SELF-PROPELLED HARVESTING MACHINE

Description

[0001] The present invention relates to a self-propelled harvesting machine, in particular a forage harvester, according to the preamble of claim 1 (US 2021 / 337735).

[0002] A self-propelled harvesting machine of the type mentioned above is known from DE 10 2020 111 993 A1. This patent describes a self-propelled harvesting machine comprising a drive motor and a front attachment drive driven by the drive motor, which includes at least one hydraulic pump configured to drive a hydraulic motor for driving a front attachment arranged on a feed device of the harvesting machine. Self-propelled harvesting machines, particularly forage harvesters, are operated with various front attachments, which differ, among other things, in their maximum permissible operating torque. Further differences between different types of front attachments can include operation at constant or variable speed and / or their direction of rotation.

[0003] Since the different types of attachments are operated with different maximum permissible torques, it is necessary and common to equip each attachment with its own overload clutch and a gearbox to limit and adjust the permissible torque and the required speed.

[0004] The invention is therefore based on the objective of further developing a self-propelled harvesting machine of the type mentioned above, which enables operation adapted to the different requirements of various types of attachments.

[0005] This problem is solved according to the invention by a self-propelled harvesting machine with the features of claim 1. Advantageous further developments are the subject of the dependent claims.

[0006] The present invention is explained in more detail below with reference to an embodiment illustrated in the drawings.

[0007] They show: Fig. 1 a schematic view of a self-propelled harvesting machine with header; Fig. 2 an exemplary and schematic perspective view of a drive system of the forage harvester; Fig. 3 an exemplary simplified circuit diagram of a hydraulic circuit of a drive train serving to drive the header; and Fig. 4 a swivel angle-speed diagram.

[0008] In Fig. 1 Figure 1 is a schematic view of a self-propelled harvesting machine 1 designed as a forage harvester 2. The harvesting machine 1 harvests or picks up crop from the field using a header 4, in order to then discharge the picked-up crop in the form of a crop stream 3 (in Fig. 1The material (indicated by a line with arrows) is fed to downstream working elements, which are designed as processing and conveying elements of the harvesting machine 1, and discharged into a loading container (not shown) by means of an unloading device. The processing and conveying elements of the harvesting machine 1, designed as a forage harvester 2, include, among other things, a feed device 5, a chopping device 6, an optional conditioning device 7, and a discharge accelerator 8. The arrow FR indicates the direction of travel.

[0009] The infeed device 5 consists of several driven roller pairs 5a, 5b arranged one behind the other in an infeed housing 5c. The header 4 can be coupled to the infeed device 5. The chopping device 6 comprises a rotating knife drum 6a equipped with knives, by means of which the ingested crop is chopped in conjunction with a counter blade. The knife drum 6a is arranged on a driven knife drum shaft 6b. Downstream of the chopping device 6 in a conveying chute in the direction of crop flow is the optional conditioning unit 7, which can be removed from the crop flow 3 if required. Downstream of the conditioning unit 7 in the conveying chute in the direction of crop flow is the discharge accelerator 8, which accelerates the crop by means of rotating throwing paddles for safe discharge through the unloading device 10, designed as a discharge spout.The discharge accelerator 8 comprises conveying elements 8a arranged non-rotatably on a shaft 8b. In the rear area of ​​the forage harvester 2, a drive motor 9 designed as an internal combustion engine is arranged as the main drive unit.

[0010] Different types of headers 4 can be attached to the intake device 5, and these are selected depending on the type of crop being processed. For example, a pick-up is used on the forage harvester 2 to collect crops laid in swaths. A disc mower is used for harvesting whole plants. When harvesting maize, a row-independent maize header or a row-dependent maize picker is attached to the intake device 5 of the forage harvester 2.

[0011] The aforementioned types of headers (not an exhaustive list) differ in their drive systems due to varying operating specifications. For example, the corn header or pick-up requires a variable drive speed, while the disc mower operates at a constant drive speed. Furthermore, the power consumption of the disc mower is higher than that of the pick-up or corn header. Consequently, the requirements for a suitable drive system vary.

[0012] In Fig. 2 An exemplary and schematic perspective view of a drive system 26 of the forage harvester 2 is shown. The schematic representation shows in particular the components of the drive system 26, which serve to transmit power to the attached header 4 and the intake device 5.

[0013] The drive motor 9 drives a distribution gearbox 11 located on the left side of the machine via a motor shaft (not shown). The distribution gearbox 11 includes an output pulley 12 mounted on a first drive shaft, which is switchably connected to the motor shaft of the drive motor 9 by a hydraulically actuated clutch 13. Furthermore, at least one hydraulic pump 14 is directly connected to the distribution gearbox 11 via a second drive shaft.

[0014] The output pulley 12 drives at least one main pulley 16, located at the end of the cutter drum shaft 6b, via a main drive belt 15. The main drive belt 15 drives the discharge accelerator 8 via a pulley 17 mounted on a shaft. The upper side of the main drive belt 15 is subjected to adjustable tension by a tensioning device 18, which comprises a tensioning roller 19 pivotable about an axis 20 and a hydraulic cylinder 21. The output pulley 12, the main drive belt 15, and the main pulley 16 form a main drive train 27 for driving the cutter drum 6a, the conditioning unit 7, and the discharge accelerator 8.

[0015] Furthermore, a hydraulic motor 22 is provided, which is arranged above the main drive belt 15. The hydraulic motor 22 is driven by at least one hydraulic pump 14. A drive shaft of the hydraulic motor 22 drives a gearbox 23, which is connected to the feeder 5 to be driven via cardan shafts 24. An additional gearbox 25 can be arranged between the cardan shafts 24. The hydraulic pump 14, the hydraulic motor 22, the gearbox 23, and the cardan shafts 24 form a separate drive train 28 for driving the feeder 5.

[0016] A further separate drive train, designated as the attachment drive 29, is provided to drive the attachment device 4. The attachment drive 29 can be arranged below the main drive belt 15. The attachment drive 29 comprises at least one hydraulic pump 34, which drives a hydraulic motor 30. Furthermore, the attachment drive 29 can have a gearbox 31 connected to an output shaft of the hydraulic motor 30, as well as at least one cardan shaft 32, which is connected to a coupling device 33 for driving the attachment device 4 arranged on the feed device 5. The coupling device 33 is preferably designed as a quick-release coupling device. The hydraulic motor 30 is supplied by the at least one hydraulic pump 34. The at least one hydraulic pump 34 of the attachment drive 29 is also connected, in particular directly, to the distribution gearbox 11 for driving purposes.

[0017] The drive train 28 for driving the feed device 5 and the attachment drive 29 for driving the attachment device 4 can be operated and controlled independently of each other.

[0018] The hydraulic motor 30 is designed as a variable displacement motor. The hydraulic pump 34 is also designed as a variable displacement pump. A control device 35 is provided for controlling the hydraulic motor 30 and the hydraulic pump 34 that drives it. The control device 35 is configured to specify a maximum displacement volume for the hydraulic motor 30. This maximum displacement volume is determined by the type of header 4 attached to the intake device 5. Thus, for different types of headers 4 used on the forage harvester 2, such as pick-ups, corn headers, or direct-cut headers, the maximum torque provided at the coupling device 33 can be set or limited according to the specific header.

[0019] The representation in Fig. 3Figure 1 shows an exemplary, highly simplified circuit diagram of a hydraulic circuit 36 ​​of the attachment drive 29, which serves to drive the attachment device 4. The hydraulic motor 30 and the hydraulic pump 34 are arranged in the closed hydraulic circuit 36. Pressure relief valves 38 can be arranged in both hydraulic lines 37, which connect the hydraulic motor 30 and the hydraulic pump 34 to each other.

[0020] The header-specific setting of the hydraulic motor 30's intake volume by the control device 35 makes it possible to set a different torque for drawing in the crop through the header 4 than for reversing. The control device 35 is configured to set or limit the intake volume to a first value for drawing in and to a second value for reversing, which may differ from the first value.

[0021] The control device 35 comprises a computing unit 40, a storage unit 41, and an operating and display unit 42. The computing unit 40 is configured to process information stored in the storage unit 41. The operating and display unit is configured for inputting and / or manually or automatically selecting the respective attachment 4 arranged on the feed device 5. Attachment-specific parameter sets for the various types and models of attachments 4 can be stored in the storage unit 41. These attachment-specific parameter sets include, among other things, maximum values ​​for torques during feed and reversing operation for the various attachment types and models.

[0022] As an alternative to manually entering or selecting the attachment device 4 arranged on the feed device 5, it is conceivable that an automatic attachment device recognition is provided in order to determine the type and type of the coupled attachment device 4.

[0023] The respective parameter set specific to the attached attachment device 4 is used according to the input or selection by an operator to control the hydraulic motor 30 in order to set the swallowing volume or swivel angle SW of the hydraulic motor 30 to limit the torque to be transmitted to the attachment device 4.

[0024] Furthermore, the operating and display unit 42 can be set up for manual input of maximum values ​​for torques in the retraction and reversing operation of the attachment device 4.

[0025] The control device 35 is designed to limit the torque to be transmitted to the attachment 4 by setting and monitoring a control current for adjusting the swivel angle SW of the hydraulic motor 30. For this purpose, the control current is detected by a sensor arrangement and the measurement signals generated by the sensor arrangement are transmitted to the control device 35 for evaluation.

[0026] The pressure relief valves 38 are arranged downstream of the hydraulic pump 34. The two pressure relief valves 38 are identical in design, so that the maximum attachment-specific torque provided at the coupling device 33 is the same regardless of the direction of rotation. Identical in this case means that the two pressure relief valves 38 have identical specifications. Each hydraulic line 37 is assigned a pressure sensor 39, which transmits the measurement signals generated by these lines to the control device 35 for evaluation.

[0027] The arrangement of the two identical pressure relief valves 38 in the hydraulic circuit 36 ​​also makes it possible to operate the hydraulic motor 30 in both directions of rotation, i.e. in retraction mode and in reversing mode, at full power.

[0028] The control device 35 is further configured to specify and set identical or differing values ​​for the intake volume or the swivel angle SW in retraction and reversing modes. In conjunction with the two identical pressure relief valves 38, this enables adaptation to the requirements of the different attachment devices 4, thereby preventing overloading of the components of the respective attachment device 4 and the attachment drive 29.

[0029] The attachment drive 29 is designed and configured for driving the attachment device 4 in a retraction operation in both left-hand and right-hand rotation.

[0030] The direction of rotation of the coupling device 33 can be reversed by an inverted control of the hydraulic pump 34. The inverted control of the hydraulic pump 34 is preferably also effected by the control device 35. With inverted control, the control device 35 controls the swivel angle of the hydraulic pump 34 such that the direction of rotation of the attachment drive 29 changes from counterclockwise to clockwise or vice versa. The same maximum speeds can be set in both directions of rotation; thus, both attachment devices 4 with a counterclockwise direction of rotation for retraction operation and attachment devices 4 with a clockwise direction of rotation for retraction operation can be coupled to the attachment drive 29 of the harvesting machine 1 without additional gearboxes or at least with a reduced number of gearboxes.

[0031] In conjunction with the two identical pressure relief valves 38 in the closed hydraulic circuit 36, the respective set torque for the retraction operation and the reversing operation is available at the coupling device 33, independent of the direction of rotation.

[0032] In Fig. 4Figure 43 shows a swivel angle-speed diagram with various torque curves 43, 44, and 45 for the hydraulic motor 30 and the attachment 4. Figure 43 denotes the limit torque curve of the hydraulic motor 30, representing its maximum technical limit, i.e., the maximum torque that the hydraulic motor 30 can provide. Figure 44 denotes the torque curve of the driven attachment 4, which is specific to the attachment 4 and results from its maximum absorbable torque. Figure 45 denotes the efficiency torque curve of the hydraulic motor 30, which is established for various load points of the attachment 4 at which the hydraulic motor 30 can be operated efficiently.

[0033] The control device 35 is configured to operate the hydraulic motor 30 in an efficiency mode, whereby the control device 35 determines the preset swivel angle SW of the hydraulic motor 30 according to a load spectrum, depending on the type of attached attachment 4 and an operating speed specific to the attachment 4. In efficiency mode, the hydraulic motor 30 can be operated at an efficient operating point, depending on the attachment being driven. The efficient operating point can be determined from the efficiency torque curve 45 of the hydraulic motor 30.

[0034] A region marked by hatching 46 between the limit torque curve 43 of the hydraulic motor 30 and the torque curve 44 of the attachment 4 defines the operating range of the hydraulic motor 30, within which it cannot be operated due to the limit torque curve 44 of the attachment 4 being driven. Compliance with the limit torque curve 44 is achieved by controlling and adjusting the two identical pressure relief valves 38.

[0035] A region marked by hatching 47 between the limit torque curve 44 of the attachment device 4 and the efficiency torque curve 45 of the hydraulic motor 30 defines a permissible operating range of the hydraulic motor 30 in which an adjustment of the swivel angle SW allows overriding of the efficiency torque curve 45 by means of control by the control device 35.

[0036] As explained above, the control device 35 is configured to actuate the hydraulic motor 30 to adjust the displacement volume or the swivel angle SW to limit the torque transmitted to the attachment 4. For this purpose, the swivel angle SW to be set can be determined based on the efficiency torque curve 45 specific to the respective attachment 4. The control device 35 sets the corresponding control current to adjust the swivel angle SW derived from the efficiency torque curve 45 for operation in efficiency mode.

[0037] The control device 35 is thus configured to control the hydraulic motor 30 depending on a set of attachment-specific parameters stored in the control device 35, so that the hydraulic motor 30 generates an attachment-specific operating torque in efficiency mode, which is lower than a maximum torque specific to the attachment 4 being driven. The attachment-specific maximum torque can be determined by the control device 35 accordingly from the limit torque curve 44 of the attachment 4. The attachment-specific operating torque can be determined by the control device 35 accordingly from the efficiency torque curve 45 of the attachment 4.

[0038] Furthermore, the control device 35 is configured to activate the hydraulic motor 30 when a load peak is detected, so that the hydraulic motor 30 increases the generated operating torque up to its maximum torque. This allows the control device to respond to short-term increases in load requirements of the attachment 4. This can be used to adapt the control of the hydraulic motor 30 to changing load requirements. For example, in the event of a short-term increase in load, the displacement volume of the hydraulic motor 30 can be increased to increase the operating torque provided by the hydraulic motor 30. For this purpose, the control device 35 can operate the hydraulic motor 30 in a boost mode.

[0039] To detect peak loads, a pressure sensor located downstream of the hydraulic pump in each of the two hydraulic lines is used. This sensor transmits the generated measurement signals to the control unit for evaluation. The storage unit 41 contains a minimum and a maximum value specific to each attachment for a detected load pressure in the hydraulic circuit 36. The detected load pressure is compared with the respective stored minimum and maximum values ​​by the processing unit 40 of the control unit 35.

[0040] The control device 35 is configured to increase the displacement volume of the hydraulic motor 30 by adjusting the swivel angle SW when the maximum value for the detected load pressure is exceeded. The swivel angle SW is adjusted until the limit torque curve 44 of the attachment 4 is reached. The adjustment of the swivel angle SW can preferably be made in steps. A stepless adjustment of the swivel angle SW is also conceivable.

[0041] If the minimum value is undershot, the control device 35 activates the hydraulic motor 30 to reduce the volume taken in by the hydraulic motor 35 by adjusting the swivel angle SW to a value such that the hydraulic motor 30 operates at the set attachment-specific operating torque, which is generated according to the efficiency torque curve 45 determined for the attachment.

[0042] For this purpose, the control device 35 can be configured to control the hydraulic motor 30 to change the absorbed volume, depending on a minimum duration of exceeding the maximum value or falling below the minimum value. This prevents unwanted oscillations of the system.

[0043] The storage unit 41 can contain at least one minimum and one maximum value specific to the attachment for a load pressure detected in the hydraulic circuit 36. The attachment-specific minimum and maximum values ​​form a transition range for switching between efficiency mode and boost mode.

[0044] According to another aspect, the control device 35 is designed to operate the coupling device 33, which is driven by the hydraulic motor 30 and designed as a quick-coupling device, and with which the attachment device 4 is connected for propulsion, at a constant speed and to keep the speed of the coupling device 33 essentially constant by controlling the hydraulic pump 30 of the attachment drive 29 independently of the drive speed of the drive motor 9 and the forward speed.

[0045] While the hydraulic motor 30 is operated with the preset swivel angle SW, the rotational speed of the coupling device 33 is controlled by the hydraulic pump 34. Within the technical limits, the rotational speed of the coupling device 33 can be kept essentially constant, independent of the drive motor speed and the forward speed. Crucially, this control counteracts engine braking from the internal combustion engine drive motor 9, thus maintaining the rotational speed of the coupling device 33 essentially constant. This ensures the operation of attachments 4 with driven components that require constant rotational speed.

[0046] This allows, for example, the cutting pattern of a direct-cutting unit to be improved by maintaining a substantially constant mower disc speed. Through the electrical control of the swivel angle SW of the hydraulic motor 30, the hydrostatic transmission between the hydraulic pump 34 and the hydraulic motor 30 counteracts the motor thrust in order to keep the speed of the coupling device 33 substantially constant. Reference symbol list

[0047] 1 Harvesting machine 27 Main drivetrain 2 Forage harvester 28 Powertrain 3 Harvested crop power 29 attachment drive 4 attachment 30 hydraulic motor 5 feed device 31 transmission 5a roller 32 driveshaft 5b roller 33 Dome facility 5c Inlet housing 34 hydraulic pump 6 shredding device 35 Control device 6a Knife drum 36 Hydraulic circuit 6b Knife drum shaft 37 hydraulic line 7 Conditioning system 38 Pressure relief valve 8 Ejection accelerator 39 Pressure sensor 8a Conveyor element 40 computing unit 8b Wave 41 Storage unit 9 drive motor 42 Control and display unit 10 Overloading device 43 Limit torque curve from 30 11 Transfer case 44 Torque curve of 4 12 output pulley 45 Efficiency-torque curve 13 coupling 46 hatching 14 hydraulic pump 47 hatching 15 Main drive belt 16 Main pulley FR Direction of travel 17 pulley SW Swivel angle of 30 18 Clamping device 19 Tensioner 20 axis 21 hydraulic cylinder 22 hydraulic motor 23 transmission 24 driveshaft 25 transmission 26 drive system

Claims

1. Self-propelled harvesting machine (1, 2), comprising an attachment drive (29) which has at least one hydraulic pump (34) configured to drive a hydraulic motor (30) for driving an attachment (4) arranged on a feed apparatus (5) of the harvesting machine (1, 2), characterized in that the attachment drive (29) is provided and configured for the left-turning and for the right-turning driving of the attachment (4) in a feed mode, wherein the harvesting machine (1, 2) comprises a control apparatus (35) for controlling the attachment drive (29), which control apparatus is configured to reverse the direction of rotation of the attachment drive (29) by means of inverted control of the hydraulic pump (34), wherein the hydraulic pump (34) and the hydraulic motor (30) are arranged in a closed hydraulic circuit (30), wherein the hydraulic pump (34) and the hydraulic motor (30) are connected to each other in a fluid-conducting manner by means of two hydraulic lines (37), and in that a pressure limiting valve (38) is arranged downstream of the hydraulic pump (34) in each case in both hydraulic lines (37), wherein the two pressure limiting valves (38) are structurally identical.

2. Self-propelled harvesting machine (1, 2) according to Claim 1, characterized in that the hydraulic motor (30) drives a coupling device (33) which is in the form of a quick coupling device and to which the attachment (4) is connected for driving.

3. Self-propelled harvesting machine (1, 2) according to Claim 2, characterized in that the control apparatus (35) is configured to adjust a speed transmitted by the coupling device (33) by controlling the hydraulic pump (34).

4. Self-propelled harvesting machine (1, 2) according to one of the preceding claims, characterized in that the control apparatus (35) is configured to adjust the displacement or pivot angle (SW) of the hydraulic motor (30) in a manner specific to the attachment.

5. Self-propelled harvesting machine (1, 2) according to Claim 4, characterized in that the control apparatus (35) is configured to adjust the displacement or the pivot angle (SW) of the hydraulic motor (30) in the feed mode and in the reversing mode in each case in a manner specific to the attachment.

6. Self-propelled harvesting machine (1, 2) according to Claim 4 or 5, characterized in that the control apparatus (35) is configured to adjust and monitor a control current for adjusting the pivot angle (SW) of the hydraulic motor (30).

7. Self-propelled harvesting machine (1, 2) according to one of Claims 4 to 6, characterized in that the control apparatus (35) is configured to specify and set the same setting values or different setting values for the displacement or the pivot angle (SW) in the feed mode and in the reversing mode.

8. Self-propelled harvesting machine (1, 2) according to one of Claims 1 to 7, characterized in that the control apparatus (35) comprises a computing unit (40), a storage unit (41) and an operating and display unit (42), wherein the computing unit (40) is configured to process information stored in the storage unit (41), wherein the operating and display unit (42) is configured to input and / or select an attachment model arranged on the feed apparatus (5).

9. Self-propelled harvesting machine (1, 2) according to Claim 8, characterized in that attachment-specific parameter sets are stored in the storage unit (41) and contain maximum values for torques in the feed mode and in the reversing mode of the various attachment models.

10. Self-propelled harvesting machine (1, 2) according to Claim 9, characterized in that the operating and display unit (42) is configured to manually input maximum values for torques in the feed mode and in the reversing mode.

11. Self-propelled harvesting machine (1, 2) according to one of the preceding claims, characterized in that the hydraulic pump (34) is designed as a variable displacement pump and the hydraulic motor (30) is designed as a variable displacement motor.