Coupling assembly for an agricultural working machine drawn by a tractor via a coupling connection

Abstract

The invention relates to a coupling assembly (1) for an agricultural working machine (3) drawn by a tractor (2) via a coupling connection (K), having at least one axle (4) and a drawbar (5), wherein the coupling connection (K) has a coupling element (6) arranged on the drawbar (5) and connectable to a corresponding mating coupling element (7) of the tractor (2), wherein a vertically acting support load (S) between the coupling element (6) and the mating coupling element (7) can be raised via a support load ballast (8), which has a clamping point (9) on the working machine on the one hand and a clamping device (11) articulated to a clamping point (10) on the tractor on the other hand, wherein the clamping device (11) is configured such that only tractive forces are transmissible between the clamping points (9, 10).

Description

[0001] Coupling arrangement for an agricultural working machine pulled by a tractor via a coupling connection

[0002] The present invention relates to a coupling arrangement for an agricultural working machine which is pulled by a tractor via a coupling connection and which has at least one driving axle and a drawbar, wherein the coupling connection has a coupling element arranged on the drawbar which can be connected to a corresponding counter-coupling element of the tractor, wherein a vertically acting support load between the coupling element and the counter-coupling element can be increased via a support load ballasting which has a tensioning device which is articulated on the one hand in a tensioning point on the working machine side and on the other hand in a tensioning point on the tractor side.

[0003] Agricultural machinery comes in various designs and is used for a wide variety of agricultural purposes. These include, for example, seed drills for sowing seeds on cultivated land, machines for spreading spreading materials such as fertilizer or lime, machines for applying pesticides, and even tillage machines for cultivating the soil on cultivated land.

[0004] Larger and heavier agricultural machines, in particular, are often designed like a trailer with at least one driving axle and a drawbar. Such machines are typically pulled across the agricultural field by an agricultural tractor, usually a tow tractor. The required tractive force is usually transferred between the tractor and the agricultural machine via a coupling connection. Numerous coupling arrangements are known in the art to provide the coupling connection between the machine and the tractor, via which the machine can usually be coupled and uncoupled from the respective tractor quickly and easily.

[0005] Such coupling arrangements, which are usually designed like a trailer hitch, frequently comprise a coupling element on the work machine side, which is often located on the drawbar of the work machine. The coupling element, for example a spherical cap or a drawbar eye, can be connected to a corresponding counter-coupling element on the tractor, such as a ball head or a drawbar bolt. Such a coupling arrangement can reliably transmit the tractive and / or braking forces required for operating the work machine or for road travel from the tractor to the work machine.

[0006] In addition to the tractive and / or braking forces, which generally act essentially horizontally, such a coupling arrangement often also involves a certain force component acting vertically between the coupling element on the work machine side and the counter-coupling element on the tractor side. This vertical component, also referred to as the vertical load, ensures a secure and reliable connection between the coupling element and the counter-coupling element. A positive vertical load generally causes the coupling element to be pressed onto the counter-coupling element, i.e., vertical compressive forces are transferred between the coupling and counter-coupling elements.In this way, a positive support load can also be used to transfer a force acting in the direction of the working area from the work machine to the tractor, in particular to its rear axle, thereby improving the tractor's traction on the working area. In agricultural practice, however, under unfavorable operating conditions, e.g. if the center of gravity of the work machine is shifted unfavorably towards its rear, which can result, for example, from the swiveling or moving of attachments, low or even negative support loads can occur. Dynamic driving forces, particularly when driving at high speed over uneven working areas, can also cause a negative support load. A negative support load can result in the coupling element no longer being pressed onto the counter-coupling element, but instead tending to lift off the counter-coupling element in a vertical direction.This can not only negatively affect the traction of the tractor, but in extreme cases it can even lead to a dangerous, unintentional release of the coupling connection.

[0007] To increase the support load and / or to avoid negative support loads, it is common practice in simple work machines to add additional weights as ballast to the drawbar. While this can generally reliably prevent a negative support load, the permanently increased weight of the work machines can lead to greater loads acting on the ground of the work area and to higher fuel consumption of the tractor.

[0008] In addition, more complex coupling arrangements with different systems for supporting load ballasting are also known in the state of the art, via which the supporting load can be adjusted as required.

[0009] For example, DE 20 2013 100 364 U1 describes a trailer with a support load ballasting system in which a tensioning device designed as a pressure cylinder is arranged between a tensioning point on the trailer and a tensioning point on the tractor. By actuating the

[0010] Tensioning devices can apply compressive forces to the coupling point between the trailer and tractor via a type of toggle mechanism, which can increase the support load.

[0011] From EP 2 883 435 B1, a further coupling arrangement with a support load ballasting is known, which is also based on the transmission of compressive forces between a tensioning point on the working machine side and a tensioning point on the tractor side.

[0012] Such coupling arrangements with drawbar load ballasting have proven to be quite effective in practice. However, a disadvantage of such coupling arrangements has been found in that the drawbar load ballasting sometimes no longer functions reliably under particularly adverse operating conditions. In particular, with such coupling arrangements, unwanted disturbing forces can also be transmitted in the opposite direction between the clamping points via the tensioning device. The introduction of such disturbing forces, which can result, for example, from uneven ground conditions, can lead to increased wear or damage to the work machine and / or the tractor under particularly adverse conditions.

[0013] Against this background, the invention has the object of specifying a coupling arrangement in which excessive wear and / or damage to components of the work machine and / or the tractor can be avoided even under unfavourable operating conditions.

[0014] This object is achieved in a coupling arrangement of the type described above by the features of patent claim 1. Advantageous further developments are specified in the dependent subclaims.

[0015] The clamping device is designed in such a way that only tensile forces can be transmitted between the clamping points. This design reliably prevents the unwanted introduction of disruptive forces via the coupling assembly. The result is a coupling assembly characterized by a low-wear, component-friendly design.

[0016] In an advantageous development of the invention, it is proposed that the tensioning device be used to adjust the force flow from the tractor to the drawbar to increase the support load. This allows a reliable increase in the support load, which is independent of the design of the work machine, in particular independent of the load distribution of the work machine. Such a design proves advantageous for reliably increasing the support load, particularly in cases where the tractor is heavier than the work machine.

[0017] It is further proposed that the clamping device be pivotally mounted at the clamping points via pivot bearings. Such a pivot allows the clamping device advantageously great freedom of movement, particularly rotational or pivotal mobility. In particular, the pivotal pivot allows the clamping device's orientation to be easily changed, which also improves ease of assembly.

[0018] It has also proven advantageous if the tensioning points are both arranged above the coupling connection or both below the coupling connection. Such arrangements allow user-friendly, easily accessible positioning of the tensioning device between the two tensioning points. Furthermore, such arrangements can prevent undesirable collisions or obstructions between the tensioning device and the coupling element and / or the counter-coupling element, for example when cornering tightly. In this context, it is proposed that the tensioning point on the tractor side be arranged closer to the coupling connection in the vertical direction than the tensioning point on the work machine side. Such an arrangement allows a vertical force component to be generated in a simple manner via the tensioning device hinged at the two tensioning points.In addition, such an arrangement can support a low-loss power flow from the tractor to the drawbar, which can advantageously enable an increase in the support load between the coupling element and the counter-coupling element.

[0019] From a design point of view, it has proven advantageous in this context if the tensioning device extends at an angle to the horizontal between the tensioning points. The vertical force component and / or the force flow on the drawbar can be changed by changing the degree of inclination to the horizontal. In this context, it has proven advantageous if the tensioning device extends at an acute angle between the tensioning points, advantageously at an angle between 10° and 80°, in particular between 20° and 70° and particularly advantageously between 30° and 60°. Alternatively, depending on the existing design conditions, other angular ranges or an essentially horizontal extension of the tensioning device between the tensioning points may also prove advantageous.

[0020] The coupling arrangement is, as described, preferably designed such that the weight of the tractor can be transferred or is shifted to the work machine, in particular the drawbar. In other words, the coupling arrangement, in particular the tensioning device, is preferably configured to shift and / or transfer the vertically acting force component required for the supporting force or support load from the tractor to the work machine. It is further proposed that the tensioning device for adjusting the support load be designed with variable length. The support load can be adjusted reliably and easily using a length-adjustable tensioning device. Furthermore, a length-adjustable tensioning device allows particularly finely adjustable adjustment of the support load via the degree of length change.

[0021] From a design perspective, it has proven advantageous in this context for the clamping device to include a transmission element for transmitting the clamping force between the clamping points. Such a transmission element allows for a targeted and uniform transmission of the clamping force between the clamping points.

[0022] In a further advantageous design, the clamping device has a clamping element for generating the clamping force. Such a clamping element allows for particularly simple and reliable generation of the clamping force.

[0023] In this context, it is proposed that the support load be increased by shortening the clamping device. This allows the support load to be increased in a simple and user-friendly manner. It is particularly preferred if the support load can be further increased by increasing the shortening of the clamping device. In particular, the extent of the shortening and the extent of the support load increase can correspond. The shortening of the clamping device can advantageously be implemented via the clamping element.

[0024] In a further preferred design embodiment, it is proposed that the transmission element be attached to the tractor-side tensioning point and / or that the tensioning element be attached to the work machine-side tensioning point. This results in a design characterized by user-friendly, easy accessibility. When attaching the transmission element, particular consideration can be given to the specific installation space requirements of the coupling connection.

[0025] It is also preferred if the transmission element is releasably attached to the tractor-side clamping point, in particular releasably without the use of tools. Such a design allows the transmission element to be attached to and removed from the clamping point in a time-saving and easy-to-assemble manner. Furthermore, such a design has proven particularly easy to maintain and repair.

[0026] In this context, it is further proposed that the transmission element be designed as a chain or cable. This results in a cost-effective and simple construction. In particular, the chain or cable can be designed as readily available standard parts. By replacing the transmission element designed as a chain or cable, the tensioning device can be quickly and flexibly adapted to other design conditions, which may result, for example, from a change in the tractor. In particular, a transmission element designed as a chain or cable allows quick and easy adaptation of the coupling arrangement to varying distances between the tensioning points.

[0027] With regard to the clamping element, it has proven advantageous if it is designed as a hydraulic cylinder. Such a hydraulic cylinder allows a reliable and even transmission of the clamping force to the transmission element. Alternatively, however, the clamping element can also be designed as an electrical, pneumatic or mechanical clamping element, for example as a clamping screw, if this should prove advantageous for the respective application. In an advantageous development of the invention, it is proposed that the clamping element designed as a hydraulic cylinder is operatively connected to a working hydraulic system of the work machine and / or the tractor. This allows the hydraulic cylinder to be supplied with hydraulic fluid in an advantageously simple manner. In particular, the clamping element can be operatively connected to a working hydraulic system of the work machine and / or the tractor via a suitable interface.

[0028] In this context, it has also proven advantageous if the clamping element is connected to a control system of the working machine and / or the

[0029] This design allows the tensioning element to be controlled in a particularly user-friendly manner, further simplifying the adjustment of the support load. Furthermore, this design can also support automated control of the tensioning element, which is advantageous in terms of autonomous

[0030] This can prove advantageous in agricultural technology. It can be particularly advantageous if the tensioning element is coupled to the control system of the work machine and / or tractor via a suitable interface, such as a wired or wireless interface.

[0031] In a further advantageous embodiment, it is proposed that the work machine-side tensioning point be rigidly connected to the drawbar. Such a design enables a defined, low-loss power transmission between the work machine-side tensioning point and the drawbar.

[0032] In this context, it has proven advantageous if the tensioning point on the work machine side is arranged on a tensioning lever that extends essentially transversely to the drawbar, in particular vertically. Using such a tensioning lever, the flow of force can be further simplified and low-loss power transmission can be achieved. Using a tensioning lever that extends essentially vertically to the drawbar, the support load can be increased in a particularly effective manner. The tensioning lever can extend from the drawbar essentially vertically upwards or vertically downwards. Depending on the installation space or other design conditions of the coupling connection, a tensioning lever that extends diagonally to the drawbar can also prove advantageous.

[0033] From a design perspective, it can also be advantageous if the tensioning lever is designed to transmit compressive forces into the drawbar. This can effectively increase the support load.

[0034] In particular, the tensioning lever can be rigidly connected to the drawbar to ensure low-loss introduction of compressive forces.

[0035] With regard to the design of the tensioning lever, it is further proposed that one end of the tensioning lever should be connected to the working machine side

[0036] tensioning point for the articulation of the tensioning device and the other end is rigidly connected to the drawbar. This allows the tensioning device in particular a great deal of freedom of movement in the area of ​​the tensioning point and at the same time allows for effective force introduction into the drawbar. Such a design also enables an advantageously large lever arm. Furthermore, with such a design the tensioning point proves to be easily accessible, which can improve user-friendliness. Alternatively, the tensioning point for the articulation of the tensioning device can also be arranged in a different area of ​​the tensioning lever, for example between its ends, in particular in a central area.

[0037] With regard to an effective increase in the support load, it has proven structurally advantageous if the clamping lever is designed as a receiving console for the clamping device, in particular for the clamping element. This results in an assembly-friendly design, which in particular allows for quick and easily accessible mounting of the clamping element.

[0038] In an advantageous development of the invention, it is proposed that the tractor-side tensioning point is adjustable to adapt the support load and / or to minimize a transverse force acting transversely to the support load. Such a configuration allows simple adjustment of the support load, in particular a quick and user-friendly change of the angle of the tensioning device relative to the horizontal. Furthermore, the transverse force can be minimized in a simple and user-friendly manner, thereby increasing the driving safety of the tractor-work machine combination. To minimize the transverse force, it has proven particularly advantageous if the tractor-side tensioning point is arranged as close as possible to the coupling point at which the coupling element and the counter-coupling element are connected.Furthermore, such a design also proves to be advantageous in that it is possible to easily adapt the coupling connection to different tractors without having to change, in particular relocate, the clamping point on the working machine side.

[0039] In this context, it has also proven advantageous if the tractor-side tensioning point is formed on a height-adjustable tensioning bracket mounted in a coupling receptacle of the tractor. Such a design allows for particularly simple and user-friendly adjustment of the support load and / or minimization of the transverse force.

[0040] In this context, it is further proposed that the clamping bracket be designed as a bolt coupling, in particular as an automatic bolt coupling. Such a bolt coupling allows for particularly quick and error-free attachment of the clamping bracket. It is particularly advantageous if a bolt coupling already present on the tractor can be used as the clamping bracket.

[0041] Furthermore, it is proposed that the clamping device be connected to the clamping bracket, which is designed as a bolt coupling, via an adapter element. Such an adapter element can further simplify the attachment of the clamping device to the clamping bracket. In this context, it can be particularly advantageous, with regard to easy assembly and low-loss power transmission, if the adapter element is designed to correspond to the bolt of the bolt coupling.

[0042] With regard to the mobility of the clamping bracket, it has also proven advantageous if it can be moved in a slide-like manner in the coupling receptacle for adjusting the tractor-side clamping point in the vertical direction. This allows the operator to adjust the tractor-side clamping point in the vertical direction with minimal effort and without risk of error. Furthermore, with such a design, the tractor-side clamping point can be adjusted with repeatable precision. The clamping point can be adjusted in particular in steps, for example, between several locking positions, or continuously.

[0043] In a further advantageous embodiment, the tractor-side clamping point is adjustable in the horizontal direction via an adjusting device, in particular a hole pattern, formed on the clamping console. Such a configuration allows user-friendly and targeted adjustment of the tractor-side clamping point in the horizontal direction. Various positions can be set with repeatable accuracy using the hole pattern. In addition to or as an alternative to a hole pattern, other adjusting devices can also be provided via which the tractor-side clamping point can be adjusted in the horizontal direction. Furthermore, the adjusting device can also be designed for combined adjustment in the horizontal and vertical directions, for example, using an obliquely arranged hole pattern.

[0044] An advantageous development of the invention provides for the tensioning lever to be configured as a component that can be retrofitted to the drawbar and / or the tensioning bracket to be configured as a component that can be retrofitted to the tractor. Such a design allows existing work machines and / or tractors to be retrofitted with a coupling arrangement that allows for an increase in the support load. Furthermore, such a design allows for easy replacement of the tensioning lever and / or the tensioning bracket, for example, for maintenance purposes or in the event of a defect.

[0045] In this context, it is preferred from a design perspective if the clamping bracket has an interface for height-adjustable attachment to the tractor. In particular, the clamping bracket can have an interface for height-adjustable attachment that corresponds to the coupling receptacle of the tractor.

[0046] With regard to the interface, it has also proven advantageous if it can be operated without tools. This results in a particularly user-friendly, time-saving design that can be operated without the need for suitable tools.

[0047] It is further proposed that the counter-coupling element be formed on a coupling bracket that is height-adjustably mounted in the coupling receptacle of the tractor. This allows the counter-coupling element to be easily adjusted in height, allowing, for example, a user-friendly adjustment of the height of the counter-coupling element to the height of the coupling element on the work machine side. Such a design can prove particularly advantageous in situations in which different work machines with different drawbar heights are to be coupled to the same tractor.

[0048] It is particularly advantageous in this context if the coupling bracket and the clamping bracket have similar interfaces for height-adjustable fastening in the coupling receptacle of the tractor.

[0049] This results in an easily adaptable, flexible structure. For example, with this design, the coupling bracket and the clamping bracket can be arranged in the same coupling receptacle of the tractor, allowing height adjustment.

[0050] According to an advantageous development of the invention, the working machine-side coupling element comprises two coupling bolts, arranged spaced apart from one another, in particular transversely to the direction of travel, which can be connected to correspondingly designed mating coupling hooks of the tractor. This results in a particularly reliable coupling connection between the tractor and the working machine, via which the tractive and braking forces can be transmitted reliably and safely. In this context, it is preferred if the coupling bolts are arranged on a coupling carrier that is pivotally mounted about a horizontal axis and extends, in particular, transversely to the direction of travel.

[0051] Such an arrangement can advantageously compensate for unevenness of the working surface transverse to the direction of travel. Furthermore, such a structure proves to be low-wear and gentle on the

[0052] Components of the work machine, in particular its chassis. A further preferred embodiment provides for the tensioning lever and / or the coupling carrier to be mounted on the drawbar so that they can rotate about a vertical axis. This allows the coupling pins to rotate advantageously with the tractor, particularly when cornering. Excessive mechanical loads on the work machine, such as twisting or disturbing torques, can be advantageously avoided. This also results in safe roadholding of the tractor-work machine combination.

[0053] In this context, it is also structurally advantageous if the counter-coupling hooks are designed as parts of the tractor's three-point hydraulic system. With such a design, the work machine can be easily connected to the tractor's three-point hydraulic system. Furthermore, with such a design, the counter-coupling hooks can be easily hydraulically adjusted in height, which allows for improved adaptation to the design of the work machine, particularly its drawbar height.

[0054] With regard to even load distribution, it is also preferred if both the coupling connection and the tractor-side tensioning point and / or the work machine-side tensioning point are arranged on a vertical longitudinal center plane of the coupling. This can result in a substantially load-symmetrical structure, which can be particularly advantageous with regard to safe driving.

[0055] With regard to the structural design of the coupling connection, it is further proposed that the coupling element and the counter-coupling element form a ball-and-socket coupling, pin coupling, jaw coupling, or fifth wheel coupling. The coupling element and the counter-coupling element can be suitably selected, particularly with regard to a reliable and secure coupling connection. In a further structurally preferred embodiment, the drawbar has two V-shaped supports, between which the tensioning lever is attached. Such a design allows for reliable and easily accessible attachment of the tensioning lever between the two V-shaped supports.

[0056] It is further proposed that the work machine be tiltable about its travel axis. In particular, a tilting moment can be generated about the work machine's travel axis, which can be used to increase the support load. In this context, the travel axis can be designed, for example, as a single axle, a tandem axle, or a triple axle.

[0057] Furthermore, from a design perspective, it is preferable for the driving axle to be a non-steered axle. This results in a simple, maintenance-friendly design in which the prevailing force and torque relationships can be analyzed relatively easily.

[0058] Further details and advantages of the invention are explained below with the aid of the accompanying drawings of exemplary embodiments. In these drawings:

[0059] Fig. 1 is a perspective view of an agricultural working machine pulled by a tractor via a coupling connection;

[0060] Fig. 2 is an enlarged, perspective side view of a first coupling arrangement for an agricultural working machine according to Fig. 1, which is pulled by a tractor via a coupling connection; Fig. 3 is a side view of the coupling arrangement according to

[0061] Fig. 2;

[0062] Fig. 4 is a plan view of the coupling arrangement according to

[0063] Fig. 3;

[0064] Fig. 5 is a perspective top view of a second coupling arrangement;

[0065] Fig. 6 is a further perspective top view of the coupling arrangement according to Fig. 5;

[0066] Fig. 7 is a side view of the coupling arrangement according to

[0067] Fig. 5;

[0068] Fig. 8 is a plan view of the coupling arrangement according to

[0069] Fig. 5, and

[0070] Fig. 9 is a perspective top view of a third coupling arrangement.

[0071] The illustration in Fig. 1 shows a partially sectioned or partial view of an agricultural combination consisting of a tractor 2, in this case a tractor, and an agricultural work machine 3. The work machine 3 is coupled to the tractor 2 via a coupling arrangement 1 and can be pulled by the latter in the direction of travel R, for example over an agricultural field.

[0072] The agricultural work machine 3 shown in detail in Fig. 1 is a seed drill, but it can also be another work machine 3, for example, for spreading seed or fertilizer. Furthermore, the work machine 3 can also be designed as a soil cultivation machine or harvesting machine.

[0073] The work machine 3 is designed in the manner of a trailer and has a chassis with an unsteered driving axle 4, which is designed as a single axle, see Fig. 1. Alternatively, the driving axle 4 can also be designed as a double or tandem axle or other multiple axle.

[0074] The driving axle 4 is connected to a drawbar 5. A coupling element 6, designed as a spherical cap, is arranged at the front end of the drawbar 5 (see also Fig. 2). Together with a corresponding counter-coupling element 7 arranged on the tractor 2, in this case a ball head, a coupling connection K is formed between the working machine 3 and the tractor 2.

[0075] The drive forces, which are generally in the form of tractive forces during forward travel, are transmitted from the tractor 2 to the work machine 3 to drive the work machine 3 via the coupling connection K. Furthermore, the coupling connection K also serves to transmit braking forces for braking the work machine 3 or compressive forces when maneuvering or reversing the work machine 3.

[0076] For the safe transmission of the tensile and / or braking forces acting essentially in a horizontal direction, a vertical force is also provided in the coupling connection K, the so-called support load S. The support load S acts as a compressive force between the coupling element 6 and the counter-coupling element 7, see Fig. 2. A positive support load S, i.e. a support load acting in the direction of the ground, ensures a safe and reliable coupling connection K between the coupling element 6 and the counter-coupling element 7. A certain positive support load S is often also prescribed by law for safety reasons.

[0077] However, the illustration in Fig. 1 shows that the entire working machine 3 is designed to be tiltable about the driving axis 4. There are comparatively long lever arms extending forward and backward from the driving axis 4. The components and parts of the working machine 3 arranged in front of and behind the driving axis 4 in the direction of travel R ensure a tilting moment about the driving axis 4.

[0078] In the working machine 3 according to Fig. 1, a storage container 3.1 is arranged in front of the driving axle 4 in the direction of travel R, for example for holding seed. Various working tools 3.2 are arranged behind the driving axle 4 in the direction of travel R. The working tools 3.2, which are only shown schematically and in detail in the illustration according to Fig. 1, can be, for example, soil cultivation tools or sowing units such as seed coulters.

[0079] Depending on the weight distribution along the longitudinal axis of the work machine 3, different turning or tipping moments arise about the travel axis 4. In particular, in situations in which the front area of ​​the work machine 3 is comparatively light - for example in the case of an empty storage container 3.1 - and at the same time the rear area of ​​the work machine 3 is comparatively heavy and / or is folded, a turning or tipping moment can arise which can lead to the drawbar 5 being lifted. Such a tipping moment can be intensified if the work tools 3.2 or other attachments are pivoted far to the rear, i.e. against the direction of travel, resulting in a particularly long lever arm around the travel axis 4. Furthermore, the risk of such a tipping moment increases the lighter the drawbar 5 is designed.Such a tipping moment, which leads to a lifting of the drawbar 5, is generally undesirable during operation of such work machines 3. This can result in a negative support load S between the coupling element 6 and the counter-coupling element 7. Such a negative support load S can in turn, in unfavorable cases, lead to the coupling element 6 tending to lift off the counter-coupling element 7 in the vertical direction. To avoid negative support loads S, the coupling arrangement 1 has a support load ballasting 8, via which the support load S can be increased. A first exemplary embodiment of a coupling arrangement 1 with a support load ballasting 8 is explained below with reference to the illustrations in Figs. 2 to 4.

[0080] As can be seen in Fig. 2, the support load ballasting 8 comprises a tensioning device 11 which extends between a tensioning point 9 on the working machine side and a tensioning point 10 on the tractor side.

[0081] The tensioning device 11 is rotatably connected to the tensioning points 9, 10 via a pivot bearing 14.1, 14.2, see Fig. 2. The coupling connection K, the tractor-side tensioning point 10 and also the work machine-side tensioning point 9 are arranged on a vertical coupling longitudinal center plane L, see Fig. 4. The tensioning device 11 is designed so that its length can be adjusted in order to adjust the support load S. By changing the length of the tensioning device 11, a tensioning force F can be generated between the tensioning points 9, 10. For this purpose, a tensioning element 11.2 is provided which, in the embodiment according to Figs. 2 to 4, is designed as a hydraulic cylinder. The tensioning element 11.2 is rotatably connected on one side to the work machine-side tensioning point 9. At its end opposite the clamping point 9, the clamping element 11.2 is connected to a transmission element 11.1 for transmitting the clamping force F between the clamping points 9, 10, see Fig. 3.The transmission element 11.1 is designed as a tension element and is pivotally connected on one side to the tensioning point 10 on the tractor. In the present exemplary embodiment, the transmission element 11.1 is designed as a chain. Alternatively, the transmission element 11.1 can also be designed as a cable or other tensioning element 11.1. When the tensioning element 11.2 is shortened, i.e., when the hydraulic cylinder is retracted, the transmission element 11.1 is tensioned and a tensioning force F in the form of a tensile force is applied between the tensioning points 9, 10. The following, with reference to the illustration in Fig. 3, explains how the tensioning force F can be used to increase the support load S. The prerequisite for increasing the support load S is that the tensioning force F has a force component Fv acting in the vertical direction. This force component Fv acting in the vertical direction, in particular towards the ground, serves to increase the support load S.

[0082] In particular, the exemplary embodiments of the coupling arrangement 1 according to the invention described below are constructed in such a way that the weight of the tractor 2 can be transferred or is shifted onto the work machine 3, in particular the drawbar 5. In other words, the coupling arrangement 1, in particular the tensioning device 11, is preferably designed to shift and / or transfer the vertically acting force component Fv required for the supporting force or support load S from the tractor 2 to the work machine 3. In the present exemplary embodiment according to FIGS. 2 to 4, the tensioning device 11 is arranged obliquely to the horizontal between the tensioning points 9, 10 to generate a vertical force component, cf.

[0083] Fig. 3. The tractor-side tensioning point 10 is arranged closer to the coupling connection K in the vertical direction than the work machine-side tensioning point 9. Both tensioning points 9, 10 are arranged above the coupling connection K. Alternatively, however, both tensioning points 9, 10 can also be arranged below the coupling connection K. Due to the oblique arrangement of the tensioning device 11, which is arranged at an angle of approximately 45° to the horizontal, the tensioning force F acting between the tensioning points 9, 10 can be divided into a horizontal force component FH and a vertical force component Fv, cf. Fig. 3. The greater the tensioning force F, the greater the vertical force component Fv. This vertical force component Fv serves to increase the support load S between the coupling element 6 and the counter-coupling element 7.

[0084] In the following, the design features of the coupling arrangement 1 are explained using the illustration in Fig. 3 to use the vertical force component Fv to increase the support load S.

[0085] A tensioning lever 12 is provided to transmit the vertical force component Fv to the drawbar 5, see Fig. 3. The tensioning lever 12 extends essentially in a vertical direction transversely from the drawbar 5 upwards.

[0086] Vertical extension also includes angled arrangements up to an angle of approximately 45° from the vertical. In an alternative embodiment, the tensioning lever 12 can also extend essentially vertically downwards from the drawbar 5. In this case, the arrangement is a mirror image of the direction of extension of the drawbar 5. The tensioning lever 12 is rigidly connected to the drawbar 5 at one end, thereby supporting a low-loss force introduction into the drawbar 5. At its end opposite the drawbar 5, the tensioning lever 12 has the working machine-side tensioning point 9, so that it is rigidly connected to the drawbar 5 via the tensioning lever 12.

[0087] The vertical force component Fv acting on the work machine-side clamping point 9 is introduced as a pressure force into the drawbar 5 via the clamping lever 12. Since the coupling element 6, which is designed as a spherical cap according to the illustrations in Fig. 2 to 4, is rigidly attached to the

[0088] Drawbar 5 is arranged, the vertical force component Fv also acts on the coupling element 6. Thus, the vertical force component Fv causes a compressive force between the coupling element 6 and the counter-coupling element 7, which is designed as a ball head and is arranged on the tractor 2. The vertical force component Fv thus essentially corresponds to the support load S.

[0089] By actuating the tensioning element 11 .2, a force flow from the tractor 2 to the working machine 3 can be adjusted via the tensioning device 11, which can be used to increase the support load S. A fraction of the

[0090] The weight of the tractor 2 is transferred to the drawbar 5 of the work machine 3. The magnitude of the support load S can be adjusted, in particular, by changing the length of the tensioning element 11.2. Furthermore, the support load S can also be influenced by the positioning of the tractor-side tensioning point 10, which is explained below using the illustrations in Figs. 3 and 4.

[0091] The tractor-side clamping point 10 is formed on a clamping bracket 13. The clamping bracket 13 is height-adjustably mounted in a coupling receptacle 2.1 of the tractor 2. The clamping bracket 13 extends between two vertically extending guide grooves of the coupling receptacle 2.1 and can be moved along the guide grooves in a slide-like manner. The clamping bracket 13 can be attached to the coupling receptacle 2.1 at different heights via an interface 17 designed as a bolt connection (see Figs. 2 and 3). The interface 17 can be designed to be operated without tools or automatically, for example, via an operating lever.

[0092] When the position of the clamping console 13 is changed manually or automatically in the vertical direction, the orientation of the clamping device 11 also changes at the same time, supported by the rotatable arrangement of the clamping points 9, 10, as can be seen in particular from Fig. 3. When the clamping console 13 is moved upwards from the position shown in Fig. 3, i.e. when the vertical distance between the coupling connection K and the clamping point 10 is increased, the vertical force component Fv becomes smaller. This results in a lower support load S. A downward movement of the clamping console 13 can correspondingly increase the support load S due to the then resulting more acute angle of the clamping device 11 relative to the horizontal.

[0093] In addition to the vertical adjustment option, the clamping bracket 13 also offers horizontal adjustment. For this purpose, various attachment points for the clamping device 11 are formed on the clamping bracket 13 in the manner of a hole pattern M (see Fig. 3). In the present embodiment, the transmission element 11.1 can be attached to four different attachment points of the hole pattern M, which are characterized by different horizontal positions. This results in four different horizontal positions for the clamping point 10. The hole pattern M is aligned slightly diagonally to the horizontal (see Fig. 3).

[0094] By adjusting the clamping point 10, a transverse force Q can be set, in particular, which acts on the drawbar ballasting 8 when cornering, see Fig. 4. A transverse force Q occurs when cornering when the tractor-side clamping point 10 is not located on the axis of rotation of the coupling connection K. The axis of rotation extends essentially vertically through the coupling connection K, i.e., the coupling element 6 and the counter-coupling element 7. With a view to minimizing the transverse force Q, it is preferable to minimize the horizontal distance of the clamping point 10 from the axis of rotation. This can be achieved by positioning the tractor-side clamping point 10 as close as possible to the axis of rotation of the coupling connection K, for example, by selecting a suitable attachment point of the hole pattern M, see Fig. 3.

[0095] The transmission element 11.1, designed as a chain, is releasably attached to the tensioning bracket 13 at the tensioning point 10 via a bolt connection, see Fig. 2. In particular, the transmission element 11.1 can be releasably attached to the tensioning bracket 13 for user-friendly assembly and disassembly, for example, via a tool-lockable bracket, such as a shackle. Similarly, the transmission element 11.1 can also be releasably attached to the tensioning element 11.2, without the need for tools.

[0096] The transmission element 11.1, designed as a chain, ensures that essentially only tensile forces can be transmitted between the tensioning points 9, 10. Force transmission directed counter to the tensioning force F is not possible with such a flexible transmission element 11.1. For this reason, disruptive forces directed counter to the tensioning force F, which can result, for example, from driving over uneven ground, cannot be transmitted. This results in a component-friendly, low-wear design.

[0097] The clamping element 11.2, designed as a hydraulic cylinder, can be operatively connected, for example via a suitable hydraulic interface, to the working hydraulics of the work machine 3 and / or the tractor 2. This allows the clamping element 11.2 to be integrated into the respective hydraulic circuits of the work machine 3 and / or the tractor 2.

[0098] In addition, the tensioning element 11.2 can be coupled to a control system of the work machine 3 and / or the tractor 2. This allows the tensioning element 11.2 to be easily controlled. In particular, the tensioning element 11.2 can be integrated into the control circuit of the work machine 3 and / or the tractor 2, which can prove advantageous, for example, with regard to use in the field of autonomous agricultural technology.

[0099] As can be seen, for example, from the illustrations in Fig. 2 and 3, the counter-coupling element 7, designed as a ball head, is formed on a coupling bracket 15. In a similar way to the clamping bracket 13, the coupling bracket 15 is also fastened in the coupling receptacle 2.1 in a height-adjustable manner. In this way, the counter-coupling element 7 can be adjusted in height like a slide, for example to set a greater ground clearance of the coupling connection K. Furthermore, the counter-coupling element 7 can be adjusted in height to the height of the coupling element 6. For a particularly user-friendly and quick adjustment of the height of the coupling bracket 15, the interface 17 is designed to be removable without tools.

[0100] The clamping bracket 13 can be retrofitted to existing work machines 3 and / or tractors 2 as shown in Figs. 1 to 4. As described above, the clamping bracket 13 can be easily mounted in an existing coupling receptacle 2.1 of a tractor 2. TI

[0101] In addition, the tensioning lever 12 can be provided not only on new work machines 3, but can also be retrofitted to the drawbar 5 of an existing work machine 3. Retrofitting can be carried out, for example, via a suitable screw connection, see Fig. 3. In particular, the tensioning lever 12 can be fastened between two V-shaped supports 5.1 of the drawbar 5, see Fig. 4. This results in a repair- and maintenance-friendly design.

[0102] In particular, the structure described both above and below has the advantage that the coupling arrangement 1 according to the invention, in particular tensioning device 8, can be used universally to the greatest extent possible on all tractors 2 with corresponding coupling receptacles 2.1 designed as trailer slides and known from the prior art.

[0103] A second embodiment of the coupling arrangement 1 is explained below with reference to the illustrations in Figs. 5 to 8, which differs from the first embodiment according to Figs. 1 to 4 by an alternative design of the coupling connection 1. The coupling arrangement 1 according to the second embodiment allows the coupling of the working machine 3 to the lower links of a three-point hydraulic system of the tractor 2, cf. Fig. 5, and is characterized by a modified position of the axis of rotation around which the working machine 3 rotates when cornering.

[0104] In the second embodiment, the coupling element 6 on the work machine side has two coupling bolts 6.1, 6.2 arranged at a distance from one another transversely to the direction of travel R, see Fig. 6. These coupling bolts 6.1, 6.2 are connected to correspondingly designed counter-coupling hooks 7.1, 7.2 of the tractor 2. As can be seen in Fig. 6, the counter-coupling hooks 7.1, 7.2 are formed at the ends of the two lower links of a three-point hydraulic system of the tractor 2. The counter-coupling hooks 7.1, 7.2 encompass a large part of the circumference of the coupling bolts 6.1, 6.2 to transmit the tractive and braking forces. A safeguard can also be provided to prevent the coupling bolts 6.1, 6.2 from accidentally becoming detached from the counter-coupling hooks 7.1, 7.2. As an alternative to counter-coupling hooks 7.1, 7.2, other suitable connecting elements, such as counter-coupling eyes or lugs, can also be provided for connection to the coupling bolts 6.1, 6.2.

[0105] The two coupling pins 6.1, 6.2 are formed at the opposite ends of a coupling carrier 6.3 extending transversely to the direction of travel, see Fig. 6. The coupling carrier 6.3 is attached to the drawbar 5 of the work machine 3 in the manner of a rocker so as to be pivotable about an axis Ai. The axis Ai extends horizontally centrally between the two coupling pins 6.1, 6.2. Such an arrangement advantageously enables the compensation of uneven ground, which can lead to a vertical offset between the two coupling pins 6.1, 6.2. An upward movement of one coupling pin 6.1 thus results in an equal downward movement of the other coupling pin 6.2. Furthermore, such an arrangement allows the work machine 3 to be coupled more easily to the tractor 2, even on uneven ground.

[0106] The coupling carrier 6.3 is also attached to the drawbar 5 so as to be rotatable about a vertical axis A2, see Fig. 6. In the second embodiment of the coupling arrangement 1, the axis A2 forms the axis of rotation around which the work machine 3 rotates when cornering. In addition to the coupling carrier 6.3, the tensioning lever 12 and thus also the tensioning point 9 on the work machine side are also attached to the drawbar 5 so as to be rotatable about the vertical axis A2, see Figs. 7 and 8. This enables not only the coupling carrier 6.3 but also the tensioning lever 12 including the tensioning point 9 to rotate when cornering with the tractor 2. Thus, the tensioning device 11 is always aligned in the direction of travel R of the tractor 2 when cornering. The tensioning force F therefore always extends in the direction of travel R of the tractor 2. Unfavorable load cases, which could lead, for example, to increased lateral forces Q or torsions when cornering, can be avoided.The result is a material-friendly and low-wear structure.

[0107] In the following, a third embodiment of the coupling arrangement 1 is explained with reference to the illustration in Fig. 9, which largely corresponds to the first embodiment according to Figs. 1 to 4, but differs from this in the design of the clamping bracket 13.

[0108] As can be seen from Fig. 9, the clamping bracket 13 is designed as an automatic bolt coupling. The bolt of the automatic bolt coupling, also referred to as a towing jaw, is connected to the chain-shaped

[0109] The transmission element 11.1 of the tensioning device is coupled. In particular, a bolt coupling already present on the tractor 2 can be used as a clamping bracket 13. For easy coupling to the bolt coupling, an adapter element 18 is arranged on the transmission element 11.1, which is ring-shaped and corresponds to the coupling bolt of the automatic bolt coupling. In the coupled state, the adapter element 18 encloses the coupling bolt of the automatic bolt coupling, so that the clamping force F can be transmitted. The adapter element 18 is arranged so as to be rotatable around the coupling bolt, which reduces unwanted transverse forces Q.

[0110] Analogous to the first embodiment of the clamping bracket according to Figs. 1 to 8, the clamping bracket 13, designed as an automatic bolt coupling, is mounted in a slide-like manner in the coupling receptacle 2.1 of the tractor 2, cf. Fig. 9. This allows the angle of the clamping device 11 relative to the horizontal to be adjusted. An interface 17 is also provided for the detachable fastening, in particular for tool-free detachment, of the clamping bracket 13, designed as an automatic bolt coupling.

[0111] The clamping bracket 13 designed as an automatic pin coupling can in particular be arranged such that the tractor-side clamping point 10 is positioned as close as possible to the axis of rotation of the coupling connection K.

[0112] The coupling arrangement 1 described above is characterized by the fact that the introduction of disruptive forces into components or parts of the work machine 3 and / or the tractor 2 can be reliably prevented. This results in a low-wear, component-protecting design.

[0113] Reference symbol list

[0114] 1 Coupling arrangement

[0115] 2 tractors

[0116] 2.1 Coupling mount

[0117] 3 working machines

[0118] 3.1 Storage container

[0119] 3.2 Work tools

[0120] 4 driving axles

[0121] 5 drawbar

[0122] 5.1 Carrier

[0123] 6 Coupling element

[0124] 6.1 Coupling bolt

[0125] 6.2 Coupling bolt

[0126] 6.3 Coupling carrier

[0127] 7 Counter coupling element

[0128] 7.1 Counter coupling hook

[0129] 7.2 Counter coupling hook

[0130] 8 Support load ballasting

[0131] 9 Clamping point

[0132] 10 clamping point

[0133] 11 Clamping device

[0134] 11.1 Transmission element

[0135] 11.2 Clamping element

[0136] 12 clamping levers

[0137] 13 Clamping console

[0138] 14.1 Pivot bearing

[0139] 14.2 Pivot bearing

[0140] 15 Clutch console

[0141] 16 Adjusting device

[0142] 17 Interface

[0143] 18 Adapter element Ai axis

[0144] A2 axis

[0145] F clamping force FH horizontal force component

[0146] Fv vertical force component

[0147] K Coupling connection

[0148] L Coupling longitudinal center plane

[0149] M Hole pattern Q Shear force

[0150] R direction of travel

[0151] S Stützlast

Claims

Patent claims 1. Coupling arrangement for an agricultural work machine (3) which is pulled by a tractor (2) via a coupling connection (K), said agricultural work machine having at least one driving axle (4) and a drawbar (5), wherein the coupling connection (K) has a coupling element (6) arranged on the drawbar (5) which can be connected to a corresponding counter-coupling element (7) of the tractor (2), wherein a vertically acting support load (S) between the coupling element (6) and the counter-coupling element (7) can be increased via a support load ballasting (8) which has a tensioning device (11) which is articulated on the one hand in a tensioning point (9) on the work machine side and on the other hand in a tensioning point (10) on the tractor side, characterized in that the tensioning device (11) is designed such that only tensile forces can be transmitted between the tensioning points (9, 10).

2. Coupling arrangement according to claim 1, characterized in that the clamping points (9, 10) are both arranged above the coupling connection (K) or both below the coupling connection (K).

3. Coupling arrangement according to one of claims 1 or 2, characterized in that the tractor-side tensioning point (10) is arranged closer to the coupling connection (K) in the vertical direction than the working machine-side tensioning point (9).

4. Coupling arrangement according to one of the preceding claims, characterized in that the tensioning device (11) is designed to be variable in length for adjusting the support load (S).

5. Coupling arrangement according to one of the preceding claims, characterized in that the clamping device (11) has a transmission element (11.1) for transmitting a clamping force (F) between the clamping points (9, 10).

6. Coupling arrangement according to claim 5, characterized in that the clamping device (11) has a clamping element (11.2) for generating the clamping force (F).

7. Coupling arrangement according to one of the preceding claims, characterized in that the working machine-side clamping point (9) is rigidly connected to the drawbar (5).

8. Coupling arrangement according to one of the preceding claims, characterized in that the working machine-side clamping point (9) is arranged on a clamping lever (12) extending substantially transversely to the drawbar (5), in particular vertically.

9. Coupling arrangement according to claim 8, characterized in that one end of the tensioning lever (12) has the working machine-side tensioning point (9) for articulating the tensioning device (11) and the other end is rigidly connected to the drawbar (5).

10. Coupling arrangement according to one of the preceding claims, characterized in that the tractor-side tensioning point (10) is adjustable to adapt the support load (S) and / or to minimize a transverse force (Q) acting transversely to the support load (S).

11. Coupling arrangement according to claim 10, characterized in that the tractor-side clamping point (10) is formed on a clamping bracket (13) which is fastened in a height-adjustable manner in a coupling receptacle (2.1) of the tractor (2).

12. Coupling arrangement according to claim 11, characterized in that the clamping bracket (13) is movable in the manner of a slide in the vertical direction in the coupling receptacle (2.1) for adjusting the tractor-side clamping point (10).

13. Coupling arrangement according to one of claims 11 or 12, characterized in that the tractor-side clamping point (10) is adjustable in the horizontal direction via an adjusting device (16), in particular a hole pattern (M), formed on the clamping bracket (13).

14. Coupling arrangement according to one of the preceding claims, characterized in that the working machine-side coupling element (6) has two coupling bolts (6.1, 6.2) which are arranged at a distance from one another, in particular transversely to the direction of travel (R), and which can be connected to correspondingly designed counter-coupling hooks (7.1, 7.2) of the tractor (2).

15. Coupling arrangement according to claim 14, characterized in that the coupling bolts (6.1, 6.2) are arranged on a coupling carrier (6.3) which is pivotally mounted about a horizontal axis (Ai) and extends in particular transversely to the direction of travel (R).

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