Kingpin for a semi-trailer of an articulated vehicle

Abstract

The present invention relates to a kingpin (1) for a semitrailer of a semi-trailer vehicle, which extends substantially along a longitudinal axis (X), with at least one wear detection means arranged in the kingpin (1) perpendicular to the longitudinal axis (X) such that wear of the kingpin (1) perpendicular to the longitudinal axis (X) can be detected optically and / or by sensors. The kingpin (1) is characterized in that the wear detection means comprises: • at least one wear element (11c, 12c) which is arranged in and / or on the kingpin (1) perpendicular to the longitudinal axis (X) such that wear of the kingpin (1) perpendicular to the longitudinal axis (X) equally wears the wear element (11c; 12c), wherein the wear element (11c, 12c) is arranged in the circumferential direction (U) at least partially, preferably completely, around the kingpin (1) • at least one cavity (11a, 11b, 12a, 12b, 14c) which extends in the circumferential direction (U) corresponding to the wear element (11c, 12c), wherein the cavity (11a, 11b, 12a, 12b, 14c) is closed fluid-tight by the wear element (11c, 12c), preferably perpendicular to the longitudinal axis (X), wherein the cavity (11a, 11b, 12a, 12b, 14c) contains a fluid at overpressure, and • at least one pressure sensor (16) which is designed to detect the pressure of the fluid in the cavity (11a, 11b, 12a, 12b, 14c), wherein the wear element (11c, 12c) is dimensioned perpendicular to the longitudinal axis (X) in such a way that the fluid can escape through a through-opening of the wear element (11c, 12c) created due to wear when a wear limit of the kingpin (1) is reached at this point on the kingpin (1).

Description

[0001] The present invention relates to a kingpin for a semi-trailer of a semi-trailer vehicle, a semi-trailer with such a kingpin and a semi-trailer vehicle with such a semi-trailer.

[0002] Today, various types of motor vehicles are used as road vehicles for the transport of goods. These include articulated vehicles, which are also colloquially known as semi-trailer trucks.

[0003] A semi-trailer vehicle is a combination consisting of a tractor unit, which can also be called a semi-trailer, and a semi-trailer, which can also be called a semi-trailer, semi-trailer or trailer. The tractor unit is a shortened truck without a loading area, whose frame, chassis or chassis instead has a fifth wheel coupling to accommodate a corresponding attachment of the semi-trailer. The semi-trailer is a comparatively long trailer without a front axle, the front of which rests with its top, viewed in the direction of travel, on the fifth wheel coupling of the tractor unit frame and is held in place by the fifth wheel coupling so that it can rotate.The pivoting connection between the tractor unit and the semi-trailer is made possible by a bolt – called a kingpin, king bolt, or kingpin – that secures the semi-trailer and is held by the fifth wheel coupling. The cylindrical and rotationally symmetrical kingpin is fixed in the front area of the frame and points downwards. The semi-trailer can also be referred to as a vehicle combination. The tractor unit can also be referred to as the front vehicle in the direction of towing, travel, or movement, and the semi-trailer can also be referred to as the rear vehicle in the direction of towing, travel, or movement.

[0004] To couple or hitch the semi-trailer to the tractor unit, the fifth wheel coupling is opened to face rearward, and the tractor unit reverses toward the semi-trailer, which is positioned on its fifth wheel supports. This causes the tractor unit frame with the fifth wheel coupling to slide under the front of the semi-trailer frame, and the kingpin to pass through the opening in the fifth wheel coupling into the interior of the semi-trailer. The tractor unit then stops, and the opening in the fifth wheel coupling is closed and locked. The vehicle / trailer combination is ready to drive. Uncoupling or uncoupling is performed in reverse.

[0005] The fixed kingpin of the semi-trailer thus not only enables a positive locking against the closed fifth wheel of the tractor unit against the direction of travel or towing, but also a rotational relative movement between the semi-trailer and the tractor unit, allowing the semi-trailer to follow the movement of the tractor unit even when cornering. Furthermore, the semi-trailer can supply the semi-trailer with electrical and hydraulic power via the rotatable connection between the tractor unit's fifth wheel and the kingpin of the semi-trailer, as described, for example, in DE 20 2007 014 589 U1.

[0006] Due to these relative movements between the kingpin and the fifth wheel coupling, during operation of the articulated vehicle, the material of at least the kingpin is subject to abrasion where the kingpin comes into contact with the fifth wheel coupling or rubs against the fifth wheel coupling. This abrasion or wear of the kingpin reduces its material strength and thus weakens the kingpin as a transmission element in the power flow between the tractor unit and the semi-trailer. This can lead to the kingpin breaking off.

[0007] Therefore, to ensure road safety, it is necessary to check the kingpin for wear on an articulated vehicle regularly, for example at specific intervals such as every six months or depending on the use of the articulated vehicle, for example, the number of kilometers driven. This has previously been done manually, i.e., by a person who measures the dimensions of the kingpin at specific, specified points using a mechanical gauge or template to determine whether the measured dimensions still meet the relevant specifications, i.e., whether the kingpin is already excessively worn and needs to be replaced or not.

[0008] The disadvantage of this is that the assessment of permissible or impermissible wear on the kingpin is left to the individual, and thus there is a certain degree of uncertainty in that the assessment may also depend on the person's attentiveness and / or experience. This can lead to the continued use of an impermissibly worn kingpin, which can endanger the roadworthiness of the articulated vehicle. It can also lead to the premature replacement of a still-usable kingpin, which can cause additional effort, additional costs, and / or unnecessary downtime of the articulated vehicle.

[0009] Another disadvantage is that wear on the kingpin can vary greatly, meaning that within the permissible time or mileage interval between two wear tests, excessive wear can be reached without being detectable at the time. This can also jeopardize the roadworthiness of the articulated vehicle.

[0010] The applicant therefore discloses a kingpin for a semitrailer of a semi-trailer vehicle from WO 2022 / 218 798 A1, which kingpin extends essentially along a longitudinal axis. The kingpin has at least one wear detection means arranged in the kingpin perpendicular to the longitudinal axis such that wear of the kingpin perpendicular to the longitudinal axis can be detected visually and / or by sensors. The wear detection means has at least one specific wear element, which is subject to wear of the kingpin in the same way as the kingpin itself at this location.

[0011] A disadvantage of the wear detection device used in WO 2022 / 218 798 A1 is that the radially aligned wear element of the wear detection device can only detect wear at specific points. With a wear detection device that extends straight through the kingpin, this can also be achieved diametrically opposite using a second wear element. However, this may be of little significance for wear at other locations on the kingpin in the circumferential direction.

[0012] For this purpose, several wear elements of this type could be used in a horizontal plane or only slightly offset from one another along the longitudinal axis in order to detect wear of the kingpin in the circumferential direction at more than just one location or at more than just two diametrically opposed locations on the kingpin. However, with an increasing number of wear elements, this would lead to an increasing weakening of the kingpin's stability, since an opening or through-hole into the interior of the kingpin would have to be provided for each wear element. This could lead to such a significant reduction in the kingpin's stability that such a wear detection device could be inadmissible.Furthermore, only specific points of the kingpin in the circumferential direction would continue to be covered and monitored for wear, which would always lead to gaps between two immediately adjacent wear elements in the circumferential direction, i.e. the wear monitoring would always remain incomplete in the circumferential direction.

[0013] One object of the present invention is to provide a kingpin for a semitrailer of an articulated vehicle of the type described above, so that the inspection of the wear of the kingpin can be simplified and / or improved. In particular, this should be able to be carried out as seamlessly or continuously as possible in the circumferential direction. In particular, this should be able to be carried out as simply, reliably, space-savingly, independently of personnel and / or automatically as possible. In any case, the road safety of the articulated vehicle should be improved or increased. At the very least, an alternative to known options for checking the wear of the kingpin should be created.

[0014] The object is achieved according to the invention by a kingpin having the features of patent claim 1, by a semitrailer having the features of patent claim 14, and by a semitrailer vehicle having the features of patent claim 15. Advantageous further developments are described in the subclaims.

[0015] The present invention thus relates to a kingpin for a semitrailer of a semi-trailer vehicle, which kingpin extends substantially along a longitudinal axis. As described above, the kingpin represents a bolt-like, rotationally symmetrical, and usually metallic projection that extends vertically downwards from the underside of the chassis. When used on a semitrailer, the longitudinal axis of the kingpin, as its axis of rotational symmetry, coincides with the axis of the vertical direction in Cartesian coordinates, i.e., with the direction of gravity, which extends perpendicular to the horizontal plane.

[0016] The kingpin has at least one wear detection means which is arranged in the kingpin perpendicular to the longitudinal axis in such a way that wear of the kingpin perpendicular to the longitudinal axis can be detected optically and / or by sensors.

[0017] According to the invention, the wear detection means comprises: • at least one wear element which is arranged in and / or on the kingpin perpendicular to the longitudinal axis in such a way that wear of the kingpin perpendicular to the longitudinal axis equally wears the wear element, wherein the wear element is arranged at least partially, preferably completely, around the kingpin in the circumferential direction, • at least one cavity which extends in the circumferential direction corresponding to the wear element, wherein the cavity is sealed fluid-tight by the wear element, preferably perpendicular to the longitudinal axis, wherein the cavity contains a fluid at overpressure, and • at least one pressure sensor which is designed to detect 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 a through-opening of the wear element caused by wear when a wear limit of the kingpin is reached at this point of the kingpin.

[0018] In other words, at least one wear element of the wear detection means is arranged within the contour or within the material of the kingpin such that both the material of the kingpin and the material of the wear element are reduced in their radial extent by the abrasion or wear that occurs on the part of the kingpin during operation, as described above. For this purpose, the at least one wear element can be arranged precisely radially or perpendicular to the longitudinal axis, or at least obliquely to the longitudinal axis in and / or on the kingpin such that the abrasion or wear can also reduce the wear element from the outside.

[0019] The present invention is based on the finding that by designing a part of the kingpin as or with a wear element, the extent of abrasion or wear of the kingpin at this point can be made visually visible from the outside and / or detectable by sensors. In any case, the condition of the wear element can be detected and monitored more easily in this way than was previously possible through regular manual inspections of the kingpin itself as described above. This can reduce the effort and thus also the cost of checking the extent of wear on the kingpin. This can also increase the reliability of the inspection result, which can firstly increase the road safety of the articulated vehicle and secondly avoid premature or unnecessary replacement of a still usable kingpin.Locating the wear element within the kingpin can minimize implementation costs and, in particular, the required installation space. In particular, continuous and significantly more regular inspection and monitoring of the extent of kingpin wear can be performed than previously possible, which can increase the road safety of the articulated vehicle and extend the service life of the kingpin.

[0020] In this case, the wear or the reaching of a predetermined radial wear limit of the wear element and thus also of the kingpin at this point of the kingpin can be detected according to the invention at least in sections and preferably completely in the circumferential direction around the kingpin, in that the wear element closes a cavity which contains a fluid under excess pressure, such as air at, for example, 6 bar to 8 bar, in a fluid-tight manner, as long as the wear of the kingpin and thus also the wear of the wear element at this point of the kingpin is within a permissible level, since the wall thickness of the wear element then remains sufficient to enclose the fluid under excess pressure in a fluid-tight manner and thus to maintain its excess pressure. However, if the wear limit is reached, the wear element is penetrated and the fluid can escape to the outside due to its excess pressure, i.e.outside the cavity. The excess pressure of the fluid trapped in the cavity is thus lost at the moment or point in time when the wear limit of the kingpin is reached. At least these two states can be distinguished by the sensor-detected pressure of the fluid in the cavity.

[0021] Due to the combination of cavity and wear element formed at least in sections in the circumferential direction, wear can be detected completely and seamlessly or continuously to this extent or along this extent in the circumferential direction, since the wear element according to the invention extends accordingly far and continuously in the circumferential direction. Thus, inadmissibly high wear can break through the wear element at any point along the circumferential direction and cause a pressure loss of the fluid, which can then be detected, which can lead to complete and seamless or continuous wear detection in the circumferential direction. By using several combinations of cavity and wear element offset from one another along the longitudinal axis, this can occur at several points or in several areas of the kingpin along the longitudinal axis.

[0022] In any case, this can be achieved completely and seamlessly in the circumferential direction by providing a ring-shaped, closed combination of cavity and wear element in the circumferential direction. In this case, the wear element can be provided as a bushing that can be pushed over the kingpin to the desired position. For this purpose, the kingpin can be split into two parts if necessary to ensure that the bushing can be positioned properly when separated. The two kingpin parts can be connected using a threaded connection or a screw connection.

[0023] In any case, these two states—whether the overpressure in the cavity is present or not—can be detected or differentiated by the pressure sensor. To this end, the pressure sensor can continuously record pressure readings as information about the pressure of the fluid in the cavity, which can then be evaluated by the pressure sensor itself and / or externally, for example, by a separate electronic element such as a control unit of the kingpin or by a control unit or the like external to the kingpin, at least to determine whether the overpressure of the fluid is still present and thus the wear element ensures the tightness of the cavity. This allows conclusions to be drawn about the permissible degree of wear of the wear element and thus also of the kingpin at this point on the kingpin.In the other case, based on the sensor-detected pressure value as information on 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 inadmissibly high wear of the kingpin at this point, which has broken through the wear element and thus connected the cavity to the environment in a fluid-carrying manner.

[0024] This can also be achieved by means of a pressure switch as a simple pressure sensor, which can then switch from one state to another when the pressure of the fluid drops due to a leak in the wear element.

[0025] In any case, a value recorded by a sensor, preferably by the pressure sensor, can be converted into a pressure value, or a value that represents the state of the pressure switch as a pressure sensor can be sent or transmitted from the pressure sensor to outside the kingpin, which can preferably be done wirelessly to avoid the expense of wiring. Alternatively or additionally, the pressure sensor itself can also evaluate the recorded pressure value of the pressure sensor to determine whether the pressure limit is met, according to which the current wear would be considered acceptable, or whether it is undershot, according to which the current wear would be considered unacceptable, cf. the two states of the pressure sensor as a pressure switch. This evaluation result could then be communicated externally in order to reduce the expense of the corresponding evaluation on the part of the pressure sensor orof the kingpin, for example by a separate kingpin control unit connected to the pressure sensor, and thus to avoid outside the kingpin.

[0026] The latter can make it advantageous to make the result of the wear monitoring according to the invention available to a control unit outside the kingpin, such as an engine control unit of the semi-trailer and / or a tractor unit, which comes from a different manufacturer than the kingpin, so that the information on the result of the wear monitoring according to the invention can be transferred via an interface without having to further coordinate the pressure sensor or the control unit of the kingpin and the independent control unit of the semi-trailer and / or a tractor unit. Information such as the pressure limit value can also be part of the pressure sensor or the control unit of the kingpin and must be made available to the independent control unit of the semi-trailer and / or a tractor unit.or a tractor unit, which would otherwise require intervention and effort at least during assembly and commissioning of the kingpin according to the invention, which can be avoided in this way.

[0027] In any case, the output, transmission or communication of corresponding information on the pressure of the fluid in the cavity can be carried out by means of a, preferably wireless, communication unit or by means of a, preferably wireless, transmission unit, which can at least transmit data or information to the outside of the kingpin, preferably wirelessly, and preferably as a, preferably wireless, transmission / reception unit can also receive data and information from outside.

[0028] This can be done automatically by the pressure sensor or by a control unit of the kingpin using the preferably wireless transmitting unit or the transmitting / receiving unit as soon as the pressure limit or wear limit is reached or the pressure switch is activated, so that the person or driver can react to this immediately. In this way, the output or transmission of this information can be limited to the case when inadmissible wear is present. Otherwise, communication can be avoided, which can save energy and prevent disruptions to the person or driver. However, the person or driver cannot then distinguish whether information about inadmissible wear is missing because the wear monitored according to the invention is permissible or within the permissible limits, or whether the pressure sensor, a control unit of the kingpin and / oror the transmitting unit or transmitting / receiving unit does not work, for example due to damage or an empty electrical energy storage device.

[0029] This information can therefore alternatively be output continuously or regularly by the pressure sensor or by a control unit of the kingpin by means of the preferably wireless transmitting unit or the transmitting / receiving unit in order to ensure that this information reaches the person or the driver. Through this continuous incoming information, for example at predetermined intervals of one hour, the person or the driver can also recognize that the pressure sensor or the control unit of the kingpin is functional. The output of this information by the pressure sensor or by a control unit of the kingpin by means of the preferably wireless transmitting unit or the transmitting / receiving unit can, if necessary, be confirmed by an acknowledgement of receipt by the person or the driver at least for the duration of the current use orthe current journey must be terminated or paused in order to save electrical energy on the part of the pressure sensor or a control unit of the kingpin as well as the transmitting unit or transmitting / receiving unit.

[0030] The output of this information by the pressure sensor or by a control unit of the kingpin via the preferably wireless transmitter or transmitter / receiver unit can, if necessary, additionally or alternatively only occur upon a query or in response to an external request, as described in more detail below. This can, for example, occur once upon commencement of use or upon the start of a journey.

[0031] In any case, this information can be output by the pressure sensor or by a control unit of the kingpin by means of the preferably wireless transmitting unit or the transmitting / receiving unit to the person or the driver in such a way that this information is transmitted wirelessly to an electronic receiving device, such as a mobile device, for example in the form of a smartphone, a tablet, or the like, of the person or the driver. Additionally or alternatively, this information can also be transmitted wirelessly by the pressure sensor or by a control unit of the kingpin by means of the preferably wireless transmitting unit or the transmitting / receiving unit to an electronic receiving device of the tractor unit, received and further processed there, and output or displayed to the driver via an output element, such as in particular a display element of the tractor unit.In this case, this information can be forwarded wirelessly from the tractor unit or its control unit to a fleet management system in order to consider and plan the replacement of the worn kingpin.

[0032] Additionally or alternatively, the unacceptably high wear of the kingpin can also be visually detected by a person because the cavity is no longer covered by the wearing element and is therefore visible. This can make it possible for a person to assess the wear purely visually. This can be done if there is no option for electronically evaluating the information from the pressure sensor, for example if the semi-trailer is separated from the tractor unit or the kingpin has been removed from the semi-trailer. This can also allow a person to regularly visually check the wear of a visually visible kingpin, particularly if the semi-trailer is parked or uncoupled. In particular, the driver of the tractor unit who is driving a third-party orunknown semi-trailer with a kingpin according to the invention, can easily and quickly visually check the wear condition of the kingpin of the semi-trailer, in particular before a, preferably wireless, data connection is directly established between a control unit of the tractor unit and a control unit of the semi-trailer or a control unit of the kingpin or its pressure sensor, in order to be able to electronically query, evaluate or display the information on the pressure of the fluid in the cavity or the wear condition of the wearing element of the kingpin. This can increase the driver's confidence in transporting the foreign or unknown semi-trailer. It can also offer the possibility of additional visual inspection by a person in order to check for a faulty pressure sensor which may have wrongly detected permissible or impermissible wear.

[0033] In any case, the wear element can be located in a location, viewed in the horizontal plane or in the cross-section of the kingpin, where particularly significant abrasion or wear typically occurs, or where unacceptably high wear is typically expected to occur first. This can increase the predictive value of the wear element accordingly.

[0034] As already mentioned, multiple wear elements can also be used along the longitudinal axis of the kingpin, either with a common pressure sensor or each with its own pressure sensor, in order to implement the previously described wear monitoring at a corresponding number of locations or in different planes of the kingpin along the longitudinal axis. This allows, in particular, multiple locations that are typically subject to significant wear to be monitored for wear simultaneously, as described above.

[0035] In any case, an electrical supply or an electrical power supply to at least the pressure sensor and preferably other electrical and / or electronic elements of the kingpin, such as a transmitting or transmitting / receiving unit and / or a lighting device, can be provided by means of an electrical energy storage device, which can be provided in and / or on the kingpin, preferably internally near the pressure sensor or integrated with the pressure sensor or another electrical or electronic element. This allows an electrical power supply to the pressure sensor and, if appropriate, several or all electrical and / or electronic elements of the kingpin to be provided directly by the kingpin itself, thus eliminating the need for an electrically conductive connection from outside the kingpin.This can keep the effort of using at least one pressure sensor as described above correspondingly low.

[0036] According to one aspect of the invention, the wear element extends perpendicular to the longitudinal axis to such an extent as corresponds to a wear limit of the kingpin at this point of the kingpin, wherein the cavity is arranged perpendicular to the longitudinal axis behind the wear element.

[0037] In other words, the wear element directly covers the cavity or a circumferential channel of the cavity radially, so that the cavity or the circumferential channel can be introduced purely radially into the kingpin, for example by drilling or milling, which can simplify implementation.

[0038] According to a further aspect of the invention, the cavity comprises: • at least one first cavity as a circumferential channel, which extends at least partially, preferably completely, in the circumferential direction around the kingpin, and • at least one second cavity as a radial channel, which extends perpendicular to the longitudinal axis in a straight line from the first cavity into the kingpin, wherein the pressure sensor is configured to detect the pressure of the fluid directed into the second cavity.

[0039] A concrete implementation option for this could be that the combination of cavity and wear element is achieved in the circumferential direction by the circumferential channel as the first cavity of the entire cavity and its coverage by the correspondingly shaped or extending wear element. At the same time, the pressure sensor can be relocated to the interior of the kingpin by fluidly connecting the circumferential channel to the pressure sensor at least at one point via the second cavity of the entire cavity as a radial channel.

[0040] According to a further aspect of the invention, the cavity further comprises: • at least one vertical cavity extending along the longitudinal axis in the kingpin, preferably in a constriction section of the kingpin, wherein the pressure sensor is configured to detect the pressure of the fluid directed into the vertical cavity.

[0041] In this way, the pressure sensor can be arranged centrally, in particular along a cavity on the longitudinal axis inside the kingpin, in order to minimize a weakening of the stability of the kingpin by the cavity for receiving the pressure sensor, by arranging the cavity for receiving the pressure sensor symmetrically on the longitudinal axis.

[0042] According to a further aspect of the invention, the kingpin has along its longitudinal axis in this order: • a mounting plate which is designed to be connected to the semi-trailer, • a transition section which connects to the mounting plate, • a constriction section, which adjoins the transition section and which is designed for a positive connection with a fifth wheel coupling of a tractor unit of the articulated vehicle, and • a final collar, which adjoins the constriction section and which closes the kingpin at the bottom, wherein the wear element is arranged in the transition section and / or in the constriction section.

[0043] Accordingly, monitoring for wear can be carried out as previously described at the corresponding points of these sections of the kingpin.

[0044] According to a further aspect of the invention, the wear element is designed to be completely closed in the circumferential direction around the kingpin, wherein the kingpin is formed at least, preferably exactly, in two parts with a first, upper kingpin part and with a second, lower kingpin part, wherein the second, lower kingpin part has at least, preferably exactly, the end collar, wherein the first, upper kingpin part and the second, lower kingpin part are fixedly connected to one another by means of a connection, preferably by means of a threaded connection.

[0045] This may be a possibility to use a bushing or the like as a wear element that is completely closed in the circumferential direction, as mentioned previously.

[0046] According to a further aspect of the invention, the transition section has a first wear element, preferably with a first cavity and with a second cavity, wherein the constriction section has a second wear element, preferably with a first cavity and with a second cavity.

[0047] This can enable the implementation of a wear detection according to the invention in sections up to completely in the circumferential direction around the kingpin at at least two different locations of the kingpin along the longitudinal axis, as already mentioned above.

[0048] According to a further aspect of the invention, the kingpin further comprises a, preferably wireless, transmitting 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 regarding the pressure of the fluid in the cavity, wherein the, preferably wireless, transmitting unit is further configured to transmit the received information of the pressure to the outside of the kingpin, preferably wirelessly.

[0049] This can represent a concrete implementation option for communicating pressure information outside the pressure sensor or kingpin, as previously mentioned. The pressure information can represent a pressure value, a pressure switch state, and / or information resulting from these, as previously mentioned.

[0050] According to a further aspect of the invention, the transmitted information of the pressure of the transmitting unit comprises the pressure of the fluid in the cavity and / or information derived from the pressure of the fluid in the cavity, as already mentioned above.

[0051] According to a further aspect of the invention, the kingpin has a plurality of wear elements, each having at least one cavity with a fluid at overpressure and each having at least one pressure sensor.

[0052] Thus, wear at multiple locations on the kingpin along the longitudinal axis can be monitored independently of one another, each with its own pressure sensor, as described above. This can increase the complexity of the multiple pressure sensors, as the pressure sensors each require installation space, incur costs for acquisition and installation, and require electrical power. However, this can represent a possibility for monitoring wear at multiple locations on the kingpin along the longitudinal axis independently of one another, according to the invention.

[0053] In this case, the pressure information transmitted by the preferably wireless transmitter unit can contain an identification of the respective pressure sensor. This allows the data from the pressure sensors to be differentiated from one another and assigned to the respective pressure sensor and thus also to the location on the kingpin that is being monitored for wear by this pressure sensor.

[0054] According to a further aspect of the invention, the preferably wireless transmitting unit is a preferably wireless transmitting / receiving unit, wherein the preferably wireless transmitting / receiving unit is designed to be requested, preferably wirelessly, to transmit the information of the pressure from outside the kingpin.

[0055] This can enable implementation as previously described.

[0056] According to a further aspect of the invention, the kingpin further comprises a lighting means which is connected to the pressure sensor at least in a signal-transmitting manner, wherein the lighting means is designed to be operated as a function of the pressure of the fluid in the cavity.

[0057] In this way, the sensor-based pressure or wear monitoring results can be displayed visually directly on the kingpin using a light source, in addition to or as an alternative to being transmitted outside the kingpin, for immediate recognition by a person. This can be particularly useful when the semitrailer is parked or uncoupled, and thus information about the cavity pressure cannot be retrieved, for example, via a tractor unit's control unit.

[0058] The light source can be implemented, in particular, as an LED. In any case, the kingpin or preferably a collar of the kingpin, in particular aligned along the longitudinal axis at the lower end and / or radially or perpendicularly to the longitudinal axis, can have the light source or a plurality of, preferably evenly distributed, light sources in the circumferential direction. The electrical supply can preferably be provided jointly with the pressure sensor and, if necessary, with a transmitting unit or a transmitting / receiving unit.

[0059] In any case, the lamp can be operated permanently or continuously in order to be able to monitor the wear status of the kingpin at any time. For this purpose, the two resulting relevant states, whether the wear of the kingpin is permissible or impermissible at at least one point along the longitudinal axis, can be differentiated by two significantly different colors of the lamp, for example, "green" for permissible wear and "red" for impermissible wear. Alternatively, the two resulting relevant states can also be differentiated by slow flashing for permissible wear and fast flashing for impermissible wear. This can also be combined with the color information as described above.

[0060] Continuous operation of the lamp also allows the person or driver to recognize that the wear detection system according to the invention is functioning. Furthermore, the associated effort of switching the lamp on and off, or the need to provide appropriate electrical means for this, such as an externally accessible switch on the kingpin, can be avoided.

[0061] If necessary, a functioning light source, and possibly a functioning control unit of the kingpin, with a simultaneously inoperative pressure sensor could lead to an output corresponding to the unacceptable wear in order to attract the attention of the person or driver.

[0062] Alternatively, the light source could also be operated, particularly in "red" and / or flashing as a warning, only when excessive wear is detected, in order to save electrical energy and avoid disturbing the surroundings or people with continuous or periodic illumination or flashing, as long as the wear is within an acceptable level. In this case, however, it would not be possible to distinguish whether no illumination or flashing occurs because the wear was detected as acceptable, or whether there is a functional failure of the wear detection system according to the invention.

[0063] According to a further aspect of the invention, the pressure sensor is a pressure switch which is designed to switch in response to a predetermined pressure drop of the fluid in the cavity.

[0064] This can be completely sufficient for implementing the invention and at the same time keep the effort for implementing the pressure sensor low.

[0065] The invention also relates to a semi-trailer with a kingpin as described above. This allows the previously described aspects of a kingpin according to the invention to be implemented and used in a semi-trailer.

[0066] The invention further relates to a semi-trailer truck with a semi-trailer as described above. This allows a semi-trailer truck to be created in order to implement and utilize the previously described aspects of a kingpin according to the invention on its semi-trailer.

[0067] Several embodiments and further advantages of the invention are illustrated and explained in more detail below in conjunction with the following figures. Fig. 1 a perspective view of a kingpin according to the invention according to a first embodiment without wear elements; Fig. 2 the representation of the Fig. 1 with wear elements; Fig. 3 a longitudinal section of the representation of the Fig. 2; Fig. 4 a longitudinal section of a kingpin according to the invention according to a second embodiment; and Fig. 5 a longitudinal section of a kingpin according to the invention according to a third embodiment.

[0068] The above figures are viewed in cylindrical coordinates. A longitudinal axis X extends. A radial direction R extends perpendicular to the longitudinal axis X, 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 simultaneously represents the vertical axis X in Cartesian coordinates, the axis of gravity or gravitational force.

[0069] Fig. 1 shows a perspective view of a kingpin 1 according to the invention according to a first embodiment without wear elements 11c, 12c. Fig. 2 shows the representation of the Fig. 1 with wear elements 11c, 12c. Fig. 3 shows a longitudinal section of the representation of the Fig. 2.

[0070] The kingpin 1 can also be referred to as a king pin 1 or king bolt 1. The kingpin 1 or its body is metallic and rotationally symmetrical to the longitudinal axis X. The kingpin 1 is formed in 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 connection 1c in the form of a threaded connection 1c.

[0071] Along the longitudinal axis X from top to bottom, the kingpin 1 has a mounting plate 10, a transition section 11, a constriction section 12, and a closure collar 13. In the first exemplary embodiment, the first, upper kingpin part 1a has the mounting plate 10 and the transition section 11, and the second, lower kingpin part 1b has the constriction section 12 and the closure collar 13.

[0072] The mounting plate 10 extends in the radial direction R significantly beyond the remaining sections and is comparatively flat at the edges along the longitudinal axis X. There, the mounting plate 10 has several 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 to the underside of a chassis (not shown) of a semi-trailer (not shown) by means of screws.

[0073] The mounting plate 10 transitions seamlessly into the transition section 11, which extends comparatively far along the longitudinal axis X and is significantly smaller than the mounting plate 10 in the radial direction R. The constriction section 12 seamlessly adjoins the transition section 11 and has an even smaller extension in the radial direction R. The constriction section 12 transitions seamlessly into the end collar 13, which approximately corresponds to the transition section 11 in the radial direction R and closes off the kingpin 1 downwards along the longitudinal axis X.

[0074] When the semitrailer is coupled to a tractor unit (not shown), the constriction section 12 is received by the fifth wheel coupling thereof and is completely enclosed in the circumferential direction U. As a result, when the articulated vehicle with semitrailer and tractor unit is in operation, abrasion or wear of the cylindrical outer surface of the kingpin 1 and in particular of its constriction section 12 can occur, which over time can weaken the cross-section or material thickness of the kingpin 1 to such an extent that reliable power transmission between the semitrailer and tractor unit via the kingpin 1 can no longer be guaranteed.

[0075] An unacceptably high level of wear in both the transition section 11 and the constriction section 12 of the kingpin 1 can be avoided according to the first embodiment of the Fig. 1 to 3 according to the invention in that the transition section 11 has a first cavity 11a as a circumferential channel 11a, which is formed along the longitudinal axis X approximately centrally in the circumferential direction Z in a continuous annular manner as a radial depression. At one point of the circumferential channel 11a of the transition section 11, a second cavity 11b extends radially in a straight line as a radial channel 11b into the transition section 11 of the kingpin 1. Due to the division of the kingpin 1 into two parts, the radial channel 11b of the transition section 11 ends in a corresponding transition circumferential channel 12d of the constriction section 12 and a transition radial channel 12e of the constriction section 12, which extends or continues the radial channel 11b of the transition section 11 towards the longitudinal axis X.

[0076] Likewise, the constriction section 12 has a first cavity 12a in the form of a circumferential channel 12a of the constriction section 12 and a second cavity 12b in the form of a radial channel 12b of the constriction section 12.

[0077] In the Fig. 3, the radial channel 11b of the transition section 11, the transition radial channel 12e of the constriction section 12 and the radial channel 12b of the constriction section 12 are shown aligned the same around the longitudinal axis X or in the circumferential direction U. However, due to the threaded connection 1c of the two kingpin parts 1a, 1b, the radial channel 11b of the transition section 11, which is formed in the first kingpin part 1a, can also be oriented differently than shown compared to the second kingpin part 1b, which has the transition radial channel 12e of the constriction section 12 and the radial channel 12b of the constriction section 12. In order to ensure that the radial channel 11b of the transition section 11, which is formed in the first kingpin part 1a, has a different orientation than shown, regardless of the alignment of the two kingpin parts 1a, 1b to one another around the longitudinal axis X orIn order to nevertheless ensure a fluid-conducting connection between the radial channel 11b of the transition section 11 of the first kingpin part 1a and the radial channel 12b of the constriction section 12 of the second kingpin part 1b in the circumferential direction U, the transition circumferential channel 12d of the constriction section 12 is provided to run continuously or annularly in the circumferential direction U.

[0078] Along the longitudinal axis X, a vertical cavity 14a of the mounting plate 10, a vertical cavity 14b of the transition section 11, a vertical cavity 14c of the constriction section 12, and a vertical cavity 14d of the end collar 13 in the form of bores with different diameters are provided in the kingpin 1, from top to bottom, in this order. However, the vertical cavity 14c of the constriction section 12 extends approximately halfway along the longitudinal axis X upwards into the transition section 11. Both the radial channel 11b of the transition section 11, or its extension by means of the transition radial channel 12e of the constriction section 12, and the radial channel 12b of the constriction section 12 end in the vertical cavity 14c of the constriction section 12, see. Fig. 3.

[0079] How to improve the clarity of the Fig. 3 and Fig. 4 only in the Fig. 5, also serves in the first embodiment of the Fig. 1 to 3, the vertical cavity 14c of the constriction section 12 serves as a pressure chamber, which is fluid-tightly sealed along the longitudinal axis X from below in the region of the vertical cavity 14d of the end collar 13 by a valve element 15 in the form of a car valve 15. Via the valve element 15, a fluid, for example air, can be filled under pressure into the vertical cavity 14c of the constriction section 12 as a pressure chamber, and the pressure can be maintained.

[0080] Along the longitudinal axis X from above, the vertical cavity 14c of the constriction section 12 is sealed fluid-tight as a pressure chamber by a pressure sensor 16 in the form of a pressure switch 16, so that the pressure within the vertical cavity 14c of the constriction section 12 as a pressure chamber can be detected by the pressure switch 16. The pressure switch 16 can assume two different switching states, depending on whether the pressure within the vertical cavity 14c of the constriction section 12 as a pressure chamber falls below or exceeds a predetermined pressure limit.

[0081] The pressure switch 16 is connected for signal transmission to a wireless transmitter / receiver unit 17, which also has an electrical energy storage device (not shown) in the form of a rechargeable and / or replaceable battery to electrically power itself and the pressure switch 16. The wireless transmitter / receiver unit 17 is sealed at the top by a dust- and dirt-tight cover 18, which is held in the mounting plate 10 by screws 19. The cover 18 is flush with the mounting plate 10 at the top.

[0082] The wireless transceiver unit 17 can receive the switching state of the pressure sensor 16 from the pressure sensor 16 or query it from the pressure switch 16 and transmit it wirelessly to the outside of the kingpin 1 regularly, for example hourly, and / or upon external request. There, the received switching state of the pressure sensor 16 can be used, for example, by an engine control unit of a tractor unit to inform the driver about the switching state of the pressure sensor 16 or the wear state of the kingpin 1 determined therefrom, in order to be able to detect and respond to any inadmissible wear as quickly as possible.

[0083] The distinction between a permissible and an impermissible state of wear of the kingpin 1 can be made possible, or the corresponding switching states of the pressure sensor 16 can be made possible according to the invention, in that both the circumferential channel 11a of the transition section 11 is closed in a fluid-tight manner to the outside or radially by a wear element 11c in the form of an annularly closed wear bushing 11c of the transition section 11 and the circumferential channel 12a of the constriction section 12 is closed in a fluid-tight manner to the outside or radially by a wear element 12c in the form of an annularly closed wear bushing 12c of the constriction section 12.

[0084] To install the two wear bushings 11c, 12c, the two kingpin parts 1a, 1b are still separated, so that the wear bushing 11c of the transition section 11 can be pushed onto the transition section 11 from below along the longitudinal axis X, and the wear bushing 12c of the constriction section 12 can be pushed onto the constriction section 12 from above along the longitudinal axis X. Fluid tightness can be achieved by subsequently pressing on the wear bushings 11c, 12c. The two kingpin parts 1a, 1b are then screwed together, as already mentioned.

[0085] Now, the vertical cavity 14c of the constriction section 12 as a pressure chamber including the circumferential channel 11a of the transition section 11, the radial channel 11b of the transition section 11, the circumferential channel of the constriction section 12, the radial channel 12b of the constriction section 12, the transition circumferential channel 12d of the constriction section 12 and the transition radial channel 12e of the constriction section 12 is filled with compressed air by means of the valve element 15, which, due to the fluid tightness of the valve element 15, the pressure switch 16 and the two wear bushings 11c, 12c, cannot escape from the vertical cavity 14c of the constriction section 12 as a pressure chamber and the channels 11a, 11b, 12a, 12b, 12d, 12e can escape.

[0086] Since the two wear bushings 11c, 12c are radially formed to exactly the extent that corresponds to the limit of permissible wear of the kingpin 1 at this point, the two wear bushings 11c, 12c seal the vertical cavity 14c of the constriction section 12 as a pressure chamber, as well as the channels 11a, 11b, 12a, 12b, 12d, 12e, in a fluid-tight manner as long as the wear of the kingpin 1 at this point remains within a permissible level. Therefore, the pressure switch 16 remains in the corresponding switch state as long as the fluid tightness is maintained and thus the overpressure of, for example, 6 bar to 8 bar is applied to the pressure switch 16.

[0087] If, during operation of the kingpin 1, a wear-related leak occurs at any point in one of the two wear bushings 11c, 12c, air escapes outward from the vertical cavity 14c of the constriction section 12, which serves as a pressure chamber, as well as from the channels 11a, 11b, 12a, 12b, 12d, 12e, causing the excess pressure of the fluid or air to rapidly decrease. As a result, the pressure falls below the pressure limit or threshold of the pressure switch 16, and the pressure switch 16 switches to the corresponding switch state, which can be communicated externally by the wireless transmitting / receiving unit 17, particularly precisely when the change in the switch state of the pressure switch 16 occurs.

[0088] This allows the tractor driver to be informed of the excessive wear on the kingpin 1 and to react accordingly. After the end of the current operation, the excessively worn wear bushing 11c, 12c can be replaced, and the vertical cavity 14c of the constriction section 12 can be refilled with compressed air as a pressure chamber.

[0089] Due to the circumferential channels 11a, 12a extending continuously in the circumferential direction U, the escape of the pressurized air can occur anywhere in the circumferential direction U and trigger the switching of the pressure switch 16. In this way, complete and gapless or stepless wear detection can be achieved in the circumferential direction U.

[0090] Fig. 4 shows a longitudinal section of a kingpin 1 according to the invention according to a second embodiment.

[0091] In this case, the first, upper kingpin part 1a has the mounting plate 10, the transition section 11, and the constriction section 12, and the second, lower kingpin part 1b has the end collar 13. In this way, the radial channel 11b of the transition section 11 can be designed to extend continuously into the vertical cavity 14c of the constriction section 12, which can reduce the manufacturing effort compared to the first embodiment, since the transition circumferential channel 12d of the constriction section 12 and the transition radial channel 12e of the constriction section 12 can be omitted.

[0092] Fig. 5 shows a longitudinal section of a kingpin 1 according to the invention according to a third embodiment.

[0093] In this case too, the first, upper kingpin part 1a has the mounting plate 10, the transition section 11 and the constriction section 12 and the second, lower kingpin part 1b has the end collar 13, so that in this case too, the radial channel 11b of the transition section 11 can be designed to extend continuously into the vertical cavity 14c of the constriction section 12.

[0094] In contrast to the previous two embodiments, a continuous wear bushing 11c, 12c is provided, which can reduce assembly effort. Furthermore, the radial channel 11b of the transition section 11 is offset by 180° around the longitudinal axis X relative to the radial channel 12b of the constriction section 12. LIST OF REFERENCE SYMBOLS (part of the description) R radial direction U circumferential direction X Longitudinal axis 1 kingpin; kingpin; king bolt 1a first, upper kingpin part 1b second, lower kingpin part 1c Connection or threaded connection between kingpin parts 1a, 1b 10 mounting plates 10a Through holes or screw holes of the mounting plate 10 11 Transition section 11a first cavity or circumferential channel of the transition section 11 11b second cavity or radial channel of the transition section 11 11c Wear element or wear bushing of the transition section 11 12 Constriction section 12a first cavity or circumferential channel of the constriction section 12 12b second cavity or radial channel of the constriction section 12 12c Wear element or wear bushing of the constriction section 12 12d Transitional circumferential channel of the constriction section 12 12e Transition radial channel of the constriction section 12 13 Final bundle 14 Vertical cavity; core drilling 14a Vertical cavity of the mounting plate 10 14b Vertical cavity of the transition section 11 14c Vertical cavity of the constriction section 12 14d Vertical cavity of the end collar 13 15 Valve element; car valve 16 Pressure sensor; pressure switch 17 (wireless) transmitter / receiver unit 18 lids 19 screws

Claims

[1] Kingpin (1) for a semi-trailer of an articulated vehicle, which extends substantially along a longitudinal axis (X), with at least one wear detection means which is arranged in the kingpin (1) perpendicular to the longitudinal axis (X) in such a way that wear of the kingpin (1) perpendicular to the longitudinal axis (X) can be detected optically and / or by sensors, characterized by , that the wear detection agent has: • at least one wear element (11c, 12c) which is arranged in and / or on the kingpin (1) perpendicular to the longitudinal axis (X) such that wear of the kingpin (1) perpendicular to the longitudinal axis (X) equally wears the wear element (11c; 12c), wherein the wear element (11c, 12c) is arranged in the circumferential direction (U) at least partially, preferably completely, around the kingpin (1), • at least one cavity (11a, 11b, 12a, 12b, 14c) which extends in the circumferential direction (U) corresponding to the wear element (11c, 12c), wherein the cavity (11a, 11b, 12a, 12b, 14c) is closed fluid-tight by the wear element (11c, 12c), preferably perpendicular to the longitudinal axis (X), wherein the cavity (11a, 11b, 12a, 12b, 14c) contains a fluid at overpressure, and • at least one pressure sensor (16) which is designed to detect the pressure of the fluid in the cavity (11a, 11b, 12a, 12b, 14c), wherein the wear element (11c, 12c) is dimensioned perpendicular to the longitudinal axis (X) such that the fluid can escape through a through-opening of the wear element (11c, 12c) created due to wear when a wear limit of the kingpin (1) is reached at this point of the kingpin (1). [2] Kingpin (1) according to claim 1, wherein the wear element (11c, 12c) extends perpendicular to the longitudinal axis (X) to such an extent as corresponds to a wear limit of the kingpin (1) at this point of the kingpin (1), wherein the cavity (11a, 11b, 12a, 12b, 14c) is arranged perpendicular to the longitudinal axis (X) behind the wear element (11c, 12c). [3] Kingpin (1) according to claim 1 or 2, wherein the cavity (11a, 11b, 12a, 12b, 14c) comprises: • at least one first cavity (11a, 12a) as a circumferential channel (11a, 12a), which extends at least partially, preferably completely, in the circumferential direction (U) around the kingpin (1), and • at least one second cavity (11b, 12b) as a radial channel (11b, 12b), which extends perpendicular to the longitudinal axis (X) in a straight line from the first cavity (11a, 12a) into the kingpin (1), wherein the pressure sensor (16) is designed to detect the pressure of the fluid directed into the second cavity (11b, 12b). [4] Kingpin (1) according to claim 3, wherein the cavity (11a, 11b, 12a, 12b, 14c) further comprises: • at least one vertical cavity (14c) which extends along the longitudinal axis (X) in the kingpin (1), preferably in a constriction section (12) of the kingpin (1), wherein the pressure sensor (16) is designed to detect the pressure of the fluid directed into the vertical cavity (14c). [5] Kingpin (1) according to one of the preceding claims, wherein the kingpin (1) has along its longitudinal axis (X) in this order: • a mounting plate (10) which is designed to be connected to the semi-trailer, • a transition section (11) which adjoins the mounting plate (10), • a constriction section (12) which adjoins the transition section (11) and which is designed for a positive connection to a fifth wheel coupling of a tractor unit of the articulated vehicle, and • a closing collar (13) which adjoins the constriction section (12) and which closes the kingpin (1) at the bottom, wherein the wear element (11c, 12c) is arranged in the transition section (11) and / or in the constriction section (12). [6] Kingpin (1) according to claim 5, wherein the wear element (11c, 12c) is completely closed in the circumferential direction (U) around the kingpin (1), wherein the kingpin (1) is at least, preferably exactly, divided into 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 one another by means of a connection (1c), preferably by means of a threaded connection (1c). [7] Kingpin (1) according to claim 5 or 6, wherein the transition section (11) has a first wear element (11c), preferably with a first cavity (11a) and with a second cavity (11b), wherein the constriction section (12) has a second wear element (12c), preferably with a first cavity (12a) and with a second cavity (12b). [8] Kingpin (1) according to one of the preceding claims, further comprising a preferably wireless transmitting unit (17) which is connected to the pressure sensor (16) at least in a signal-transmitting manner in order to receive at least one item of information regarding the pressure of the fluid in the cavity (11a, 11b, 12a, 12b, 14c), wherein the preferably wireless transmitting unit (17) is further configured to transmit the received pressure information to the outside of the kingpin (1), preferably wirelessly. [9] Kingpin (1) according to claim 8, wherein the transmitted information of the pressure of the transmitting unit (17) comprises the pressure of the fluid in the cavity (11a, 11b, 12a, 12b, 14c) and / or information derived from the pressure of the fluid in the cavity (11a, 11b, 12a, 12b, 14c). [10] Kingpin (1) according to claim 8 or 9, with several wear elements (11c, 12c) each having at least one cavity (11a, 11b, 12a, 12b, 14c) with a fluid at overpressure and each having at least one pressure sensor (16), wherein the pressure information transmitted by the preferably wireless transmitting unit (17) preferably contains an identification of the respective pressure sensor (16). [11] Kingpin (1) according to one of claims 8 to 10, wherein the, preferably wireless, transmitting unit (17) is a, preferably wireless, transmitting / receiving unit (17), wherein the, preferably wireless, transmitting / receiving unit (17) is designed, preferably wirelessly, to be requested to transmit the information of the pressure from outside the kingpin (1). [12] Kingpin (1) according to one of the preceding claims, further comprising a lighting means which is connected to the pressure sensor (16) at least in a signal-transmitting manner, wherein the illuminant is designed to be operated as a function of the pressure of the fluid in the cavity (11a, 11b, 12a, 12b, 14c). [13] Kingpin (1) according to one of the preceding claims, wherein the pressure sensor (16) is a pressure switch (16) which is designed to switch in response to a predetermined pressure drop of the fluid in the cavity (11a, 11b, 12a, 12b, 14c). [14] Semi-trailer with a kingpin (1) according to one of the preceding claims. [15] An articulated vehicle with a semi-trailer according to claim 14.

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