Tyre test bench, system, method for testing, and method for manufacturing and testing tyres

Abstract

The invention relates to a tyre test bench (1) comprising: a frame (3) and a tyre holder (5) which is mounted thereon and on which a tyre (13) with a tread surface (15) can be rotatably mounted about a first rotational axis (17); a running drum (7), which is mounted on the frame (3) and is rotatably mounted about a second rotational axis (23), with a circumferential drum surface (21); a force measuring device (9) and temperature measuring device (11) which are mounted on the frame (3); and a compression device which can apply positive pressure to a pressurised gaseous medium in the tyre (13), wherein the tyre (13) can be positioned on the tyre holder (5) such that, when the tyre (13) rotates about the first rotational axis (17) in one rotational direction and the running drum (7) rotates about the second rotational axis (23), the tread surface (15) of the tyre (13) rolls on the drum surface (21), wherein the force measuring device (9) is designed to detect a tangential force (27) which, when the tread surface (15) of the tyre (13) rolls on the drum surface (21), acts tangentially on the tyre (13) perpendicular to the first rotational axis (17) and in the rotational direction of the tyre (13), and wherein the temperature measuring device (11) is designed to detect the temperature of the pressurised gaseous medium. The invention also relates to a system (41), a method for testing, and a method for manufacturing and testing.

Description

[0001] Tire test bench, system, method for testing and method for manufacturing and testing tires

[0002] The present invention relates to a tire test bench, a system, a method for testing and a method for manufacturing and testing tires.

[0003] Tire test stands and methods using these tire test stands for testing tires are known from the prior art. A tire test stand known from the prior art, for example, comprises a frame and a tire holder attached to the frame. A tire with a tread rotatable about a first axis of rotation can be attached to the tire holder. The tire test stand known from the prior art can also comprise a running drum attached to the frame and mounted rotatably about a second axis of rotation, with a drum surface rotating about the second axis of rotation. The tire test stand can also comprise a force detection device attached to the frame.When the tire is attached to the tire holder, the tire holder can be positioned so that when the tire rotates about the first axis of rotation in one direction of rotation and the running drum rotates about the second axis of rotation, the tire's tread rolls on the drum surface of the running drum. The force detection device is configured to detect a tangential force which, when the tire rolls with its tread on the drum surface of the running drum, acts tangentially on the tire at a contact point between the tread and the drum surface, perpendicular to the first axis of rotation and in the direction of rotation of the tire. In this case, the drum surface can also be referred to as a road substitute and is intended to approximately simulate the conditions on a road.

[0004] The tire test stands described can be used to determine the rolling resistance of a tire. Determining the rolling resistance can be the only test step or one of several test steps performed by the tire test stand. If rolling resistance is determined using a tire test stand, the tire test stand can also be referred to as a rolling resistance measuring machine or rolling resistance testing machine. To determine the rolling resistance, the tire rolls with its tread on the drum surface of the running drum in such a way that rolling in one direction of movement is simulated. The tire is loaded with a force acting radially on the tire. Since the tire deforms during rolling, the contact point or the contact surface between the tread and the drum surface is located in front of the tire as seen in the simulated direction of movement.At least in contrast to the idealized case in which the tire does not deform when rolling and thus the contact point or contact area is intersected in the radial direction of the tire by a straight line that runs along the radius of the tire, the contact point or contact area is located further in front of the tire as seen in the simulated direction of movement. Due to the shifted contact point or the shifted contact area, a resultant normal force acts on the tire in the direction of movement, offset from the first axis of rotation and opposite to the direction of rotation. This normal force results in the tangential force, which acts tangentially on the tire at a contact point between the tread and the drum surface, perpendicular to the first axis of rotation and in the direction of rotation of the tire. The rolling resistance of the tire can be determined using the tangential force.

[0005] In general, it is desirable that the tires can be tested with particular precision and, in particular, that a particularly precise statement can be made about the rolling resistance.

[0006] It is therefore the object of the present invention to test tires particularly precisely and, in particular, to determine the rolling resistance of the tire particularly precisely.

[0007] According to a first aspect of the invention, the stated object is achieved by a tire test stand having the features of patent claim 1. The tire test stand has a frame, a tire holder attached to the frame, to which a tire with a tread can be mounted so as to be rotatable about a first axis of rotation, a running drum attached to the frame and mounted so as to be rotatable about a second axis of rotation, the drum having a drum surface rotating about the second axis of rotation, a force detection device attached to the frame, a temperature detection device attached to the frame, and a compressor device which can apply excess pressure to a gaseous pressure medium in the tire.When the tire is attached to the tire holder, the holder can be positioned so that when the tire rotates about the first axis of rotation in one direction of rotation and the running drum rotates about the second axis of rotation, the tire's tread rolls on the drum surface of the running drum. The force detection device is configured to detect a tangential force which, when the tire rolls with its tread on the drum surface of the running drum, acts on the tire perpendicular to the first axis of rotation and tangentially in the direction of rotation of the tire. The temperature detection device is configured to detect a temperature of the gaseous pressure medium. Preferably, the tire test bench is a uniformity tire test bench, which can also be referred to as a uniformity tire test bench or uniformity machine.

[0008] The tire test bench has the compressor device. The compressor device can pressurize a gaseous pressure medium, preferably air or nitrogen, in the tire. The compressor device is preferably attached to the frame. The compressor device preferably has a compressor element that can pressurize the gaseous pressure medium. The compressor device is preferably connected to one end of a supply line, which can be connected to the tire at a second end such that the pressurized pressure medium can be fed from the compressor device via the supply line into the tire, so that when the tire is pressurized, the gaseous pressure medium is arranged in the tire. The gaseous pressure medium can therefore be arranged in the tire, namely when the gaseous pressure medium in the tire is pressurized.Alternatively, the gaseous pressure medium can also be arranged in sections in the tire, for example while the tire is pressurized and the gaseous pressure medium is already arranged in sections in the tire and is arranged in sections in the supply.

[0009] When the tire is attached to the tire holder, the holder can be positioned so that when the tire rotates about the first axis of rotation in one direction of rotation and the running drum rotates about the second axis of rotation, the tire rolls with its tread on the drum surface of the running drum. The tire test bench preferably has a tire drive unit which drives the tire, which is rotatably attached to the tire holder, in the direction of rotation. The direction of rotation in which the tire rotates can also be referred to as the tire rotation direction. The tire test bench preferably has a tire braking unit which can brake the tire, which is rotatably attached to the tire holder, when it rotates in the tire rotation direction. With the help of the tire braking unit, the rotational speed of the tire can be reduced when it rotates in the tire rotation direction.The tire test bench preferably has a drum drive unit that can drive the running drum in a drum rotation direction. The tire test bench preferably has a drum braking unit that can brake the running drum when it rotates in the drum rotation direction. Thus, with the aid of the drum braking unit, the rotational speed of the running drum can be reduced when it rotates in the drum rotation direction.

[0010] The tire test bench has the force detection device. The force detection device is designed to detect a tangential force which, when the tire rolls with its tread on the drum surface of the running drum, acts on the tire perpendicular to the first axis of rotation and tangentially in the direction of rotation of the tire. In this context, the tangential force acting on the tire perpendicular to the first axis of rotation and tangentially in the direction of rotation of the tire means that the tangential force acts in a plane running perpendicular to the first axis of rotation and along a first straight line running perpendicular to a second straight line which also extends in the plane and extends in the radial direction of the tire such that it passes through the first axis of rotation and a contact point between the tread and the drum surface.The tangential force acts in a direction along the first straight line in which a section of the tire between the first axis of rotation and the contact point between the tread and drum surface also moves due to the rotational movement of the tire about the first axis of rotation. The rolling resistance of the tire can be determined using the detected tangential force. For example, the detected tangential force corresponds to the rolling resistance of the tire. In addition to the force detection device being set up to detect the tangential force, the force detection device is preferably also set up to detect a radial force acting on the tire. The radial force preferably corresponds to the force acting on the tire from the running drum in the radial direction of the tire. The radial force can be used to simulate a load acting on the tire from a vehicle on which the tire is mounted.Additionally or alternatively, in addition to being configured to detect the tangential force, the force detection device is preferably also configured to detect a lateral force acting on the tire. The lateral force preferably acts from the running drum onto the tire parallel to the first axis of rotation or parallel to the second axis of rotation. The radial force and / or the lateral force can be taken into account in addition to the tangential force when testing the tire.

[0011] The force detection device or at least a portion of the force detection device can be attached, for example, to the tire holder and via the latter to the frame, so that the force detection device can detect the tangential force perpendicular to the first axis of rotation, regardless of how the first axis of rotation is arranged and, in particular, also regardless of how the first axis of rotation and the second axis of rotation are arranged relative to one another.Alternatively or additionally, the force detection device or at least a portion of the force detection device can be attached to a drum holder which is attached to the frame and on which the running drum is rotatably mounted, and to the frame via the drum holder, so that the force detection device can detect the tangential force perpendicular to the second axis of rotation, regardless of how the second axis of rotation is arranged and in particular also regardless of how the first axis of rotation and the second axis of rotation are arranged relative to one another.

[0012] The force detection device is preferably designed and arranged such that a first section of the force detection device is arranged on a first side of the tire, viewed along the first axis of rotation, and a second section of the force detection device is arranged on a second side of the tire opposite the first side, viewed along the first axis of rotation. Alternatively or additionally, the force detection device is preferably further designed and arranged such that a third section of the force detection device is arranged on a first side of the running drum, viewed along the second axis of rotation, and a fourth section of the force detection device is arranged on a fourth side of the running drum opposite the third side, viewed along the second axis of rotation.

[0013] The tire test bench has the temperature detection device. The temperature detection device is configured to detect a temperature of the gaseous pressure medium. By detecting the temperature of the gaseous pressure medium, a conclusion can be drawn about the temperature of a section of the tire that is particularly severely deformed during rolling, or at least is spatially located particularly close to the section of the tire that is particularly severely deformed during deformation. In particular, based on the temperature of the gaseous pressure medium, it is possible to deduce the temperature of the inside of the tire, which defines the space in which the gaseous pressure medium is located when the tire is pressurized.In particular, the temperature-dependent deformability of sections of the tire can be taken into account when determining rolling resistance, for example, when rolling resistance is to be determined for a specific reference temperature. By detecting the temperature of the gaseous pressure medium, an indirect but nevertheless particularly precise temperature detection of the section of the tire that is crucial for deformation can be ensured, thus achieving a particularly precise determination of rolling resistance. Both the tangential force and the temperature of the gaseous pressure medium can be detected, so that each detected tangential force can be assigned a detected temperature that is present at least in an area adjacent to the area of ​​the tire that is subject to particularly severe deformation.Thus, in particular, the temperature can be detected at least near the portion of the tire whose temperature-dependent deformability has a particularly strong influence on rolling resistance. The temperature detection device preferably has one or more temperature detection elements, each temperature detection element configured to detect a temperature of the gaseous pressure medium. For example, the temperature detection device has a first temperature detection element, a second temperature detection element, and a third temperature detection element.

[0014] The first temperature sensing element preferably comprises a temperature sensor. The first temperature sensing element is preferably designed to be brought into contact with the gaseous pressure medium, such that the temperature sensor detects the temperature of the gaseous pressure medium when the first temperature sensing element is in contact with the gaseous pressure medium. The second temperature sensing element preferably comprises a temperature sensor. The second temperature sensing element is preferably designed to be brought into contact with the gaseous pressure medium, such that the temperature sensor detects the temperature of the gaseous pressure medium when the second temperature sensing element is in contact with the gaseous pressure medium.Preferably, the third temperature sensing element is mounted on the frame and is arranged in a surrounding of the tire and is configured to detect a temperature of a surrounding of the tire when the tire is mounted on the tire holder.

[0015] Preferably, a plurality of tangential forces and a plurality of temperatures are recorded for one or more tires, and from this, a specific temperature dependence of the tangential force or a specific temperature dependence of the rolling resistance is preferably determined. For example, using a regression analysis, a function can be determined that best describes the temperature dependence of the tangential force according to a specific mathematical criterion. This function or another function can in turn be used to determine a rolling resistance of the tire based on a recorded temperature and a recorded tangential force. For example, using the function or another function, a rolling resistance of the tire for a reference temperature can be determined based on a recorded temperature and a recorded tangential force.For example, the rolling resistance of the tire for a specific reference temperature can be determined from a sum of the measured tangential force and a product of a coefficient and the measured temperature or other functions.In contrast to tire test stands known from the prior art, the tire test bench has the particular advantage that a rolling resistance of the tire can be determined in a particularly precise manner, since the temperature of the gaseous pressure medium can be taken into account for determining the rolling resistance, for example for a specific reference temperature, wherein the gaseous pressure medium is in contact with a section of the tire that is particularly strongly deformed when the tire rolls, or at least the temperature of the gaseous pressure medium can be taken into account, wherein the gaseous pressure medium is arranged spatially close to the section of the tire that is particularly strongly deformed when the tire rolls.

[0016] In summary, it can be stated that tires can be tested particularly precisely using the tire test bench and, in particular, the rolling resistance of the tire can be determined particularly precisely.

[0017] The first axis of rotation and the second axis of rotation are preferably arranged parallel to one another. A parallel arrangement of the first axis of rotation and the second axis of rotation ensures that straight-ahead driving can be simulated with the tire test bench. The first axis of rotation and the second axis of rotation can preferably also be pivoted relative to one another, i.e. the first axis of rotation can be pivoted relative to the second axis of rotation or the second axis of rotation can be pivoted relative to the first axis of rotation or both the first axis of rotation can be pivoted relative to the second axis of rotation and the second axis of rotation can be pivoted relative to the first axis of rotation. If the first axis of rotation and the second axis of rotation are pivoted relative to one another out of the parallel arrangement, cornering can be simulated.

[0018] The tire test bench preferably has a tire drive unit, a tire braking unit, a drum drive unit, and a drum braking unit. The tire drive unit can drive a rotational movement of the tire. The tire braking unit can brake the rotational movement of the tire, i.e., reduce the rotational speed of the tire in a tire rotation direction. The drum drive unit can drive a rotational movement of the running drum. The drum braking unit can brake the rotational movement of the running drum, i.e., reduce the rotational speed of the running drum in a drum rotation direction.

[0019] The tire test bench preferably comprises means adapted to perform the steps already described and the steps described later. The means preferably comprise a processor and a data memory adapted to perform the corresponding steps.

[0020] In one embodiment, the temperature sensing device comprises a first temperature sensing element arranged outside the tire and configured to detect the temperature of the gaseous pressure medium. If the first temperature sensing element is arranged outside the tire and configured to detect the temperature of the gaseous pressure medium, detecting the temperature of the gaseous pressure medium is particularly easy to implement because the first temperature sensing element can be provided in a rotationally fixed manner with respect to the frame, which in particular enables wired transmission of signals provided by the first temperature sensing element and representing the detected temperature. The first temperature sensing element can therefore detect the temperature of the gaseous pressure medium before or after the gaseous pressure medium is arranged in the tire.For example, the first temperature sensing element can detect the temperature of the gaseous pressure medium when the tire is subjected to overpressure, i.e. while the gaseous pressure medium is introduced into the tire to generate the overpressure. The first temperature sensing element is preferably arranged in a feed line so that the temperature of the gaseous pressure medium flowing through the feed line can be detected. The temperature thus detected can be used to determine the rolling resistance of the tire, thus providing a particularly precise determination of the rolling resistance, for example at a predetermined reference temperature. In one embodiment, the temperature sensing device has a second temperature sensing element that is arranged inside the tire and is configured to detect the temperature of the gaseous pressure medium.If the second temperature sensing element is arranged within the tire and configured to sense the temperature of the gaseous pressure medium, the temperature of a portion of the tire can be sensed particularly precisely, at least indirectly, in particular since the temperature can be sensed when the tire rotates about the first axis of rotation and thus also while the tire is deforming and while the tangential force is sensed. The sensed temperature thus corresponds in particular to the temperature present at the deforming portion of the tire or is at least particularly close to this temperature.The second temperature sensing element preferably has a transmitter that can wirelessly transmit a signal representing the sensed temperature to a receiver of the tire test bench, so that the second temperature sensing element can rotate together with the tire about the first axis of rotation and, at the same time, a temperature of the gaseous pressure medium can be sensed. The second temperature sensing element can therefore sense the temperature of the gaseous pressure medium when at least a portion of the gaseous pressure medium or the entire gaseous pressure medium is arranged in the tire, for example when the tire is pressurized. The temperature sensed in this way can be used to determine the rolling resistance of the tire, thus providing a particularly precise determination of the rolling resistance, for example at a predetermined reference temperature.

[0021] In one embodiment, the temperature detection device is configured to detect a temperature of the gaseous pressure medium when the tire is attached to the tire holder. When the temperature detection device is configured to detect a temperature of the gaseous pressure medium when the tire is attached to the tire holder, a particularly time-efficient test of the tire is ensured, since the tire can already be attached to the tire holder while the temperature is detected, and no additional temperature detection steps need to be provided. In one embodiment, the temperature detection device has a third temperature detection element configured to detect a temperature of an environment surrounding the tire when the tire is attached to the tire holder. The temperature of the environment surrounding the tire can further refine the determination of the rolling resistance.

[0022] According to a second aspect of the invention, the object stated at the outset is achieved by a system having the features of patent claim 6. The system is designed to produce a plurality of tires and to test at least one of the plurality of tires. The system comprises a tire test bench according to the first aspect of the invention and a manufacturing device for producing the plurality of tires. With the aid of the system, the plurality of tires can be produced and subsequently the plurality of tires or a subset of the plurality of tires can be tested by detecting a corresponding tangential force for each tire of the plurality or for each tire of the subset and detecting a temperature of the gaseous pressure medium for the corresponding tire.The features, technical effects and / or advantages described in connection with the tire test bench according to the first aspect of the invention also apply at least analogously to the system according to the second aspect of the invention, so that a corresponding repetition is omitted at this point.

[0023] According to a third aspect of the invention, the object mentioned above is achieved by a method having the features of patent claim 7. The method is provided for testing at least one of a plurality of tires using a tire test bench according to the first aspect of the invention. The method comprises the following steps: in a first step, detecting a tangential force using the force detection device, and in a second step, detecting a temperature of the gaseous pressure medium using the temperature detection device.In particular, in contrast to methods known from the prior art, the method has the advantage that a rolling resistance of the tire can be determined in a particularly precise manner, since for the determination of the rolling resistance, for example for a specific reference temperature, the temperature of the gaseous pressure medium and thus the temperature of a section of the tire that is particularly strongly deformed when the tire rolls can be deduced or at least the temperature of the section of the tire can be taken into account that is arranged at least spatially close to the section of the tire that is particularly strongly deformed when the tire rolls.The features, technical effects and / or advantages described in connection with the tire test bench according to the first aspect of the invention and those described in connection with the system according to the second aspect of the invention also apply at least analogously to the method according to the third aspect of the invention, so that a corresponding repetition is omitted at this point.

[0024] In one embodiment, the second step is performed before the first step. In this case, the temperature of the gaseous pressure medium can be detected in a particularly simple manner using a temperature sensing element arranged outside the tire, in particular since the temperature sensing element can be provided in a rotationally fixed manner with respect to the frame, which in particular enables a wired transmission of signals that can be provided by the temperature sensing element and represent the detected temperature and can be transmitted, for example, to the previously described means of the tire test bench.

[0025] In one embodiment, the second step is carried out during the first step. If the second step is carried out during the first step, a particularly time-efficient test of the tire is ensured. Furthermore, if the second step is carried out during the first step, the temperature of the gaseous pressure medium and thus the temperature of the section of the tire that deforms particularly strongly can be detected particularly precisely, at least indirectly, in particular since the temperature can be detected when the tire rotates about the first axis of rotation and thus also while the tire is deforming and while the tangential force is detected. The detected temperature is therefore particularly close to the temperature that prevails at the deforming section of the tire.Preferably, when the temperature is detected when the tire rotates about the first axis of rotation, the temperature detection device comprises a temperature detection element which is arranged within the tire and is configured to detect the temperature of the gaseous pressure medium.

[0026] In one embodiment, the second step is performed after the first step. In this case, the temperature of the gaseous pressure medium can be detected in a particularly simple manner using a temperature sensing element arranged outside the tire, in particular since the temperature sensing element can be provided in a rotationally fixed manner with respect to the frame, which in particular enables a wired transmission of signals that can be provided by the temperature sensing element and represent the detected temperature and can be transmitted, for example, to the previously described means of the tire test bench.

[0027] In one embodiment, the method further comprises the following step: determining a rolling resistance of the tire as a function of the detected temperature and the detected tangential force. For example, a rolling resistance of the tire for a reference temperature can be determined using a function based on a detected temperature and a detected tangential force.

[0028] In one embodiment, the method further comprises the following step: comparing the determined rolling resistance with a reference value. If the rolling resistance of the tire is less than the reference value, the tire is assigned to a first group. If the rolling resistance of the tire is greater than or equal to the reference value, the tire is assigned to a second group. It can therefore be checked whether the rolling resistance at the reference temperature lies within a permissible range, and corresponding further steps can be initiated depending on whether the tire has been assigned to the first group or the second group.Preferably, the reference value is a reference value for a specific temperature, so that the reference value for the detected temperature is determined using the detected temperature, and the detected tangential force or the rolling resistance determined from the detected tangential force is compared with the reference value. Alternatively, the reference value can also be a reference value for a specific temperature, so that the detected tangential force is first converted or standardized to a specific reference temperature using the detected temperature, and then the standardized tangential force is compared with the reference value for the reference temperature.

[0029] According to a fourth aspect of the invention, the object stated at the outset is achieved by a method having the features of patent claim 13. The method is provided for producing and testing tires. The method comprises the following steps: producing a plurality of tires and testing at least one tire of the produced plurality of tires using a method according to the third aspect of the invention. With the aid of the method for producing and testing tires, the plurality of tires can be produced and then the plurality of tires or a subset of the plurality of tires can be tested by detecting a corresponding tangential force for each tire of the plurality or for each tire of the subset and detecting a temperature of the gaseous pressure medium for the corresponding tire.The features, technical effects and / or advantages described in connection with the tire test bench according to the first aspect of the invention, those described in connection with the system according to the second aspect of the invention and those described in connection with the method according to the third aspect of the invention also apply at least analogously to the method according to the fourth aspect of the invention, so that a corresponding repetition is omitted at this point.

[0030] Further features, advantages, and possible applications of the present invention will become apparent from the following description of the exemplary embodiments and the figures. All described and / or illustrated features, individually and in any combination, constitute the subject matter of the invention, regardless of their composition in the individual claims or their references. In the figures, the same reference numerals continue to represent the same or similar objects. Figures 1 and 2 show schematic representations of an embodiment of a tire test bench according to the invention.

[0031] Figure 3 shows a schematic representation of an embodiment of a system according to the invention,

[0032] Figure 4 shows a schematic representation of an embodiment of a method for testing according to the invention, and

[0033] Figure 5 shows a schematic representation of an embodiment of a method for manufacturing and testing according to the invention.

[0034] Figures 1 and 2 show schematic representations of an embodiment of a tire test stand 1 according to the invention. The tire test stand 1 comprises a frame 3, a tire holder 5 attached to the frame 3, a running drum 7 attached to the frame 3, a force detection device 9 attached to the frame 3, and a temperature detection device 11 attached to the frame 3.

[0035] A tire 13 with a tread 15 is attached to the tire holder 5 so as to be rotatable about a first axis of rotation 17. The tread 15 is arranged so as to rotate around the first axis of rotation 17. Figures 1 and 2 show a tire rotation direction 19 in which the tire 13 rotates. The running drum 7 has a drum surface 21. The running drum 7 is mounted so as to be rotatable about a second axis of rotation 23, and the drum surface 21 is arranged so as to rotate around the second axis of rotation 23. Figures 1 and 2 show a drum rotation direction 25 in which the running drum 7 rotates.

[0036] Then, when the tire 13 is attached to the tire holder 5, the tire holder 5 can be positioned such that when the tire 13 rotates about the first axis of rotation 17 in a direction of rotation which, in Figures 1 and 2, corresponds to the tire rotation direction 19, and the running drum 7 rotates about the second axis of rotation 23, i.e., rotates in the drum rotation direction 25 in Figures 1 and 2, the tire 13 rolls with its tread 15 on the drum surface 21 of the running drum 7. In the position of the tire holder 5 shown in Figures 1 and 2, the tire 13 rolls with its tread 15 on the drum surface 21 of the running drum 7. The force detection device 9 is designed to detect a tangential force 27, shown in Figure 2 by means of an arrow.The tangential force 27 acts when the tire 13 rolls with its tread 15 on the drum surface 21 of the running drum 7, perpendicular to the first axis of rotation 17 and tangentially on the tire 13 in the direction of rotation of the tire 13. Because the tire 13 rolls with its tread 15 on the drum surface 21 of the running drum 7, rolling of the tire 13 on a flat surface can be simulated, wherein it is simulated that the tire 13 moves in the tire rotation direction 19 shown in Figures 1 and 2 in a direction over the flat surface when rolling, which corresponds to the tire rotation direction 19 on a side of the first axis of rotation 17 opposite a contact point between the tire 13 and the running drum 7, ie to the right in Figure 2. The simulated direction can also be referred to as direction of movement 29 and is symbolized in Figure 2 by an arrow.The tangential force therefore acts opposite to the direction of movement 29. When the tire 13 rolls on the running drum 7, the tire 13 deforms, particularly in front of the first axis of rotation 17 as seen in the direction of movement 29, such that a force perpendicular to the first axis of rotation 17 and in front of the first axis of rotation 17 in the direction of movement 29, i.e., to the right of the first axis of rotation 17 in Figure 2, counteracts the rotational movement of the tire 13, opposite to the tire's direction of rotation 19. This force reacts by producing the tangential force 27, which acts opposite to the direction of movement 29.

[0037] The tangential force 27 can be measured using the force detection device 9. The rolling resistance of the tire 13 can be determined using the measured tangential force 27. For example, the measured tangential force 27 corresponds to the rolling resistance of the tire 13.

[0038] The tire test bench 1 also has a compressor device 31. The compressor device 31 can pressurize a gaseous pressure medium in the tire 13. The compressor device 31 is also attached to the frame 3, although this is not shown in Figure 1. The compressor device 31 has a compressor element that can pressurize the gaseous pressure medium. The compressor device 31 is connected to one end of a feed line 33, which can be connected to the tire 13 at a second end such that the pressurized pressure medium can be conveyed from the compressor device 31 via the feed line 33 into the tire 13, so that when the tire 13 is pressurized, the gaseous pressure medium is arranged in the tire 13.The gaseous pressure medium can therefore be arranged in the tire 13, namely when the gaseous pressure medium in the tire 13 is pressurized. Alternatively, the gaseous pressure medium can also be arranged in sections in the tire 13, namely, for example, while the tire 13 is pressurized and the gaseous pressure medium is already arranged in sections in the tire 13 and in sections in the supply line 33.

[0039] The temperature detection device 11 is configured to detect a temperature of the gaseous pressure medium. By detecting the temperature of the gaseous pressure medium, a conclusion can be drawn about the temperature of a section of the tire 13 that is particularly severely deformed during the deformation of the tire 13 during rolling, or at least is spatially located particularly close to the section of the tire 13 that is particularly severely deformed during the deformation of the tire 13. Specifically, based on the temperature of the gaseous pressure medium, it is possible to deduce the temperature of the inside of the tire 13, which defines the space in which the gaseous pressure medium is located when the tire 13 is pressurized.In particular, the temperature-dependent deformability of sections of the tire 13 can be taken into account when determining the rolling resistance, for example, when the rolling resistance is to be determined for a specific reference temperature. By detecting the temperature of the gaseous pressure medium, an indirect but nevertheless particularly precise temperature detection of the section of the tire 13 that is crucial for deformation can be ensured, thus achieving a particularly precise determination of the rolling resistance. Thus, both the tangential force 27 and the temperature of the gaseous pressure medium can be detected, so that each detected tangential force 27 can be assigned a detected temperature that is present at least in an area adjacent to the area of ​​the tire 13 that is subject to particularly severe deformation.Thus, in particular, the temperature can be detected at least in the vicinity of the section of the tire 13 whose temperature-dependent deformability has a particularly strong influence on the rolling resistance.

[0040] For example, multiple tangential forces and multiple temperatures can be recorded for one or more tires 13, and from this, a specific temperature dependence of the tangential force 27 or a specific temperature dependence of the rolling resistance can be determined. For example, using a regression analysis, a function can be determined that best describes the temperature dependence of the tangential force 27 according to a specific mathematical criterion. This function or another function can in turn be used to determine a rolling resistance of the tire 13 based on a recorded temperature and a recorded tangential force 27. For example, using the function or another function, a rolling resistance of the tire 13 for a reference temperature can be determined based on a recorded temperature and a recorded tangential force 27.For example, the rolling resistance of the tire 13 for a specific reference temperature can be determined from a sum of the detected tangential force 27 and a product of a coefficient and the detected temperature or other functions. In contrast to tire test benches known from the prior art, the tire test bench 1 has the particular advantage that the rolling resistance of the tire 13 can be determined particularly precisely, since, for determining the rolling resistance, for example for a specific reference temperature, the temperature of the section of the tire 13 that is at least spatially close to the section of the tire 13 that deforms particularly strongly when the tire 13 rolls can be taken into account.

[0041] The temperature detection device 11 of the embodiment of the tire test bench 1 according to the invention shown in Figures 1 and 2 has a first temperature detection element 35, a second temperature detection element 37, and a third temperature detection element 39. The first temperature detection element 35 is arranged outside the tire 13 and is configured to detect the temperature of the gaseous pressure medium. If the first temperature detection element 35 is arranged outside the tire 13 and is configured to detect the temperature of the gaseous pressure medium, detecting the temperature of the gaseous pressure medium is particularly easy to implement because the first temperature detection element 35 can be provided in a rotationally fixed manner with respect to the frame 3, which in particular enables a wired transmission of signals provided by the first temperature detection element 35 and representing the detected temperature.The first temperature sensing element 35 can thus detect the temperature of the gaseous pressure medium before or after the gaseous pressure medium is arranged in the tire 13. For example, the first temperature sensing element 35 can detect the temperature of the gaseous pressure medium when the tire 13 is subjected to overpressure, i.e., while the gaseous pressure medium is being introduced into the tire 13 to generate the overpressure. The first temperature sensing element 35 is arranged in the supply line 33 so that the temperature of the gaseous pressure medium flowing through the supply line can be detected.

[0042] The second temperature sensing element 37 is arranged inside the tire 13 and is configured to detect the temperature of the gaseous pressure medium. If the second temperature sensing element 37 is arranged inside the tire 13 and is configured to detect the temperature of the gaseous pressure medium, the temperature of a section of the tire 13 can be detected at least indirectly with particular precision, in particular since the temperature can be detected when the tire rotates about the first axis of rotation and thus also while the tire is deforming and while the tangential force is detected. The detected temperature thus corresponds in particular to the temperature present at the deforming section of the tire or at least comes particularly close to this temperature.Preferably, the second temperature sensing element 37 has a transmitter that can wirelessly transmit a signal representing the detected temperature to a receiver of the tire test bench 1, so that the second temperature sensing element 37 can rotate together with the tire 13 about the first axis of rotation 17 and, at the same time, a temperature of the gaseous pressure medium can be detected. The second temperature sensing element 37 can therefore detect the temperature of the gaseous pressure medium when at least a portion of the gaseous pressure medium or the entire gaseous pressure medium is arranged in the tire 13, for example, when the tire 13 is pressurized.

[0043] The first temperature sensing element 35 and the second temperature sensing element 37 are each configured to detect a temperature of the gaseous pressure medium when the tire 13 is mounted on the tire holder 5. The temperature sensing device 11 is thus configured to detect a temperature of the gaseous pressure medium when the tire 13 is mounted on the tire holder 5. This ensures a particularly time-efficient inspection of the tire 13, since the tire 13 can already be mounted on the tire holder 5 while the temperature is being detected, and no additional temperature sensing steps are required.

[0044] With the aid of the first temperature detection element 35 and the second temperature detection element 37, temperatures of the gaseous pressure medium can be detected, wherein these temperatures can be used to determine the rolling resistance of the tire 13 and thus a particularly precise determination of the rolling resistance can be provided, for example at a predetermined reference temperature.

[0045] The third temperature sensing element 39 is mounted on the frame 3 and is arranged in a surrounding area of ​​the tire 13 and configured to detect a temperature of the surrounding area of ​​the tire 13 when the tire 13 is mounted on the tire holder 5. The temperature of the surrounding area of ​​the tire 13 can further refine the determination of the rolling resistance.

[0046] The tire test stand 1 further comprises a tire drive unit, a tire braking unit, a drum drive unit, and a drum braking unit, although these components are not shown in Figures 1 and 2. The tire drive unit can drive a rotational movement of the tire 13. The tire braking unit can brake the rotational movement of the tire 13, i.e., reduce the rotational speed of the tire 13 in the tire rotation direction 19. The drum drive unit can drive a rotational movement of the running drum 7. The drum braking unit can brake the rotational movement of the running drum 7, i.e., reduce the rotational speed of the running drum 7 in the drum rotation direction 25.

[0047] Figure 3 shows a schematic representation of an embodiment of a system 41 according to the invention. The system 41 is provided for producing a plurality of tires 13 and for testing at least one tire 13 of the plurality of tires 13. The system 41 has two tire test stands 1 according to Figures 1 and 2 and a manufacturing device 43 for producing the plurality of tires 13. With the aid of the system 41, the plurality of tires 13 can be produced and then the plurality of tires 13 or a subset of the plurality of tires 13 can be tested by detecting a corresponding tangential force 27 for each tire 13 of the plurality or for each tire 13 of the subset and detecting a temperature of the gaseous pressure medium for the corresponding tire 13.

[0048] Figure 4 shows a schematic representation of an embodiment of a method for testing according to the invention, and Figure 5 shows a schematic representation of an embodiment of a method for manufacturing and testing according to the invention.

[0049] The method shown in Figure 4 is for testing at least one tire 13 of a plurality of tires 13 using a tire test bench 1 shown in Figures 1 and 2. The method shown in Figure 4 has a first step 101, a second step 102, a third step 103, a fourth step 104, and a fifth step 105. In the first step 101, a tangential force 27 is detected using the force detection device 9. In the second step 102, a temperature of the gaseous pressure medium is detected using the temperature detection device 11. In the method shown in Figure 4, the second step 102 is carried out after the first step 101. In an alternative embodiment of the testing method, the second step 102 is carried out before the first step 101.Alternatively, in a further alternative embodiment of the testing method, the second step 102 is performed during the first step 101. In the fourth step 104, a rolling resistance of the tire 13 is determined as a function of the detected temperature and the detected tangential force 27. In the fifth step 105, the determined rolling resistance is compared with a reference value, and if the rolling resistance of the tire 13 is less than the reference value, the tire 13 is assigned to a first group, and if the rolling resistance of the tire 13 is greater than or equal to the reference value, the tire 13 is assigned to a second group.

[0050] By detecting the temperature of the gaseous pressure medium, an indirect but nevertheless particularly precise statement can be made about the actual temperature of the tire 13 or at least a particularly precise statement about the actual temperature of the gaseous pressure medium in contact with the tire 13. The actual temperature of the tire 13 can thus be determined particularly precisely, in particular significantly more precisely than in the case in which the temperature in the vicinity of the tire 13 is determined and it is assumed that this temperature approximately corresponds to the temperature of the tire 13. Thus, the determined tangential force 27 or the determined tangential forces can be assigned to a particularly precisely determined temperature or temperatures.In particular, if a rolling resistance is determined using the recorded tangential force 27 and a temperature is recorded, and the rolling resistance for a reference temperature, such as 25°C, is estimated or standardized based on these values ​​of the recorded tangential force 27 and the recorded temperature, this estimation can provide particularly precise results, allowing particularly reliable statements to be made as to whether the estimated rolling resistance for a specific tire 13 at the reference temperature lies within a permissible interval. For example, if the estimated rolling resistance at 25°C is lower than a reference rolling resistance for 25°C, the tire 13 passes the test with an "OK" rating and is assigned to the first group. However, if the estimated rolling resistance at 25°C is equal to or greater than the reference rolling resistance for 25°C, the tire 13 fails the test with a "not OK" rating and is assigned to the second group.The more precisely the rolling resistance at 25 °C is estimated, the more precise the test result and the more reliably the tires 13 can be divided into “OK” and “not OK” groups, ie into the first group or the second group.

[0051] The method for producing and testing tires 13 illustrated in Figure 5 additionally includes, compared to Figure 4, a sixth step 106 in which a plurality of tires 13 are produced. Subsequently, in the first step 101, the second step 102, the third step 103, the fourth step 104, and the fifth step 105, at least one tire 13 of the produced plurality of tires 13 is tested.

[0052] Additionally, it should be noted that "comprising" does not exclude other elements or steps, and "a" or "an" does not exclude a plurality. Furthermore, it should be noted that features described with reference to one of the above embodiments can also be used in combination with other features of other embodiments described above. Reference signs in the claims are not to be considered as limitations.

[0053] Reference symbol

[0054] Tire test bench

[0055] Frame

[0056] Tire holder

[0057] Running drum

[0058] Force detection device

[0059] Temperature recording device

[0060] Tires

[0061] Tread first axis of rotation

[0062] Tire rotation direction

[0063] Drum surface second axis of rotation

[0064] Drum rotation direction

[0065] Tangential force

[0066] Direction of movement

[0067] Compressor device

[0068] Feed first temperature sensing element second temperature sensing element third temperature sensing element

[0069] system

[0070] Manufacturing device first step second step third step fourth step fifth step 106 sixth step

Claims

Patent claims 1. Tire test stand (1) with a frame (3), a tire holder (5) attached to the frame (3), to which a tire (13) with a tread (15) can be mounted so as to be rotatable about a first axis of rotation (17), a running drum (7) attached to the frame (3) and mounted so as to be rotatable about a second axis of rotation (23) and having a drum surface (21) rotating about the second axis of rotation (23), a force detection device (9) attached to the frame (3), a temperature detection device (11) attached to the frame (3), and a compressor device which can apply overpressure to a gaseous pressure medium in the tire (13), wherein, when the tire (13) is attached to the tire holder (5), the latter can be positioned so that when the tire (13) rotates about the first axis of rotation (17) in one direction of rotation and the running drum (7) rotates about the second axis of rotation (23),the tire (13) rolls with its tread (15) on the drum surface (21) of the running drum (7), wherein the force detection device (9) is designed to detect a tangential force (27) which, when the tire (13) rolls with its tread (15) on the drum surface (21) of the running drum (7), acts perpendicular to the first axis of rotation (17) and tangentially in the direction of rotation of the tire (13), and wherein the temperature detection device (11) is designed to detect a temperature of the gaseous pressure medium.

2. Tire test bench (1) according to one of the preceding claims, wherein the temperature detection device (11) has a first temperature detection element (35) which is arranged outside the tire (13) and is configured to detect the temperature of the gaseous pressure medium.

3. Tire test bench (1) according to one of the preceding claims, wherein the temperature detection device (11) has a second temperature detection element (37) which is arranged inside the tire (13) and is configured to detect the temperature of the gaseous pressure medium.

4. Tire test stand (1) according to one of the preceding claims, wherein the temperature detection device (11) is arranged to detect a temperature of the gaseous pressure medium when the tire (13) is attached to the tire holder (5).

5. Tire test bench (1) according to one of the preceding claims, wherein the temperature detection device (11) has a third temperature detection element (39) which is arranged to detect a temperature of the surroundings of the tire (13) when the tire (13) is attached to the tire holder (5).

6. System (41) for producing a plurality of tires (13) and for testing at least one tire (13) of the plurality of tires (13), wherein the system (41) comprises a tire test bench (1) according to one of the preceding claims and a manufacturing device (43) for producing the plurality of tires (13).

7. A method for testing at least one tire (13) of a plurality of tires (13) with a tire test bench (1) according to one of claims 1 to 5, the method comprising the following steps: In a first step (101), detecting a tangential force (27) using the force detection device (9), and In a second step (102), detecting a temperature of the gaseous pressure medium using the temperature detection device (11).

8. Method according to the preceding claim, wherein the second step (102) is carried out before the first step (101).

9. Method according to one of the preceding claims, wherein the second step (102) is carried out during the first step (101).

10. The method according to any one of the preceding claims, wherein the second step (102) is performed after the first step (101).

11. A method according to any one of the preceding claims, further comprising the following step: Determining a rolling resistance of the tire (13) as a function of the detected temperature and the detected tangential force (27).

12. The method according to claim 11, further comprising the step of: comparing the determined rolling resistance with a reference value, wherein if the rolling resistance of the tire (13) is less than the reference value, the tire (13) is assigned to a first group, and wherein if the rolling resistance of the tire (13) is greater than or equal to the reference value, the tire (13) is assigned to a second group.

13. A method for manufacturing and testing tires (13), the method comprising the following steps: Manufacturing a variety of tires (13) and Testing at least one tire (13) of the manufactured plurality of tires (13) using a method according to one of claims 7 to 12.

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