WO2022218799A1

WO2022218799A1 - Coupling bolt for a towing vehicle of a vehicle combination

Info

Publication number: WO2022218799A1
Application number: PCT/EP2022/059217
Authority: WO
Inventors: Stefan Rühlicke
Original assignee: Rühlicke GmbH
Priority date: 2021-04-12
Filing date: 2022-04-07
Publication date: 2022-10-20
Also published as: DE102021109065B3; EP4323208A1

Abstract

The present invention relates to a coupling bolt (12) for a towing vehicle (3) of a vehicle combination (3, 4) which extends substantially along a longitudinal axis (X'). The coupling bolt (12) is characterised by having at least one wear detection means (6) which is aligned perpendicular to the longitudinal axis (X') and arranged in the coupling bolt (12) in such a way that wear of the coupling bolt (12) perpendicular to the longitudinal axis (X') can be detected optically and/or by sensors.

Description

DESCRIPTION

Coupling pin for a towing vehicle of a vehicle combination

The present invention relates to a coupling bolt for a towing vehicle of a vehicle combination according to the preamble of patent claim 1, a towing vehicle with such a coupling bolt according to patent claim 14 and a vehicle combination with such a towing vehicle according to patent claim 15.

In order to enable a towing vehicle to tow a trailer, it is necessary to power-transmittingly and detachably connect the towing vehicle and trailer to one another. Such towing vehicles can be, for example, a passenger car, a truck, a bus, a construction machine, a forestry or agricultural vehicle, a military vehicle or another land vehicle, in particular another road vehicle or off-road vehicle. Such towing vehicles can be moved or drive by means of their own drive, i.e. they can be vehicles with their own drive. A towing vehicle can move at least one trailer with it as a vehicle without its own drive or pull it behind it. A trailer is usually used to transport loads and can be, for example, a car trailer, a truck trailer, a caravan, a horse trailer, a boat trailer and the like. Trailers have at least one wheeled axle and often at least two wheeled axles. Trailers can also be designed for private, sporting and commercial use, for example in freight forwarding, in the construction industry, in agriculture and the like. Towing vehicle and trailer can also be referred to together as a vehicle combination. The towing vehicle can also be referred to as the front vehicle in the towing, driving or moving direction and the trailer can also be referred to as the rear vehicle in the towing, driving or moving direction of the vehicle combination.

A detachable connection between the towing vehicle and the trailer is usually implemented using a so-called hitch for hitching the trailer to the towing vehicle, which is designed as a system in at least two parts and has a coupling device on the towing vehicle and on the trailer, which are held there and are detachably connected to one another be able. Several trailers can also be detachably connected to one another in this way. Various types of trailer couplings are known, such as bolt couplings and jaw couplings or bolt coupling systems and jaw coupling systems, in which a shaft or a drawbar extends from the trailer to the towing vehicle and has an eyelet at the end as a through opening in the vertical direction, which also can be referred to as a towing eyelet or as a coupling eyelet. At the opposite end, the shank is formed, for example, as a flange and fixedly attached to the frame of the trailer by means of screws. On the part of the towing vehicle, a bracket is fixedly attached to the frame of the towing vehicle in the case of a bolt coupling, which bracket has two surfaces in the vertical direction, each with a through-opening in the vertical direction. The two passage openings are arranged in alignment with one another. The trailer towing eye can be received between the two surfaces of the tow vehicle bracket. All three through-holes can be connected to each other in the vertical direction by a bolt, also called a coupling bolt, which can rest on the upper surface by means of thickening and be secured at the lower end. This can be done in a comparable way with a jaw coupling or a jaw coupling system.

AT 412268 B discloses a towing eye of a coupling with a coupling element comprising, in particular, a ring, a ball socket or the like, a spacer element and a flange with corner regions having a substantially rectangular, in particular substantially square, base.

With such trailer couplings, for example, there must be a certain distance of a few millimeters between the inside diameter of the towing eye of the trailer drawbar and the outside diameter of the coupling bolt of the towing vehicle in order to be able to make the respective positive connection at all. This means that there is play, particularly in the longitudinal direction as the essential direction of travel, movement or pulling, which is required for connecting or coupling, but when driving a certain relative movement essentially in the travel, movement - Allows the direction of pull between the towing vehicle and the trailer or between the coupling pin and the towing eye.

The disadvantage of this play between the coupling bolt and the towing eye when driving is that the towing eye and the coupling bolt can rub and/or collide with one another and this can result in abrasion or wear on these components due to the forces present. This mechanical wear can not only reduce the material thickness of the coupling bolt over the long term and thereby weaken the coupling bolt as a transmission element in the power flow between trailer and towing vehicle, but also increasingly increase the play, which then leads to larger relative movements and the resulting stronger forces with increasing mechanical wear can lead. It is therefore necessary for the traffic safety of a trailer to check the coupling bolt of the towing vehicle for wear regularly, for example at certain intervals such as every six months or depending on the use of the trailer, for example depending on the kilometers driven. So far, this has been done manually, ie by a person using a mechanical test gauge or template to measure the dimensions of the coupling bolt at certain specified points in order to determine whether the measured dimensions still meet the relevant specifications or not, ie the coupling bolt is already excessively worn and may or may not need to be replaced.

The disadvantage here is that the assessment of permissible or impermissible wear of the coupling pin is left to the individual person and there is therefore a certain degree of uncertainty in that the assessment can also depend on the attentiveness and/or experience of the person. This can result in a coupling pin that is excessively worn to an inadmissible extent being used, which can jeopardize the road safety of the trailer. This can also lead to a coupling bolt that can still be used being replaced prematurely, which can cause additional effort, additional costs and/or an unnecessary breakdown of the towing vehicle.

Another disadvantage of this is that the wear of the coupling pin of the towing vehicle can vary greatly and thus an impermissibly high level of wear can already be reached within the permissible time or kilometer interval between two wear tests, without this being able to be determined at this moment. This can also endanger the traffic safety of the trailer.

EP 3421272 A1 describes a trailer hitch for connecting a trailer to a towing vehicle. The hitch includes a wearable support member which is arranged to abut a connecting portion of a tongue mounted on the trailer when the connecting portion, ie the towing eye, is received by the hitch socket and positioned in a towing position. The trailer hitch also includes a movable coupling element, i.e. a coupling pin, having a first position to allow the connecting portion, i.e. the towing eye, to move into and out of the towing position, and a second position for securing the connecting portion, i.e. towing eye, in the Towing position, the second position being such that the connecting portion, when entering and leaving the towing position, pushes the coupling element, ie the coupling pin, to perform a movement. The trailer hitch further includes a magnitude sensor configured to provide a measure indicative of a magnitude of the movement, thereby being able to detect that an amount of wear of the support member exceeds a predetermined threshold. It will thus the wearable supporting element of the coupling receptacle of the trailer coupling of the towing vehicle is monitored for wear, but neither the coupling pin nor the towing eye.

One object of the present invention is to provide a coupling bolt for a towing vehicle of a vehicle combination of the type described at the outset, so that checking the wear of the coupling bolt can be simplified and/or improved. In particular, the wear of the coupling bolt should be able to be monitored more regularly than before and in particular even continuously. In particular, this should be able to take place as simply, reliably, space-savingly, independently of persons and/or automatically as possible. In any case, this should in particular improve or increase the traffic safety of the trailer. At the very least, an alternative to the known options for checking the wear of the coupling pin should be created.

The object is achieved according to the invention by a coupling bolt with the features of patent claim 1, by a towing vehicle with the features of patent claim 14 and by a vehicle combination with the features of patent claim 15. Advantageous developments are described in the dependent claims.

The present invention thus relates to a coupling bolt for a towing vehicle of a vehicle combination, which extends essentially along a longitudinal axis. As described above, the coupling bolt is a bolt-like, rotationally symmetrical and usually metallic projection which extends vertically downwards from the underside of the chassis in the vertical direction. The longitudinal axis of the coupling bolt 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 perpendicularly to the horizontal plane when used on a towing vehicle.

The coupling bolt according to the invention is characterized by at least one wear detection means, which is arranged in the coupling bolt perpendicular to the longitudinal axis in such a way that wear of the coupling bolt can be detected optically and/or by sensors perpendicular to the longitudinal axis. In other words, a wear detection means is arranged within the contour or within the material of the coupling bolt in such a way that both the material of the coupling bolt and the material of the wear detection means are affected by the abrasion or wear that occurs on the part of the coupling bolt during operation, as described above , be reduced in their radial extent. For this purpose, the at least one wear detection means can be arranged exactly radially or perpendicularly to the longitudinal axis or at least obliquely to the longitudinal axis in the coupling bolt so that the abrasion or wear can also reduce the wear detection means from the outside.

The present invention is based on the finding that by designing part of the coupling bolt as or with a wear detection means, the degree of abrasion or wear of the coupling bolt at this point can be made optically recognizable from the outside and/or can be detected by sensors. In any case, the condition of the

Wear detection means are easier to detect or monitor in this way than was previously possible by regular manual checks of the coupling pin itself as described above. This can reduce the effort and thus also the costs of checking the degree of wear of the coupling pin. This can also increase the reliability of the result of the check, which on the one hand increases the traffic safety of the trailer of the vehicle combination and on the other hand can prevent premature or unnecessary replacement of a coupling bolt that can still be used. In this case, arranging the wear detection means within the coupling bolt can keep the implementation effort and in particular the installation space required for this low. In particular, a continuous or much more regular control or monitoring of the degree of wear of the coupling pin than previously known can take place, which can increase the traffic safety of the trailer of the vehicle combination and the duration of use of a coupling pin.

The wear detection means is preferably arranged in at least one horizontal cavity of the coupling bolt, the wear detection means having at least one first wear element of a first color which is arranged between the outer edge of the horizontal cavity and a wear limit. The first color of the wearing element differs significantly from the color of the material of the coupling bolt itself. In other words, at least one colored wearing element, in particular made of a colored plastic, can be used as a wear detection means, which can be introduced into a corresponding cavity of the coupling bolt and to the outside flush with the contour or surface of the coupling bolt and can be visually recognized by a person. If the colored wearing element has not yet been completely worn down, the person can visually recognize the colored wearing element and from this it can be concluded that the coupling bolt has been subjected to permissible wear. If the colored wearing element is no longer visually recognizable to the person, the person can conclude from this that the colored wearing element has been completely worn down and the limit of permissible wear has therefore been reached or exceeded. This can represent a particularly simple implementation of the present invention, which can allow a person to regularly visually check the wear. In particular, the driver of the towing vehicle that is to couple a trailer, you can easily and quickly visually check the state of wear of the towing vehicle's coupling pin. This can increase the driver's confidence in using a strange or unfamiliar tow vehicle.

The wear detection means can also have at least two differently colored wear elements, which are arranged radially one behind the other in order to increase the informative value, as will be described in more detail below.

Alternatively or additionally, the wear detection means can enable electronic monitoring of the state of wear or the wear limit of the coupling bolt, as will be described in more detail below.

In any case, the wear detection means can be arranged in the horizontal plane or viewed in the cross section of the coupling bolt at a point at which particularly significant abrasion or wear usually occurs or at which an impermissibly high degree of wear is usually to be expected first. This can correspondingly increase the informative value of the wear detection means.

Viewed in the horizontal plane or in the cross section of the coupling bolt, several identical or different wear detection means can also be used in order to be able to carry out the wear monitoring described above at a correspondingly large number of points on the coupling bolt. In this way, in particular, a number of points, which are usually subject to significant wear, can be monitored for wear at the same time, as described above. In this case, for example, at least one sensory wear detection means can be used at a point on the coupling bolt that is difficult or impossible to detect optically for the person or for the driver. At least one optical wear detection means can be used at a point on the coupling bolt which the person or the driver can easily or easily detect optically.

Several identical or different wear detection means can also be arranged offset from one another in the vertical direction, i.e. along the longitudinal axis, in order to monitor different sections of the coupling bolt and/or several points of a section of the coupling bolt as described above, as will be described in more detail below becomes. In this way, too, the informative value of the wear detection means can be correspondingly increased.

According to one aspect of the invention, the wear detection means is arranged in at least one horizontal cavity of the coupling pin, wherein the wear detection means comprises at least a first wear element of a first colour, which is located between the outer edge of the horizontal cavity and a wear limit, and having at least one second wear member of a second, different color located within the wear limit. In this way, the first color of the first wear element can be recognized by the person or the driver and a conclusion can be drawn as to permissible wear of the coupling pin. If the person or the driver visually recognizes the second color of the second wearing element, this can be used to conclude that the coupling bolt is wearing in an unacceptable manner.

Thus, as a further development of the previously described only one colored wearing element, it can be concluded from the optically recognized second color of the second wearing element that the second wearing element is still present. If only a first colored wear element were to be used, its absence could be due to the permissible wear limit being reached as well as to the fact that the single-colored wear element has become detached and fallen out of the coupling bolt. In this case, a still usable coupling pin would be evaluated as worn and unnecessarily replaced. This can be avoided by this aspect of the invention.

According to a further aspect of the invention, the wear detection means has at least one lamp, which is arranged within the horizontal cavity and/or within a vertical cavity of the coupling bolt and is designed to transilluminate the first wear element through the second wear element. The light source can be implemented in particular as an LED. In particular, the lamp can be operated permanently or continuously in order to be able to check the state of wear of the coupling bolt at any time. Furthermore, a corresponding effort to switch the lamp on and off or to have to provide appropriate electrical options for this, such as a switch on the coupling bolt that is accessible from the outside, can be avoided.

The materials of the first and second wearing element, for example made of plastic, can be colored accordingly and translucent, so that the materials of the first and second wearing element can be illuminated radially from the inside or "from behind" and the light in the color of the last X-rayed wear element exits to the outside. In this way, the previously described aspect of the two-colored wear detection means can be further improved in terms of its recognisability or its ability to provide information for the person or for the driver, since the color can be visually perceived better due to the glow. It can do this make it easier or possible for the person or the driver, particularly in the dark, in poor visibility and/or when the surface of the coupling pin is dirty, to visually recognize the wear detection means per se and in particular its color. In this case, providing the coupling bolt with a vertical cavity can create sufficient installation space within the coupling bolt in order to arrange the at least one light source and in particular a plurality of light sources there. In particular, a weakening of the coupling bolt can be sufficiently avoided by a correspondingly small vertical cavity, so that the coupling bolt can perform its force-transmitting function without restriction.

According to a further aspect of the invention, the wear detection means has at least one electrical energy store, preferably within a vertical cavity, which is designed to supply electricity to at least the lighting means, preferably also a detection unit and/or a wireless communication unit. As a result, electrical energy can be supplied to the lamp and possibly several or all lamps directly from the coupling bolt itself, so that an electrically conductive connection to the electrical energy supply from outside the coupling bolt can be dispensed with. This can correspondingly keep the expense of using at least one light source low, as described above. In particular when using LEDs as light sources, which usually have a very low electrical energy requirement, permanent or continuous operation of the light source can be guaranteed by the electrical energy store, even for years, so that there is no need to recharge or replace the electrical energy store can. If necessary, other electrical or electronic components of the

Wear detection means are also supplied electrically by the electrical energy storage device, so that the use of additional or separate electrical energy storage devices can be dispensed with.

According to a further aspect of the invention, the wear detection means is arranged in at least one horizontal cavity of the coupling bolt, the wear detection means having at least one first wear element, which is arranged between the outer edge of the horizontal cavity and a wear limit, and at least one second wear element, which is arranged within the wear limit at least one electrically conductive element of an electrical circuit is arranged at the wear limit in such a way that the electrically conductive element is severed by the wear of the coupling bolt when the wear reaches the wear limit, the wear detection means, preferably within a vertical cavity, having a detection unit , which is designed to monitor the electrical conductivity of the electrically conductive element and, preferably when cutting through the electrically conductive n elements to output corresponding information. The two wear elements can be the previously described two single-colored first and second wear elements or two wear elements of any desired same color. This aspect of the invention is based on the finding that, in addition to or as an alternative to the previously described optical options for monitoring wear and tear by the person or by the motorist, a sensory option for monitoring can also be created. For this purpose, an electrically conductive element such as an electrical conductor or an electrical conductor loop can be guided precisely up to the wear limit of a permissible wear of the coupling bolt at this point, which can take place in particular within the second wear element as a plastic part, for example, which at the same time can be first wear element can be covered or protected as a plastic part, for example, to the outside.

In this case, the first, outer wear element is abraded or worn out together with the coupling pin until the wear limit is reached. When the wear limit is reached, the electrically conductive element is also subject to abrasion or wear, which acts on the coupling pin from the outside. The electrically conductive element is rubbed off in such a way that it is severed so that the electrically conductive element can no longer transmit an electric current or no longer have an electric voltage across the electrically conductive element, which can be detected by the detection unit. The detection unit can thus automatically conclude that the wear limit has been reached.

Corresponding information can be output from the detection unit to the outside. If several wear detection means are used, the information from the detection unit can also contain information which contains the identification of the respective worn or severed electrically conductive element or its detection unit, so that the location of the permissible wear that has been reached or exceeded can be identified.

In any case, corresponding information can be output by means of a wireless communication unit, which can transmit at least data or information wirelessly to the outside of the coupling bolt and can preferably also receive data and information from the outside. This can be done automatically by the detection unit immediately when the wear limit is reached, so that the person or the driver can react to this immediately. This information can be output by the detection unit continuously or regularly, in order to ensure that this information reaches the person or the motorist. The output of this information by the detection unit can optionally be terminated by an acknowledgment of receipt by the person or the driver in order to save electrical energy by the detection unit. The output of this information on the part of the detection unit can, if necessary, additionally or alternatively only take place in the event of a query or in response to a request from outside, as will be described in more detail below. In any case, the detection unit can output this information to the person or the driver in such a way that this information is sent wirelessly to an electronic receiving device such as a mobile terminal device, for example in the form of a smartphone, a tablet or the like of the person or the driver is sent. Additionally or alternatively, this information can also be sent wirelessly by the detection unit to an electronic receiver of the towing vehicle, received and processed there and output or displayed to the driver via an output element such as in particular a display element of the towing vehicle. In this case, this information can optionally be forwarded wirelessly by the towing vehicle or its control unit to a fleet management system in order to be able to take into account and plan the replacement of the worn coupling pin there.

According to a further aspect of the invention, the wear detection means has, preferably within a vertical cavity, at least one wireless communication unit, preferably a wireless transmitter unit, which is designed to wirelessly transmit at least one item of information from the detection unit to the outside of the coupling bolt. Through this, the corresponding properties already described above can be implemented.

According to a further aspect of the invention, the wireless communication unit is designed to be prompted wirelessly from outside the coupling bolt to transmit information from the detection unit. As a result, the corresponding properties already described above can be implemented.

According to a further aspect of the invention, the wirelessly transmitted information from the detection unit contains the state of the electrically conductive element and/or information derived from the state of the electrically conductive element. The state of the electrically conductive element can be distinguished at least as to whether the electrically conductive element is severed or not. Information derived from this on the part of the detection unit can be that the corresponding wear limit is recognized as having been reached or not yet reached. However, the latter conclusion can also be made where the wirelessly transmitted information from the detection unit is received and further processed, which can simplify the implementation of the detection unit and thus save electrical energy, costs and/or installation space there.

According to a further aspect of the invention, the coupling bolt has a coupling section along its longitudinal axis, which is designed to engage in a coupling eyelet of a coupling eyelet along the longitudinal axis, the wear detection means, preferably at least a first wearing element and a second wearing element, being arranged at least once in the coupling section is. Correspondingly, wear can be monitored at the corresponding points of the coupling section of the coupling bolt, as described above. According to a further aspect of the invention, the wear detection means, preferably at least a first wear element and a second wear element, is arranged at least twice, preferably diametrically opposite one another with respect to the longitudinal axis, in the coupling section. This can increase the number of locations within the coupling portion of the coupling pin that can be monitored for wear as previously described. Arranging the two wear detection means diametrically opposite one another in relation to the longitudinal axis, ie offset from one another by 180° in the plane of the cross section, can make it possible to monitor the wear as evenly distributed as possible.

According to a further aspect of the invention, the wear detection means, preferably at least a first wear element and a second wear element, is arranged in at least two pairs, preferably as a pair diametrically opposite one another to the longitudinal axis and particularly preferably in pairs offset at right angles to one another, in the coupling section. Thus, the total of four wearing elements can be arranged in one plane of the cross section, in particular offset by 90° to one another. As a result, the uniformity of the monitoring of the coupling pin for wear can be further increased.

According to a further aspect of the invention, the detection unit is designed to monitor the electrical conductivity of all electrically conductive elements and, preferably when at least one of the electrically conductive elements is severed, to output corresponding information. In this way, the effort involved in using a plurality of detection units can be avoided, with one detection unit being designed to be able to monitor all electrically conductive elements at the same time. At the same time, this can reduce the electrical energy consumption and/or the installation space required.

According to a further aspect of the invention, the wirelessly transmitted information from the detection unit also contains an identification of the severed electrically conductive element. This can enable the individual electrically conductive elements to be distinguished even when using a single detection unit.

The invention also relates to a towing vehicle with a coupling pin as described above. As a result, the previously described aspects of a coupling bolt according to the invention can be implemented in a towing vehicle and used there.

The invention also relates to a combination of vehicles with a towing vehicle as described above. In this way, a combination of vehicles can be created in order to implement and use the previously described aspects of a coupling bolt according to the invention in its towing vehicle. Several exemplary embodiments and further advantages of the invention are shown purely schematically and explained in more detail below in connection with the following figures. It shows:

FIG. 1 shows a schematic side view of a vehicle combination according to the invention with a coupling bolt according to the invention according to a first exemplary embodiment;

FIG. 2 shows a detail view of FIG. 1, partly in section;

FIG. 3 shows a schematic side view, partly in section, of the coupling bolt according to the invention according to the first exemplary embodiment;

FIG. 4 shows a schematic side view, partly in section, of a coupling bolt according to the invention according to a second embodiment;

FIG. 5 shows a schematic side view, partly in section, of a coupling bolt according to the invention according to a third exemplary embodiment; and FIG. 6 shows a cross section through the transition section of the coupling bolt according to the first embodiment of FIG.

The above figures are viewed in Cartesian or in cylindrical coordinates. A longitudinal direction X, which can also be referred to as depth X or length X, extends in Cartesian coordinates. A transverse direction Y, which can also be referred to as width Y, extends perpendicularly to the longitudinal direction X. A vertical direction Z, which can also be referred to as the height Z, extends perpendicularly both to the longitudinal direction X and to the transverse direction Y. The longitudinal direction X and the transverse direction Y together form the horizontal X, Y, which can also be referred to as the horizontal plane X, Y. A longitudinal axis X' also extends in the vertical direction Z in cylindrical coordinates. 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′.

Figure 1 shows a schematic side view of a vehicle assembly 3, 4 according to the invention with a trailer hitch 1, 2 with a coupling pin 12 according to the invention according to a first embodiment. In a direction of travel A, which can also be referred to as direction of movement A or as direction of train A, the combination of vehicles 3, 4 has a vehicle 3 in front in direction of train A, which can also be referred to as towing vehicle 3, and a vehicle 4 at the rear in direction of train A , which can also be referred to as trailer 4. The combination of vehicles 3, 4 can travel in the direction of travel A on a surface 5.

A first coupling device 1 is fixedly arranged on the towing vehicle 3 in the longitudinal direction X at the rear thereof, which coupling device points in the longitudinal direction X toward the trailer 4 . In the longitudinal direction X there is also a second coupling device 2 on the front side of the trailer 4 facing the towing vehicle 3 stationary on a frame 40 or on a frame 40 of the trailer 4 arranged. The two coupling devices 1, 2 connect the towing vehicle 3 to the trailer 4 in a force-transmitting manner in the longitudinal direction X and thus together form the trailer coupling 1, 2, which can also be referred to as a trailer coupling system 1, 2.

FIG. 2 shows a detailed view of FIG. 1, partly as a sectional representation. The trailer hitch 1, 2 according to the first exemplary embodiment of FIGS. 1 to 3 and 6 is designed as a bolt coupling or as a bolt coupling system. Correspondingly, the first coupling device 1 of the towing vehicle 3 has a coupling receptacle 10 with a coupling mouth 11 which, in the longitudinal direction X, accommodates a coupling eyelet 21 of a shaft 20 of the second coupling device 2 . The coupling eyelet 21 of the second coupling device 2 can also be referred to as a towing eyelet 21 . The coupling eyelet 21 is annular at the end of the shank 20 integral therewith, i. H. integral, formed, which from the trailer 4 shows away. In the middle, the coupling eyelet 21 forms a coupling eyelet 22 running in the vertical direction Z, into which the coupling bolt 12 of the first coupling device 1 is inserted from above in the vertical direction Z in order to create a positive connection of the two coupling devices 1, 2. The coupling eye 22 can also be referred to as a coupling eye 22 , as a towing eye 22 or as a towing eye socket 22 . The shank 20 can also be referred to as a trailer shank 20 or as a towing shank 20 . The shaft 20 can also be referred to as a drawbar 20 or as a trailer drawbar 20 .

FIG. 3 shows a schematic side view, partially in section, of the coupling bolt 12 according to the invention according to the first exemplary embodiment. The coupling bolt 12 or its body is metallic in one piece, d. H. integrally, as well as rotationally symmetrical to the longitudinal axis X '.

The coupling bolt 12 has a coupling section 13 approximately in the middle along the longitudinal axis X′. When the trailer 4 is coupled to the towing vehicle 3 , the coupling section 13 is received by its coupling eye 22 and completely enclosed in the circumferential direction U. During operation of the vehicle combination 3, 4 with trailer 4 and towing vehicle 3, this can lead to abrasion or wear of the cylindrical outer surface of the coupling bolt 12 in the coupling section 13, which over time reduces the cross section or the material thickness of the coupling section 13 of the Coupling bolt 12 can weaken in such a way that a reliable power transmission between trailer 4 and towing vehicle 3 via the coupling bolt 12 can no longer be guaranteed.

According to the invention, the wear of the coupling bolt 12 in the area of the coupling section 13 according to the first exemplary embodiment in FIGS. 1 to 3 and 6 can be checked by a person, for example the driver of the vehicle combination 3, 4, more easily, quickly and/or more frequently than previously known or be monitored by the clutch section 13 a continuous horizontal cavity 15 is present, which extends radially across the longitudinal axis X' from one side of the respective cylindrical outer surface to the opposite side of the outer surface. A wear detection means 6 is introduced into the horizontal cavity 15, which is materially bonded there, for example by an adhesive between the inner surface of the horizontal cavity 15 and the outer surface of the wear detection means 6, or non-positively, for example by an at least slight oversize of the outer contour of the wear detection means 6 compared to the horizontal cavity 15, is held.

The wear detection means 6 has a first, outer colored wear element 60 at the edge, between which a second, inner colored wear element 61 is arranged. The first two outer colored wear elements 60 are cohesive, for example by gluing or by a one-piece, d. H. integral, manufacture, with the intermediate second, inner colored wearing element 61 connected. The two first, outer colored wear elements 60 have a different color than the second, inner colored wear element 61 . The two first, outer colored wear elements 60 are preferably green, in particular neon green, and the second, inner colored wear element 61 is red, in particular neon red. The transition or the boundary between a first, outer, colored wear element 60 and the corresponding second, inner, colored wear element 61 is provided by the dimensioning of the wear elements 60, 61 in such a way that this transition corresponds to the permissible wear limit of the coupling section 13 of the coupling bolt 12.

If the towing vehicle 3 is parked without a trailer 4 and the coupling bolt 12 is moved into the closed state, i.e. into its lower position, the coupling bolt 12 according to the invention is accessible in the horizontal plane X, Y and can be used in particular by a person such as be viewed visually by the driver who wants to connect the towing vehicle 3 to its trailer 4 . Depending on the orientation, the person can see the wear detection means 6 of the coupling section 13 from at least one side or from both sides with the eye and can determine whether (in each case) the first, outer colored wear element 60 or the second, inner wear element 61 is visible outside.

If the person recognizes the first, outer colored wear element 60, it can be concluded from this that at this point of the coupling section 13 of the coupling bolt 12 the wear of the material of the coupling bolt 12, which correspondingly also reduces the respective wear detection means 6 in its radial extent, is still in is within a permissible range. If the person recognizes the second, inner colored wearing element 61, it can be concluded from this that at this point of the coupling section 13 of the coupling bolt 12 the first, outer, colored wear element 60 has been completely worn away and therefore the second, inner, colored wear element 61 lying radially underneath is visible from the outside. This means that at this point of the coupling section 13 of the coupling pin 12 the permissible wear has already been reached or exceeded and the trailer 4 can no longer be used safely on the towing vehicle 3 . Rather, the coupling pin 12 is to be replaced.

FIG. 4 shows a schematic side view, partially in section, of a coupling bolt 12 according to the invention according to a second exemplary embodiment. In this case, a vertical cavity 14 in the form of a core bore 14 is also provided along the longitudinal axis X′, into which the previously described floral cavity 15 opens radially. Correspondingly, a second, inner, colored wear element 61 is arranged in the floral cavity 15 as described above, which extends radially outwards to the respective first, outer colored wear element 60 and radially inwards to the end of the floral cavity 15 . As described above, the wear elements 60, 61 are designed in different colors, with the respective material also being designed to be translucent.

A light source 62 in the form of an LED 62 is arranged radially outwards at the radially inner ends of the second, inner colored wearing elements 61 in such a way that the wearing elements 60, 61 are illuminated radially outwards by the light of the respective LED 62 when the LED 62 is operated. The LEDs 62 can be supplied with electrical energy for continuous or permanent operation from an electrical energy store 66 in the form of a battery 66 which is also arranged within the vertical cavity 14 . The operation of the LEDs 62 can be started when the coupling bolt 12 is mounted on the towing vehicle 3 and can stop until the electrical energy of the battery 66 has been used up.

Also in this case of the second exemplary embodiment of FIG. 4, the corresponding points of the coupling section 13 of the coupling bolt 12 can be visually checked for wear by a person as described above with regard to the first exemplary embodiment of FIGS. In this case, a light in the color of the first, outer colored wear element 60 can be visually perceived by the person as long as the wear limit is observed, as described above. If the wear limit is reached or exceeded at one point of the coupling section 13 of the coupling bolt 12, the first, outer colored wearing element 60 is worn down at this point and the light of the corresponding LED 62 emerges in the color of the second, inner colored wearing element 61 out.

Accordingly, the person can make a distinction between permissible and impermissible wear based on the color of the light, which can be visually perceived at the respective location. As a result, the wear control according to the invention of the Coupling bolt 12 according to the first exemplary embodiment in FIGS. 1 to 3 and 6 can be improved for the person in that the colored wear detection means 6, in particular in the dark or in poor visibility conditions, for example in rain or fog, or if the outer surface of the coupling bolt is dirty 12, can be perceived better or more reliably than without this backlighting. In particular, in the dark or in poor visibility conditions, the person can do without illuminating the coupling bolt 12 with a flashlight, for example, in order to be able to visually identify the wear detection means 6 . Likewise, the expense of having to clean or wipe a soiled surface of the coupling pin 12 in order to be able to visually identify the wear detection means 6 can be dispensed with.

FIG. 5 shows a schematic side view, partially in section, of a coupling bolt 12 according to the invention according to a third exemplary embodiment. In this case, the coupling bolt

12 as described in the second exemplary embodiment of FIG. 4, which also applies to the extension of the wearing elements 60, 61, which can be colored as described in the first exemplary embodiment of FIGS.

In each case, an electrically conductive element 63 in the form of a conductor loop 63 extends through the respective second, inner wear element 61 in such a way that the conductor loops 63 run at the boundary between the first, outer wear element 60 and the second, inner wear element 61 or .reversed. All conductor loops 63 are electrically conductively connected to a detection unit 64 which is arranged inside the vertical cavity 14 and can also be referred to as a control unit 64 . The detection unit 64 is connected in a signal-transmitting manner to a wireless communication unit 65 which is also arranged within the vertical cavity 14 and can emit at least wireless signals, which is why the wireless communication unit 65 can also be referred to as a transmission unit 65 . Both the detection unit 64 and the transmission unit 65 are electrically conductively connected to the battery 66 and are operated by electrical energy from the battery 66 .

In this case, the wear of the coupling pin reaches 12 at one point of the coupling portion

13 is the wear limit, the corresponding conductor loops 63 are thereby abraded and severed. The detection unit 64 can determine for each of the conductor loops 63 whether the conductor loops 63 are continuously electrically conductively closed or severed. This can be done, for example, by the application of a measurement voltage by the detection unit 64 . As a result, the detection unit 64 can differentiate for the points of the coupling section 13 of the coupling bolt 12 at which the conductor loops 63 are provided, whether there the wear is still at a permissible level or not. Corresponding information can be transmitted wirelessly from the detection unit 64 to the outside of the coupling bolt 12 by means of the transmission unit 65 .

This information can be received, for example, by a hand-held device such as a mobile terminal device such as a smartphone of a person or the driver of the vehicle combination 3, 4 and displayed there. This information can be sent continuously, but this can increase the consumption of electrical energy. This information can also only be sent when the person or the motorist requests the coupling bolt 12 according to the invention to do so by providing appropriate information, which can also be done on the smartphone. As a result, the corresponding information can be queried as required, what electrical energy consumption of the coupling bolt according to the invention

Reduce 12 and thus increase the service life of the detection unit 64 and the transmitter unit 65.

This information can, for example, also be received by a control unit of the towing vehicle 3 and displayed there to the driver. In this case, too, the information can be transmitted continuously by the coupling bolt 12 according to the invention or only after a request by the control unit of the towing vehicle 3 . In any case, the information obtained can be displayed to the driver of the towing vehicle 3 in order to be informed about the roadworthy condition of the coupling pin 12, in particular during operation of the vehicle combination 3, 4.

In any case, the detection unit 64 can distinguish between the different conductor loops 63 so that the information transmitted to the outside can also contain an identification of the respective conductor loops 63 . Thus, if one of the first, outer wearing elements 60 reaches its limit and the corresponding conductor loop 63 is severed, the person or the driver can be informed specifically at which point of the coupling section

13 of the coupling pin 12 the permissible wear is reached or fallen below.

LIST OF REFERENCE NUMBERS (part of the description)

A direction of travel; direction of movement; pulling direction

X longitudinal direction; Depth; length

Y transverse direction; Broad

Z vertical direction; Height

X, Y Horizontal; horizontal plane

R radial direction

U circumferential direction

X' longitudinal axis

1, 2 hitch; hitch system; coupling devices

1 first coupling device of the vehicle in front in direction A 3

10 clutch pocket

11 coupling mouth

12 coupling bolts

13 coupling section

14 vertical cavity; core drilling

15 horizontal cavity of the coupling section 13

2 second coupling device of the rear vehicle in the pulling direction A 4

20 (trailer) drawbar; (Trailer/train) shaft

21 coupling eyelet; towing eye; Ball Head Coupling

22 coupling eye; coupling eyelet; drawbar eye; drawbar bushing

3, 4 vehicle network

3 vehicle in front in train direction A; towing vehicle

4 rear vehicle in train direction A; follower

40 frame; frame

5 underground

6 wear detection means 60 first, outer (colored) wearing elements

61 second, inner (colored) wear elements

62 bulbs; LEDs

63 electrically conductive elements; conductor loops 64 detection unit; control unit

65 wireless communication unit or wireless transmission unit

66 electrical energy storage; battery

Claims

PATENT CLAIMS

1. Coupling pin (12) for a towing vehicle (3) of a vehicle combination (3, 4), which extends essentially along a longitudinal axis (C'), characterized by at least one wear detection means (6) which is perpendicular to the longitudinal axis (C') aligned in the coupling bolt (12) in such a way that wear of the coupling bolt (12) can be detected optically and/or by sensors perpendicularly to the longitudinal axis (C').

2. Coupling bolt (12) according to Claim 1, characterized in that the wear detection means (6) is arranged in at least one horizontal cavity (15) of the coupling bolt (12), the wear detection means (6) having at least one first wear element (60) of a first color located between the outer edge of the horizontal cavity (15) and a wear limit, and having at least one second wear element (61) of a second, different color located within the wear limit.

3. Coupling bolt (12) according to claim 2, characterized in that the wear detection means (6) has at least one lamp (62) which is arranged inside the horizontal cavity (15) and/or inside a vertical cavity (14) of the coupling bolt (12) and is designed to transilluminate the first wear element (60) through the second wear element (61).

4. Coupling pin (12) according to Claim 3, characterized in that the wear detection means (6), preferably within a vertical cavity (14), has at least one electrical energy store (66), which is designed to contain at least the lighting means (62), preferably also a detection unit (64) and/or a wireless communication unit (65) to supply electricity.

5. Coupling bolt (12) according to one of the preceding claims, characterized in that the wear detection means (6) is arranged in at least one horizontal cavity (15) of the coupling bolt (12), the wear detection means (6) having at least one first wear element (60), located between the outer edge of the horizontal cavity (15) and a wear limit, and having at least one second wear element (61) located within the wear limit, at least one electrically conductive element (63) of an electrical circuit being so located at the wear limit is, so that the electrically conductive element (63) is severed by the wear of the coupling bolt (12) when the wear reaches the wear limit, the wear detection means (6), preferably within a vertical cavity (14), having a detection unit (64), which is formed, the electrical conductivity t of the electrically conductive element (63) and, preferably when the electrically conductive element (63) is severed, to output corresponding information.

6. Coupling bolt (12) according to claim 5, characterized in that the wear detection means (6), preferably within a vertical cavity (14), has at least one wireless communication unit (65), preferably a wireless transmitter unit (65), which is designed to transmit at least one item of information from the detection unit (64) wirelessly to the outside of the coupling bolt (12).

7. Coupling bolt (12) according to claim 6, characterized in that the wireless communication unit (65) is designed to be requested wirelessly from outside the coupling bolt (12) to transmit information from the detection unit (64).

8. Coupling bolt (12) according to claim 6 or 7, characterized in that the wirelessly transmitted information from the detection unit (64) contains the state of the electrically conductive element (63) and/or information derived from the state of the electrically conductive element (63). contains.

9. Coupling bolt (12) according to one of the preceding claims, characterized in that the coupling bolt (12) has a coupling section (13) along its longitudinal axis (C'), which is designed to fit into a coupling eye (22) of a coupling eyelet (21). along the longitudinal axis (C'), wherein the wear detection means (6), preferably at least a first wear element (60) and a second wear element (61), is arranged at least once in the coupling portion (13).

10. Coupling pin (12) according to claim 9, characterized in that the wear detection means (6), preferably at least one first wear element (60) and one second wear element (61), at least twice, preferably diametrically opposed to the longitudinal axis (C'). , Is arranged in the coupling section (13).

11. Coupling bolt (12) according to claim 9 or 10, characterized in that the wear detection means (6), preferably at least one first wear element (60) and one second wear element (61), at least twice in pairs, preferably as a pair diametrically opposed to the longitudinal axis (C') opposite one another and particularly preferably offset in pairs at right angles to one another, is arranged in the coupling section (13).

12. Coupling bolt (12) according to any one of claims 5 to 8 and according to any one of claims 10 or

11, characterized in that the detection unit (64) is designed to monitor the electrical conductivity of all electrically conductive elements (63) and, preferably when at least one of the electrically conductive elements (63) is severed, to output corresponding information.

13. Coupling bolt (12) according to claim 12, characterized in that the wirelessly transmitted information of the detection unit (64) also contains an identification of the severed electrically conductive element (63).

14. Towing vehicle (3) with a coupling pin (12) according to any one of the preceding claims.

15. Vehicle combination (3, 4) with a towing vehicle (3) according to claim 14.