METHOD FOR TRANSVERSE DISPLACEMENT OF A MOWER OF AN AGRICULTURAL VEHICLE

Abstract

A method is provided for transverse displacement of a front mower or a rear mower of an agricultural vehicle along a transverse direction running transversely to a longitudinal axis of the vehicle. The method includes defining the transverse displacement as a function of a determined steering angle of the vehicle. During cornering of the vehicle, the method also includes generating an overlap between a mowing area of the front mower and a mowing area of the rear mower along the transverse direction.

Claims

1. A method for transverse displacement of a front mower or at least one rear mower of an agricultural vehicle along a transverse direction running transversely to a longitudinal axis of the vehicle, the method comprising: defining the transverse displacement as a function of a determined steering angle of the vehicle; and during cornering of the vehicle, generating an overlap between a mowing area of the front mower and a mowing area of the rear mower along the transverse direction.

2. The method of claim 1, wherein the transverse displacement is determined as a function of at least one of a wheelbase of the vehicle, a front longitudinal distance along the longitudinal axis between a front axle of the vehicle and a front mower, a rear longitudinal distance along the longitudinal axis between a rear axle of the vehicle and a rear mower, a mowing width of the front mower along the transverse direction, a distance along the transverse direction between a first rear mower and a second rear mower, a predetermined overlap between the front mower and the rear mower along the transverse direction.

3. The method of claim 1, further comprising limiting the transverse displacement by a limit value.

4. The method of claim 1, further comprising providing the front mower or the rear mower with an actuator for transverse displacement.

5. The method of claim 1, further comprising providing one rear mower on each side of the vehicle longitudinal axis in the transverse direction.

6. The method of claim 1, further comprising defining the transverse displacement based on at least one of a wheelbase of the vehicle.

7. The method of claim 1, further comprising defining the transverse displacement based on a front longitudinal distance along the longitudinal axis between a front axle of the vehicle and a front mower.

8. The method of claim 1, further comprising defining the transverse displacement based on a rear longitudinal distance along the longitudinal axis between a rear axle of the vehicle and a rear mower.

9. The method of claim 1, further comprising defining the transverse displacement based on a mowing width of the front mower along the transverse direction.

10. The method of claim 1, further comprising defining the transverse displacement based on a distance along the transverse direction between a first rear mower and a second rear mower.

11. The method of claim 1, further comprising defining the transverse displacement based on a predetermined overlap between the front mower and the rear mower along the transverse direction.

12. A method for transverse displacement of a front mower or at least one rear mower of an agricultural vehicle along a transverse direction running transversely to a longitudinal axis of the vehicle, the method comprising: defining the transverse displacement as a function of a determined steering angle of the vehicle; during cornering of the vehicle, generating an overlap between a mowing area of the front mower and a mowing area of the rear mower along the transverse direction; and limiting the transverse displacement by a limit value.

13. The method of claim 12, wherein the transverse displacement is determined as a function of at least one of a wheelbase of the vehicle, a front longitudinal distance along the longitudinal axis between a front axle of the vehicle and a front mower, a rear longitudinal distance along the longitudinal axis between a rear axle of the vehicle and a rear mower, a mowing width of the front mower along the transverse direction, a distance along the transverse direction between a first rear mower and a second rear mower, a predetermined overlap between the front mower and the rear mower along the transverse direction.

14. The method of claim 12, further comprising providing the front mower or the rear mower with an actuator for transverse displacement.

15. The method of claim 12, further comprising providing one rear mower on each side of the vehicle longitudinal axis in the transverse direction.

16. A method for transverse displacement of a front mower or a rear mower of an agricultural vehicle along a transverse direction running transversely to a longitudinal axis of the vehicle, the method comprising: providing the front mower or the rear mower with an actuator for transverse displacement; defining the transverse displacement as a function of a determined steering angle of the vehicle; and during cornering of the vehicle, generating an overlap between a mowing area of the front mower and a mowing area of the rear mower along the transverse direction.

17. The method of claim 16, wherein the transverse displacement is determined as a function of at least one of a wheelbase of the vehicle, a front longitudinal distance along the longitudinal axis between a front axle of the vehicle and a front mower, a rear longitudinal distance along the longitudinal axis between a rear axle of the vehicle and a rear mower, a mowing width of the front mower along the transverse direction, a distance along the transverse direction between a first rear mower and a second rear mower, a predetermined overlap between the front mower and the rear mower along the transverse direction.

18. The method of claim 16, further comprising limiting the transverse displacement by a limit value.

19. The method of claim 16, further comprising providing one rear mower on each side of the vehicle longitudinal axis in the transverse direction.

20. The method of claim 16, wherein the transverse displacement is determined as a function of a wheelbase of the vehicle, a front longitudinal distance along the longitudinal axis between a front axle of the vehicle and a front mower, a rear longitudinal distance along the longitudinal axis between a rear axle of the vehicle and a rear mower, a mowing width of the front mower along the transverse direction, a distance along the transverse direction between a first rear mower and a second rear mower, and a predetermined overlap between the front mower and the rear mower along the transverse direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above-mentioned aspects of the present disclosure and the manner of obtaining them will become more apparent and the disclosure itself will be better understood by reference to the following description of the embodiments of the disclosure, taken in conjunction with the accompanying drawings, wherein:

[0027] FIG. 1 shows a schematic plan view of an agricultural vehicle with an indicated transverse displacement of a front mower while cornering,

[0028] FIG. 2 shows a schematic representation of a valve unit for a transverse displacement of the front mower according to FIG. 1,

[0029] FIG. 3 shows a schematic plan view of an agricultural vehicle with an indicated transverse displacement of a rear mower while cornering, and

[0030] FIG. 4 shows a schematic representation of a valve unit for a transverse displacement of the two rear mowers according to FIG. 3.

[0031] Corresponding reference numerals are used to indicate corresponding parts throughout the several views.

DETAILED DESCRIPTION

[0032] The embodiments of the present disclosure described below are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present disclosure.

[0033] FIG. 1 schematically shows an indication of an agricultural vehicle 10 in the form of a tractor having a front axle 12 and a rear axle 14. The distance between the two axles 12, 14 constitutes a wheelbase 1. The vehicle 10 has a vehicle longitudinal axis 18 arranged in the longitudinal direction 16. The vehicle 10 supports a front mower 20 which is arranged a front longitudinal distance l.sub.F from the front axle 12 along the longitudinal axis 18. A mowing width of the front mower 20 or the mowing bar thereof in the transverse direction 24 is designated b.sub.F. Two mowers 22-1, 22-2 are arranged in the rear area of the vehicle 10. A rear longitudinal distance l.sub.H in the longitudinal direction 16 is defined between the mowers and the rear axle 14. Along a transverse direction 24 arranged transversely to the longitudinal direction 16, the cutting edge of the rear mower 22-1 is a distance b.sub.H from the opposing cutting edge of the second mower 22-2. This corresponds to the standard starting position of the rear mower 22-1, 22-2 without transverse displacement along the transverse direction 24.

[0034] FIG. 1 shows an actuator in the form of a hydraulic cylinder 26 as an integrated component of the front mower 20. Depending on the activation, the actuator or hydraulic cylinder 26 effects a transverse displacement of the front mower 20 along the transverse direction 24. A specific length change b.sub.Zy1 of a working length of the hydraulic cylinder 26, as shown in FIG. 2, effects a calculated necessary transverse displacement b.sub.Q of the front mower 20. The specific change of length b.sub.Zy1 is dependent on a transmission ratio i.sub.F=b.sub.Q/b.sub.Zy1 between the transverse displacement b.sub.Q and the change of length b.sub.Zy1. The change of length b.sub.Zy1 calculated to be necessary in each case is achieved by appropriate control of the hydraulic cylinders 26 by a valve unit 28. The valve unit 28 controls a supply pressure p.sub.V for the hydraulic cylinder 26. The valve unit 28 in FIG. 2 is designed as a 4/3 way valve.

[0035] In the embodiment in FIG. 1, a transverse displacement b.sub.Q of the front mower 20 is implemented in order to generate a desired or specified overlap b.sub.O. This overlap b.sub.O is formed along the transverse direction 24 between a mowing area 30 of the front mower 20 and a mowing area 32 of the rear mower 22-1.

[0036] To generate the overlap b.sub.O, the necessary transverse displacement b.sub.Q of the front mower 20 is first calculated as a function of a steering angle of the vehicle 10. This transverse displacement b.sub.Q is then converted into a corresponding change of length b.sub.Zy1 of the hydraulic cylinder 26 as a function of the transmission ratio i.sub.F.

[0037] For the calculation of the necessary transverse displacement b.sub.Q for the desired or specified overlap b.sub.O, it is assumed that both the front mower 20 and the rear mowers 22-1, 22-2 are in a standard starting position symmetrically to the vehicle longitudinal axis 18 and without transverse displacement along the transverse direction 24. The subsequently explained calculation of the transverse displacement b.sub.Q of the front mower 20 according to FIG. 1 can also be used correspondingly for asymmetrically arranged mowers. For the calculation in the embodiment according to FIG. 1, the following boundary conditions will be defined.

[0038] For a transverse displacement b.sub.Q=0, the front mower 20 is arranged symmetrically to the longitudinal axis 18 and the condition =0 applies for the steering angle , i.e. the vehicle 10 is in straight-ahead travel along the longitudinal direction 16.

[0039] Here, b.sub.Q>0 signifies a transverse displacement of the front mower 20 to the left relative to a forward travel of the vehicle 10. This corresponds to the case illustrated in FIG. 1 with a leftward curve along the travel direction 34. The steering angle is defined by the condition >0.

[0040] Moreover, b.sub.Q<0 signifies a transverse displacement of the front mower 20 to the right relative to a forward travel of the vehicle 10. The steering angle is defined by the condition <0.

[0041] From these definitions, a maximum limit value b.sub.Q.sup.Max for the technically possible displacement range of the front mower 20 along the transverse direction 24 results for b.sub.Q>0 and a minimum limit value b.sub.Q.sup.Min results if b.sub.Q<0, even if a larger (positive) or smaller (negative) value for the transverse displacement b.sub.Q is calculated according to the method.

[0042] For >0 and b.sub.Qb.sub.Q.sup.Max:

b.sub.Q=sin(arccos((l+l.sub.F)/r.sub.Hi))r.sub.Hi+r+b.sub.Ob.sub.F/2.(1)

[0043] For <0 and b.sub.Qb.sub.Q.sup.Min:

b.sub.Q=sin(arccos((l+l.sub.F)/r.sub.Hi))r.sub.Hirb.sub.O+b.sub.F/2.(2)

[0044] The two curve radii r and r.sub.Hi are defined relative to a curve center point 36 in FIG. 1 as follows:

r=l/|tan()|,(3)

r.sub.Hi=(l.sub.H.sup.2+(b.sub.H/2r).sup.2).sup.1/2.(4)

[0045] In FIG. 3, the front mower 20 is in a standard symmetrical starting position relative to the longitudinal axis 18, while the two rear mowers 22-1 and 22-2 will be displaced along the transverse direction 24. The two rear mowers 22-1 and 22-2 each have an actuator in the form of a hydraulic cylinder 26. Depending on the activation, the actuator or hydraulic cylinder 26 effects a transverse displacement of the respective rear mower 22-1, 22-2 along the transverse direction 24. As illustrated in FIG. 4, the specific change of length b.sub.Zy11, b.sub.Zy12 of a working length of the respective hydraulic cylinder 26 effects a calculated necessary transverse displacement b.sub.Q1, b.sub.Q2, respectively, of the rear mower 22-1, 22-2. The specific change of length b.sub.Zy11, b.sub.Zy12, respectively, is dependent on a transmission ratio i.sub.H1=b.sub.Q1/b.sub.Zy11, i.sub.H2=b.sub.Q2/b.sub.Zy12 between the respective transverse displacement b.sub.Q1, b.sub.Q2 and the change of length b.sub.Zy11, b.sub.Zy12. The change of length b.sub.Zy11, b.sub.Zy12 calculated to be necessary in each case is achieved by appropriate control of the respective hydraulic cylinder 26 by a valve unit 28. The valve unit 28 controls a supply pressure p.sub.V for the hydraulic cylinder 26. The valve units 28 in FIG. 2 are each designed as a 4/3 way valve.

[0046] In the embodiment shown in FIG. 3, transverse displacements b.sub.Q1, b.sub.Q2, respectively, of the rear mowers 22-1, 22-2 are produced in order to generate a desired or specified overlap b.sub.Oi, b.sub.Oa. The overlap b.sub.Oi is formed along the transverse direction 24 between the mowing area 30 of the front mower 20 and the mowing area 32 of the rear mower 22-1, while the overlap b.sub.Oa is formed along the transverse direction 24 between the mowing area 30 of the front mower 20 and a mowing area 38 of the rear mower 22-2.

[0047] To generate the respective overlap b.sub.Oi, b.sub.Oa, the necessary transverse displacement b.sub.Q1, b.sub.Q2 of the rear mower 22-1, 22-2 is first calculated as a function of a steering angle of the vehicle 10. These transverse displacements are then converted as a function of the respective transmission ratio i.sub.H1, i.sub.H2 into the corresponding change of length b.sub.Zy11, b.sub.Zy12 of the respective hydraulic cylinder 26.

[0048] In the calculation of the necessary transverse displacement for the desired or specified overlap b.sub.Oi, b.sub.Oa, it is again assumed that both the front mower 20 and the rear mowers 22-1, 22-2 are in a standard starting position symmetrically to the vehicle longitudinal axis 18 and without transverse displacement along the transverse direction 24. The subsequently explained calculation of the transverse displacements b.sub.Q1, b.sub.Q2 can also be used correspondingly for asymmetrically arranged mowers. For the calculation in the embodiment according to FIG. 3, the following boundary conditions will be defined.

[0049] At a steering angle =0, the vehicle 10 is traveling straight-ahead along the longitudinal direction 16 and the transverse displacements are b.sub.Q1=0, b.sub.Q2=0. A steering angle >0 signifies a leftward curve along the travel direction 34 in FIG. 3. <0 accordingly signifies a rightward curve along the travel direction 34.

[0050] Here, b.sub.Q1>0, b.sub.Q2>0 respectively signify a transverse displacement of the respective rear mower 22-1, 22-2 toward the longitudinal axis 18. Further, b.sub.Q1<0, b.sub.Q2<0 respectively signify a transverse displacement of the respective rear mower 22-1, 22-2 away from the longitudinal axis 18. The maximum technically possible displacement range of the respective rear mower 22-1, 22-2 along the transverse direction 24 is limited by a respective maximum limit value b.sub.Q1.sup.Max, b.sub.Q2.sup.Max for b.sub.Q1>0, b.sub.Q2>0 and a minimum limit value b.sub.Q1.sup.Min, b.sub.Q2.sup.Min for b.sub.Q1<0, b.sub.Q2<0, even if a larger (positive) or smaller (negative) value for the respective transverse displacement b.sub.Q1, b.sub.Q2 is calculated according to the method.

[0051] In addition to the above-mentioned boundary conditions, the following holds for the necessary transverse displacement b.sub.Q1 of the rear mower 22-1 for <0 and b.sub.Q1<b.sub.Q1.sup.Max:

b.sub.Q1=sin(arccos(l.sub.H/r.sub.Fa))r.sub.Farb.sub.Oa+b.sub.H/2,(5)

and for >0 and b.sub.Q1b.sub.Q1.sup.Min:

b.sub.Q1=sin(arccos(l.sub.H/r.sub.Fi))r.sub.Fi+rb.sub.Oib.sub.H/2.(6)

[0052] The curve radii r, r.sub.Fi and r.sub.Fa relative to the curve center point 36 in FIG. 3 are defined as follows:

[0053] r is defined by equation (3),

r.sub.Fi=((l+l.sub.F).sup.2+(b.sub.F/2r).sup.2).sup.1/2,(7)

r.sub.Fa=((l+l.sub.F).sup.2+(b.sub.F/2r).sup.2).sup.1/2.(8)

[0054] For the necessary transverse displacement b.sub.Q2 of the rear mower 22-2 the following holds with >0 and b.sub.Q2b.sub.Q2.sup.Max:

b.sub.Q2=sin(arccos(l.sub.H/r.sub.Fa))r.sub.Farb.sub.Oa+b.sub.H/2,(9)

and with <0 and b.sub.Q2b.sub.Q2.sup.Min:

b.sub.Q2=sin(arccos(l.sub.H/r.sub.Fi))r.sub.Fi+rb.sub.Oib.sub.H/2.(10)

[0055] While exemplary embodiments incorporating the principles of the present disclosure have been disclosed hereinabove, the present disclosure is not limited to the disclosed embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of the disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this disclosure pertains and which fall within the limits of the appended claims.