Vehicle wheel with measuring and monitoring device for a vehicle

Abstract

The present invention relates to a vehicle wheel and an associated monitoring device, comprising a rim part 203, a disc part and a measuring device 210 with at least one measuring sensor for detecting forces acting on the vehicle wheel. In order to provide the measuring device in a simple manner and to make it possible to determine the dynamic and static load forces on the vehicle wheel during driving operation, according to the invention a metal strip 111 is attached to the outside of the rim part 203 by adhesive connection and a measuring device is assigned to the metal strip, the measuring device 210 comprising a bending strut provided with at least one measuring sensor and connected to the metal strip at two spaced apart fastening zones, or the measuring sensor comprises several differently oriented strain gauges connected to the metal strip for local detection of deformations of the metal strip between the fastening zones.

Description

[Technical Field]

[0001] The invention relates to a vehicle wheel having a rim part with a rim flange, a rim shoulder and a rim well base for supporting a tire, a disc part having a hub connection flange with bolt holes and a transition part with ventilation holes and connected to the rim part for non-rotatably fastening the vehicle wheel to the vehicle, and a measuring device fastened to the vehicle wheel so as to be co-rotatable, the measuring device having at least one measurement sensor for detecting forces acting on the vehicle wheel and having a transceiver coupled to the measurement sensor for transmitting load data detected by the measurement sensor to a component external to the vehicle wheel, in particular to a vehicle-side monitoring device having an evaluation device. The invention further relates to a monitoring device for a vehicle having several vehicle wheels, in which at least one vehicle wheel has a measuring device with a measurement sensor and a transceiver coupled to the measurement sensor and a vehicle-side evaluation device for measuring signals of the measurement sensor. [Background technology]

[0002] In particular, heavy goods vehicles and regular goods vehicles are subject to weight restrictions for certain roads. To determine the load capacity within a vehicle, weight sensors may be permanently installed between the vehicle chassis and the vehicle's load area. Each of these load sensors is intended to exclusively detect the weight on the load area of ​​the goods vehicle. These sensors do not provide any other data about other vehicle conditions, and are not designed or equipped to detect other conditions such as mass distribution, temperature, tire pressure, wheel camber, etc. Such load conditions and other detected operating conditions may affect how vehicle systems respond during driving modes.

[0003] WO 2017 / 048762 A1 discloses a monitoring device having a load detection device fastened to the outer periphery of a vehicle wheel rim so that the sensor is positioned protected from environmental influences inside the tire under pressure. The load detection device includes a strain gauge for determining impact loads acting on the vehicle wheel under both static and dynamic conditions. For this purpose, the force generated during rotation of the vehicle wheel is determined as a sinusoidal signal, and the wheel load is determined by the maximum value recorded. Static loads can also be detected by detecting the rotational position of the monitoring device relative to the wheel contact area, if necessary, to determine the load by correlating the strain gauge measurement signal with previously recorded measurement data under different loads. In the known solution, the monitoring device's housing is fastened to the rim well base, preferably by adhesive bonding, and has a lower portion that curves according to the curvature of the well base. Additional sensors can be arranged in the housing to detect various vehicle conditions, such as wheel clamping force, wheel load, axle load, mass distribution, ambient temperature, wheel temperature, and tire pressure. The information obtained through the sensors can be used in various systems such as, but not limited to, Traction Control System (TCS), Anti-lock Braking System (ABS), Electronic Brakeforce Distribution (EBD), Anti-roll Stabilizer (AAR), Anti-collision Braking System (CMBS), Pre-collision Braking System (CMB), All Wheel Drive (AWD), Tire Pressure Control System (TPMS), Tire Wear and Damage Control Logging, among others. In order to permanently supply energy to the monitoring device, a piezoelectric element and an energy generating circuit are provided within the housing to convert the energy generated by the vibration of the piezoelectric element into electrical energy, which can be stored as needed.

[0004] WO 2021 / 048761 A1 discloses a modified version of a monitoring device for vehicle wheels, in which the housing has two circumferentially spaced-apart fastening zones, a bending strut as an essential element of the monitoring device is arranged between the fastening zones, and a measurement sensor, in particular a strain gauge, is arranged directly on the bending strut to determine the load force acting on the respective vehicle wheel via the deformation of the bending strut. To secure the housing, an adapter plate with threaded holes can be glued to the outer periphery of the vehicle wheel, or a fixing pin or screw can be fastened to the outer periphery of the vehicle wheel, thereby interacting with the fastening zones. This design allows the actual measurement sensor to be replaced relatively easily, and the corresponding housing can be attached to vehicle wheels with different wheel geometries.

[0005] US Patent Application Publication No. 2021 / 0023893 also discloses a measuring device and a vehicle wheel, by which the dynamic load on the vehicle wheel is determined. However, in this case, the sensor is not arranged on the actual rim, but on the disk portion of the vehicle wheel, i.e., on the spokes of the disk portion or, for example, on the annular portion of the disk portion, including the air vents. The actual sensor preferably consists of a capacitive sensor having two sensor surfaces separated from each other by a dielectric material, and the sensor is arranged on a sensor sheet on the surface of the disk portion. When the vehicle wheel deforms due to different loads, the two sensor surfaces also deform, thereby generating an electrical signal used to determine the wheel load. The magnitude of the signal depends on the angular position of the sensor relative to the wheel contact area and is greatest when the sensor is located above the wheel contact area. The document cites empirical data, which shows a linear relationship between tire pressure and the actual measurement signal. Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present invention is to create a vehicle wheel that can be equipped with a measuring device in an even simpler way in order to be able to determine the dynamic load on the vehicle wheel during driving operation and also the static load force by means of a suitable measuring device. [Means for solving the problem]

[0007] To solve this problem, according to a first solution concept of the present invention: - a metal strip is attached to the radially outer side of the rim section, and at least one measuring sensor is assigned to the metal strip; the metal strip has a lower side and an upper side and at least one subsection having a constant thickness in the circumferential direction between the lower side and the upper side, - the underside of the metal strip is connected to the outside of the rim along the section by means of an adhesive connection; - the measuring device has a bending support provided with at least one measuring sensor, which support is connected to the metal strip in two fastening zones spaced apart from each other in the circumferential direction of the rim for local detection of deformation of the metal strip between the fastening zones; - the metal strip has a length in the circumferential direction of the vehicle wheel that is greater than the distance between the fastening zones from each other It is proposed that:

[0008] The present invention proposes a metal strip with fastening elements that is fastened to the rim of a vehicle wheel as an additional element, and then a measuring device with a measurement sensor is fastened, preferably removably, to the fastening elements of the metal strip. By inserting the metal strip, there is a high degree of flexibility in terms of adapting to different wheel geometries. The sensor does not measure directly on the surface of the rim, but only indirectly via deformation of the metal strip. A secure connection between the metal strip and the surface of the actual vehicle wheel can be achieved, for example, preferably via a suitable adhesive connection.

[0009] In the first solution concept described above, it is particularly advantageous if the fastening zone consists of two anchor pins or anchor nuts which are fastened circumferentially offset from one another on the cover side of the metal strip, and which can preferably be welded or brazed to the metal strip.

[0010] The metal strip can preferably be partially provided with recesses between the fastening zones, which is particularly advantageous if the recesses are mounted symmetrically relative to the fastening zones, thereby making it possible to avoid measurement deviations due to the recesses.

[0011] According to one solution variant, the metal strip can extend only partially over the periphery of the rim. However, according to an alternative solution variant, it can prove advantageous if the metal strip extends completely over the periphery of the rim. In particular, in the second solution variant, it is particularly advantageous if the metal strip has at least two subsections with different strip widths transverse to the circumferential direction.

[0012] According to all the above-mentioned variants of the first solution concept, it is particularly advantageous if the measuring device is provided with a housing and an electrical circuit which is arranged in the housing together with the transceiver, the bending support and the measuring sensor, and the measuring device is preferably fastened to the fastening zone as a unit in a separable and replaceable manner.

[0013] According to a further variant of the first solution, the metal strip of one measuring device may comprise several sections, preferably with thinner metal strips constituting the outer periphery section and thicker metal sheet strips constituting the inner periphery section, with the bending struts consisting of a central metal sheet strip fixed between the inner ends of the facing metal sheet strips, and preferably with the measurement sensor fixed to the underside of the central metal sheet strip. Preferably, in this variant, the outer metal sheet strips are fastened to the outside of the rim section by adhesive connection. Furthermore, preferably, the outer sections of each metal strip are fastened along their entire periphery extension, and the inner sections are fastened to the outside of the rim section along part of the periphery extension, and preferably the metal sheet strips constituting the inner periphery section include a step of reducing the thickness of the lower side so that the lower side is moved away from the outside of the rim section.

[0014] With this arrangement, the adhesive of the adhesive connection transmits the displacement of the bonded fixing points on the thin metal strip to the thicker metal plate strip, which in turn transmits the displacement to the central metal strip forming the bending support and equipped with the measurement sensor, generating a deformation signal for the bending support. The strain gauges forming the measurement sensor are preferably installed only on the bottom surface of the bending support, where both strain forces (bending and axial) are summed. It is particularly advantageous if the measurement sensor is designed as a measuring surface with four strain gauges, of which two are oriented in the circumferential direction and two further strain gauges are oriented transversely to the circumferential direction, preferably parallel to the wheel axis.

[0015] According to the most preferred variant using the aforementioned measuring devices, two measuring devices each having a measuring sensor on its bending strut are positioned offset from each other in the circumferential direction, the distance of the two measuring sensors relative to each other in the circumferential direction being preferably 40°. According to this embodiment, it is advantageous if the measuring sensor is connected by a cable connection to an electronic circuit, a transceiver and a power supply, which preferably forms a component or additional part of a tire pressure measuring system (TPMS) assigned to the vehicle valve.

[0016] In order to solve the above mentioned problem, according to a second alternative solution concept according to the invention: - a metal strip is attached to the radially outer side of the rim portion, and at least one measurement sensor is assigned to the metal strip; the metal strip has a lower side and an upper side and at least one subsection having a constant thickness in the circumferential direction between the lower side and the upper side, - the underside of the metal strip is connected to the outside of the rim along the section by means of an adhesive connection; - the measuring device has at least one measuring sensor connected to the metal strip with several of the strain gauges oriented differently for local detection of deformations of the metal strip, - the metal strip has a circumferential length greater than the partial circumferential length covered by the strain gauge of the measuring sensor; It is proposed that:

[0017] Here, too, according to the invention, a metal strip is used that is glued to the surface of the rim of the vehicle wheel. However, the measuring device cannot be replaced here, but the actual measuring sensor is arranged directly on the metal strip in order to detect the deformation of the metal strip locally. Nevertheless, the advantage remains that the metal strip that is fastened to the periphery of the vehicle wheel as an additional element offers a relatively high degree of flexibility in terms of adaptation to different wheel geometries, so that the prepared measuring device that is arranged on the metal strip can be adapted to different wheel geometries.

[0018] According to an advantageous embodiment, the measuring sensor with the strain gauge is covered by a plastic cover, in particular a plastic strip which is glued onto the upper side of the metal strip.

[0019] It is particularly advantageous if the measurement sensor is designed as a measuring surface with four strain gauges, of which two strain gauges are oriented in the circumferential direction and two further strain gauges are oriented transversely to the circumferential direction. It is also advantageous if the measurement sensor is connected by a cable connection to an electronic circuit, a transceiver and a power supply, which forms a component or additional part of a tire pressure measuring device (TPMS) assigned to the vehicle valve.

[0020] In all variants, it is particularly advantageous if at least two measurement sensors, distributed around the periphery of the rim and operating independently, form one another and are positioned offset from one another in the circumferential direction, the distance of the two measurement sensors relative to one another in the circumferential direction being preferably at least 20°, in particular 22.5° in some variants or 40° in different embodiments. A corresponding arrangement makes it possible to measure the static load on all vehicle wheels mounted on the vehicle when the vehicle is stationary, regardless of the angular rotational position of the vehicle wheels. The latter is based on the finding that, at a certain rotational angle, it is not possible to mathematically determine the static load from the measured value if only one measurement sensor is present per vehicle wheel. The load measured by the sensor depends on the angular position (rotational angle) α of the sensor's position relative to the wheel contact area. The basic mathematical approach is that, assuming a constant weight load L, a constant internal tire pressure p, and a constant ambient temperature T during a 360° rotation, the sensor value e determined by the sensor is a periodic function that depends on the rotational angle α during a complete wheel rotation. Essentially, the mathematical approach is based on the formula: e=f(α,L,T,P) If it is assumed that there is a linear relationship between the tire pressure and temperature and the sensor value set by the sensor, this function can be mathematically divided into several components, namely: e=e0(T,P+g(P)*L*c(α)

[0021] With this mathematical assumption, - e0 forms part of the weight load independent function, - c(α) forms part of the proportional dependence on the weight load as a periodic function. c(α) corresponds to a periodic function that ideally repeats with each revolution of the wheel, which is why the following applies: c(α)=c(α+2kπ) - g(P) is a scaling factor that reflects the pressure-dependent effect of the stiffness of the wheel-tire system.

[0022] These formulas and conditions are useful when determining the static load due to gravitational forces. A prerequisite for this is, among other things, the determination of the ratio coefficient e0. This is carried out in a suitable calibration method to determine the displacement coefficient of the respective curve depending on temperature and tire pressure. In a further calibration method, c(α) is then determined by multiple measurements, for which corresponding measurements are carried out at different angular positions of the sensor.

[0023] After the individual coefficients have been suitably determined by a calibration method, the dynamic weight load is calculated by the formula L=e amp / k(P) whereby the following applies to dynamic measurements: e amp =e max -e min k(P)=g(P)*(c(α) max -c(α) min )

[0024] Therefore, if the vehicle wheel calibration reference curves are available through calibration for the respective internal tire pressures, it is not necessary to know the rotation angle and temperature to determine the dynamic load.

[0025] The static weight load of each vehicle wheel can be determined by the following formula:

number

[0026] In all designs, the metal strip can be made of stainless steel, light alloy, metal alloy, or high-grade steel. The metal strip must have a constant thickness of 0.03 mm to 0.25 mm, especially in the section where the measuring sensor is also located, and in particular 0.05 mm to 0.2 mm. Furthermore, the metal strip must have a width of more than 15 mm in the section.

[0027] The connection between the metal strip and the surface of the rim part is preferably made via an adhesive bond, the adhesive having an elastic modulus of at least 50 MPa, preferably more than 200 MPa, particularly preferably more than 450 MPa, the thickness of the adhesive in the area of ​​the adhesive bond being preferably less than 0.25 mm, most preferably less than 0.125 mm.

[0028] The adhesive is preferably selected from acrylic, cyanoacrylate, or silicone-based adhesives. The adhesive can be applied in particular to the underside of the metal strip and to both outer sides of the rim portion. The thickness of the adhesive can be approximately equal to the thickness of the metal strip of the partial section, or can be greater than the thickness of the metal strip of the partial section.

[0029] The present invention also relates to a monitoring device for a vehicle having several vehicle wheels, at least one of which is designed according to one of the solution approaches of the present invention and is likewise provided with a metal strip, to which a measuring device with a measurement sensor and a transceiver coupled to the measurement sensor are assigned, and a vehicle-side evaluation device is available for the measurement signals of the measurement sensor. According to the present invention, the monitoring device is designed and configured to be able to determine the dynamic load during driving operation and the static load on the associated vehicle wheel in a stationary state of the vehicle from the measurement signals of the measurement sensor, in which to determine the dynamic load by the evaluation device, the measurement signal amplitude between the measured maximum signal value and the measured minimum signal value in one rotation of the wheel is determined and compared with amplitude values ​​from a vehicle wheel calibration reference curve to determine a deviation factor, in which the rotation angle between the sensor position and the wheel contact position is determined, and in which the evaluation device compares the measured signal values ​​with reference values ​​from the vehicle wheel calibration reference curve for the same rotation angle, and several vehicle wheel calibration reference curves for different temperatures and internal tire pressures are stored in the evaluation device. It is particularly advantageous that the continuously determined measurements during the dynamic measurement of the respective vehicle and weight load can be used to determine the load-independent element e0, via which the curve displacement at different temperatures and tire pressures is then determined based on a previous calibration, which is required for the static load calculation. With a suitable prior calibration, the static load can be determined from the signal value via the load-independent element e0, independently of the pressure and temperature.

[0030] Further advantages and designs of the invention result from the following description of exemplary embodiments which are illustrated diagrammatically in the drawings. [Brief explanation of the drawings]

[0031] [Figure 1] 1 shows a highly simplified, not-to-scale, plan view of a vehicle wheel with an attached measuring device according to a first exemplary embodiment and a schematically shown tire pressure valve for a tire pressure control system (TPMS). [Figure 2] 1 shows a measurement device according to a first exemplary embodiment in a schematic top view; [Figure 3] 2 shows the measuring device according to FIG. 1 in a schematic detailed cross section through the rim and the measuring device. [Figure 4] 3 shows a measurement device similar to that of FIGS. 1 and 2 according to a second exemplary embodiment; [Figure 5] 1 shows a perspective view of a measuring device according to a second exemplary embodiment attached to a rim portion; [Figure 6] 6 shows the measurement device of FIG. 5 with the housing removed. [Figure 7] 7 shows a schematic simplified top view of the measurement setup of FIG. 6. [Figure 8] The diagram shows a highly simplified schematic diagram of the relationship between rotation angle and wheel contact area. [Figure 9] 2 shows a highly simplified example of a diagram showing periodic measurement signal values ​​of several measured wheel revolutions divided into different parts; [Figure 10] 1, and shows a schematic representation of a measuring device arrangement and a diagrammatically illustrated tire pressure valve for a tire pressure control system (TPMS) according to a further alternative third embodiment; [Figure 11] The measuring device arrangement according to FIG. 10 is shown in a side cross-sectional view of a vehicle wheel. [Figure 12] 1 shows a schematic enlarged side view of one of the measuring devices according to a third embodiment; [Figure 13] The measurement device is shown schematically in a bottom view. DETAILED DESCRIPTION OF THE INVENTION

[0032] In FIG. 1 , a vehicle wheel is generally designated by the reference numeral 1 and comprises, as known per se, a disk portion 2 and a rim portion 3. The vehicle wheel can be constructed integrally from cast parts made, for example, from a light alloy, or the disk portion 2 and the rim portion 3 are manufactured separately and then connected to each other, preferably with a welded joint, to form an assembled vehicle wheel. The disk portion 2 serves functionally for non-rotatable fastening of the vehicle wheel 1 to the hub of a vehicle (not shown). The rim portion 3 is made from plastic and serves functionally to support a tire (not shown) that is inflated to an internal pressure recommended by the vehicle manufacturer, with only the tire being in contact with the ground. To support and mount the tire, the rim portion 3 comprises, as known per se, two rim flanges 4, two rim shoulders 5, and a multi-stage rim well base 6. The rim shoulders serve to radially support the tire, and the rim flanges serve to axially support the tire. The disc portion 3, shown here only partially, is provided with bolt holes for mounting the vehicle wheel 1 to the hub on the hub connection surface and furthermore is provided in the transition portion with vents (not shown) for cooling the brakes. Vehicle wheels can have different geometries and designs, which is why the vehicle wheels shown are of a symbolic nature only and do not limit the invention in this respect.

[0033] In the exemplary embodiment shown in Figure 1, a tire pressure valve 8 of a tire pressure monitoring system (RDKS) is also shown schematically, which is not further shown. The tire pressure valve 8 is provided with at least one internal tire pressure sensor, an energy source for providing energy, and a transceiver for transmitting measurement signals from the internal tire pressure sensor to the tire pressure control device of the vehicle, in order to display the current internal tire pressure of each tire to the driver, as currently specified for new vehicles. Vehicle wheels with tire pressure valves of any construction for tire pressure control systems are known to those skilled in the art, which is why they will not be further described here.

[0034] A measuring device 10, further arranged radially outside the rim part 3 of the vehicle wheel, is essential to the invention. In FIG. 1, the measuring device 10 is arranged in the transition of the rim well base 6 between the well base bottom 7 and one of the rim shoulders 5. The measuring device 10 consists of a metal strip 11 glued to the outer periphery of the rim part 3 by an adhesive connection. The metal strip 11 is then provided with a measuring sensor 12 in the center of its longitudinal and lateral extent, as can be clearly seen in FIGS. 2 and 3, which is equipped with a total of four strain gauges 13, 14, as approximately shown in the schematic diagram of FIG. 2. Two strain gauges 13 are oriented in the circumferential direction, i.e., in the direction of rotation of the vehicle wheel rotating around the wheel axis, and two strain gauges 14 are oriented transversely to the circumferential direction. The individual strain gauges 13, 14 are connected in the manner of a Wheatstone measuring bridge to provide the deformation of the metal strip as a sensor measurement signal. The measuring sensor 12 measures the deformation of the metal strip 11, which corresponds to the deformation of the vehicle wheel 1 in the region of the rim portion 3. The extent and direction of the deformation depend on the weight of the vehicle together with the respective load and, in the case of a moving vehicle, also on the dynamic load. Furthermore, there is the influence of the mounted tire as well as the influence of the tire's internal pressure and temperature.

[0035] As can be clearly seen in Figures 1 to 3, the metal strip 11 has a length that is much greater than the size of the measurement sensor 12 and a width that is somewhat greater. The entire metal strip, including the measurement sensor 12, is covered by a plastic cover 15 on the periphery of the measuring device 12. The entire underside 17 of the metal strip 11 and the underside 19 of the plastic cover that extends beyond it are fixed to the surface of the rim component 3 by an adhesive layer 16, which is shown diagrammatically in Figure 3. In the exemplary embodiment shown, the adhesive layer 16 has a thickness D K is the thickness D of the metal strip 11 S2 and 3, the metal strip 11 has a constant thickness D between its upper side 18 and its lower side 17 along its entire circumferential length. S However, it is quite possible that the thickness is only constant in the area where the measurement sensor or sensors are arranged.

[0036] Figure 4 shows a slight modification of the measuring device according to Figure 2. The main difference is that the measuring device 110 according to Figure 4 is provided with two measurement sensors 112A, 112B, which are arranged offset from one another in the circumferential direction on the metal strip 111 of the measuring device 110. Here, too, the entire metal strip 111 together with the two measurement sensors 112A, 112B is entirely covered by a plastic cover 115, and fastening to the vehicle wheel is carried out by adhesive connections on the underside of the plastic cover 115 and on the underside of the metal strip 111, respectively, as in the previous exemplary embodiment. When the measuring device 110 is provided with two measurement sensors 112A, 112B that are arranged offset from one another in the circumferential direction, the distance between the two measurement sensors 112A, 112B can be selected so that in the mounted state the angular distance between the two measurement sensors 112A, 112B is at least 20° in the circumferential direction, preferably even at least 22.5°. The overall length of the metal strip 111 within the measuring device 110 must be correspondingly long.

[0037] 5-7 show yet another alternative embodiment. As in the previous exemplary embodiment, the measurement is performed indirectly via a metal strip 211, which is fastened to the outside of the rim 203 of the vehicle wheel by an adhesive connection (not shown) and, in this respect, fully senses and transmits deformations of the rim. A measuring device 210 provided with a housing 218 is fastened to the metal strip 211, i.e., to two anchor nuts 219 circumferentially spaced apart from each other, as can be clearly seen in FIG. 6. Here, the measuring device 210 has a bending support 220, the two ends of which are fixed on the anchor nuts 219, offset from each other in the circumferential direction, by removable fastening screws 221. A strain gauge (not shown) is then fastened to the bending support 220. A power source and a transceiver can also be arranged in the housing 218 so that the measuring sensor 210 can be replaced with another measuring sensor if necessary. The anchor nuts can be made from the same material as the metal strip 211 and can be welded or brazed to the metal strip 211, but they can also be made in other ways, for example fastened to the metal strip 211 by an adhesive connection. The metal strip 211 can be provided with one or, as here, several recesses 222 between the two anchor nuts 219, the recesses 222 being preferably positioned symmetrically with respect to and between the two anchor nuts 219.

[0038] Here, too, the metal strip 211 extends in the circumferential direction beyond the anchor nut 219. The anchor nut 219 is arranged in a region of the metal strip 211 that has a first, larger width B1 transverse to the circumferential direction. The subsection 211A of the metal strip 211, in which the anchor nut 219 and the recess 222 are arranged, is followed by a narrowed subsection 211B, the width B2 of which is preferably equal to or less than 50% of the width B1 of the subsection 211A. The subsection 211B can extend over the remaining periphery of the rim part 203 (FIG. 5), thus providing a full circumferential arrangement of the metal strip 211.

[0039] FIG. 8 serves as an illustrative diagram of the rotation angle α between the position of the wheel contact area A, where the total wheel load L is supported on the ground, and the actual current position P of the sensor arrangement of the measurement sensor of the measuring device, which rotates with the vehicle wheel. At each position of the measurement sensor position P relative to the contact area A or each rotation angle α, the deformation of the rim section can be measured by a strain gauge and returned as a measurement signal to the evaluation device. This causes the measurement signal to follow a periodic path that depends on the angle α (or over time t, in the case of a moving vehicle), as shown in FIG. 9. FIG. 9 again reveals the dependency between the load-dependent part g(P)*L*c(α) and the non-load-dependent element e0 explained above, via which the deviations of the curves at different temperatures and tire pressures can be determined after conventional calibration. Reference is also made to the formulas explained in the introduction to the explanation.

[0040] 10-13 show a third alternative embodiment. A vehicle wheel is generally designated by reference numeral 301 and includes a disk portion 302 and a rim portion 303, as known per se. The rim portion 303 also includes two rim flanges 304, two rim shoulders 305, and a multi-stage rim well base 306, as known per se. The disk portion 303, shown only partially here, is provided with bolt holes 340 and vent holes 341, which may have different positions and configurations, as known per se to those skilled in the art. A measuring device array 350, comprising two identical measuring devices 310, is further arranged radially outward of the rim portion 303 of the vehicle wheel. The measuring device array 350, comprising the two independent measuring devices 310, is located at the transition of the rim well base 306 between the well base bottom 307 and one of the rim shoulders 305. The measurement device array 350 consists of two measurement devices 310, both of which have the same configuration and structure, and is shown in detail and schematic form in Figures 11 and 12. Each of the measurement devices 310 is symmetrically arranged in the valve hole 308 and includes a valve and a tire pressure monitoring system (RDKS) referenced 360. The tire pressure monitoring system 360 includes several elements, including a housing, a battery, and electronic circuitry (not shown) within the housing, which here also serves for detection, monitoring, and transmission of the sensor signals of each of the measurement devices 310 to a monitoring device on the vehicle, on which the wheels are mounted.

[0041] The construction principle of each of the measuring devices 310 can best be seen from FIGS. 12 and 13. Each of the measuring devices 310 comprises, on opposite peripheral edges, an outer first section constructed of a metal band strip 371 and a second section constructed of a metal plate strip 372. The metal band strip 371 and the metal plate strip 372 are fixed to each other, preferably by welding or soldering. The underside of the metal band strip 371 is fixed to the outside of the rim by an adhesive layer, referenced 381 in FIG. 13. The same adhesive layer is also used to fix the circumferentially outer part of the metal plate strip 372 to the outside of the rim. The metal plate strip 372 is thicker than the metal band strip 371 and also has a longer circumferential extension, while the widths of the metal plate strip 372 and the metal band strip 371 are identical. In FIG. 13, the dashed line 385 indicates the line where the metal plate strip 372 starts and the metal band strip 371 ends. The metal sheet strip 372 has a thickness-reducing step 375 on its bottom surface, and the adhesive layer 381 extends over substantially the entire extended length of the metal band strip 371, but only up to the vicinity of the thickness-reducing step 375 on the bottom surface of the metal sheet strip 372. Due to the thickness-reducing step 375, a gap exists between the inner periphery of the metal sheet strip 372 and the outer rim. Finally, the bending struts 320 are fixed between the inner ends of the metal sheet strips 372 facing each other. The bending struts 320 are formed by the central metal band strip 377 and have a smaller thickness and also a smaller width compared to the metal sheet strips 372.

[0042] The measurement sensor 312 preferably has a configuration very similar to that of the measurement sensor shown in FIG. 2 and described in connection with that embodiment, and therefore has a total of four strain gauges, of which two strain gauges 313 are oriented in the circumferential direction, i.e., in the direction of rotation of the vehicle wheel rotating around the wheel axis, and two strain gauges 314 are oriented transversely to the circumferential direction. The individual strain gauges 313, 314 are connected in the manner of a Wheatstone measurement bridge to form the bending strut 320 and provide the deformation of the metal band strip 377 used as the bending strut 320. The measurement sensor 312 measures the deformation of the central metal band strip 377 or the bending strut 320, respectively, between the respective sections of the metal band strip 371 and the metal tape strip 372, which is fixed to the rim by an adhesive connection, thus detecting both peripheral and transverse deformations. To detect both axial and circumferential deformations, it is sufficient to arrange the measurement sensor 312 on the bottom surface of the central metal band strip 377.

[0043] In a preferred embodiment, as shown in FIGS. 10 and 11 , two measurement devices 310 are installed symmetrically with respect to the valve hole and the tire pressure monitoring system, which is located above the valve inserted in the valve hole. The entire electronics of the tire pressure monitoring system, including the battery, can be used by connecting the measurement sensors 312 to the electronics, preferably with wiring. No additional connections are required between the individual measurement devices and the tire pressure monitoring system and their electronics. The length and position of each measurement device are preferably configured so that the two centers of each of the central metal band strips are offset by 40°. The centers of each of the central metal band strips 377 correspond to the center positions of the measurement sensors 312. Fixing each metal band strip of the measurement device to the outside of the rim by gluing is simple, and the same sensor can be used for any type of wheel and wheel size. The two measurement sensors of the measurement device array 350 easily avoid the risk of zero crossing. It is also possible to measure wheel loads even when the vehicle is stationary, even when the vehicle is unaware.

[0044] The measuring device does not need to be fixed to the wheel rim at the valve hole location, but may be used in a different location depending on the most deforming zone. The greater the deformation, the better the load estimation error of the measuring arrangement with the measuring device. By adding an additional gyroscope sensor, indirect vehicle speed measurement may also be realized.

[0045] Numerous variations will become apparent to those skilled in the art from the foregoing description and are intended to be included within the scope of the appended claims.

Claims

1. A vehicle wheel comprising: a rim portion (203) having a rim flange, a rim shoulder, and a rim well base for supporting a tire; a disc portion having a hub connection flange with bolt holes and a transition portion with ventilation holes, the disc portion connected to the rim portion for non-rotatably fastening the vehicle wheel to a vehicle; and a measurement device (110) fastened to the vehicle wheel so as to be co-rotatable, the measurement device having at least one measurement sensor for detecting forces acting on the vehicle wheel, and a transceiver coupled to the measurement sensor for transmitting load data detected by the measurement sensor to a component external to the vehicle wheel. a metal strip (111) is attached radially outside said rim portion (203), said at least one measurement sensor (112) being assigned to said metal strip; the metal strip has a lower side and an upper side and at least one subsection with a constant thickness in the circumferential direction between the lower side and the upper side, the underside of the metal strip is connected to the outside of the rim along the section by an adhesive connection, - the measuring device (110) comprises a bending strut (220) provided with the at least one measuring sensor, which strut is connected to the metal strip in the two fastening zones spaced apart from each other in the circumferential direction of the rim for local detection of deformations of the metal strip between the two fastening zones; and - said metal strip (211) has a length in the circumferential direction of said vehicle wheel that is greater than the distance between said two fastening zones; A vehicle wheel comprising:

2. 2. A vehicle wheel according to claim 1, characterized in that the fastening zone consists of two anchor pins or anchor nuts (219) circumferentially offset with respect to each other and fastened to the upper side of the metal strip.

3. 2. A vehicle wheel according to claim 1, characterized in that the metal strip (211) is partially provided with recesses (222) between the fastening zones, said recesses being mounted symmetrically relative to said fastening zones.

4. The metal strip may extend only partially over the periphery of the rim portion, or the metal strip may extend completely over the periphery of the rim portion, and the metal strip may have a different strip width (B １ , B ２ 2. A vehicle wheel according to claim 1, having at least two subsections (211A, 211B) with a axially extending axial groove.

5. 2. The vehicle wheel according to claim 1, characterized in that the measuring device (210) is provided with a housing (218) and an electric circuit which is arranged in the housing together with the transceiver, the bending strut (219) and the measuring sensor, and the measuring device is fastened to the fastening zone as a unit in a separable and replaceable manner.

6. 2. A vehicle wheel according to claim 1, characterized in that the metal strip (311) of one measuring device (310) comprises several sections, with thinner metal band strips constituting the outer sections of the periphery and thicker metal plate strips constituting the inner sections of the periphery, and the bending strut consists of a central metal band strip fixed between the inner ends of the metal plate strips facing each other.

7. 7. Vehicle wheel according to claim 6, characterized in that two measuring devices, each having a measuring sensor on its bending strut, are positioned offset from one another in the circumferential direction.

8. 2. A vehicle wheel according to claim 1, characterized in that the measurement sensor (12, 112, 312) is designed as a measuring surface with four strain gauges (13, 14, 313, 314), of which two strain gauges (13) are oriented in the circumferential direction and two further strain gauges (14) are oriented transversely to said circumferential direction, or the measurement sensor is connected by a cable connection to an electronic circuit, the transceiver and a power supply, which form components or additional parts of a tire pressure measuring device (TPMS) assigned to a vehicle valve.

9. 2. A vehicle wheel according to claim 1, characterized in that at least two measurement sensors (112A, 112B) distributed on the periphery of the rim portion are positioned offset from each other in the circumferential direction, the distance of the two measurement sensors relative to each other in the circumferential direction being at least 20°.

10. 1. A monitoring device for a vehicle having several vehicle wheels, the monitoring device comprising at least one vehicle wheel according to claim 1, provided with a metal strip (11; 111) by means of which a measuring device (10) having a measurement sensor (12) and a transceiver coupled to said measurement sensor are associated, and the monitoring device comprises an evaluation device for the measurement signals of said measurement sensor, characterized in that the monitoring device is designed and constructed in such a way that the dynamic load during driving operations can be determined from the measurement signals of the measurement sensors, and in that in order to determine the dynamic load by the evaluation device, a measurement signal amplitude between the measured maximum signal value and the measured minimum signal value within one revolution of the wheel is determined and compared with an amplitude value from a vehicle wheel calibration reference curve to determine a deviation factor.

11. A monitoring device for a vehicle having several vehicle wheels, the monitoring device comprising at least one vehicle wheel as claimed in claim 1, provided with a metal strip (11; 111) whereby a measuring device (10) having a measurement sensor (12) and a transceiver coupled to said measurement sensor is associated, and the monitoring device has an evaluation device for the measurement signals of said measurement sensor, characterized in that the monitoring device is designed and formed in such a way that the static load in the stationary state of the vehicle on the associated vehicle wheel can be determined from the measurement signals of the measurement sensor, and in order to determine the static load, a rotation angle between the sensor position and the wheel contact position is determined, and by means of the evaluation device the measured signal values ​​are compared with reference values ​​from a vehicle wheel calibration reference curve for the same rotation angle, and several vehicle wheel calibration reference curves for different temperatures and internal tire pressures are stored in the evaluation device.

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