Articulated Lorry Having a Tractor and a Trailer, Tractor, Trailer and Method for Axle Load Distribution in the Case of an Articulated Lorry

Abstract

An articulated lorry that includes a tractor which has a fifth-wheel coupling and a trailer which has a connecting element which is reversibly detachably connected at a connection point to the fifth-wheel coupling. A tensioning device relieves a load on a wheel axle of the trailer, loads a drive axle of the trailer, and applies a force that counteracts a relative pivoting movement between the tractor and the trailer around a pivot axis which is oriented parallel to a transverse vehicle direction of the tractor and/or of the trailer. The tensioning device tensions the tractor to the trailer.

Claims

1.-9. (canceled)

10. An articulated lorry, comprising: a tractor which has a fifth-wheel coupling; a trailer which has a connecting element which is reversibly detachably connected at a connection point to the fifth-wheel coupling; and means for relieving a load on a wheel axle of the trailer and for loading a drive axle of the trailer and for applying a force that counteracts a relative pivoting movement between the tractor and the trailer around a pivot axis which is oriented parallel to a transverse vehicle direction of the tractor and/or of the trailer; wherein the means comprise a tensioning device that tensions the tractor to the trailer to apply the force.

11. The articulated lorry according to claim 10, wherein the tensioning device applies a torque acting around the connection point that relieves the load on the wheel axle of the trailer and that loads the drive axle of the trailer.

12. The articulated lorry according to claim 10, wherein the tensioning device is disposed in a longitudinal vehicle direction of the tractor between a driver cab of the tractor and the connection point or wherein the connection point is disposed in the longitudinal vehicle direction of the tractor between the driver cab and the tensioning device.

13. The articulated lorry according to claim 10, wherein the means comprise a roller, wherein the tensioning device is supportable in a rollable manner with respect to the tractor or with respect to the trailer by the roller when the force is applied.

14. The articulated lorry according to claim 10, wherein the tensioning device is disposed in a vehicle vertical direction of the tractor at least in a region below a coupling plate of the fifth-wheel coupling.

15. The articulated lorry according to claim 10, wherein the means comprise a height-changing device, wherein a distance in a vehicle vertical direction of the tractor between a partial region of a body of the articulated lorry and a wheel of the articulated lorry is adjustable by the height-changing device.

16. An apparatus, comprising: means for relieving a load on a wheel axle and for loading a drive axle and for applying a force that counteracts a relative pivoting movement between a tractor and a trailer around a pivot axis which is oriented parallel to a transverse vehicle direction of the tractor and/or of the trailer; wherein the means comprise a tensioning device that tensions the tractor to the trailer to apply the force.

17. A method for axle load distribution in an articulated lorry which includes a tractor which has a fifth-wheel coupling and which includes a trailer which has a connecting element which is reversibly detachably connected at a connection point to the fifth-wheel coupling, comprising the steps of: relieving a load on a wheel axle of the trailer, loading a drive axle of the trailer, and applying a force that counteracts a relative pivoting movement between the tractor and the trailer around a pivot axis which is oriented parallel to a transverse vehicle direction of the tractor and/or of the trailer by a tensioning device that tensions the tractor to the trailer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 is a schematic side view of an articulated lorry known from the prior art; and

[0026] FIG. 2 is a schematic side view of an articulated lorry which comprises means to relieve the load of at least one wheel axle of a trailer and to load at least one drive axle of the tractor.

DETAILED DESCRIPTION OF THE DRAWINGS

[0027] With regard to FIG. 1, reference is made here to the statements in the introductory part of the description.

[0028] FIG. 2 shows an articulated lorry 10, which comprises a tractor 20 and a trailer 50, as well as a coordinate system related to the articulated lorry 10, the coordinate system being defined by a longitudinal vehicle direction x, a transverse vehicle direction y and a vertical vehicle direction z. The longitudinal vehicle direction x, the transverse vehicle direction y and the vertical vehicle direction z can be related to both the tractor 20 and to the trailer 50, since respective longitudinal axes of the tractor 20 and of the trailer 50, which are not shown separately here, are oriented parallel to each other or aligned with each other. Such an orientation of the longitudinal axes results, for example, from a longer straight travel line of the articulated lorry 10.

[0029] The trailer 20 comprises a front axle designed as a steering axle 23, having steerable wheels 24 and a drive axle 21 having drivable wheels 22. By means of the wheels 22, 24, the tractor 20 is supported with respect to an underlying surface U. The wheels 22 can be driven, for example, by means of an internal combustion engine, not depicted in more detail here, of the tractor 20. The tractor 20 also has a fifth-wheel coupling 30.

[0030] The trailer 50 has a connecting element 52, designed as a king pin in the present case, which is reversibly detachably connected to the fifth-wheel coupling 30 at a common connection point 51.

[0031] The articulated lorry 10 comprises means M for relieving the load on respective wheel axles 54 of the trailer 50 and for loading the drive axle 21 of the tractor 20. Respective wheels 55 of the trailer 50 are fixed to the wheel axles 54, by means of which respective wheels the trailer 50 is supported relative to the ground U.

[0032] At least one force F, illustrated by an arrow in FIG. 2, can be applied by the means M, which counteracts a relative pivoting movement SB between the tractor 20 and the trailer 50 around a pivot axis SA. In the present case, the pivot axis SA is oriented parallel to the transverse vehicle direction y of the tractor 20 and the trailer 50. The means M can be switched between a respective active state and a respective passive state by means of a control unit of the tractor 20 or of the trailer 50, which is not depicted in more detail here.

[0033] In the present case, the pivot axis SA extends through a swivel joint 33 of the fifth-wheel coupling 30. A coupling plate 31 of the fifth-wheel coupling 30 is rotatably coupled to a coupling base body 32 of the fifth-wheel coupling 30 by the swivel joint 33. The coupling base body 32 is fixed to a frame and thus to a body of the tractor 20. The coupling plate 31 can be designed for at least indirect reversibly detachable connection to the connecting element 52 (king pin).

[0034] The means M comprise tensioning devices 60, 61, 62, 63, by means of which the tractor 20 can be tensioned with the trailer 50 and the force F counteracting the relative pivoting movement SB can thereby be applied. In FIG. 2, a total of four of the tensioning devices 60, 61, 62, 63 are shown, each of which is capable of applying the force F. Thus, already one of the tensioning devices 60, 61, 62, 63 is sufficient to exert the force F. However, FIG. 2 serves to depict various possibilities for the arrangement of the respective tensioning devices 60, 61, 62, 63. In the present case, the tensioning devices 60, 61, 63 are assigned to the tractor 20, whereas the tensioning device 62 is assigned to the trailer 50. In other words, the tractor 20 comprises the tensioning devices 60, 61, 63 and the trailer 50 comprises the tensioning device 62.

[0035] The tensioning devices 60, 61 are arranged in the vertical vehicle direction z below the coupling plate 31 of the fifth-wheel coupling 30. In contrast, the tensioning devices 62, 63 are each arranged adjacent to the coupling plate 31 in the vehicle longitudinal direction x. The tensioning devices 60, 61, 62, 63 can be actuated mechanically, electrically and additionally or alternatively hydraulically. The tensioning devices 60, 61, 62, 63 can each be designed to be telescopic. For this purpose, the tensioning devices 60, 61, 62, 63 can comprise, for example a threaded spindle, a hydraulic cylinder or a pneumatic cylinder.

[0036] Preferably, the tensioning devices 60, 61, 62, 63 can be self-locking in their respective active state. This means that—depending on the design of the tensioning devices 60, 61, 62, 63—there is no need for a power supply or for pressurised hydraulic fluid or pressurised gas in the active state, which enables particularly energy-saving operation of the tensioning devices 60, 61, 62, 63 as required.

[0037] In the present case, the tensioning devices 61, 63 are arranged in the longitudinal vehicle direction x of the tractor 20 between a driver's cab 26 of the tractor 20 and the connection point 51.

[0038] If one of the two tensioning devices 61, 63 is shifted from its passive state to its active state, the respective tensioning device 61, 63 exerts the force F as a tensile force, by means of which the trailer 50 is pulled in the direction opposite to an arrow direction of the vertical vehicle direction z and thus in the direction of the tractor 20, as can be seen from FIG. 2.

[0039] The tensioning device 63, which is connected on the one hand to the frame and thus to the body of the tractor 20, can be coupled to a guide rail 56 arranged on the trailer 50 and can thus engage or hook behind the guide rail 56 in order to exert the force F as a tensile force. The tensioning devices 62, 63 each comprise a roller arrangement 70, via which the tensioning devices 62, 63 can be supported in a rollable manner relative to the tractor 20 or relative to the trailer 50 when the force F is applied. In FIG. 2, it can be seen that the tensioning device 63 is hooked behind, i.e., coupled to the guide rail 56 via the roller arrangement 70, such that the tensioning device 63 can roll on the guide rail 56 when the force F is applied via the roller arrangement 70, for example when the articulated lorry 10 changes from straight-ahead travel to cornering or vice versa. The tensioning device 62 can, for example, be fixed to the trailer 50 and, when the force F is applied via its roller arrangement 70, roll on the frame and thus on the body of the tractor 20 when the articulated lorry 10 changes from straight-ahead travel to cornering or vice versa.

[0040] Furthermore, the connection point 51 is arranged in the longitudinal vehicle direction x of the tractor 20 or of the trailer 50 between the driver's cab 26 of the tractor 20 and the tensioning devices 60, 62. The tensioning devices 60, 62 can exert the force F in their respective active state as a compressive force oriented in the direction of the arrow of the vertical vehicle direction z.

[0041] All tensioning devices 60, 61, 62, 63 are designed to apply, in their respective active state, a torque T acting around the connecting point 51, as illustrated in the present case by a curved arrow, to relieve the load on the wheel axles 54 of the trailer 50 and to simultaneously load the drive axle 21 of the tractor 20. The torque T acts, when the articulated lorry 10 is travelling straight ahead, around the pivot axis SA oriented in the transverse vehicle direction y, or around the connection point 51.

[0042] Furthermore, in the present case, the means M comprise two height-changing devices HE, of which one height-changing device HE is assigned to the tractor 20 and of which another height-changing device HE is assigned to the trailer 50. By means of the height-changing devices HE, in each case a distance D in the vehicle vertical direction z of the tractor 20 or of the trailer 50 between at least one partial region TB of a body of the articulated lorry 10 and at least one of the wheels 22, 24 or 55 of the articulated lorry 10 can be adjusted. The height-changing devices HE can also be switched from their respective passive state to their respective active state by means of the control device. In the present case, the height-changing devices HE are designed as a respective active chassis of the tractor 20 or the trailer 50. To adjust the distance D, just one of the height-changing devices HE can be sufficient.

[0043] By applying the torque T and additionally or alternatively by applying the force F in conjunction with changing the distance D by means of at least one of the height changing devices HE, a weight force component F_AT of the trailer 50 can be at least partially displaced from the wheel axles 54 and thus from the respective wheels 55 in the longitudinal vehicle direction x and thus in the direction of the swivel joint 33 or the connection point 51. This results in a relief of the wheel axles 54 and, at the same time, in a loading of the drive axle 21 of the tractor 20. An axle load increase 25 is thus effected at the drive axle 21, such that an improved power transmission 27 can be effected with particularly low slip between the respective wheels 22 of the drive axle 21 and the ground U even if the trailer 50 is unloaded and the trailer 50 accordingly has a low trailer weight force and exerts it on the ground U. Thus, the means 10 enable an overall improved traction, i.e., reduced slip due to the axle load increase 25, i.e., the load on the drive axle 21.

[0044] For axle load distribution in the articulated lorry 10, switching the respective means M to their respective active state M can relieve the load on the wheel axles 54 of the trailer 50 as well as load the drive axle 21 of the trailer 20 and apply the force F which counteracts the relative pivoting movement SB between the tractor 20 and the trailer 50 around the pivot axis SA.

[0045] In summary, in the articulated lorry 10, which comprises the tractor 20 and the trailer 50, the axle load increase 25 can be effected on the drive axle 21 to counteract poor traction conditions of the driveable wheels 22 on the ground U due to wetness or ice despite the low trailer weight force. By means of the articulated lorry 10 or the tractor 20 or the trailer 50, slippage, i.e., excessive slippage of the driveable wheels 22, can thus be counteracted and a grip of the wheels 22 on the ground can be improved. As a result, costly aggregates, for example of an all-wheel drive or of a hydraulic auxiliary drive, can be dispensed with and costly towing activities can be dispensed with even when the articulated lorry 10 is used on a construction site where the ground U may be unsurfaced.

[0046] Just one of the described tensioning devices 60, 61, 62, 63 is sufficient to apply the torque T or apply the force F via the swivel joint 33, which enables folding compensation between the tractor 20 and the trailer 50, in particular in the transverse vehicle direction y. As a result, the axle load increase 25, which can also be referred to as axle load lifting, can be effected at the drive axle 21, whereby an improved ground adhesion and thus an improved adhesive force between the driveable wheels 22 and the ground U can be achieved. As a result, it is possible to move the articulated lorry 10 even when the ground U is icy, wet or muddy.

[0047] Depending on the arrangement of the respective tensioning device 60, 61, 62, 63, the force F can be exerted as a tensile force or as a compressive force. Although not shown further in FIG. 2, one of the tensioning devices 60, 61, 62, 63 could also apply the torque T directly to the swivel joint 33.

[0048] By means of the tensioning devices 60, 61, 62, 63, it is possible to block the relative pivoting movement SB via the swivel joint 33 and to effect the axle load increase 25 by changing the distance D between at least the partial area TB of the body of the articulated lorry 10 and at least one of the wheels 22, 24, 55 of the articulated lorry 10, wherein the change of the distance D can already be effected by merely one of the height-changing devices HE. The blocking can be effected directly at the swivel joint 33 by locking by means of the tensioning devices 60, 61, 62, 63 or by using the tensioning devices 60, 61, 62, 63 as spacers, wherein even small actuating forces can be sufficient to switch the respective tensioning devices 60, 61, 62, 63 between their passive state and their active state. If the pivoting movement SB is blocked, the axle load distribution of the articulated lorry 10 can be changed by changing the distance D, thus causing the axle load increase 25. Exceeding the axle load limit values can be excluded, since the height-changing devices HE, which can comprise an air suspension, can be designed for the corresponding axle load increase 25.

[0049] By means of the present articulated lorry, the tractor 20 and/or the trailer 50, a starting aid for moving the articulated lorry 10 on unsurfaced ground U can be provided by the targeted axle load increase 25 occurring at the drive axle 21 of the tractor 20.

[0050] By applying the torque T and additionally or alternatively by applying the force F in conjunction with changing the distance D by means of at least one of the height-changing devices HE, the tractor 20 and the trailer 50 can be kept angled at least slightly relative to one another in a plane spanned in FIG. 2 by the vehicle longitudinal direction x and the vehicle vertical direction z, as a result of which the axle load increase 25 can be effected.

[0051] The tractor 20, which is coupled to the trailer 50 via the fifth-wheel coupling 30, can first be lowered at the partial area TB and thus at the drive axle 21 by means of the height-changing device HE associated with the tractor 20 (by switching the height-changing device HE from its passive state to its active state), for example. As a result, the distance D between the partial area TB of the body and the driveable wheels 22 can firstly be reduced and the tractor 20 can be angled relative to the trailer 50. Subsequently, the force F and additionally or alternatively the application of the torque T can be effected by at least one of the tensioning devices 60, 61, 62, 63, whereby the pivoting movement SB can be prevented or blocked. Subsequently, the distance D can be increased again in order to thereby effect the loading of the drive axle 21, i.e., the axle load increase 25 as well as the unloading of the wheel axles 54 of the trailer 50.