Coupling device for combination

Abstract

The invention relates to a coupling device for a vehicle combination extending along a longitudinal axis, comprising a wear detection device comprising: a wear element arranged in and / or on the coupling device aligned perpendicular to the longitudinal axis, the wear element is arranged around the coupling device in the circumferential direction in such a way that wear of the coupling device perpendicular to the longitudinal axis equalizes or solely wears the wear element, the wear element being arranged around the coupling device in the circumferential direction, a cavity extending in the circumferential direction in a manner corresponding to the wear element, the cavity being sealed in a fluid-tight manner by the wear element, and a pressure sensor for detecting the pressure of the fluid in the cavity wherein the wear element is dimensioned perpendicular to the longitudinal axis in such a way that the fluid can escape through the wear-induced through-opening of the wear element when a wear limit of the coupling device is reached at this point of the coupling device.

Description

TECHNICAL FIELD

[0001] The invention relates to a coupling device for a combination, and in particular to a kingpin for a semitrailer of a semitrailer vehicle, and to a coupling bolt for a towing vehicle of a road train. BACKGROUND

[0002] Today, various types of motor vehicles are used as road vehicles for transporting goods. This also includes those combinations with a self-propelled vehicle with a drive as a towing vehicle and at least one towed vehicle. The combination can also be described as a vehicle combination with a vehicle located in the front in the towing, travel or movement direction and a vehicle located in the rear in the towing, travel or movement direction. If the towing vehicle unit can tow a semitrailer, the combination can be referred to as a tractor trailer, or colloquially as a tractor unit. If the truck can tow a trailer, the combination can be referred to as a road train.

[0003] The tractor trailer is therefore a combination of a tractor unit, which can also be referred to as a tractor, and a semitrailer, which can also be referred to as a semi or trailer. The tractor unit is a short truck without a loading area, the frame or chassis of which instead has a drawbar coupling to receive a corresponding fastening of the semitrailer. The semitrailer is a relatively long trailer without a front axle, the front region of which, viewed in the direction of travel, is located above the drawbar coupling of the frame of the tractor unit and is held in place rotatably by the drawbar coupling. The rotatable connection between the tractor unit and the semitrailer can be implemented by means of a bolt, which is referred to as a drawbar kingpin, kingbolt or kingpin, as a fastening for the semitrailer, which is held by the drawbar coupling. For this purpose, the drawbar kingpin, which is cylindrical and rotationally symmetrical, is fixed in the front region of the frame and points downwards.

[0004] In order to couple or hitch the semitrailer to the tractor unit, the drawbar coupling is opened backwards and the tractor unit is driven backwards towards the semitrailer positioned on its drawbar support, so that the frame of the tractor unit with the drawbar coupling slides under the front region of the frame of the semitrailer and the drawbar kingpin enters its interior through the opening in the drawbar coupling. Then, the tractor unit is stopped and the opening in the drawbar coupling is closed and locked. The combination is ready for driving. Uncoupling or unhooking is carried out in reverse.

[0005] Thus, the fixed drawbar kingpin of the semitrailer not only allows a mating engagement of the closed drawbar coupling of the towing vehicle unit against the direction of travel or traction, but also allows a rotational relative movement between the semitrailer and the towing vehicle unit, so that the semitrailer can follow the movements of the towing vehicle unit even when turning. The rotatable connection between the drawbar coupling of the towing vehicle unit and the drawbar kingpin of the semitrailer can also be used to supply the semitrailer with electrical power and hydraulic pressure from the towing vehicle unit, as described in DE 20 2007 014 589 U1.

[0006] Due to these relative movements of the drawbar kingpin and the drawbar coupling to each other, during operation of the towing trailer, at least material wear of the drawbar kingpin occurs at the locations where the drawbar kingpin is in contact with or rubs against the drawbar coupling. This wear or this abrasion of the drawbar kingpin reduces its material thickness and accordingly weakens the function of the drawbar kingpin as a transmission element in the force flow between the towing vehicle unit and the semitrailer. This can lead to a tear of the drawbar kingpin.

[0007] Therefore, for the road safety of the towing trailer, it is necessary to regularly check the wear of the drawbar kingpin, for example at certain intervals, for example every half year or depending on the use of the towing trailer, for example depending on the driven kilometers. So far, this is done manually, i.e. by personnel who use mechanical test gauges or templates to measure the dimensions of the drawbar kingpin at certain specified points in order to determine whether the measured dimensions still meet the corresponding specifications, i.e. whether the drawbar kingpin has been excessively worn and needs to be replaced.

[0008] The disadvantage of this is that the assessment of the permissible wear or impermissible wear of the drawbar kingpin is made by specific personnel and thus there is a certain uncertainty, since the assessment can also depend on the concentration of the personnel and / or on the experience of the personnel. This can lead to the fact that excessively worn drawbar kingpins are still used, which can endanger the road safety of the towing trailer. This can also lead to the fact that still usable drawbar kingpins are replaced too early, which can lead to additional effort, additional costs and / or unnecessary downtime of the towing trailer.

[0009] Another disadvantage is that the wear of the drawbar kingpin can occur in very different ways and thus, within the permissible time interval or kilometer interval between two wear tests, an unacceptably high degree of wear can already have been reached, which cannot be detected at that time. This also endangers the road safety of the towing trailer.

[0010] The same applies to combinations in the form of road trains or towing vehicles and trailers. That is, in order to enable a towing vehicle to tow a trailer, the towing vehicle and the trailer need to be connected in a force-transmitting and detachable manner. Such towing vehicles can be, for example, passenger cars (personal vehicles), trucks (cargo vehicles), buses, construction machinery, forestry or agricultural vehicles, military vehicles or any other land vehicle, in particular any other road vehicle or off-road vehicle. Such towing vehicles can move or be driven by means of their own drive, i.e. they can be vehicles with their own drive. The towing vehicle can move by itself or pull at least one trailer behind it which is a vehicle without its own drive. The trailer is usually used for transporting goods and can be, for example, a personal motor vehicle trailer, a cargo motor vehicle trailer, a house trailer, a horse transport trailer, a boat transport trailer, etc. The trailer has at least one wheel axle with wheels and usually at least two wheel axles with wheels. The trailer can also be designed for private, sports or commercial use, for example in the freight forwarding industry, the construction industry, the agricultural industry, etc.

[0011] The implementation of the detachable connection between the towing vehicle and the trailer is usually carried out with the use of so-called trailer coupling devices for attaching the trailer to the towing vehicle, which are designed as a system with at least two components and have coupling equipment on the towing vehicle and on the trailer, which are each held there and can be detachably connected to each other. In this way, several trailers can also be detachably connected to each other.

[0012] Various types of trailer coupling devices are known, such as bolt trailer coupling devices and jaw trailer coupling devices or bolt coupling systems and jaw coupling systems, in which a shaft or tow bar extends from the trailer to the towing vehicle and has at the end a hook as a through opening in the vertical direction, which can also be referred to as a towing hook or coupling hook. At the opposite end, the shaft is designed, for example, as a flange and is fixedly fastened to the trailer frame by means of a screw. On the towing vehicle side, in the case of a bolt coupling device, a fastening piece is fixedly attached to the frame of the towing vehicle, which has two surfaces in the vertical direction, each with a through opening in the vertical direction. The two through openings are aligned with each other. The towing hook of the trailer can be accommodated between the two surfaces of the fastening piece of the towing vehicle. All three through holes can be connected to each other in the vertical direction by means of a bolt, also referred to as a coupling bolt, which can rest on the upper surface by means of a thickening and be fixed at the lower end. This can be done in a similar way to a jaw coupling device or a jaw coupling system.

[0013] In the case of such trailer coupling devices, for example between the inner diameter of the draw hook of the trailer drawbar and the outer diameter of the coupling bolt of the towing vehicle, a certain distance of a few millimeters must exist in order to be able to fully realize the corresponding form-locked connection. This results in a play, in particular in the longitudinal direction as the basic direction of travel, movement or traction, which is necessary for the connection or coupling, but which allows a certain relative movement between the towing vehicle and the trailer or between the coupling bolt and the draw hook in the direction of travel, movement or traction substantially during travel.

[0014] The disadvantage of this play between the coupling pin and the draw hook when driving is that the draw hook and the coupling pin can rub against each other and / or collide with each other, which can lead to abrasion or wear on these parts due to the forces present. This mechanical wear can not only reduce the material thickness of the coupling bolt over time and thus weaken the coupling bolt as a transmission element in the power flow between the trailer and the towing vehicle, but can also gradually enlarge the play, which can then cause greater relative movements and produce stronger forces with increasing mechanical wear.

[0015] Therefore, in order to road safety of the road train, it is also necessary to regularly check the wear of the coupling bolt of the towing vehicle, as previously described with regard to the towed trailer. The disadvantages of such previously known controls described above with regard to the towed trailer also apply to the road train.

[0016] The applicant is therefore known from WO 2022 / 218798 A1 a fifth wheel kingpin for a semitrailer of a towed trailer, which extends essentially along a longitudinal axis. The fifth wheel kingpin comprises at least one wear detection device, which is arranged in the fifth wheel kingpin aligned perpendicularly to the longitudinal axis in such a way that a wear of the fifth wheel kingpin perpendicularly to the longitudinal axis can be detected visually and / or by means of a sensor. The wear detection device comprises at least one specific wear element, which at this point is subjected to the wear of the fifth wheel kingpin in the same way as the fifth wheel kingpin itself.

[0017] The applicant is also known from WO 2022 / 218799 A1 a coupling bolt for a towing vehicle of a vehicle combination, which extends essentially along a longitudinal axis. The coupling bolt comprises at least one wear detection device, which is arranged in the coupling bolt aligned perpendicularly to the longitudinal axis in such a way that a wear of the coupling bolt perpendicularly to the longitudinal axis can be detected visually and / or by means of a sensor. The wear detection device comprises at least one specific wear element, which at this point is subjected to the wear of the coupling bolt in the same way as the coupling bolt itself.

[0018] A disadvantage of the wear detection device used in WO 2022 / 218798 A1 and WO 2022 / 218799 A1 is that the radially aligned wear elements of the wear detection device can only detect wear at specific points. This can also be done diametrically opposite with the aid of a second wear element in the case of a wear detection device that extends linearly through the drawbar kingpin or through the coupling bolt. However, this can not be meaningful for wear at other points on the drawbar kingpin or coupling bolt in the circumferential direction. Drawbar kingpins and coupling bolts can also be referred to collectively or inclusively as coupling devices.

[0019] To this end, a plurality of wear elements of this type can be used in the horizontal plane or along the longitudinal axis only slightly offset from one another in order to be able to detect wear of the drawbar kingpin or coupling bolt in the circumferential direction at more than just one point or more than just two diametrically opposite points on the drawbar kingpin or coupling bolt. However, as the number of wear elements increases, this will result in an increasing weakening of the stability of the drawbar kingpin or coupling bolt, since an opening or through-opening into the interior of the drawbar kingpin or coupling bolt must be provided for each wear element. This can result in a significant reduction in the stability of the drawbar kingpin or coupling bolt, so that such a wear detection device can not be permissible. Furthermore, only specific points of the drawbar kingpin or coupling bolt in the circumferential direction will continue to be covered and monitored for wear, which will always result in a gap between two immediately adjacent wear elements in the circumferential direction, i.e. the wear monitoring in the circumferential direction will always be incomplete. SUMMARY

[0020] It is an object of the present application to provide a coupling device for a combination, and in particular a drawbar kingpin of a semitrailer of a towing vehicle and / or a coupling bolt of a towing vehicle of a road train of the type described above, so that the checking of the wear of the coupling device or kingpin and / or coupling bolt can be simplified and / or improved. In particular, this should be possible as seamlessly or continuously as possible in the circumferential direction. In particular, this should be as simple, reliable, space-saving, independent of personnel and / or individual as possible. In any case, in particular the road safety of the combination and in particular of the towing vehicle or road train should be improved or increased thereby. At least an alternative to a known option for checking the wear of the coupling device for a combination or drawbar kingpin and / or coupling bolt should be created.

[0021] The present application therefore relates to a coupling device for a vehicle combination, preferably for a fifth wheel kingpin of a semitrailer or for a coupling bolt of a road train, which coupling device extends essentially along a longitudinal axis. Therein, the coupling device denotes a bolt-like, rotationally symmetrical and generally metallic protrusion, which protrusion preferably extends vertically downwards in the vertical direction as a fifth wheel kingpin from the underside of the chassis of the semitrailer or as a coupling bolt of the side of the road train, as described above. The longitudinal axis of the coupling device, which is the rotationally symmetrical axis of the coupling device, coincides with an axis in the vertical direction in Cartesian coordinates, i.e. with the direction of gravity, which extends perpendicular to the horizontal plane.

[0022] The coupling device comprises at least one wear detection device, which is arranged in the coupling device aligned perpendicular to the longitudinal axis in such a way that the wear of the coupling device perpendicular to the longitudinal axis can be detected visually and / or by means of a sensor.

[0023] According to the application, the wear detection device comprises:

[0024] at least one wear element, which is arranged in and / or on the coupling device aligned perpendicular to the longitudinal axis in such a way that the wear of the coupling device perpendicular to the longitudinal axis wears the wear element equally or uniquely,

[0025] wherein the wear element is arranged at least partially, preferably completely, around the coupling device in the circumferential direction,

[0026] at least one cavity, which extends in the circumferential direction in a manner corresponding to the wear element, wherein the cavity is sealed in a fluid-tight manner by the wear element, preferably perpendicular to the longitudinal axis, and

[0027] at least one pressure sensor, which is designed to detect the pressure of the fluid in the cavity,

[0028] wherein the wear element is dimensioned perpendicular to the longitudinal axis in such a way that, when the wear limit of the coupling device is reached at this point of the coupling device, the fluid can escape through the through-opening of the wear element caused by the wear.

[0029] In other words, on the one hand, the arrangement of the at least one wear element of the wear detection device within the contour or the material of the coupling device, which can preferably be a fifth wheel kingpin for a semitrailer of a towing vehicle or a coupling bolt for a towing vehicle of a road train, is such that both the material of the coupling device and the material of the wear element are reduced in their radial extent during operation as described above as a result of the abrasion or wear occurring on the components of the coupling device. On the other hand, the at least one wear element of the wear detection device can be designed and arranged on the contour or the material of the coupling device in such a way that the wear of the coupling device perpendicular to the longitudinal axis uniquely wears the wear element, since the wear element can uniquely come into contact with the counterpart of the coupling to another vehicle, i.e. the coupling device does not otherwise come into contact with the counterpart of the coupling to another vehicle perpendicular to the longitudinal axis, or at least not in such a way that this contact can cause wear.

[0030] To this end, the at least one wear element can be arranged in and / or on the coupling device precisely radially or perpendicular to the longitudinal axis or at least inclined to the longitudinal axis in such a way that the abrasion or wear can also or only reduce the wear element from the outside.

[0031] The application is based on the finding that by designing a part of the coupling device as a wear element or as having a wear element, the extent of the abrasion or wear of the coupling device at this point can be able to be visually recognized from the outside and / or able to be detected by a sensor. In any case, the condition of the wear element can be more easily detected or monitored in this way than was previously possible by regular manual inspection of the coupling device, such as in particular the fifth wheel kingpin and the coupling bolt itself as described above. This can reduce the effort for checking the extent of wear of the coupling device and accordingly also the costs of this check. This can also improve the reliability of the results of the check, which on the one hand improves the road safety of the combination and on the other hand can prevent the premature or unnecessary replacement of a coupling device that is still usable. Arranging the wear element inside the coupling device can keep the effort and in particular the required installation space to a minimum. In particular, the extent of wear of the coupling device can be checked or monitored continuously or more frequently than was previously known, which can improve the road safety of the combination and the service life of the coupling device.

[0032] According to the application, as long as the wear of the coupling device and thus the wear of the wear element at this point of the coupling device has a permissible level, the wear element and thus the coupling device at this point of the coupling device can be detected at least partially and preferably completely in the circumferential direction by the wear element fluid-tightly closing a cavity containing a fluid under overpressure, such as in particular air under overpressure of for example 6 to 8 bar, in that the wall thickness of the wear element remains sufficient to fluid-tightly enclose the fluid under overpressure and thus to maintain its overpressure. If, however, the wear limit is reached, the wear element is penetrated and the fluid can escape to the outside, i.e. to the outside of the cavity, due to its overpressure. Thus, at the moment or time at which the wear limit of the coupling device is reached, the overpressure of the fluid enclosed in the cavity is lost. At least these two states can be distinguished by means of the pressure of the fluid in the cavity detected by the sensor.

[0033] Due to the combination of the cavity at least partially formed in the circumferential direction and the wear element, the wear of the coupling device can be detected completely and seamlessly or steplessly in the circumferential direction to this extent or along this extent, since the wear element according to the application extends correspondingly far and continuously in the circumferential direction. Thus, an impermissible high wear can penetrate the wear element at any point along the circumferential direction and cause a loss of pressure of the fluid, which can then be detected, so that a complete and seamless or stepless wear detection of the coupling device in the circumferential direction can be achieved. By using a plurality of combinations of cavities and wear elements offset from one another along the longitudinal axis, this can be done along the longitudinal axis at a plurality of points or in a plurality of regions of the coupling device.

[0034] In any case, this can be achieved completely in the circumferential direction in a seamless or stepless manner by providing the combination of cavity and wear element in the shape of a closed ring in the circumferential direction. In this case, the wear element can be provided as a bushing which can be pushed onto the coupling device in the desired position. To this end, the coupling device as a traction seat kingpin can be designed in two parts, if necessary, in order to be able to position the bushing in a detached state. The two kingpin parts can be connected by means of a threaded connection or a screw connection.

[0035] In any case, both cases can be detected or distinguished by the pressure sensor, regardless of whether an overpressure is present in the cavity or not. To this end, the pressure sensor can continuously detect a pressure measurement as information of the pressure of the fluid in the cavity, which can then be evaluated by the pressure sensor itself and / or externally to the pressure sensor, for example by a separate electronic element such as a control unit of the coupling device or by a control unit external to the coupling device, etc., in order to at least determine whether an overpressure of the fluid is still present and whether the wear element thus ensures the tightness of the cavity, from which it can be concluded that the permissible wear level of the wear element, and thus also of the coupling device at this point on the coupling device, can be concluded.

[0036] In another case, based on the pressure value detected by the sensor as information of the pressure of the fluid in the cavity, if the pressure is below a predetermined limit value or corresponds to the ambient pressure, it can be concluded that the wear element is leaking, which can be attributed to an impermissible high wear of the coupling device at this point, which has penetrated the wear element and thus has connected the cavity to the environment in a fluid-conducting manner.

[0037] This can also be achieved by means of a pressure switch as a simple pressure sensor, which can be switched from one state to another when the pressure of the fluid drops due to a leak in the wear element.

[0038] In any case, the value detected by the sensor, preferably by the pressure sensor, can thus be converted into a pressure value, or a value representing the state of the pressure switch as a pressure sensor can be transmitted or sent from the pressure sensor to the outside of the coupling device, which can preferably be done in a wireless manner in order to avoid wiring work. Alternatively or additionally, the pressure sensor itself can evaluate the detected pressure value in order to determine whether the said pressure limit value is met (in accordance with which the current wear would be considered permissible) or whether the said pressure limit value is too low (in accordance with which the current wear would be considered impermissible); see the two states of the pressure sensor as a pressure switch. This evaluation result can then be communicated externally in order to carry out a corresponding evaluation effort in terms of the pressure sensor or the coupling device, for example in terms of a separate control unit of the coupling device, which is connected to the pressure sensor, and thus avoid implementing the respective evaluation externally to the coupling device.

[0039] This work can advantageously make the results of the wear monitoring according to the application available to a control unit outside the coupling device, such as an engine control unit of the combined vehicle, such as in particular the engine control unit of the semitrailer and / or tractor unit, which comes from a different manufacturer than the coupling device, so that the information of the results of the wear monitoring according to the application can be transmitted via an interface without further coordination of the control unit of the pressure sensor or the coupling device and the control unit of the combined vehicle, such as the semitrailer and / or tractor unit, independently thereof. The information such as the pressure limit value can also be part of the control unit of the pressure sensor or the coupling device and does not have to be made available to the independent control unit of the semitrailer and / or tractor unit, which would otherwise require intervention and effort at least during the assembly and commissioning of the coupling device according to the application, which can be avoided in this way.

[0040] In any case, the output, transmission or communication of the corresponding information of the pressure of the fluid in the chamber can be carried out by means of a preferably wireless communication unit or by means of a preferably wireless transmission unit, which can transmit data or information at least preferably in a wireless manner to the outside of the coupling device and, preferably, as a preferably wireless transmission / reception unit, also from the outside.

[0041] Once the pressure limit value or the wear limit or the pressure switch is actuated, this can be carried out automatically by the pressure sensor or by the control unit of the coupling device by means of a preferably wireless transmission unit or transmission / reception unit, so that the person or driver can immediately react. This allows the output or transmission of this information to be limited to the case that the wear has occurred which is not allowed. Otherwise, communication can be avoided, so that energy can be saved and disturbances to the person or driver can be avoided. However, the person or driver cannot distinguish whether the information about the wear which is not allowed is missing because the wear monitored according to the application is allowed or within the allowed limits, or whether the pressure sensor, the control unit of the coupling device and / or the transmission unit or transmission / reception unit is not working, for example, due to damage or empty energy storage.

[0042] The information can thus alternatively be output continuously or periodically by the pressure sensor or by the control unit of the coupling device by means of a preferably wireless transmission unit or transmission / reception unit to ensure that the information reaches the personnel or the driver. By means of this continuous input information, for example in cycles of predetermined time intervals, for example one hour, the personnel or the driver can also recognize that the pressure sensor or the control unit of the coupling device is functioning properly. If necessary, at least for the duration of the current use or the current journey, the output of the information by the pressure sensor or by the control unit of the coupling device by means of a preferably wireless transmission unit or transmission / reception unit can be terminated or suspended by means of the receipt confirmation by the personnel or the driver in order to save electrical energy in respect of the pressure sensor or the control unit of the coupling device and in respect of the transmission unit or transmission / reception unit.

[0043] If necessary, additionally or alternatively, the output of the information by the pressure sensor or by the control unit of the coupling device by means of a preferably wireless transmission unit or transmission / reception unit can only take place on request or in response to a request from the outside, as will be described in more detail below. This can be done, for example, once at the beginning of the use or the journey.

[0044] In any case, the pressure sensor or the control unit of the coupling device can output the information to the personnel or the driver by means of a preferably wireless transmission unit or transmission / reception unit in such a way that the information is transmitted in a wireless manner to an electronic receiver of the personnel or the driver, such as a mobile device in the form of a smartphone or a tablet computer, for example. Additionally or alternatively, the information can also be transmitted in a wireless manner by the pressure sensor or by the control unit of the coupling device by means of a preferably wireless transmission unit or transmission / reception unit to an electronic receiver of the towing vehicle unit, where it is received and further processed, and then output or displayed to the driver via an output element, such as in particular a display element on the towing vehicle unit. In this case, if necessary, the information can be transmitted in a wireless manner from the towing vehicle unit or its control unit to a fleet management system in order to be able to take into account and plan there the replacement of the worn-out kingpin of the coupling device.

[0045] Additionally or alternatively, the unprepared high wear of the coupling device can also be detected visually by the person, since the cavity is no longer covered by the wear element and thus is visible. This can enable the person to assess the wear purely visually. This can be done if the possibility of electronically evaluating the information of the pressure sensor is not present at this moment, for example if the semitrailer is separated from the towing vehicle unit or the towing seat kingpin is removed from the semitrailer. This can also allow the person to carry out regular visual checks of the visually perceptible wear of the coupling device on the semitrailer, for example parked or unparked. For example, a driver of a towing vehicle unit to be coupled with a semitrailer that is not familiar or unknown to him as a coupling device according to the application can easily and quickly visually check the wear condition of the towing seat kingpin of the semitrailer, in particular before a preferably wireless data connection is established directly between the control unit of the towing vehicle unit and the control unit of the semitrailer or the control unit of the towing seat kingpin or its pressure sensor, in order to be able to electronically query and evaluate or display information on the pressure of the fluid in the cavity or on the wear condition of the wear element of the towing seat kingpin. This can increase the driver's confidence when towing an unfamiliar or unknown semitrailer. This can also provide the opportunity for an additional visual check by the person to check a faulty pressure sensor that can have erroneously detected permissible or impermissible wear.

[0046] In any case, the wear element can be arranged at a point in the horizontal plane or in the cross section of the coupling device at which particularly pronounced abrasion or wear usually occurs or at which the first reaching of impermissible high wear is usually expected. This can thus increase the informative value of the wear element.

[0047] Viewed along the longitudinal axis of the coupling device, a plurality of wear elements with a common pressure sensor or each with its own pressure sensor can also be used, as already mentioned, in order to be able to implement the above-mentioned wear control at a corresponding number of points of the coupling device along the longitudinal axis or in different planes. In particular, this allows the simultaneous monitoring of the wear of a plurality of points that are usually subject to pronounced wear, as described above.

[0048] In any case, the power supply or the electrical power supply of at least the pressure sensor and preferably of further electrical and / or electronic elements of the coupling device, such as a transmitting unit or transmitting / receiving unit and / or an illumination device, can be provided by means of an electrical energy storage device, which can be arranged in and / or on the coupling device, preferably internally near the pressure sensor or integrated with the pressure sensor or another electrical or electronic element. This allows the electrical power supply of the pressure sensor and, if applicable, of a plurality or all of the electrical and electronic elements of the coupling device to be provided directly by the coupling device itself, so that an electrically conductive connection from outside the coupling device can be dispensed with. This can keep the effort of using at least one pressure sensor as described above correspondingly low.

[0049] According to one aspect of the application, the wear element extends perpendicular to the longitudinal axis to a degree corresponding to a wear limit of the coupling device at this point of the coupling device, wherein the cavity is arranged behind the wear element perpendicular to the longitudinal axis.

[0050] In other words, the wear element directly radially covers the cavity or the circumferential channel of the cavity, so that the cavity or the circumferential channel can be introduced purely radially into the coupling device, for example by drilling or milling, so that the implementation can be simplified.

[0051] According to a further aspect of the application, the cavity comprises:

[0052] • at least one first cavity, which is a circumferential channel, which extends at least partially, preferably completely, around the coupling device in the circumferential direction, and

[0053] • at least one second cavity, which is a radial channel, which extends linearly from the first cavity into the coupling device perpendicular to the longitudinal axis,

[0054] wherein the pressure sensor is designed to detect the pressure of the fluid directed into this second cavity.

[0055] This can represent a specific implementation option, in which the combination of the cavity and the wear element in the circumferential direction is achieved by the circumferential channel of the first cavity as the entire cavity and its correspondingly shaped or extended wear element. At the same time, by fluidically connecting the circumferential channel at least at one point to the pressure sensor by means of the second cavity of the entire cavity as the radial channel, the pressure sensor can be repositioned to the interior of the coupling device.

[0056] According to a further aspect of the application, the cavity further comprises:

[0057] • at least one vertical cavity, which extends in the coupling device along the longitudinal axis, preferably in the constricted portion of the kingpin,

[0058] wherein the pressure sensor is designed to detect the pressure of the fluid directed into this vertical cavity.

[0059] In this way, the pressure sensor can be arranged centrally in the coupling device, in particular inside the kingpin along the cavity on the longitudinal axis, in order to minimize the weakening of the stability of the coupling device by the cavity for receiving the pressure sensor by arranging the cavity for receiving the pressure sensor symmetrically on the longitudinal axis.

[0060] According to a further aspect of the application, the coupling device is a kingpin, wherein the kingpin has, along its longitudinal axis, in the following order:

[0061] • an installation plate, which is designed to be connected to the semitrailer,

[0062] • a transition portion, which adjoins the installation plate,

[0063] • a constricted portion, which adjoins the transition portion and is designed for a connection to a towing seat coupling profile of a towing vehicle unit of the towing vehicle, and

[0064] • an end collar, which adjoins the constricted portion and terminates the towing seat kingpin downward,

[0065] wherein a wear element is arranged in the transition portion and / or the constricted portion.

[0066] Thus, at the corresponding points of these portions of the towing seat kingpin, a monitoring of the wear can be carried out as described above.

[0067] According to a further aspect of the application, the wear element is designed to be completely closed around the towing seat kingpin in the circumferential direction, wherein the towing seat kingpin is at least, preferably exactly, formed as two parts with a first upper kingpin part and a second lower kingpin part, wherein the second lower kingpin part has at least, preferably exactly, an end collar, wherein the first upper kingpin part and the second lower kingpin part are fixedly connected to each other by means of a connection, preferably by means of a threaded connection.

[0068] A bushing or the like, which is completely closed in the circumferential direction as described above, can be used as a wear element.

[0069] According to a further aspect of the application, the transition portion has a first wear element, which preferably has a first cavity and a second cavity, wherein the constricted portion has a second wear element, which preferably has a first cavity and a second cavity.

[0070] This can make it possible to achieve the wear detection according to the application in the circumferential direction at least in two different points of the towing seat kingpin along the longitudinal axis, partially to completely, as already mentioned above.

[0071] According to a further aspect of the application, the coupling device is a coupling bolt, wherein the coupling bolt has a coupling portion with a spherical portion, which is designed to be received by a coupling eye of the coupling hook, wherein the spherical portion of the coupling portion is at least partially, preferably completely, formed by the wear element.

[0072] In this case, the coupling device according to the application can be implemented as a coupling bolt for a towing vehicle of a road train in order to implement the application according to specific technical features of the coupling bolt or in order to adapt the coupling bolt to the application. Thus, the coupling bolt serves as a part of a coupling mount having a coupling mouth of the towing vehicle. The coupling mouth of the coupling mount of the towing vehicle accommodates a coupling hook of an axle of a trailer, which can also be referred to as a towing hook, for coupling the vehicles of a vehicle combination or a vehicle combination. The coupling hook is ring-shaped and formed as one piece, i.e. integrally formed with the axle at an end facing away from the trailer. The coupling hook forms a coupling eye in the middle, which extends vertically, into which a coupling bolt of the towing vehicle is inserted from above in the vertical direction in order to form a form-locking connection between the two vehicles. The coupling eye can also be referred to as a coupling hook eye, a towing hook eye or a towing hook bushing. The axle can also be referred to as a trailer axle or a towing axle. The axle can also be referred to as a drawbar or a trailer drawbar.

[0073] The part of the coupling bolt of the towing vehicle, which is surrounded by the coupling hook of the trailer (when the two vehicles are in the coupled state) and which lies in the same horizontal plane as the coupling hook, can be referred to as a coupling part, wherein the coupling part of the coupling bolt can extend slightly beyond this common horizontal plane both downwards and upwards along a vertical axis in order to ensure contact between the interior of the coupling hook and the exterior of the coupling bolt by means of the coupling part even in the event of a vertical movement or displacement between the coupling hook and the coupling bolt.

[0074] Here, it is known to provide a spherical part at the position in the coupling part which extends precisely along the vertical axis at the previously described common horizontal plane of the coupling hook and the coupling bolt, which extends radially away from the longitudinal axis of the coupling bolt, which coincides with the vertical axis during use, as a thickening or protrusion. The spherical part can be uniform and continuous in the circumferential direction. Furthermore, the spherical part can extend obliquely upwards and / or downwards along the longitudinal axis in order to move into the cylindrical cross-section of the coupling bolt or its coupling part.

[0075] Since it is precisely the spherical part of the coupling part which is at least partially in contact with the coupling hook and wears, a wear element can be precisely provided there when the coupling device is implemented as a coupling bolt according to the application in order to be able to detect or identify wear according to the application, as described above. The wear element can be formed or provided partially in or on the spherical part of the coupling part. Alternatively, the spherical part of the coupling part can also be formed completely or exclusively by the wear element, which can simplify implementation.

[0076] In any case, the wear element can be designed as a wear bushing and can be pressed from the outside onto or into the ball-shaped portion of the coupling portion, in particular into a first cavity or a circumferential channel provided there in the form of a groove. If the ball-shaped portion of the coupling portion is formed completely or exclusively by the wear element, the ball-shaped portion of the coupling portion can also be formed completely as a wear bushing.

[0077] According to a further aspect of the application, the coupling device further comprises a preferably wireless transmission unit, which is connected to the pressure sensor at least in a signal-transmitting manner in order to receive at least one item of information about the pressure of the fluid in the cavity, wherein the preferably wireless transmission unit is further designed to transmit the received information of the pressure, preferably in a wireless manner, to the outside of the coupling device.

[0078] This can be a specific implementation option to communicate the information of the pressure to the pressure sensor or to the outside of the coupling device, as already mentioned above. The information of the pressure can represent a pressure value, a pressure switch state and / or information derived therefrom, as already mentioned above.

[0079] According to a further aspect of the application, the transmitted information of the pressure of the transmission unit comprises the pressure of the fluid in the cavity and / or one item of information derived from the pressure of the fluid in the cavity, as already mentioned above.

[0080] According to a further aspect of the application, the coupling device has a plurality of wear elements, each having at least one cavity and each having at least one pressure sensor.

[0081] Thus, the wear at a plurality of points on the coupling device along the longitudinal axis can be monitored independently of one another, the plurality of points each having its own pressure sensor as described above. This can increase the effort due to the plurality of pressure sensors, since each pressure sensor requires installation space, generates purchase and installation costs and has to be electrically powered. However, this can represent the possibility according to the application to monitor the wear of a plurality of points of the coupling device independently of one another along the longitudinal axis.

[0082] In this case, the information of the pressure transmitted by the preferably wireless transmission unit can contain an identification of the associated pressure sensor. In this way, the data from the pressure sensors can be distinguished from one another and assigned to the corresponding pressure sensor and thus also to the point on the coupling device whose wear is monitored by this pressure sensor.

[0083] According to a further aspect of the application, the preferably wireless transmission unit is a preferably wireless transmission / reception unit, wherein the preferably wireless transmission / reception unit is designed to be requested to transmit the information of the pressure, preferably in a wireless manner, from the outside of the coupling device.

[0084] This can allow the embodiments as previously described.

[0085] According to another aspect of the application, the coupling device further comprises a lighting device, which is connected at least in a signal-transmitting manner to the pressure sensor, wherein the lighting device is designed to be operated depending on the pressure of the fluid in the chamber.

[0086] In this way, in addition to or as an alternative to the transmission to the outside of the coupling device, it is also possible to use the lighting device to display the result of the pressure or wear monitoring by the sensor directly in a visual manner on the coupling device, so that this can be directly identified there by the personnel. This can be particularly useful, for example, when the semitrailer is parked or uncoupled and thus cannot, for example, use the control unit of the towing vehicle unit to query information about the pressure in the chamber.

[0087] In particular, the lighting device can be implemented as an LED. In any case, the coupling device or preferably an end collar of the coupling device can have the lighting device or a plurality of preferably uniformly distributed lighting devices in the circumferential direction, which is in particular aligned along the longitudinal axis and / or radially or perpendicular to the longitudinal axis at the lower end. Preferably, a power supply can be provided together with the pressure sensor and, if necessary, together with the transmission unit or transmission / reception unit.

[0088] In any case, the operation of the lighting device can in particular be permanent or continuous in order to be able to check the wear condition of the coupling device at any time. For this purpose, the two resulting relevant states, i.e. whether the wear of the coupling device is permissible or not permissible at least at one point along the longitudinal axis, can be distinguished by two distinctly different colors of the lighting device, for example by "green" representing permissible wear and "red" representing impermissible wear. Alternatively, the two resulting relevant states can also be distinguished by slow flickering in the case of permissible wear and rapid flickering in the case of impermissible wear. This can also be combined with the color information as described above.

[0089] By continuously operating the lighting device, the personnel or driver can also recognize that the wear detection according to the application is functioning properly. Furthermore, the corresponding effort for switching on and off the lighting device or for providing a corresponding electrical option for this, such as an externally accessible switch on the coupling device, can be avoided.

[0090] If necessary, in the event of a simultaneous failure of the pressure sensor, the properly functioning lighting device of the coupling device and possibly the properly functioning control unit can lead to an output corresponding to impermissible wear in order to attract the attention of the personnel or driver.

[0091] Alternatively, the lighting device may be activated only when unacceptable wear is detected, specifically displayed as "red" and / or flashing for warning purposes, in order to save energy, and as long as the wear is at an acceptable level, it will not disturb the surrounding environment or people through continuous or periodic lighting or flashing. However, in this case, it is impossible to distinguish whether the lack of lighting or flashing is due to wear being detected as permissible, or whether there is a functional malfunction in the wear detection according to the invention.

[0092] According to another aspect of the invention, the pressure sensor is a pressure switch designed to switch in response to a predetermined pressure drop in the fluid in the cavity.

[0093] This is perfectly sufficient for implementing the present invention, and at the same time, it keeps the workload for implementing the pressure sensor low.

[0094] The present invention also relates to a vehicle, preferably a semi-trailer or tractor, having a coupling device, preferably a towing kingpin or coupling bolt, as described above. Therefore, the previously described aspects of the coupling device according to the invention can be implemented and used in vehicle combinations or vehicles within combinations. Attached Figure Description

[0095] Several exemplary embodiments and additional advantages of the invention are shown and explained in more detail below, in conjunction with the accompanying drawings, purely schematically. In the drawings:

[0096] Figure 1 A schematic side view depiction of a vehicle assembly having a coupling device according to the invention, based on a first to third exemplary embodiment, is shown;

[0097] Figure 2 A schematic side view of a vehicle assembly having a coupling device according to the invention, according to a fourth exemplary embodiment, is shown;

[0098] Figure 3 A perspective drawing of a coupling device according to the invention, based on a first exemplary embodiment, is shown, the coupling device being in the form of a traction seat masterpin without wear elements;

[0099] Figure 4 A wear element is shown. Figure 3 The description;

[0100] Figure 5 It shows Figure 4 The longitudinal section depicted;

[0101] Figure 6 A longitudinal section of the traction seat masterpin according to the invention, based on a second exemplary embodiment, is shown.

[0102] Figure 7 A longitudinal section of a fifth wheel kingpin according to the application is shown according to a fourth exemplary embodiment.

[0103] Figure 8 A perspective depiction of a coupling device according to the application is shown according to a fourth exemplary embodiment, which coupling device is in the form of a coupling bolt with a wear element; and

[0104] Figure 9 A depiction of a longitudinal section is shown Figure 8

[0105] Figure 1 and Figure 2 is observed in Cartesian coordinates, without the corresponding axes being depicted. A direction of travel A is depicted, which can also be referred to as a direction of movement A or a direction of traction A.

[0106] Figures 3 to 9 is observed in cylindrical coordinates. A longitudinal axis X extends. Perpendicular to the longitudinal axis X, a radial direction R extends away from the longitudinal axis X. A circumferential direction U extends perpendicular to the radial direction R and around the longitudinal axis X. The longitudinal axis X at the same time represents a vertical axis in Cartesian coordinates, i.e. the axis of gravity or the axis of the earth's gravity. DETAILED DESCRIPTION

[0107] Figure 1 A schematic side view of a vehicle combination 3, 4 with a coupling device 1 according to the application is shown according to the first to third exemplary embodiments.

[0108] The vehicle combination 3, 4, which can also be referred to as a combination 3, 4, in this case has a front vehicle 3 in the direction of traction A as a towing vehicle 3 in the form of a tractor unit 3 and a rear vehicle 4 in the direction of traction A in the form of a semitrailer 4. The vehicle combination 3, 4 can therefore also be referred to as a tractor unit 3, 4 or a towing trailer 3, 4. The vehicle combination 3, 4 can perform a travel movement on the ground 5 in the direction of travel A, in the direction of movement A or in the direction of traction A.

[0109] The tractor unit 3 has a fifth wheel coupling, which can receive the fifth wheel kingpin 1 as a coupling device 1 of the semitrailer 4 and holds this horizontally such that the fifth wheel kingpin 1 can be rotated relative to the fifth wheel coupling around the longitudinal axis X. The fifth wheel coupling and the fifth wheel kingpin 1 connect the tractor unit 3 to the semitrailer 4 in a force- transmitting manner in the longitudinal direction X.

[0110] Figure 2 A schematic side view of a vehicle combination 3, 4 with a coupling device 2 according to the application is shown according to the fourth embodiment. ​

[0111] In this case, the vehicle combination 3, 4 has as a front vehicle 3 in the pulling direction A a truck 3 in the form of a truck 3 and as a rear vehicle 4 in the pulling direction A a trailer 4 in the form of a trailer 4. The vehicle combination 3, 4 can therefore be referred to as a road train 3, 4.

[0112] On the truck 3, at its rear opposite the pulling direction A, a coupling mount with a coupling eye and a coupling bolt 2 is fixedly arranged as a coupling device 2, wherein the coupling mount or its coupling eye points towards the trailer 4 opposite the pulling direction A. Furthermore, in the pulling direction A, a shaft or a drawbar is fixedly arranged on the front of the trailer 4 or on a frame of the trailer 4 facing the truck 3. The shaft extends from the trailer 3 towards the truck 3 and has at an end a hook as a coupling hook into which the coupling bolt 2 of the truck 3 can be engaged from above along a longitudinal axis X or vertical axis. The coupling hook and the coupling bolt 2 connect the truck 3 to the trailer 4 in the longitudinal direction X in a force- transmitting manner.

[0113] Figure 3 A perspective depiction of a coupling device according to the application according to a first exemplary embodiment is shown, which coupling device is in the form of a tow hitch kingpin 1 without wear elements 11c, 12c. Figure 4 A depiction of a coupling device according to the application with wear elements 11c, 12c is shown. Figure 3 A depiction of a coupling device according to the application with wear elements 11c, 12c is shown. Figure 5 A depiction of a coupling device according to the application with wear elements 11c, 12c is shown. Figure 4 A longitudinal section of a depiction of a coupling device according to the application with wear elements 11c, 12c is shown.

[0114] Figure 1 The tow hitch kingpin 1 of the semitrailer 4 in the coupling device according to the application can also be referred to as a kingpin 1 or king bolt 1. The tow hitch kingpin 1 or its body is made of metal and is rotationally symmetrical about the longitudinal axis X. The tow hitch kingpin 1 is designed as two parts and consists of a first upper kingpin part 1a and a second lower kingpin part 1b, which are connected to one another by means of a connecting part 1c in the form of a threaded connection 1c.

[0115] Along the longitudinal axis X from top to bottom, the tow hitch kingpin 1 has a mounting plate 10, a transition portion 11, a constricted portion 12 and an end collar 13. In the first exemplary embodiment, the first upper kingpin part 1a has the mounting plate 10 and the transition portion 11, and the second lower kingpin part 1b has the constricted portion 12 and the end collar 13.

[0116] The mounting plate 10 extends significantly beyond the other portions in the radial direction R and is relatively flat at the edge along the longitudinal axis X. There, the mounting plate 10 has a plurality of through openings 10a along the longitudinal axis X as screw holes 10a of the mounting plate 10, through which the mounting plate 10 can be fixedly fastened with screws to the underside of a chassis (not shown) of a semitrailer (not shown).

[0117] The mounting plate 10 seamlessly transitions into a transition portion 11 which extends relatively far along the longitudinal axis X and is significantly smaller in the radial direction R than the mounting plate 10. A constricted portion 12 adjoins the transition portion 11 continuously and has an even smaller extension in the radial direction R. The constricted portion 12 seamlessly merges into an end collar 13 which corresponds approximately to the transition portion 11 in the radial direction R and terminates the tow hitch spindle 1 downwardly along the longitudinal axis X.

[0118] When the semitrailer is coupled to a tractor unit (not shown), the constricted portion 12 is received by the tow hitch coupling of the semitrailer and is completely enclosed in the circumferential direction U. Thereby, during operation of the towing trailer with the semitrailer and the tractor unit, abrasion or wear of the cylindrical outer surface of the tow hitch spindle 1, in particular of its constricted portion 12, can occur which can weaken the cross section or material thickness of the tow hitch spindle 1 over time to such an extent that a safe force transmission between the semitrailer and the tractor unit via the tow hitch spindle 1 can no longer be ensured.

[0119] According to Figures 1 to 3 the first exemplary embodiment according to the application, excessive wear in both the transition portion 11 and the constricted portion 12 of the tow hitch spindle 1 can be detected according to the application, since the transition portion 11 has a first cavity 11a as a circumferential channel 11a which is formed approximately centrally in the circumferential direction Z along the longitudinal axis X as a continuous annular radial recess. At one point of the circumferential channel 11a of the transition portion 11, a second cavity 11b extends as a radial channel 11b in a straight line radially into the transition portion 11 of the tow hitch spindle 1. Since the tow hitch spindle 1 is divided into two parts, the radial channel 11b of the transition portion 11 ends in a corresponding transition circumferential channel 12d of the constricted portion 12 and a transition radial channel 12e of the constricted portion 12 which extends or continues the radial channel 11b of the transition portion 11 towards the longitudinal axis X.

[0120] Likewise, the constricted portion 12 has a first cavity 12a in the form of a circumferential channel 12a of the constricted portion 12 and a second cavity 12b in the form of a radial channel 12b of the constricted portion 12.

[0121] In Figure 3In the diagram, the radial channels 11b of the transition portion 11, the transition radial channels 12e and 12b of the contraction portion 12 are shown aligned in the same manner around the longitudinal axis X or in the circumferential direction U. However, due to the threaded connection 1c of the two kingpin components 1a and 1b, the radial channels 11b of the transition portion 11 formed in the first kingpin component 1a may also be oriented differently from those shown, compared to the second kingpin component 1b which has the transition radial channels 12e and 12b of the contraction portion 12. To ensure fluid conduction connection between the radial channels 11b of the transition portion 11 of the first kingpin component 1a and the radial channels 12b of the contraction portion 12 of the second kingpin component 1b, regardless of the alignment of the two kingpin components 1a and 1b around the longitudinal axis X or in the circumferential direction U, the transition circumferential channel 12d of the contraction portion 12 is configured to extend continuously or circumferentially in the circumferential direction U.

[0122] Along the longitudinal axis X, within the main pin 1 of the traction seat, from top to bottom, are sequentially arranged a vertical cavity 14a of a mounting plate 10 in the form of holes of different diameters, a vertical cavity 14b of a transition portion 11, a vertical cavity 14c of a contraction portion 12, and a vertical cavity 14d of an end collar 13. However, the vertical cavity 14c of the contraction portion 12 extends upward along the longitudinal axis X to approximately halfway into the transition portion 11. The radial channel 11b of the transition portion 11, or its extension via the transition radial channel 12e of the contraction portion 12, and the radial channel 12b of the contraction portion 12, both terminate in the vertical cavity 14c of the contraction portion 12. (See [reference needed]). Figure 3 .

[0123] If only Figure 5 The text is incomplete and appears to be a fragment of a larger document. A more coherent translation would require the full context. Figure 3 and Figure 4 The clarity, in Figures 1 to 3 In a first exemplary embodiment, the vertical cavity 14c of the contraction portion 12 also serves as a pressure chamber, which is sealed from below along the longitudinal axis X in a fluid-impermeable manner using a valve element 15 in the form of an automotive valve 15 in the region of the vertical cavity 14d of the end collar 13. Fluid, such as air, can be filled under pressure into the vertical cavity 14c of the contraction portion 12 as a pressure chamber via the valve element 15, and the pressure can be maintained.

[0124] Along the longitudinal axis X from above, the vertical cavity 14c of the contraction section 12 is sealed as a pressure chamber in a fluid-impermeable manner by a pressure sensor 16 in the form of a pressure switch 16, so that the pressure within the vertical cavity 14c of the contraction section 12, which serves as a pressure chamber, can be detected by the pressure switch 16. The pressure switch 16 can exhibit two different switching states depending on whether the pressure within the vertical cavity 14c of the contraction section 12, which serves as a pressure chamber, is below or exceeds a predetermined pressure limit value.

[0125] The pressure switch 16 is connected for signal transmission with a wireless transmitting / receiving unit 17, which likewise has an electrical energy storage device (not shown) in the form of a rechargeable and / or replaceable battery, in order to power itself and the pressure switch 16. The wireless transmitting / receiving unit 17 is sealed in a dust- and dirt-proof manner on top by a cover 18, which is held in the mounting plate 10 by means of screws 19. The cover 18 is flush with the mounting plate 10 on top.

[0126] The wireless transmitting / receiving unit 17 can receive the switch state of the pressure sensor 16 from the pressure switch 16 or query the switch state from the pressure switch 16 and transmit the switch state wirelessly to the outside or to the outside of the tow hitch kingpin 1 at regular intervals, for example every hour, and / or on the basis of an external request. There, the received switch state of the pressure sensor 16 can be used, for example, by the engine control unit of the towing vehicle unit to inform the driver of the switch state of the pressure sensor 16 or the wear state of the tow hitch kingpin 1 determined therefrom, in order to be able to detect any impermissible wear as quickly as possible and react to it.

[0127] According to the application, a permissible and impermissible wear state of the tow hitch kingpin 1 or a corresponding switch state of the pressure sensor 16 can be distinguished, since the circumferential channel 11a of the transition portion 11 is sealed in a fluid-tight manner with respect to the outside or radially by a wear element 11c in the form of a ring-closed wear bushing 11c of the transition portion 11, and the circumferential channel 12a of the constricted portion 12 is sealed in a fluid-tight manner with respect to the outside or radially by a wear element 12c in the form of a ring-closed wear bushing 12c of the constricted portion 12.

[0128] In order to assemble the two wear bushings 11c, 12c, the two kingpin parts 1a, 1b are still separated, so that the wear bushing 11c of the transition portion 11 can be pushed onto the transition portion 11 from below along the longitudinal axis X and the wear bushing 12c of the constricted portion 12 can be pushed onto the constricted portion 12 from above along the longitudinal axis X. Fluid-tightness can be achieved by subsequently pressing the wear bushings 11c, 12c. Then, as described above, the two kingpin parts 1a, 1b are screwed together.

[0129] At this point, the vertical cavity 14c of the constriction portion 12 as a pressure chamber, the circumferential channel 11a of the transition portion 11, the radial channel 11b of the transition portion 11, the circumferential channel of the constriction portion 12, the radial channel 12b of the constriction portion 12, the transition circumferential channel 12d of the constriction portion 12 and the transition radial channel 12e of the constriction portion 12 are filled with compressed air by means of the valve element 15, which compressed air cannot escape from the vertical cavity 14c of the constriction portion 12 as a pressure chamber and the channels 11a, 11b, 12a, 12b, 12d, 12e due to the fluid-tightness of the valve element 15, the pressure switch 16 and the two wear bushes 11c, 12c.

[0130] Since the two wear bushes 11c, 12c are formed radially to exactly the extent corresponding to the permissible wear limit of the towing seat kingpin 1 at this point, the two wear bushes 11c, 12c seal the vertical cavity 14c of the constriction portion 12 as a pressure chamber and the channels 11a, 11b, 12a, 12b, 12d, 12e in a fluid-tight manner as long as the wear of the towing seat kingpin 1 at this point is within the permissible level. Thus, as long as the fluid-tightness is maintained and thus an overpressure of, for example, 6 to 8 bar is applied to the pressure switch 16, the pressure switch 16 remains in the corresponding switching state.

[0131] If a wear-related leak occurs at any point in one of the two wear bushes 11c, 12c in the operation of the towing seat kingpin 1, air escapes from the vertical cavity 14c of the constriction portion 12 as a pressure chamber and from the channels 11a, 11b, 12a, 12b, 12d, 12e to the outside, whereby the overpressure of the fluid or air decreases rapidly. Thereby, the pressure limit value or pressure threshold value of the pressure switch 16 is undershot and the pressure switch 16 changes to the corresponding other switching state, which can be communicated outwardly by the wireless transmitting / receiving unit 17, in particular exactly at the change in the switching state of the pressure switch 16.

[0132] Thus, the driver of the towing vehicle unit can be informed of the impermissible wear of the towing seat kingpin 1 in order to react accordingly. Thus, after the end of the current operation, the excessively worn wear bushes 11c, 12c can be replaced and the vertical cavity 14c of the constriction portion 12 as a pressure chamber can be refilled with compressed air.

[0133] Due to the circumferential channels 11a, 12a, which are formed continuously in the circumferential direction U, the escape of air under overpressure can occur anywhere in the circumferential direction U and in each case triggers the switching of the pressure switch 16. In this way, a complete and seamless or stepless wear detection in the circumferential direction U can be realized.

[0134] Figure 6A longitudinal section of a kingpin 1 according to the application is shown according to a second exemplary embodiment.

[0135] In this case, the first upper kingpin part la has a mounting plate 10, a transition portion 11 and a constricted portion 12, and the second lower kingpin part lb has an end collar 13. In this way, the radial channel 1 lb of the transition portion 11 can be designed to extend continuously into the vertical cavity 14c of the constricted portion 12, which can reduce the manufacturing effort compared to the first exemplary embodiment, since the transition circumferential channel 12d of the constricted portion 12 and the transition radial channel 12e of the constricted portion 12 can be dispensed with.

[0136] Figure 7 A longitudinal section of a kingpin 1 according to the application is shown according to a third exemplary embodiment.

[0137] In this case, the first upper kingpin part la also has a mounting plate 10, a transition portion 11 and a constricted portion 12, and the second lower kingpin part lb has an end collar 13, so that in this case too, the radial channel 1 lb of the transition portion 11 can be designed to extend continuously into the vertical cavity 14c of the constricted portion 12.

[0138] Unlike the two preceding exemplary embodiments, a continuous wear bushing 11c, 12c is provided, which can reduce the assembly effort. Furthermore, the radial channel 1 lb of the transition portion 11 is arranged offset by 180° about the longitudinal axis X relative to the radial channel 12b of the constricted portion 12.

[0139] Figure 8 A perspective depiction of a coupling device 2 according to the application is shown according to a fourth exemplary embodiment, which coupling device is in the form of a coupling bolt 2 with a wear element 21c. Figure 9 A longitudinal section of the depiction of Figure 8 is shown.

[0140] In this case, the coupling device 2 according to the application is realized by means of a coupling bolt 2 of a truck 3 in a manner comparable to the kingpin 1 of the three preceding exemplary embodiments. Figure 2

[0141] The coupling bolt 2 according to the application is essentially made of metal as a single piece, i.e. integrally or from a single piece, and has an essentially cylindrical shape extending along a longitudinal axis X. An upper portion along the longitudinal axis X represents a mounting portion 20 for fixedly fastening in a corresponding mounting of a coupling mounting of a truck 3, as already described with regard to Figure 2 .

[0142] ​Downwards along the longitudinal axis X, the mounting portion 20 is followed by a coupling portion 21 of considerable length, which terminates at the bottom with an end collar 23. The coupling portion 21 is radially smaller than the mounting portion 20 and has a radially protruding thickening in about its upper half, which radially corresponds to the mounting portion 20 at its center along the longitudinal axis X and tapers, i.e. decreases, upwards and downwards along the longitudinal axis Y towards the radially smaller extent of the coupling portion 21. This radially protruding thickening can be referred to as a ball portion, which according to the application is formed by a wear element 21c in the form of a wear bushing 21c of the coupling portion 21.

[0143] According to the application, the coupling bolt 2 or its coupling portion 21 also has a first cavity 21a in the form of a circumferential channel 21a of the coupling portion 21, which is formed centrally along the longitudinal axis X along the wear bushing 21c and is isolated from the outside by the wear bushing 21c in a fluid-tight or gas-tight manner. Likewise, the coupling bolt 2 or its coupling portion 21 has a second cavity 21b in the form of a radial channel 21b of the coupling portion 21, which extends radially through the coupling portion 21 and thus reaches the circumferential channel 21a twice diametrically opposite the longitudinal axis X or moves into the circumferential channel 21a in a fluid-conducting manner. The radial channel 21b or its two portions thus connects the circumferential channel 21a with a vertical cavity 24, which extends from the end collar 23 at the bottom along the longitudinal axis X to the upper end of the mounting portion 20 and is designed as a core hole 24. Therein, the vertical cavity 24 in the region of the end collar 23 is wider radially than the vertical cavity 24d of the end collar 23. Likewise, the upper portion of the vertical cavity 24 has a radially larger volume.

[0144] Also in the case of the coupling bolt 2 as a coupling device 2 according to the application, the wear condition of the coupling bolt 2 or its coupling portion 21 is monitored by means of an overpressure of, for example, 6 to 8 bar, which is detectable or recognizable by a sensor, by the core hole 24 as a pressure chamber and the circumferential channel 21a and the radial channel 21b being filled with air under overpressure and then being hermetically sealed, which can be done by means of a valve element 25 in the form of an automotive valve 25, which is arranged in the vertical cavity 24d of the end collar 23.

[0145] Along the longitudinal axis X, a pressure sensor 26 is arranged as a pressure switch 26 at the other end of the vertical cavity 24 opposite the valve element 25 and aligned with its sensor element towards the pressure chamber or vertical cavity 24 in order to switch between two states depending on the pressure present there. A wireless transmission / reception unit 27 is also arranged at this end of the vertical cavity 24 and connected to the pressure sensor 26 for signal transmission. There is also provided an electrical energy storage device there for the power supply of the pressure sensor 26 and the wireless transmission / reception unit 27. This end of the vertical cavity 24 is sealed from the outside in a fluid-tight manner by means of a cover 28 held by a screw 29 in order to protect against dust and moisture.

[0146] Thus, as long as the fluid-tightness is maintained and thus an overpressure is applied to the pressure switch 26, the pressure switch 26 remains in the overpressure switch state. However, if during the operation of the coupling bolt 2 a wear-related leak occurs at any point of the wear bushing 21c, air escapes from the vertical cavity 24 as pressure chamber and from the channels 21a, 21b to the outside, whereby the overpressure of the fluid or air decreases rapidly. Thereby, the pressure limit value or pressure threshold value of the pressure switch 26 is undershot and the pressure switch 26 changes to the corresponding other switch state, which can be communicated to the outside by the wireless transmission / reception unit 27, in particular exactly at the change of the switch state of the pressure switch 26.

[0147] List of reference signs (part of the description)

[0148] A direction of travel; direction of movement; direction of pull

[0149] R radial direction

[0150] U circumferential direction

[0151] X longitudinal axis

[0152] 1 coupling device; kingpin; main pin; main bolt

[0153] 1a first upper kingpin part

[0154] 1b second lower kingpin part

[0155] 1c connection or threaded connection between the kingpin parts 1a, 1b

[0156] 10 mounting plate

[0157] 10a through opening or screw hole of the mounting plate 10

[0158] 11 transition

[0159] 11a first cavity or circumferential channel of the transition 11

[0160] 11b second cavity or radial passage of the transition portion 11

[0161] 11c wear element or wear bushing of the transition portion 11

[0162] 12 constriction portion

[0163] 12a first cavity or circumferential passage of the constriction portion 12

[0164] 12b second cavity or radial passage of the constriction portion 12

[0165] 12c wear element or wear bushing of the constriction portion 12

[0166] 12d transition circumferential passage of the constriction portion 12

[0167] 12e transition radial passage of the constriction portion 12

[0168] 13 end collar

[0169] 14 vertical cavity; core hole

[0170] 14a vertical cavity of the mounting plate 10

[0171] 14b vertical cavity of the transition portion 11

[0172] 14c vertical cavity of the constriction portion 12

[0173] 14d vertical cavity of the end collar 13

[0174] 15 valve element; automotive valve

[0175] 16 pressure sensor; pressure switch

[0176] 17 (wireless) transmitting / receiving unit

[0177] 18 cover

[0178] 19 screw

[0179] 2 coupling device; coupling bolt

[0180] 20 mounting portion

[0181] 21 coupling portion

[0182] 21a first cavity or circumferential passage of the coupling portion 21

[0183] 21b second cavity or radial passage of the coupling portion 21

[0184] 21c wear element or wear bushing of the coupling portion 21 spherical portion

[0185] 23 end collar

[0186] 24 vertical cavity; core hole

[0187] 24d vertical cavity of end collar 23

[0188] 25 valve element; automotive valve

[0189] 26 pressure sensor; pressure switch

[0190] 27 (wireless) transmitting / receiving unit

[0191] 28 cover

[0192] 29 screw

[0193] 3, 4 vehicle combination; combination; towing vehicle unit or trailer; road train

[0194] 3 front vehicle in the direction of travel A; towing vehicle; towing vehicle unit; truck

[0195] 4 rear vehicle in the direction of travel A; semitrailer; trailer

[0196] 5 ground

Claims

1. Coupling device (1; 2) for a vehicle combination (3, 4), preferably for a drawbar kingpin (1) of a semitrailer (4) of a tractor trailer combination (3, 4) or for a coupling bolt (2) of a towing vehicle (3) of a road train (3, 4), which coupling device extends essentially along a longitudinal axis (X), which coupling device has at least one wear detection means which is arranged in the coupling device (1; 2) aligned perpendicularly to the longitudinal axis (X) in such a way that a wear of the coupling device (1; 2) perpendicular to the longitudinal axis (X) can be detected visually and / or by means of a sensor, characterized in that the wear detection means comprises: • at least one wear element (11c, 12c; 21c) which is arranged in and / or on the coupling device (1; 2) aligned perpendicularly to the longitudinal axis (X) in such a way that a wear of the coupling device (1; 2) perpendicular to the longitudinal axis (X) wears the wear element (11c; 12c; 21c) equally or exclusively, wherein the wear element (11c, 12c; 21c) is arranged at least partially, preferably completely, around the coupling device (1; 2) in a circumferential direction (U), • at least one cavity (11a, 11b, 12a, 12b, 14c; 21a, 21b, 24) which extends in the circumferential direction (U) in a manner corresponding to the wear element (11c, 12c; 21c), wherein the cavity (11a, 11b, 12a, 12b, 14c; 21a, 21b, 24) is sealed in a fluid-tight manner by the wear element (11c, 12c; 21c), preferably perpendicularly to the longitudinal axis (X), • at least one pressure sensor (16; 26) which is designed to detect a pressure of a fluid in the cavity (11a, 11b, 12a, 12b, 14c; 21a, 21b, 24), wherein the wear element (11c, 12c; 21c) is dimensioned perpendicularly to the longitudinal axis (X) in such a way that, when a wear limit of the coupling device (1; 2) is reached at this point of the coupling device (1; 2), the fluid can escape through a through-opening of the wear element (11c, 12c; 21c) caused by the wear.

2. Coupling device (1; 2) according to claim 1, wherein the wear element (11c, 12c; 21c) extends perpendicularly to the longitudinal axis (X) to an extent corresponding to the wear limit of the coupling device (1; 2) at this point of the coupling device (1; 2), wherein the cavity (11a, 11b, 12a, 12b, 14c; 21a, 21b, 24) is arranged behind the wear element (11c, 12c; 21c) perpendicularly to the longitudinal axis (X).

3. Coupling device (1; 2) according to claim 1 or 2, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ wherein the cavities (11a, 11b, 12a, 12b, 14c; 21a, 21b, 24) comprise: • at least one first cavity (11a, 12a; 21a) as a circumferential channel (11a, 12a; 21a) extending at least partially, preferably completely, around the coupling device (1; 2) in the circumferential direction (U), and • at least one second cavity (11b, 12b; 21b) as a radial channel (11b, 12b; 21b) extending linearly from the first cavity (11a, 12a; 21a) into the coupling device (1; 2) perpendicular to the longitudinal axis (X), wherein the pressure sensor (16; 26) is designed to detect the pressure of the fluid directed into the second cavity (11b, 12b; 21b).

4. The coupling device (1; 2) according to claim 3, wherein the cavities (11a, 11b, 12a, 12b, 14c; 21a, 21b, 24) further comprise: • at least one vertical cavity (14c; 24) extending along the longitudinal axis (X) in the coupling device (1; 2), preferably in the retraction portion (12) of the drawbar kingpin (1), wherein the pressure sensor (16; 26) is designed to detect the pressure of the fluid directed into the vertical cavity (14c; 24).

5. The coupling device (1; 2) according to any one of the preceding claims, wherein the coupling device (1) is a drawbar kingpin (1), wherein the drawbar kingpin (1) has in succession along its longitudinal axis (X): • a mounting plate (10) designed to be connected to the semitrailer, • a transition portion (11) adjoining the mounting plate (10), • a retraction portion (12) adjoining the transition portion (11) and designed for a connection with a drawbar socket profile of a tractor unit of the towed trailer, and • an end collar (13) adjoining the retraction portion (12) and terminating the drawbar kingpin (1) downward, wherein the wear elements (11c, 12c) are arranged in the transition portion (11) and / or in the retraction portion (12).

6. The coupling device (1; 2) according to claim 5, wherein the wear elements (11c, 12c) are formed completely closed around the drawbar kingpin (1) in the circumferential direction (U), wherein the drawbar kingpin (1) is formed at least, preferably exactly, as two parts with a first upper kingpin part (1a) and a second lower kingpin part (1b), wherein the second lower kingpin part (1b) has at least, preferably exactly, the end collar (13), ​ wherein the first upper kingpin part (1a) and the second lower kingpin part (1b) are fixedly connected to each other by means of a connection (1c), preferably by means of a threaded connection (1c).

7. Coupling device (1; 2) according to claim 5 or 6, wherein the transition portion (11) has a first wear element (11c) which preferably has a first cavity (11a) and a second cavity (11b), wherein the transition portion (11) has a first wear element (11c) which preferably has a first cavity (11a) and a second cavity (11b), 8. Coupling device (1; 2) according to any one of the preceding claims, wherein the coupling device (2) is a coupling bolt (2), wherein the coupling bolt (2) has a coupling portion (21) with a spherical portion which is designed to be received by a coupling eye of a coupling hook, wherein the spherical portion of the coupling portion (21) is at least partially, preferably completely, formed by the wear element (21c), wherein the wear element (21c) preferably forms the spherical portion of the coupling portion (21) alone and / or is designed as a wear bushing (21c).

9. Coupling device (1; 2) according to any one of the preceding claims, the coupling device further comprising a preferably wireless transmission unit (17; 27) which is at least signalingly connected to the pressure sensor (16; 26) in order to receive at least one item of information about the pressure of the fluid in the cavities (11a, 11b, 12a, 12b, 14c; 21a, 21b, 24), wherein the preferably wireless transmission unit (17; 27) is further designed to transmit the received information of the pressure, preferably wirelessly, to the outside of the coupling device (1; 2).

10. Coupling device (1; 2) according to claim 9, wherein the transmitted information of the pressure of the transmission unit (17; 27) comprises the pressure of the fluid in the cavities (11a, 11b, 12a, 12b, 14c; 21a, 21b, 24) and / or one item of information derived from the pressure of the fluid in the cavities (11a, 11b, 12a, 12b, 14c; 21a, 21b, 24).

11. Coupling device (1; 2) according to claim 9 or 10, the coupling device having a plurality of wear elements (11c, 12c; 21c) which each have at least one cavity (11a, 11b, 12a, 12b, 14c; 21a, 21b, 24) and each have at least one pressure sensor (16; 26), wherein the information of the pressure transmitted by the preferably wireless transmission unit (17; 27) preferably contains the identification of the associated pressure sensor (16; 26).

12. Coupling device (1; 2) according to any one of claims 9 to 11, wherein said preferably wireless sending unit (17; 27) is a preferably wireless sending / receiving unit (17; 27), wherein said preferably wireless sending / receiving unit (17; 27) is designed to preferably wirelessly request from outside of said coupling device (1; 2) to send said information of said pressure.

13. The coupling device (1; 2) according to any one of the preceding claims, said coupling device further comprising an illumination means, said illumination means being at least signal-wise connected to said pressure sensor (16; 26), wherein said illumination means is designed to be operated depending on said pressure of said fluid in said cavity (11a, 11b, 12a, 12b, 14c; 21a, 21b, 24).

14. The coupling device (1; 2) according to any one of the preceding claims, wherein said pressure sensor (16; 26) is a pressure switch (16; 26) designed to switch in response to a predetermined pressure drop of said fluid in said cavity (11a, 11b, 12a, 12b, 14c; 21a, 21b, 24).

15. A vehicle (3; 4), preferably a semitrailer (4) or a towing vehicle (3), having a coupling device (1; 2) according to one of the preceding claims, preferably a towing eye main pin (1) or a coupling bolt (2).

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