is designed in such a way that the rollers can be rotated increasingly by given amounts. In accordance with this embodiment of the invention, the engine of the brake test station is used not only to rotate the wheel during the brake test procedure, but also to rotate the wheel increasingly during the tire test procedure. . The problem with this solution is that the brake test station engine is usually designed as a strong engine to provide sufficient wheel traction in order to perform the brake test procedure. In the brake test procedure, the wheel is driven to a particular maximum speed, then the brakes are applied to the wheel to slow down or stop the rollers driven by the engine. The engine control required for this procedure is not adapted to rotate the wheel on the brake test station at a low speed, leaving control of the rotation increasingly. Accordingly, a suitable motor control method and apparatus is needed in order to adapt the brake test station of the state of the art to the present purpose. In other words, in the combination of the known tire tester of German Patent Application No. 42 31 578 A1 and a prior art brake test stand on a single machine, certain changes and provisions have to be made to make possible this combination. Despite control of the specialized motor required for the machine, a combination machine as provided in the present application, has distinct advantages over the state of the art, with respect to cost and operation. The tire test apparatus of the invention comprises an air pressure element for altering the pressure of the tire, a test head, and a computer, which before and after an alteration in the air pressure procedure, using coherent radiation, a respective interferogram is made of the surface of the rim, and the interferogram is converted into a module 2? t image, which in turn is processed to give an image in gray value, and where, based on to a comparison of the images in gray value information is obtained with respect to any defects in the rim, and the apparatus is characterized by at least one set of driven rollers on which the motor vehicle can be driven with the rims that are go to examine, a setting element for the test head, which will move the test head to a predetermined distance from the rim to produce the interferograms, and a control element for the roller assembly in order to rotate the wheel increasingly by an amount corresponding to a test segment, when the examination of the previous test segment is concluded. A further convenient development of the apparatus of the invention is characterized in that the motor is adapted to be operated by an element of a frequency converter, which is adapted to be controlled by a computer. This is the most reliable way to control the engine of the brake test station, so that it increasingly moves the wheel at a low speed during the tire test procedure.

A further convenient development of the apparatus of the invention is characterized by a sensor roller, which responds to the increasing rotation of the rim, and by means of a synchronizer, supplies a corresponding signal to the computer, which switches the motor pulse to deactivated, when the wheel has been rotated increasingly through an additional test segment. By using this configuration, a feedback related to the increasing movement of the wheel can be produced, and can be used to accurately control the increasing movement of the wheel on the brake test station. A further convenient development of the apparatus of the invention is characterized in that the computer comprises a memory, wherein a table with size data is provided, as necessary for the increasing rotation of a wheel, in a manner dependent on the size of the wheel . Computer memory ensures that as little expert knowledge as possible is needed to run the machine. A further convenient development of the apparatus of the invention is characterized in that the positioning element comprises a slider X for moving the test head in a direction perpendicular to the axes of the rollers, a dislizer Y for moving the test head in a parallel direction to the axes of the rollers, and a Z slider to move the test head perpendicularly to the axes of the rollers, perpendicular to the supporting surface, and 90 ° with the Z slider. These positioning elements provide accurate movement of the head test with respect to the rim. A further convenient development of the apparatus of the invention is characterized in that the positioning element comprises a column Z and two parallel guides, and, respectively, two pivot arms. These mechanical laying elements can be operated easily, and are strong enough for the hazardous environment of automobile service stations and the like. A further convenient development of the apparatus of the invention is characterized in that the setting elements can be stopped, when the test head has reached the test position, to ensure well-defined conditions during the measurements. A further convenient development of the apparatus of the invention is characterized by a handle with which the test head can be placed in a test position to improve the easy operation of the apparatus. A further convenient development of the apparatus of the invention is characterized by a pushbutton switch, to cause the positioning element to stop, the control button being more particularly configured in the vicinity of the handle for greater convenience of operation.

A convenient embodiment of the tire test apparatus of the invention is characterized by a device that establishes the distance, to establish the distance between the test sleeve and rim. Preferably, the distance-setting device comprises two obliquely-established diodes on the end of the test head, the beams of these diodes intersecting at the test distance. This distance-setting device allows to adjust the distance without touching the wire by means of an optical element. The distance setter device can be easily operated. A convenient embodiment of the tire testing apparatus of the invention is characterized in that the distance-setting device comprises a mechanical sensor on the test head, whose sensor, upon reaching the test distance, contacts the rim. This is a mechanical version of the distance-setting device that is simple and adapts to a harsh environment. A convenient embodiment of the tire test apparatus of the invention is characterized in that the distance-setting device comprises an ultrasonic range-matching element. This distance-setting device is another device that does not need to touch the rim, which is also convenient if the accessible surface has some profile.

A convenient embodiment of the tire testing apparatus of the invention is characterized by a valve that can be established both with respect to the size of its opening, as well as with respect to the opening time. This valve enables rapid and automatic setting of tire pressure under the control of a computer, which only controls the size of the valve opening and valve opening time. This also has the advantage of minimizing the time needed to perform a complete test cycle. A further convenient development of the apparatus of the invention is characterized in that the air pressure element is integrated into the test head to protect this part of the apparatus. A further convenient development of the apparatus of the invention is characterized in that the air pressure element is adapted to control the air pressure of the rim, where, for each test step, the rim pressure is reduced by one step , and after concluding the test, it returns to the nominal pressure again. As already mentioned above, this minimizes the time needed to complete a complete test process cycle. A further convenient development of the apparatus of the invention is characterized by two sets of rollers and two positioning elements with test heads. Preferably, the units comprising the positioning elements and a test head are associated with the roller assemblies of a brake test station. In accordance with the above, the tire test is integrated into the brake test, which offers advantages both with regard to costs and also with respect to the price of the equipment. A further convenient development of the apparatus of the invention is characterized by a central computing element for controlling the functions of the tire testing apparatus, preferably integrating the computing element with the computing element of the brake test station. By combining the computing element of the test apparatus with the computing element of the brake test station, some savings can be made with respect to the hardware required, which reduces costs and improves reliability. A further convenient development of the apparatus of the invention is characterized by a monitor for displaying the results of the measurement, and which also serves to display the information in relation to the brake test. This is another system that shares the hardware to reduce costs. The working modalities of the invention will now be described with reference to the accompanying drawings. Figure 1 shows diagrammatically, in a plan view, a tire test apparatus according to a first embodiment of the invention, which uses the roller assemblies of a brake test station. Figure 2 shows a partially diagrammatic plan view of a further embodiment of the tire test apparatus of the invention of Figure 1. Figure 3 shows a diagrammatic plan view of part of a further embodiment of the tire test apparatus of according to the present invention. Figure 4 shows a diagrammatic plan view of part of a further embodiment of the tire testing apparatus in accordance with the present invention. Figure 5 shows a diagrammatic lateral elevation of the working mode in accordance with the Figure. Figure 6 shows a lateral elevation of the working mode of Figure 4. With reference to Figures 1 and 2, a first embodiment of the tire testing apparatus of the invention will be described. It will be seen that a brake test station 2 comprises the roller assemblies 4 and 6, and, respectively, 8 and 10, of which, each single roller 4 and 10 is driven by a motor 12 and 14. The other respective roller 6 and 8 have free wheels. Between rollers 4 and 6, and, respectively, 8 and 10 of the assemblies, there is a respective sensor roller 16, and, respectively, 18. The roller assemblies and the impulse motors are configured in a cavity 20 in the floor. A vehicle is driven in the direction of the arrow F, on the roller assemblies, such that, for example, its front wheels are configured on the two sets of rollers. Figures 1 and 2 show a front wheel 22 of a motor vehicle, whose tires are to be tested or examined. Figure 1 further shows a front wheel 24, which has a diameter smaller than the wheel 22, and belongs to another motor vehicle. The different sizes of the wheels 22 and 24 are only assumed for the explanation of the way in which this working mode of the invention works. In Figure 1, two setter elements 30 and 32 are illustrated, with the control elements 34 and 36, and also the test heads 38 and 40. The setter elements 30 possess a slider X 42, a slider Y 44, and a Z slide 46. The Y slider 44 serves to adjust the distance between the test head 38 and the side surface of the rim 22, while the Z 46 slider makes it possible to adjust the middle part of the test head to the level of the axle. the wheels of different sizes. In the illustrated work mode, the X direction of the X slider 42 is perpendicular to the axes of the rolls 4 and 6, the Y direction of the Y slider is parallel to the axes of the rolls 4 and 6, and the axis of the Z slider it is perpendicular to the axes of the rollers 4 and 6, perpendicular to the support surface, and at 90 ° with the X direction. The slider X 42 and the slider Y 44 are supported by means of the linear bearings 48, and, respectively, 50, with the arrow guides, and the slider Z 46 is movably supported by means of the linear bearings 52, 54, 56, and 58 on the guide columns 60 and 62. The slider X 42, the slider Y 44, and the slider Z 46, are respectively provided with fastening elements (not shown), making it possible for the sliders to be stopped in a test position, wherein the test head 38 is located in a position for the test operation to be performed of the tires. The control element 34 has the controller for the air pressure element, which comprises a pressure hose 64 and a valve 66, which can be connected to the inlet valve of the rim. The valve 66 can be adjusted both with respect to its opening (setting the discharge speed), as well as for opening and closing, in such a way that the alteration of the pressure in the rim can be adjusted, both using the opening position of the rim. valve, as well as using the time during which the valve is opened. A handle 35 is provided on the control element 34, with which the control element 34 and the test head 38 can be moved manually along the three axes, until the test position is reached. When the test position is reached, the stopping element for the three sliders is activated, using a push button switch 37, which is provided on the handle 35. The test head 38 configured on the Z 46 slider, is shown in Figure 2 in an end view, and laser diodes 68 for the interferograms will be seen. In addition, two diodes 70 and 72 are provided, which serve to assert the correct distance between the test head 38 and the side wall of the rim 22. For this purpose, the two laser diodes 70 and 72 are to be set obliquely. in the visible range where your laser beams make an angle with each other, and intersect at the point corresponding to the correct distance between the test head and the side surface of the rim. When the test head 38 is moved using the slider, towards the rim 22, it will be at the test distance, when the two laser beams form a single point on the side wall of the rim 22. Finally, the Figure shows diagrammatically a lens 73 of a camera, which takes photographs of the tire being tested. The rotation speed of the motors 12 and 14 will be controlled by means of a controlled frequency converter (not illustrated) by the central computer unit of the tire test apparatus, such that the speed is a relatively constant value low. The sensor rollers 16 and 18 detect the rim, in order to produce a signal by means of synchronizers, which is equal to the amount by which the rim has been rotated. On the computer, the output signal from the synchronizers is used to deactivate the pulse motor when the rim has increasingly rotated by an amount corresponding to the size of a test segment. In the case of the embodiment illustrated in Figure 2, a test segment is equal to 1/8 of the total periphery of the rim, such that the rim must be rotated seven additional steps or increments in order to verify the rim completely. The conductors for compressed air, for the supply of electric power to the test head, and for a data line leading to the computer unit, are connected to the control element 34 and the test head 38. In addition, the motors 12 and 14, and the synchronizers of the sensor rollers 16 and 18, are connected to the computer unit, the connection lines and the computer unit not being illustrated in order to make the drawing more direct. In Figure 3, an additional embodiment of the tire test apparatus will be seen, the parts equivalent to those of Figures 1 and 2 having the same reference numerals.

In this embodiment, the control element is integrated in the test head 74, and the test head is connected by means of two parallel guides 76 and 78 with a column Z 80. The test head 74, as described above , it is put into position with the help of the handle 35 and then the two parallel guides 76 and 78, and also the column 80, stop as in the previous mode. As shown in Figure 3, with these setters, it is possible to move the test head 74 as far as the separate test distance, both in the case of large wheels such as wheel 22, as well as in the case of small wheels as the wheel 24, as indicated in the phantom lines. Figures 4 to 6 show a further embodiment of the tire test apparatus of the invention, carrying the parts equivalent to those of the previous Figures, the same reference numerals. The departure from the working mode of Figure 3 in Figure 4 is that instead of the parallel guides 76 and 78 of Figure 3, pivot arms 82 and 84 are employed. This is an additional way to easily put the test head 74 in the position where the correct distance is maintained from the side surfaces of the rim 22. Then, the pivot arms 82 and 84, and also the column Z 80, are stopped. In all embodiments of the invention, a central computer element is provided to control the functions of the tire test apparatus, this computer element being integrated into the computer of the brake test station, so that here also the complexity of the hardware is reduced. In addition, the monitor is also used to indicate the readings of the measurement, for tire testing, to the extent that the information relevant to the two test methods is displayed on the same monitor. The manner of operation of the described working examples of the tire test apparatus of the invention is as follows: Firstly, the vehicle is driven over the two sets of rollers of a brake test station, such that its front wheels that carry the tires that are going to be tested, rest on them, being able to run the driven rollers at different speeds, under the control of the computer, both to perform the brake exams, as well as to test the tires. The next step is to move a respective test head towards the rim, to stay at a predetermined distance from it, to produce the interferogram and stop at that position. After driving the vehicle on the roller assembly, the air pressure valves are connected to the rims. Before performing the first test sequence, the specific data for the wheel, and, respectively, the size data for the increasing rotation of the roller set, such as, for example, the pulse duration at a constant speed of rotation, are supplied. that depend on the dimensions of the tire, the computer as an input, or, respectively, are searched in a Table. Then the tire is examined on a first rim segment of the rim, using the aforementioned method. After the first test segment has been tested, the wheel is rotated by the roller assembly by a pitch equal to the size of a test segment, the driven rollers of the assemblies being controlled by means of a computer, and a way dependent on the output signals of a sensor roller synchronizer. When the next wheel test segment has been placed in position, a quiet time is allowed to take place to ensure that the measurement is not affected by the tire drag after the increasing rotation, and only after this quiet time , an additional rotation of the rim is activated with the test head, in order to test the next segment. Later, test sequences and other incremental steps are made in the rotation of the wheels, until the entire tire has been tested. For each test sequence, as already mentioned, between a first series of interferograms and a second series of interferograms, the pressure is reduced, this also being controlled by the computer element. The reduction in pressure, therefore, occurs in stages, reducing the pressure in each test sequence by one step. Once the test has been completed, the air pressure of the tire is then returned to the pressurized state, also using the valve and the control element connected with it. Once the front wheel test has been completed, the vehicle is moved, so that its rear wheels are on the roller assemblies, and the test procedure for the rear wheels is repeated. In accordance with the above, then the examination of the wheels on the four wheels of the vehicle is completed. Certain modifications are possible in the working examples of the invention, without departing from the scope of the invention. For example, the positioning element may have carriages with rollers with which the test heads can be moved to the wheels. The adjustment of the distance between the test head and the wheel can be done mechanically using a sensor on the test head, which, when the desired test distance is reached, is coupled to the rim, or a finding element can be used of ultrasonic range. It would be feasible to provide only sets of rollers intended for tire testing, or to simultaneously examine the wheels of the front axle and the rear axle.

Claims (30)

1. A method for testing tires, where, before and after an alteration in tire pressure, a respective interferogram of the rim surface is produced, using coherent radiation, and the interferogram becomes a 2p module image, which in turn is processed to obtain an image in gray value, and in which case, from a comparison of the images in gray value, the information is obtained with respect to any defects present in the rim, characterized in that, to test the rim in a motor vehicle: (a) the motor vehicle with the wheel that mounts the rim to be examined, is driven in such a way that the rim is on a set of motor driven rollers; (b) a test head configured to produce interferograms moves to the rim, to be at a predetermined distance from it; (c) the rim is checked to determine defects on a first rim test segment, (d) the wheel is further rotated by the roller set by an amount equal to a test segment, and ( e) and steps (c) and (d) are repeated until the entire tire has been examined.

2. The method as claimed in claim 1, characterized in that, between the increasing rotation of the wheel and the activation of the test head to test a test segment, a quiet recovery time of a duration is allowed to elapse. determined.

3. The method as claimed in claim 1, characterized in that, the drive motor of the roller assembly is operated using a computer by means of a controllable frequency converter.

4. The method as claimed in the claim

3, characterized in that, the additional increasing rotation of the motor is detected, and an input signal corresponding to the computer is fed.

5. The method as claimed in the claim

4, characterized in that the size data, such as the size of the tire, is communicated for an additional increased rotation of the wheel, to the computer, or is searched in a computer table.

6. The method as claimed in claim 1, characterized in that, the test head moves in the X, Y, and Z directions, in order to put it in the test position for wheels of different sizes.

7. The method as claimed in claim 1, characterized in that, when the test head is moved towards the rim, the distance of the test head from the rim is monitored, and a signal is displayed when the test head has reached the test distance, and because then the test head stops.

The method as claimed in claim 1, characterized in that, the pressure of the rim is reduced by a pressure passage for each test step, and after the test has been carried out, it is returned to the nominal pressure.

The method as claimed in claim 1, characterized in that two sets of rollers are used for the simultaneous testing of the tires of the front and rear wheels of a vehicle.

The method as claimed in any of the preceding claims, characterized in that the roller assemblies of a brake test station are used, the impulse control being adapted for the roller assemblies of the brake test station so that the rollers turn increasingly in addition for previously determined amounts.

11. A tire test apparatus for carrying out the method as claimed in claim 1, which comprises an air pressure element for altering the pressure of the tire, a test head, and a computer, which before and after an alteration in the air pressure, using coherent radiation, they produce a respective interferogram of the surface of the rim, and convert the interferogram into a 27r module image., which in turn is processed to produce an image in gray value, and where, based on the images in gray value, information is obtained with respect to any defects in the rim, characterized by a set of driven rollers (4 and 6), where the wheel with the tire to be tested, can be configured by driving a vehicle that has that wheel, a setting element for the test head (38 and 74), with which it is going to moving the test head at a predetermined distance from the rim to produce the interferograms, and by a control element for the roller set (4 and 6), in order to rotate the wheel increasingly by an amount corresponding to a test segment, when the examination of the previous test segment is concluded.

12. The apparatus as claimed in claim 11, characterized in that the motor (12) is adapted to be operated by means of a frequency converter, which is adapted to be controlled by a computer.

The apparatus as claimed in claim 11, characterized by a sensor roller (16) that responds to the increasing rotation of the rim (22), and by means of a synchronizer supplies a corresponding signal to the computer that deactivates the impulse of the engine, when the wheel has been rotated increasingly through an additional test segment.

14. The apparatus as claimed in the claim

13, characterized in that the computer comprises a memory, wherein a table with the size data is provided, as is necessary for the increasing rotation of a wheel in a manner dependent on the size of the wheel. The apparatus as claimed in any of claims 11 to 14, characterized in that the positioning element comprises a slider X for moving the test head (38) in a direction perpendicular to the axes of the rollers (4 and 6), a Y slider to move the test head (38) in a direction parallel to the axes of the rollers (4 and 6), and a .Z slider to move the test head (38) perpendicularly to the axes of the rollers ( 4 and 6), perpendicular to the support surface and 90 ° with the slider Z.

16. The apparatus as claimed in any of claims 11 to 14, characterized in that the laying element comprises a Z-column (80), and two parallel guides

(76 and 78), and, respectively, two pivot arms (82 and 84). The apparatus as claimed in claim 15 or claim 16, characterized in that the positioning element can be stopped when the test head has reached the test position.

18. The apparatus as claimed in any of claims 15 to 17, characterized by a mantle (35) with which the test head can be placed in a test position.

19. The apparatus as claimed in any of claims 15 to 18, characterized by a push-button switch (37), for causing the positioning elements to stop, this pressure button being configured more particularly in the vicinity of the handle (35). ).

The apparatus as claimed in claim 11, characterized in that the distance adjustment device, for adjusting the distance between the test head (38 and 74) and the rim.

The apparatus as claimed in claim 20, characterized in that the distance adjustment device comprises two obliquely established diodes (70 and 72) on the end of the test head (38 and 74), the beams intersecting from these diodes at the test distance.

22. The apparatus as claimed in claim 20, characterized in that the distance adjustment device comprises a mechanical sensor (60) on the test head (54), whose sensor, upon reaching the test distance, makes contact with rim.

23. The apparatus as claimed in claim 20, characterized in that the distance adjustment device comprises a finding element of the ultrasonic range.

24. The apparatus as claimed in claim 11, characterized by a valve (66) that can be adjusted both with respect to the size of its opening, and also with respect to the opening time.

25. The apparatus as claimed in claim 11, characterized in that the air pressure element is integrated into the test head.

26. The apparatus as claimed in claim 11 or claim 25, characterized in that the air pressure element is adapted to control the air pressure of the rim, such that for each pressure test step of the the rim is reduced by one step, and after the conclusion of the test, it returns to the nominal pressure again.

27. The apparatus as claimed in any of claims 11 to 26, characterized by two sets of rollers and two setter elements with test heads.

The apparatus as claimed in any of claims 11 to 27, characterized in that the units comprising the setter elements and the test head are associated with the roller assemblies of a brake test station.

29. The apparatus as claimed in claim 11, characterized by a central computing element for controlling the functions of the tire testing apparatus, preferably integrating the computing element with the computing element of the brake test station.

30. The apparatus as claimed in any of claims 11 to 29, characterized by a monitor for displaying the measurement results, and which also serves to display the information in connection with the brake test.

SUMMARY

In the tire examination method, before and after an alteration in tire pressure, a respective interferogram of the rim surface is produced, using coherent radiation, and the interferogram becomes a module 27r image, which on the other hand, it is processed to obtain an image in gray value, and in which case, from a comparison of the images in gray value, the information is obtained with respect to any defects present in the rim. To test a rim, the wheel, which carries the rim to be tested, is configured on a set of driven rollers, by driving the vehicle with the wheel, a test head is moved towards the rim to be at a distance of test previously determined from it to produce the interferograms; In a first test segment, the tire is examined to determine defects; the rim is rotated increasingly by the roller assembly with an amount equal to the size of a test segment, and in this way many test segments are examined, until the complete rim is tested. The tire test apparatus has an air pressure element to alter the pressure of the tire, a test head, and a computer. In addition, the apparatus comprises at least one set of driving rollers on which the vehicle tire to be tested can be configured, driving the vehicle; a setting element for the test head, with which the test head is to be advanced to produce the interferograms towards the rim, as far as a previously determined test distance from the rim, and a control element for the set of rollers, in order to rotate the wheel increasingly by an amount corresponding to a test segment, when the test of the previous test segment is concluded.

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