SUPPORT LOAD MEASUREMENT

Description

[0001] The invention relates to a trailer support wheel with a measuring device and a method for the support load of a trailer support wheel with the features of the independent claims.

[0002] Trailer support wheels for the drawbar of an uncoupled vehicle trailer are known in various designs. The trailer support wheel can be rigid or length-adjustable and can have a rigid or movable, particularly spring-loaded, wheel bearing.

[0003] There are legal requirements for the height of the support load of the coupled vehicle trailer acting on a vehicle coupling of a towing vehicle, which can vary depending on the type of towing vehicle.

[0004] Measuring devices for recording this support load on the drawbar are known from practice, whereby this vertical support load also acts on a trailer support wheel that is extended with ground contact.

[0005] DE 203 13 356 U1 and EP 1 510 424 A2 disclose a measuring device mounted on the trailer support wheel that mechanically measures the load-dependent deflection of the spring-loaded wheel bearing and displays this value visually on a scale on the trailer support wheel. The scale values ​​indicate the support load value determined from the deflection using the spring characteristic curve. This measuring technology is inaccurate and sensitive to environmental influences such as corrosion, contamination, and the like.

[0006] DE 10 2004 058 829 A1 deals with a trailer support wheel and a pressure sensor on the support wheel, which is designed as a strain gauge and is arranged at the upper shaft end of the support wheel.

[0007] DE 699 25 904 T2 concerns a sensor for dynamic axle forces and moments on a motorcycle while driving.

[0008] DE 196 53 117 C1 addresses wheels for sports equipment, with a wheel body mounted on a non-rotatable axle and dynamometers arranged in the running surface of the wheel body and / or on an axle mount, and designed as piezo elements. They are used to measure ground contact and / or to determine the angle between the wheel's contact direction and the effective direction of travel during travel.

[0009] DD 279 062 A1 generally teaches a force measuring axis which has an optical system for force and strain measurement that is integrated into central openings of the force measuring axis.

[0010] EP 0 154 728 A1 relates to an industrial load cell which is inserted between machine parts and which has a deformation-detecting pin with blind holes at the ends and strain measuring elements inserted therein.

[0011] Document US 4 095 660 discloses a measuring device for measuring the load on a leaf spring of a truck.

[0012] The object of the present invention is to provide a better measuring technique for the support load of a trailer drawbar or a trailer support wheel.

[0013] The invention solves this problem with the features in the independent claims.

[0014] The claimed measuring technology, i.e. the measuring device and the measuring method for determining the said support load and the trailer support wheel equipped with the measuring technology as well as the vehicle trailer, have various advantages.

[0015] The measuring device is a standalone unit that can be installed on a trailer jockey wheel by the manufacturer as original equipment, but can also be retrofitted or converted to an existing trailer jockey wheel. The measuring device can also include a rotating wheel body and a wheel carrier. The trailer jockey wheel equipped with a measuring device can also be a standalone component. It can be installed on a vehicle trailer as original equipment or replaced or converted as a retrofit or conversion.

[0016] The claimed measuring technology, i.e., the measuring device and the measuring method, comprise a measuring means that can be mounted or is mounted on the trailer support wheel. The measuring means comprises an elongated wheel axle journal for the wheel body, on which a load-measuring element is arranged between the journal ends. The wheel axle journal is preferably formed in one piece. It consists of a resilient material, e.g., metal, in particular steel. The wheel axle journal can have an external contour profiled in the axial direction. The wheel axle journal can be formed, for example, as a cast or formed, preferably metallic, part.

[0017] The claimed measurement technology has the advantage that the vertical load can be measured at the point of force transmission from the wheel body to the wheel carrier and the trailer support wheel. The vehicle trailer is uncoupled from the towing vehicle and the trailer support wheel is lowered to the ground, with the vertical load (F) acting on the trailer support wheel. This is a particularly direct measurement method that is less susceptible to failure than previously known measurement technology. The claimed measurement technology offers higher and better load measurement accuracy.

[0018] The measured support load can be displayed to the operator, possibly in conjunction with a warning signal if a limit is exceeded. The operator can react appropriately, e.g., by changing the size and / or position or distribution of the trailer load. The measured support load can be displayed on the trailer support wheel. It can also be transmitted to remote receivers for display and, if necessary, processing of the measured values. The mass or total weight of the vehicle trailer can also be deduced from the support load measured on the trailer support wheel.

[0019] The load measuring element can be present individually or in multiple units. It can record load-dependent changes in the wheel axle journal. These can be changes in stress, deformation, or other types of journal changes. The load measuring element can be designed in different ways for this purpose. In a preferred embodiment, the load measuring element comprises a sensor that records force and / or deformation, e.g., a strain gauge. The load measuring element can be arranged at a suitable location on the wheel axle journal, e.g., on its casing. Other possible designs of the load measuring element include piezo sensors, capacitive sensors, or SAW sensors (surface acoustic wave sensors) for measuring force and / or strain.

[0020] The wheel axle journal can have a support area for the wheel body and at least one end support area for the wheel carrier, with a load-measuring element arranged on the wheel axle journal at an axial intermediate area between the support areas. The wheel axle journal can be designed for one-sided mounting or support on the wheel carrier. In this case, two support areas can result, with an intermediate area and the load element being assigned there.

[0021] In a preferred embodiment, the wheel axle journal is mounted on the wheel carrier at both front ends. It has a central support area for the wheel body and several, in particular two, end-side support areas for the wheel carrier. This can result in three support areas with two intermediate areas. A load-measuring element can be arranged on the wheel axle journal at each of these intermediate areas.

[0022] The intermediate region can be thinner than the axially adjacent support regions. The thinner intermediate region is more easily deformed and improves measurement accuracy. The preferably one-piece design of the wheel axle journal is also advantageous in this regard. The intermediate region can also have perforations forming axial and preferably parallel webs. In the installed position, the axial webs are located on the top and bottom of the wheel axle journal. The wheel axle journal can have a flat surface on at least one side of the intermediate region(s), in particular on the webs. A load measuring element can be arranged here. The flat surface can also be designed as a flattened area on an unperforated intermediate region. In the installed position, the flat surface is preferably aligned horizontally.

[0023] At the support areas, the wheel axle journal can be essentially cylindrical. The respective intermediate area does not need to be thinned. It can have essentially the same circumferential contour as the support areas. Such an intermediate area can optionally have a flattened portion. Alternatively, other shapes of the wheel axle journal and its outer contour, preferably profiled in the axial direction, are possible, e.g., a cuboid shape or a mixture of cuboid and cylindrical shapes.

[0024] A wheel bearing element can be arranged on the support area for the wheel body. This can be designed, for example, as a tubular bearing, particularly as a bearing sleeve. It provides a pivot bearing and, if necessary, guidance for the wheel body. The wheel axle journal can have a fixing device for securing it to the wheel carrier at one or both front end areas. The fixing device can be arranged on said support area. It can ensure that the wheel axle journal is non-rotatably received and supported on the wheel carrier.

[0025] The electrical or other recording of the load-dependent internal changes in the wheel axle journal enables a variety of ways of processing the measured data. The measuring device can have an evaluation unit that is or can be connected to the measuring device, in particular the load measuring element. The evaluation unit can evaluate the measured data, for example, electrically or electronically. The measuring device can also have a communication unit with which the measured data and / or the evaluation result can be communicated externally. Communication can be wired or wireless, in particular via radio, Bluetooth, Wi-Fi or the like. The measuring device can also include a power supply. This can be a separate power supply in the form of batteries, rechargeable batteries or the like. The power supply can be connectable to or connected to the other components of the measuring device.In another embodiment, the power supply can be designed as a connection to, for example, an electrical system of the vehicle trailer or in another way.

[0026] The measuring device can have a preferably mobile control unit and a display. The mobile control unit can be a remote control, which can also be used to start and stop the measuring process. The remote control can be, for example, a dedicated control device or an app for a smartphone, tablet or other universal portable computer. The app can, for example, generate a mask for displaying the measurement result and the support load on a monitor of the portable computer. Alternatively or additionally, a display can be on the dashboard of a towing vehicle. A display can also be arranged on the trailer support wheel. Via said communication unit, preferably wireless communication can take place with a mobile control unit or an app and a towing vehicle.

[0027] The measuring device can be arranged on a trailer support wheel in various ways. The arrangement of said components is possible, for example, on one or preferably several, in particular two, support arms of the wheel carrier. The support arm(s) can be aligned transversely or diagonally to a support shaft of the trailer support wheel and, if necessary, protrude away from it. The wheel body is arranged laterally offset from the support shaft. This is advantageous for a movable wheel bearing. The support arm(s) can alternatively be arranged flush with the support shaft.

[0028] A fork-shaped wheel carrier, for example, allows for a protected arrangement of the evaluation unit and / or the communication unit and / or the power supply on the inside of the wheel carrier's support arms. A fork-shaped wheel carrier is also advantageous for a movable wheel bearing, where the wheel body can deflect springily or, if necessary, be pivoted upwards to save space.

[0029] There are various options for arranging the wheel carrier with the wheel axle pivot and the wheel body on the trailer jockey wheel. The wheel carrier can be rigidly or flexibly mounted on the support shaft or on a length adjustment mechanism on the trailer jockey wheel. A spring-loaded, flexible arrangement of the wheel carrier is particularly advantageous. This improves comfort when moving the vehicle trailer with the trailer jockey wheel extended. Suspension also reduces the external loads acting on the measuring device during maneuvering. Furthermore, the measuring technology is independent of any spring-loaded wheel bearings, and their accuracy is not negatively affected by them.

[0030] The measuring device can be calibrated by the manufacturer and / or after installation on a trailer support wheel.

[0031] Further advantageous embodiments of the invention are specified in the subclaims.

[0032] The invention is illustrated schematically and by way of example in the drawings. In detail: Figure 1: A side view of a vehicle trailer in coupling position and a trailer support wheel with a measuring device for the support load, Figure 2: A perspective view of the trailer support wheel with the measuring device, Figure 3: A side view of the trailer support wheel of Figure 2 , Figure 4: a section through the trailer support wheel according to section line IV-IV of Figure 3 , Figure 5: a longitudinal section through the trailer support wheel according to section line VV of Figure 4 , Figure 6: an exploded view of the trailer support wheel of Figure 2, Figure 7: a sectional and perspective detailed view of the measuring device, Figure 8: an enlarged longitudinal section through a wheel axle pin of the measuring device and a wheel body, Figure 9: a perspective view of a deformed wheel axle pin and Figure 10: a representation of the force flow on the trailer support wheel extended with ground contact.

[0033] The invention relates to a trailer support wheel with a measuring device (2) and to a measuring method for the support load of a trailer support wheel (7). The invention further relates to the trailer support wheel (7) equipped with a measuring device (2) and to a vehicle trailer (1) equipped with the trailer support wheel (7) and the measuring device (2).

[0034] Figure 1shows a vehicle trailer (1) in side view and in the coupling position to an indicated towing vehicle. The vehicle trailer (1) is a roadworthy vehicle. It has a chassis (3) with a front drawbar (4) and a trailer coupling (6) arranged at the front end of the drawbar. The drawbar (4) is preferably a rigid drawbar. It can be designed as a tubular drawbar or as a V-drawbar. The trailer coupling (6) is designed, for example, as a ball-and-socket coupling. The chassis (3) has parallel longitudinal members and, if necessary, also cross members. An axle arrangement (5) is arranged on the chassis (3), which comprises one or more axles with trailer wheels on both sides. In Figure 1A single axle is shown. Alternatively, multiple axles are possible, e.g. in the form of a tandem axle. A body of any type is arranged on the chassis (3). A trailer battery or other energy storage device can also be arranged on the chassis (3) or elsewhere. The energy storage device can be charged from the towing vehicle's electrical system when the vehicle is towed, or from a socket when the vehicle is uncoupled. A trailer support wheel (7) is mounted on the drawbar (4) using a suitable fitting. For the Figure 1 In the trailer operation shown in the coupling position to a towing vehicle, the trailer support wheel (7) is raised. The lowered position with contact with a ground (34) is shown in dashed lines.

[0035] In the coupling position shown, the trailer coupling (6) rests on the vehicle coupling of the towing vehicle with a vertical support load or support force (F). The height of the support load (F) is limited by legal requirements. On the one hand, there is a limit for the maximum support load of the trailer coupling (6) and the trailer (1). Furthermore, there is a maximum support load of the motorized towing vehicle, which can vary depending on the type of towing vehicle or motor vehicle.

[0036] The support load (F) acts on the trailer coupling (6) when the drawbar (4) is coupled. When the trailer (1) is uncoupled from the towing vehicle and the trailer support wheel (7) is lowered with contact with the ground (4), the support load (F) acts on the trailer support wheel (7). Figure 10 illustrates the existing force flow through the trailer support wheel (7) from the contact point on the ground (34) to the mounting point on the drawbar (4).

[0037] The support wheel (7) is equipped with a measuring device (2) for the support load. The measuring device (2) can be installed as original equipment during production of the trailer support wheel (7). Alternatively, it can be retrofitted or converted to an existing trailer support wheel (7). Furthermore, an existing trailer support wheel of the vehicle trailer (1) can be exchanged for a trailer support wheel (7) according to the invention with a measuring device (2). The mounting fittings are usually standardized. They also allow the aforementioned height adjustment of the trailer support wheel (7).

[0038] The measuring device (2) comprises a measuring means (17) and a display (31) for the measured support load. The display (31) can be arranged on the trailer support wheel (7). Alternatively or additionally, it can be arranged on a mobile and preferably portable control unit (30).

[0039] The mobile control unit (30) can be a dedicated control device. Alternatively, the control unit (30) can be a universal portable computer from the consumer sector, e.g., a smartphone, a tablet, or the like. In this case, the measuring device (2) comprises an app that can be installed and stored on the control unit (30) and that generates a display (31) on its monitor, e.g., a touchscreen. This can, for example, be a mask for displaying the measured value of the support load reported by the measuring device (17).

[0040] The mobile control unit (30) can further include control means for controlling the measuring device (2), in particular for starting and stopping the otherwise preferably automatic measuring process. The relevant control technology can be arranged in the evaluation unit (27). The control means can also be generated by the app on the monitor of the universal portable computer.

[0041] The trailer support wheel (7) has a rotatable wheel body (8), a wheel carrier (9), and a support shaft (11). The support shaft (11) can be mounted on the drawbar (3) or at another suitable location on the vehicle trailer (1) via the mounting bracket and can be secured at least temporarily, e.g., by clamping. The support shaft (11) can be designed as a straight tube or in another way. The trailer support wheel (7) can have a length adjustment (12), which is formed, e.g., by a crank at the upper end of the shaft and by an axially adjustable adjusting body (13) with the interposition of a spindle drive or the like. The crank rotates, e.g., a gear spindle, which moves a spindle nut connected to the adjusting body (13) up and down. The adjusting body (13) is held and guided in the support shaft (11) in a rotationally fixed and axially adjustable manner. The adjusting body (13) can also be designed as a straight tube or in another way.

[0042] The wheel carrier (9) can be rigidly connected to the length adjustment (12), in particular to the adjusting body (13). In the absence of a length adjustment (12), the wheel carrier (9) can be rigidly connected to the support shaft (11).

[0043] In the Figures 2 to 10 Another embodiment of a movable connection of the wheel carrier (9) to the length adjustment (12) or the adjusting body (13) is shown. The wheel carrier (9) is connected via a pivot bearing (15) with a horizontal pivot axis (33) to a boom (14), which in turn is attached to the lower end of the adjusting body (13). In another embodiment not shown, the boom (14) can also be attached to the support shaft (11).

[0044] The wheel carrier (9) has at least one, preferably several, in particular two, support arms (10). The wheel carrier (9) and the support arm(s) (10) extend transversely or obliquely to the support shaft (11). They laterally space the wheel body (8) from the support shaft (11). The extension arm (14) also extends transversely or obliquely to the support shaft (11) or to the adjusting body (13).

[0045] In the embodiment shown, the wheel carrier (9) has a fork-like shape with two parallel support arms (10) projecting forward and spaced apart from one another. At the rear end, the wheel carrier (9) engages with a support projection between the boom (14) into the support shaft (11) and the internal adjusting body (13). The support projection is connected to and supported by a spring (16) located in the adjusting body (13). Under the action of the support load (F) in the extended state, the wheel carrier (9) and the wheel body (8) can pivot upwards via the pivot bearing (15), with the downward pivoting movement being resiliently supported on the support projection by the spring (16). The spring (16) presses the lifted and relieved wheel body (8) back into its original position.

[0046] The measuring device (17) is mountable or mounted on the trailer support wheel (7). The measuring device (17) comprises an elongated, preferably one-piece wheel axle journal (18) for the rotatable wheel body (8), wherein a load measuring element (23) is arranged on the wheel axle journal (18) in the region between the front journal ends. The wheel axle journal (18) preferably has an outer contour profiled in its axial direction, wherein the journal region with the load measuring element (23) has a different outer contour than other journal regions, in particular than the journal ends. The load measuring element (23) can be present individually or in multiples. Each can consist of one or more parts. In the embodiments shown, the load measuring element (23) is arranged on the casing of the wheel axle journal (16). The wheel axle journal (18) is made, for example, of metal, in particular steel. It is designed, for example, as a cast and / or formed part.

[0047] The load-measuring element (23) preferably comprises a force and / or deformation-sensing sensor (24). This sensor has, for example, an electrical, optical, or laser-structured strain gauge. Furthermore, the sensor (24) can comprise an optical detection unit, e.g., a laser measurement unit.

[0048] The measuring device (2) comprises an evaluation unit (27) that is connected to the load measuring element (23) for signaling and, if necessary, power. The evaluation unit (27) determines the support load or support force (F) acting on the trailer support wheel (7) from the measured values ​​reported by the load measuring element (23) based on a previous calibration.

[0049] The measuring device (2) can further comprise a communication unit (28) and / or a power supply (29). These can be connected to the evaluation unit (27). The power supply (29) is designed, for example, as an electrical battery arrangement or as a rechargeable electrical accumulator. It supplies the components of the measuring device (2) with electrical energy. The communication unit (28) can establish a communication connection between the evaluation unit (27) and the display (31) and, if necessary, another receiver. The communication connection can be wired or, preferably, wireless. In particular, a communication connection can be established with the mobile control unit (30), e.g., via radio, Bluetooth, infrared light, or the like.

[0050] The measuring device (17) and the wheel axle pin (18) are shown in the sectional views of Figure 7 and 8 shown enlarged. Figure 9shows the wheel axle journal (18) in a deformed state under the influence of the support load (F).

[0051] The preferably straight wheel axle journal (18) has a central support area (19) for the wheel body (8) and two end support areas (20) for the wheel carrier (9) or the carrier arms (10). The wheel body (8) is rotatably received, guided, and supported on the wheel axle journal (18) in the hub area at the central support area (19), with the interposition of a wheel bearing element (25), e.g. a bearing sleeve. The wheel axle journal (18) is received and supported on the wheel carrier (9) and its carrier arms (10) at the end support areas (20). This reception and support are preferably rotationally fixed. The wheel axle journal (18) can be positioned and fixed on the carrier arms (10) by means of a fixing device (26).

[0052] A load-measuring element (23) is arranged on the wheel axle journal (18) at an axial intermediate region (21) between the support regions (19, 20). In the illustrated embodiment with the wheel journal mounts on both sides, for example, there are two intermediate regions (21), each with a load element (23).

[0053] In another embodiment not shown, a wheel axle journal (18) can be received and supported on one side of the wheel carrier (9) and on a carrier arm (10). In this case, there are, for example, two support areas (19, 20) and a single intermediate area (21) with a load-measuring element (23).

[0054] The respective intermediate region (21) is, for example, thinner than the axially adjoining support regions (19, 20). The respective intermediate region (21) can also have a perforation through which axial webs (22) are formed, which are preferably aligned parallel to one another. The perforation and the axial webs (22) are aligned horizontally in the installed position of the wheel axle journal (18). The respective intermediate region (21) has, at least on one side, a flat surface on which a load measuring element (23) can be arranged and fastened in a suitable manner. In the embodiment shown, the flat surface is present on at least one side of at least one of the webs (22). For example, the flat surface is arranged on the upper side of the upper web (22), which faces upwards in the installed position.

[0055] Otherwise, the wheel axle pin (18) preferably has a cylindrical shape at the support areas (19, 20). The side surfaces of the respective intermediate area (21) can also be rounded. The front support areas (20) can also have a hole or groove for a rotationally fixed mounting on the respective support arm (10) and for the fixing means (26).

[0056] When the trailer support wheel (7) is extended with ground contact, the support load (F) or the reaction force on the wheel body (8) acts at the point of contact with the ground (34). The force is transmitted via the support surface (19) to the wheel axle journal (18), which is held and supported on the other hand by the front support area(s) (20) on the wheel carrier (9). Under the action of this force, the wheel axle journal (18) changes. The change manifests itself, for example, in a change in stress and possibly also in a deformation of the wheel axle journal (18), which can be recorded using the load measuring element (23). A deformation and change in stress is particularly evident in the respective tapered intermediate area (21), in particular in the webs (22) thinned by the perforation.

[0057] The respective sensor (24), particularly strain gauges, can accurately detect such stress changes and deformations. This type of measurement technology is particularly suitable for vehicle trailers (1) with a relatively low permissible vertical load (F), e.g., approximately 1,000 N.

[0058] How Figures 6 to 8 As illustrated, the evaluation unit (27), the communication unit (28), and the power supply (29) are arranged on the inside of the support arms (10). They can extend laterally into the wheel body (8). For this purpose, the wheel body (8) can have a wide tread and a recessed rim with a thin central rim web.

[0059] How Figure 6 and 7 As illustrated, the wheel axis (32) of the wheel axle journal (18) and the wheel body (8), as well as the pivot axis (33) of the pivot bearing (15), can be aligned parallel. They can extend horizontally in the installed position.

[0060] Various modifications to the embodiments shown and described are possible. In particular, other designs and measuring methods of the load measuring element (22) are possible. The load measuring element (2) is preferably arranged directly on the wheel axle journal (18). Alternatively, it can be arranged at a short distance from the wheel axle journal (18). It can detect journal changes under load, e.g., deformations, stress changes, or the like, in a contact-based or non-contact manner, e.g., optically, capacitively, inductively, or the like. Such journal changes can also lead to a detectable change in the surface properties of the wheel axle journal (18).

[0061] Alternatively or in addition to the spring-loaded wheel bearing shown, a pivoting wheel bearing is also possible. This causes the wheel body (8) to pivot automatically upward when the adjusting body (13) is raised over a stop or the like. This allows ground clearance to be gained. Furthermore, the features of the previously described embodiments and the mentioned variants can be combined with one another in any desired manner within the scope of the claims. LIST OF REFERENCE SYMBOLS

[0062] 1Vehicle trailer 2Measuring device for support load 3Chassis 4Drawbar 5Axle arrangement 6Trailer coupling 7Trailer support wheel 8Wheel body 9Wheel carrier 10Carrier arm 11Support shaft 12Length adjustment 13Adjusting body, adjusting tube 14Boom 15Pivot bearing 16Spring 17Measuring device 18Wheel axle journal 19Support area 20Support area 21Intermediate area, journal area thinned 22Web 23Load measuring element 24Strain gauge 25Wheel bearing element, bearing bush 26Fastening device 27Evaluation unit 28Communication unit 29Power supply 30Control unit 31Display 32Wheel axle 33Pivot axle 34Subsurface

Claims

1. Trailer support wheel having a measuring device (2) for the tongue load acting on the trailer support wheel (7), wherein the trailer support wheel (7) has a rotatable wheel body (8) and a wheel carrier (9), characterized in that the measuring device (2) has a measuring means (17) mounted on the trailer support wheel (7), wherein the measuring means (17) comprises an elongate wheel axle journal (18) for the wheel body (8), on which a load measuring element (23) is arranged between the journal ends.

2. Trailer support wheel according to Claim 1, characterized in that the load measuring element (23) is arranged on the casing of the wheel axle journal (18) and the load measuring element (23) preferably comprises a force- and / or deformation-recording sensor (24), in particular a strain gauge.

3. Trailer support wheel according to Claim 1 or 2, characterized in that the wheel axle journal (18) has a support region (19) for the wheel body (8) and at least one end-side support region (20) for the wheel carrier (9), wherein a load measuring element (23) is arranged on the wheel axle journal (18) at an axial intermediate region (21) between the support regions (19, 20).

4. Trailer support wheel according to Claim 3, characterized in that the intermediate region (21) is flattened and / or thinned in relation to the adjoining support regions (19, 20), wherein preferably the intermediate region (21) is perforated so as to form preferably parallel axial webs (22).

5. Trailer support wheel according to any of Claims 1 to 4, characterized in that the wheel carrier (9) has at least one carrier arm (10), which receives the wheel axle journal (18) at an end-side support region (20), wherein preferably the wheel axle journal (18) is rigidly received on the carrier arm(s) (10) and mounted in a rotationally fixed manner using a fixing means (26).

6. Trailer support wheel according to Claim 3, 4 or 5, characterized in that the wheel body (8) is arranged rotatably on the support region (19) of the wheel axle journal (18) using a wheel bearing element (25).

7. Trailer support wheel according to any of Claims 1 to 6, characterized in that that the measuring device (2) has an evaluation unit (27), which is connected to the measuring means (17), and preferably a communication unit (28) and preferably a power supply (29), wherein preferably the evaluation unit (27) and / or the communication unit (28) and / or the power supply (29) are / is arranged on the wheel carrier (9).

8. Trailer support wheel according to any of Claims 1 to 7, characterized in that the measuring device (2) has a preferably mobile operating unit (30) and a display (31).

9. Trailer support wheel according to any of Claims 1 to 8, characterized in that the wheel carrier (9) is rigidly or movably, in particular resiliently deflectingly movably, mounted on a support shaft (11) or on a length adjustment means (12) of the trailer support wheel (7), wherein preferably the wheel carrier (9) is oriented transversely or obliquely in relation to the support shaft (11).

10. Trailer support wheel according to Claim 9, characterized in that the wheel carrier (9) is rotatably mounted via a pivot bearing (15) on a boom (14) connected to the support shaft (11) or the length adjustment means (12) and is supported on a spring (16) on the support shaft (11) or on the length adjustment means (12).

11. Vehicle trailer comprising a chassis (3), an axle arrangement (5) with trailer wheels, a drawbar (4), a trailer coupling (6) at the end of the drawbar and a trailer support wheel (7) having a measuring device (2) for the tongue load acting on the trailer support wheel (7), wherein the trailer support wheel (7) has a rotatable wheel body (8) and a wheel carrier (9), characterized in that the trailer support wheel (7) having the measuring device (2) is designed according to any of Claims 1 to 10.

12. Method for determining a tongue load of a trailer support wheel (7) having a measuring device (2), wherein the trailer support wheel (7) is equipped with a rotatable wheel body (8) and with a wheel carrier (9) and the measuring device (2) has a measuring means (17) mountable or mounted on the trailer support wheel (7), characterized in that that the tongue load is determined with a measuring means (17) which comprises an elongate wheel axle journal (18) for the wheel body (8), on which a load measuring element (23) is arranged between the journal ends.

13. Method according to Claim 12, characterized in that the measurement data from the measuring means (17) is evaluated, e.g. electrically or electronically, using a connected evaluation unit (27), wherein preferably the measuring device (2) preferably wirelessly communicates the measurement data from the measuring means (17) and / or an evaluation result from the evaluation unit (27) by means of a communication unit (28) to the outside.

14. Method according to Claim 12 or 13, characterized in that the measuring device (2) is operated with a preferably mobile operating unit (30), which has a display (31), wherein the measuring process is started and terminated preferably with the mobile operating unit (30).

15. Method according to Claim 13 or 14, characterized in that the measuring device (2) is operated using a dedicated operating device or using an app for a smartphone, tablet or another universal portable computer, wherein preferably the app generates a mask for the display of the measurement result and the tongue load on a monitor of the portable computer and / or a display of the measurement result and the tongue load on a dashboard of a towing vehicle.