Field chopper with an adjustment device for splitting between counter-cutter and chopping blades

Description

[0001] The present invention relates to a forage harvester according to the preamble of claim 1. Furthermore, the present invention relates to a method for operating a forage harvester, in particular for adjusting a gap between a counter-blade and chopping knives of a chopping device of the forage harvester.

[0002] Forage harvesters of the type mentioned above comprise a chopping device with a cutting drum with chopping knives arranged thereon, wherein the cutting drum is partially surrounded by a drum housing. Furthermore, the chopping device comprises a counter-blade that interacts with the chopping knives and is releasably attached to a counter-blade support. The counter-blade can be advanced toward the chopping knives by means of an adjusting device having a control device and at least one actuator, thereby adjusting a gap between the counter-blade and the chopping knives. Crop fed to the cutting drum is chopped by the interaction of the chopping knives and the counter-blade.

[0003] During chopping, wear and tear particularly occurs in the area of ​​the cutting edges of the chopper knives, which reduces cut quality and crop throughput. In addition, the counter-blade is also subject to wear, which exacerbates the reduction in cut quality and crop throughput. Wear on the chopper knives and counter-blade results in a change in the cutting geometry of the chopper knives and an increase in the engagement gap between the chopper knives and counter-blade. The cutting geometry of the chopper knives can be restored by regrinding the chopper knives, while the engagement gap between the chopper knives and counter-blade can be regularly adjusted by adjusting the counter-blade. Both measures can be performed automatically on today's forage harvesters without the need to visit a workshop.The challenge with the counterblade adjustment is to optimally determine the respective amount of adjustment. This is particularly challenging because, as mentioned above, both the chopping blades and the counterblade are subject to wear.

[0004] From DE 10 2017 117 966 A1, it is known to evaluate measurement data from two knock sensors and two contactless distance sensors to adjust the counter-blade detachably attached to a counter-blade support. During the counter-blade advance process, the knock sensors monitor whether contact occurs between the counter-blade and a chopping blade. A predetermined gap size for the engagement gap is set using the two distance sensors. The knock sensors and the distance sensors are each attached in pairs to the ends of the counter-blade support. The distance sensors determine the distance between the counter-blade support and the chopping blades. The actuators for adjusting the engagement gap are controlled using a geometric parameter that is calibrated based on the sensor data from the knock sensors.

[0005] DE 100 26 296 C2 also describes a forage harvester of the type mentioned above. The gap between the counterblade and the chopping blades is determined by direct or indirect measurement. Direct measurement uses knock sensors, while indirect, non-contact measurement determines the length of the spark gap between the chopping blades and the counterblade. These components are electrically insulated from each other and, when a high-voltage source is switched on, are positioned opposite each other as poles at the distance of the engagement gap. The latter embodiment, in particular, is not suitable due to the required complexity and safety considerations.

[0006] DE 10 2011 005 317 A1 discloses a measuring system for determining the wear condition of chopper knives.

[0007] EP 1 072 185 A1 discloses an adjustment device for the cutting gap on shredders with a device evaluating an electrical current flow.

[0008] From EP 2 559 334 A1 a method and a device for detecting the condition of a cutting device is known.

[0009] DE 10 2017 201 423 A1 discloses an arrangement for detecting the degree of wear of chopper knives of a chopper drum of a forage harvester.

[0010] Based on the above-mentioned prior art, the object of the invention is to further develop a forage harvester of the type mentioned at the outset in such a way that it is characterized by a simplified and improved determination of the gap size.

[0011] This object is achieved in a self-propelled forage harvester according to the preamble of claim 1 by the features of the characterizing part of claim 1. Advantageous further developments are the subject of the subclaims.

[0012] According to claim 1, a forage harvester is proposed which comprises a chopping device with a cutting drum with chopping knives arranged thereon, wherein the cutting drum is partially surrounded by a drum housing, and with a counter-blade which interacts with the chopping knives and is detachably fastened to a counter-blade carrier, wherein the counter-blade can be advanced onto the chopping knives by means of an adjusting device having a control device and at least one actuator, whereby a gap between the counter-blade and the chopping knives is adjusted. According to the invention, the adjusting device comprises at least one distance sensor for detecting a distance between the counter-blade and the drum housing. Here, the at least one distance sensor is designed to determine the position of the counter-blade carrier relative to the drum housing.The control device is connected to the at least one sensor via a wireless or wired communication means. The control device is configured to evaluate the sensor data of the at least one distance sensor.

[0013] According to the invention, the at least one distance sensor operates in a contact or contactless manner and is designed to determine the position of the counter-blade carrier relative to the drum housing.

[0014] It is advantageous that sensor data is continuously generated during the work process by means of at least one, in particular contactless, distance sensor, thus enabling continuous monitoring of the gap dimension. Preferably, the at least one distance sensor can be configured to determine an absolute position along a measuring path. The at least one distance sensor is designed, in particular, as an absolute value sensor.

[0015] The at least one distance sensor comprises at least two sensor components, one sensor component being arranged on the drum housing and the other sensor component being assigned to the counterblade support. Preferably, the at least one distance sensor can be a magnetic tape sensor. Particularly preferably, two distance sensors are provided. The magnetic tape sensor comprises a read head and a magnetic tape. Magnetoresistive sensors or Hall sensors can be located in the read head.

[0016] The counter-blade support can be pivotally mounted on pivot bearings arranged axially parallel to the rotational axis of the knife drum. Two opposing lever arms are connected to the end of the counter-blade support and extend essentially vertically to the counter-blade support. The counter-blade support can be pivotally mounted on a base by the arrangement of the pivot bearings, with the base being fixedly mounted on the drum housing.

[0017] Preferably, the additional sensor component can be arranged on the lever arm adjacent to the sensor component arranged on the drum housing or on the adjacent pivot bearing. Due to this arrangement, the sensor components of the at least one distance sensor are located substantially away from the crop flow fed to the chopping device. Particularly preferably, one sensor component of the distance sensor is arranged on the respective lever arm, and the corresponding additional sensor component is arranged on the respective outer side of the drum housing. Preferably, when the at least one distance sensor is designed as a magnetic tape sensor, the reading head is attached to the drum housing, while the magnetic tape is arranged on the lever arm or the pivot bearing.

[0018] According to a preferred development, the at least one distance sensor can have at least one protective device that at least partially encloses at least one of the sensor components. In this way, contamination or wear caused by dust deposits generated during the grinding process of chopping blades and counterblades can be counteracted.

[0019] In particular, the protective device can be designed as a sheath or housing made of plastic. In the case of a non-contact distance sensor, the protective device designed as a sheath or housing can, in particular, completely enclose the sensor component designed as a magnetic strip.

[0020] Alternatively or additionally, the protective device can be designed as a frame element or a brush. The protective device designed as a frame element or brush partially encloses the at least one distance sensor or its sensor components, so that the penetration of grinding dust can be prevented or at least reduced.

[0021] According to a preferred development, the at least one distance sensor can be assigned a cleaning device that is configured to keep the sensor components essentially free of dust generated during a grinding process. In this way, grinding dust that accumulates on the at least one distance sensor, particularly despite the presence of a protective device, can be removed, for example by blowing or vacuuming.

[0022] The control device can be configured to automatically control the cleaning device depending on at least one parameter in order to remove dust generated by a sanding process. One possible parameter can be the result of a plausibility check of the sensor values ​​generated by the at least one distance sensor, which can be performed by the control device. However, it is also conceivable that the cleaning device can be controlled in conjunction with the execution of the sanding process, before, during, and / or after a sanding process, in order to remove the dust.

[0023] Furthermore, the control device can comprise an input / output unit configured to specify a value for the gap dimension to be maintained, which can be verified by the at least one distance sensor arranged according to the invention. In particular, the specified gap dimension to be maintained can be selected and subsequently verified based on specific values ​​stored in the control device, particularly in the µm range.

[0024] Preferably, the control device can comprise a computing unit and a memory unit in which at least two selectable adjustment methods are stored for automatically executing an adjustment process for adjusting the counterblade, which adjustment processes are executed by the computing unit. An operator can initiate the execution of the adjustment process, which is then automatically executed by the control device, using an input / output unit connected to the control device.

[0025] A "Fast" method, a "Precise" method, a "Wear Optimization" method, and / or a "Manual" method can be stored in the memory unit as selectable adjustment methods. For this purpose, the control device can be configured to control the adjusting device in the "Precise" adjustment method so that the smallest possible parallel gap is set between the counterblade and the knife drum, which is based on a specification, in particular by an operator or the control device. In the latter case, at least one value for the gap can be stored in the control device as a retrievable default.

[0026] Furthermore, the control device can be configured to control the adjusting device in the "quick" adjustment mode, such that a regrinding process of the chopping blades and / or the counterblade is followed, in particular immediately, by a simplified adjustment process. During the simplified adjustment process, the counterblade approaches the cutting drum until a chopping blade first touches it, in order to then adjust the distance between the counterblade and the chopping blades to a predefined gap, in particular one specified by the operator, by controlling the adjusting device. Contact between the counterblade and one of the chopping blades of the cutting drum can be detected by at least one knock sensor.

[0027] Furthermore, the control device can be configured to control the adjusting device in the "Manual" adjustment method so that a manual adjustment of the counter blade can be carried out by means of a gauge or a tool.

[0028] According to the "Fast" adjustment method, the focus is on compensating for wear on the counterblade through a regrinding process, followed by a simplified adjustment process. The simplified adjustment process involves bringing the counterblade closer to the cutting drum until a chopping blade first touches it, in order to then adjust the distance between the counterblade and the chopping blades to a predefined gap, e.g., specified by the operator, by controlling at least one actuator of the adjustment device. Contact between the counterblade and the chopping blades is detected by at least one knock sensor, preferably several knock sensors, which are preferably arranged on the counterblade support. Preferably, only a limited number of repetitions of the selectable "Fast" adjustment method is provided. This is intended to prevent a decrease in adjustment accuracy.According to the "Precise" adjustment method, the adjustment process to be performed is characterized by a high degree of precision and therefore requires a longer execution time. In the "Precise" adjustment method, the smallest possible parallel gap is set between the counterblade and the knife drum, which is based on a specification from the operator or the control device. The adjustment process in the "Precise" adjustment method involves touching the counterblade on both sides against the outer sections of the knife drum until contact with one of the chopping knives is detected.This allows for geometric deviations on the cutting drum, the chopping knives, and / or the counterblade, which may be due to wear or damage caused by a foreign object, to be taken into account. These geometric deviations are averaged out during the subsequent parallel adjustment of the counterblade to set the smallest possible gap. The "wear optimization" adjustment method is characterized by the fact that any wear on the chopping knives and / or the counterblade is determined in terms of quantity by evaluating the adjustment travel. If wear exceeds a predefined threshold, the control device can generate a notification to the operator, prompting them to shorten the intervals for performing the regrinding process and / or the "Fast" or "Precise" adjustment methods.The warning can be communicated to the operator, preferably via the input / output unit in the forage harvester cab. The "Manual" adjustment method allows the operator to manually adjust the counterblade using a suitable tool, such as a gauge. The latter adjustment method is a possible option if the "Fast" and "Precise" adjustment methods cannot be performed automatically due to a malfunction in the adjustment device.

[0029] Furthermore, the control device can be configured to preset the counterblade depending on the crop type and / or the implementation of a front attachment change. In this case, target values ​​for the gap width can be stored in the memory unit of the control device for different crop types. If, for example, a change in the crop type is set via an operator input via the input / output unit, a value for the gap width previously set manually by the operator is overridden by the stored, crop-specific value. This override also occurs when the front attachment is changed, the implementation of which can also be transmitted to the control device via an operator input via the input / output unit. Alternatively, a change in the crop type and / or the front attachment can be detected, for example, by a sensor device on the forage harvester.

[0030] Furthermore, the control device can be configured to continuously determine the position of the counter-blade support during ongoing harvesting. This allows, for example, the function of a respective braking device on the lever arms of the adjusting device to be monitored. An unintentional movement of the counter-blade can thus be detected, which is attributable to the release of one or both braking devices on the lever arms. Likewise, the position of the counter-blade can be monitored. A further aspect is that a change in the position of the counter-blade relative to the counter-blade support due to foreign objects can be detected.

[0031] Preferably, the control device can be configured to derive a measure to be executed depending on the position of the counter-blade carrier determined during ongoing harvesting. A change in position due to a movement of the counter-blade carrier relative to the cutterhead caused by external influences beyond a limit value triggers a measure to protect the chopping knives and the counter-blade from damage or to prevent a reduction in chopping quality.

[0032] The action to be taken can be the issuing of a warning or the stopping of the knife drum. If the limit value is exceeded, an unintentional movement of the counter-blade carrier towards or away from the knife drum leads to at least a warning, which can be issued by an optical-acoustic signal device. This can preferably be an output by the input / output unit. At least a visual warning can be issued by the input / output unit. In particular, if the counter-blade carrier moves unintentionally towards the knife drum, exceeding the limit value can result in the knife drum stopping and / or the activation of the adjusting device in order to distance the counter-blade from the knife drum.

[0033] Further preferably, the control device can be configured to determine and output, after a restart of at least the chopping device, in particular the main drive train of the forage harvester, a deviation from the last set value for the gap dimension before the restart by means of the at least one distance sensor. In this way, undesirable displacements can be detected. Furthermore, the control device can be configured to output an indication of a detected displacement. In particular, this indication can be associated with an instruction to readjust the counterblade using one of the "quick" or "precise" adjustment methods.

[0034] Further preferably, the control device can be configured to detect a change in the distance between the chopper drum and the counterblade compared to a distance determined before the change after a change of an attachment for picking up crop material, and to derive an action upon detection of a change in distance. The action to be derived can be a warning or an instruction to be issued.

[0035] The action can be the issuance of a warning and / or the execution of an adjustment procedure for the counterblade. These actions can preferably be carried out automatically by the control device.

[0036] The control device can preferably be configured to determine and output wear data of the chopping knives and / or the counterblade depending on the adjustment path covered by the counterblade carrier. The adjustment path covered during the respective adjustment process is recorded and summed up. If a predeterminable limit value for a total adjustment path is exceeded, the control device outputs an indication via the input / output unit that the end of the service life of the chopping knives and / or the counterblade has been reached. This is intended to inform the operator that the service life of at least the counterblade has ended. In particular, the drum radius, i.e. the envelope radius of the chopping knives, can be automatically calculated by the control device based on the adjustment path covered by the counterblade during an adjustment process, whereby the knife condition is automatically determined.

[0037] In particular, the control device can be configured to determine and output wear costs. The output occurs on the forage harvester via the input / output unit and / or an external data processing device communicating with the control device. The external data processing device can be, for example, a backend system for farm management software or a mobile device, a so-called smartphone.

[0038] In a preferred embodiment, the control device can be configured to determine, as part of the automatic execution of an adjustment process, a geometric deviation, in particular crowning, of the shape of the counterblade or the chopping blade shape that exceeds a threshold value provided for this purpose. To this end, the control device can control the actuators of the adjustment device in such a way that, first, on an outer side, the counterblade contacts the knife drum along an adjustment path until contact occurs, and then the adjustment path is completely retracted. Following this, the contact is then carried out on the opposite outer side and the retraction is carried out.Subsequently, based on the traveled adjustment path on each outer side of the knife drum, a parallel position of the counter-blade can be determined by averaging, and the counter-blade can be advanced until it contacts the knife drum. Based on the evaluation of the adjustment paths during contact on the two outer sides of the knife drum and the evaluation of the adjustment path during the subsequent parallel advance, the control device can compare this with a threshold value stored in the memory unit of the control device for the maximum difference in the adjustment paths and, if necessary, derive an appropriate action.

[0039] When the limit value is exceeded for the first time, the control device can issue a notification via the input / output unit that the regrinding intervals need to be shortened. Furthermore, a regrinding process and a subsequent adjustment process can be automatically initiated by the control device. Following the automatically executed regrinding and adjustment processes, a check can be performed to determine whether a geometric deviation still exists after their completion.

[0040] According to a preferred development, the control device can be configured to determine a replacement of chopping knives and / or counter-blades and / or a manual change in the gap setting and / or the arrangement of chopping knives and / or counter-blades. For this purpose, a change in the gap can be detected when the forage harvester is put into operation by the signals from the at least one distance sensor, compared to a previously stored gap value, indicating a change in the position of the counter-blade holder relative to the drum housing. If a predeterminable or predefined difference value between the gap last determined during harvesting and the gap after restarting the machine is exceeded, the operator is signaled that the counter-blade is not adjusted or is incorrectly adjusted.The control device can be designed to provide the operator of the forage harvester with a notification that the counter-blade is not adjusted or is incorrectly adjusted and that an adjustment process must be carried out.

[0041] The control device can preferably be configured to automatically move the counter-blade into a parking position and / or a calibration position. Using the input / output unit, the operator can trigger a control command and transmit it to the control device in order to move the counter-blade into the parking position and / or a calibration position by controlling the at least one actuator. In the parking position and / or the calibration position, the counter-blade assumes a defined absolute position relative to the drum housing. In the parking position, the counter-blade can be made accessible by pivoting open the feed housing. This allows, for example, the counter-blade to be aligned with respect to a reference point on the drum housing after disassembly due to a crop-type-related or wear-related change or after rotation on the counter-blade carrier.The alignment of the counter blade with respect to the reference point on the drum housing can be done using a gauge.

[0042] According to a further teaching according to claim 26, which has independent significance, a method for operating a forage harvester is claimed. Reference is made to all statements regarding the proposed forage harvester. In particular, the method for operating a forage harvester is provided according to claims 1 to 25.

[0043] The present invention is explained in more detail below with reference to an embodiment shown in the drawings.

[0044] They show: Fig. 1 a schematic representation of a forage harvester in a side view; Fig. 2 a schematic and perspective representation of a drum housing; Fig. 3 a detailed view of the drum housing according to Fig. 2 ; Fig. 4 the detailed view of the drum housing according to Fig. 3from the rear; Fig. 5 shows an example of a flow diagram of an adjustment process for a counter-blade; and Fig. 6 shows an example of a flow diagram when a geometric deviation of the counter-blade and / or knife drum is detected during the adjustment process.

[0045] In Fig. 1 A self-propelled forage harvester 1 is shown schematically in a side view, which is provided with an attachment 2. In the Fig. 1A corn header is schematically indicated as the front attachment 2, however, other attachments such as a pickup can also be attached to the forage harvester 1. The front attachment 2 takes the crop from the field and conveys it to an intake device 3, which in the exemplary embodiment consists of a roller group with upper and lower intake rollers 4, 5. The intake rollers 4, 5 of the intake device 3 exert a pressing force on the taken up crop. The intake device 3 conveys the crop, which has been compacted into a crop mat, to a chopping device 6, which has a knife drum 7 driven to rotate about a rotation axis 29 and has chopping knives 8 arranged distributed over its circumference. The chopping knives 8 cut the crop mat fed in by the intake device 3 at a counter blade 9. The cut orChopped crop is thrown into a downstream discharge chute 10 by the rotational movement of the knife drum 7, from where it is processed by a post-processing device 11, also referred to as a conditioning device or corn cracker, which is optionally arranged in the crop flow path, depending on the equipment of the forage harvester 1, and is further accelerated by a downstream post-accelerator 12 and conveyed through a discharge chute 13 into a transport vehicle.

[0046] A drive motor 19 is provided to drive the working units of the forage harvester 1, i.e., the front attachment 2, the intake device 3, the chopping device 6, and the accelerator 12. The working units can be connected to the output shaft of the drive motor 19 via a main drive train (not shown). The drive motor 19 also serves, among other things, to operate a hydrodynamic drive of the forage harvester 1.

[0047] The forage harvester 1 comprises a driver's cab 17 in which an input / output unit 18 is arranged. Furthermore, the forage harvester 1 comprises a control device 14, which includes a memory unit 15 for storing data and a computing unit 16 for processing the data stored in the memory unit 15. The control device 14 is configured to control at least the chopping device 6. The input / output unit 18 comprises a display and input means.

[0048] In Fig. 2 is a schematic and perspective view of a drum housing 20 of the chopping device 6. The drum housing 20 has a substantially circular-cylindrical shape and encloses the - in Fig. 2not shown - knife drum 7 in sections in the circumferential direction. The counter-blade 9 is detachably fastened to a counter-blade carrier 23, here and preferably by screw connections 22. The counter-blade carrier 23 is arranged axially parallel to the axis of rotation 29 of the knife drum 7. Two opposing lever arms 24 are connected to the ends of the counter-blade carrier 23 and extend essentially vertically to the counter-blade carrier 23. The lever arms 24 run parallel to side walls 25 of the drum housing 20. The opposing side walls 25 of the drum housing 20 delimit the knife drum 7 in the axial direction.

[0049] The counter-blade support 23 is movably mounted on a base 26, such as a frame element, fixedly arranged on the drum housing 20 to enable radial adjustment of the counter-blade 9 toward and away from the cutting drum 7. The counter-blade support 23 is mounted on the base 26 by an arrangement of pivot bearings 27 such that the counter-blade support 23 can pivot about a pivot axis 28 to enable radial adjustment of the counter-blade 9. The pivot axis 28 of the counter-blade support 23 extends parallel to the rotation axis 29 of the cutting drum 7.

[0050] An adjusting device 30 is provided for adjusting the counter-blade 9. More precisely, the adjusting device 30 has at least one actuator 21 on both sides of the drum housing 20. The respective actuator 21 is connected to the correspondingly arranged lever arm 24 of the counter-blade carrier 23. The components of the adjusting device 30 are identical to one another on both sides of the drum housing 20. The lever arms 24 of the counter-blade carrier 23 are adjustably mounted on the base 26 and in particular on the drum housing 20 and are connected to the counter-blade carrier 23, so that the radial adjustment of the counter-blade carrier 23 can be driven by an adjusting movement of the lever arms 24. For this purpose, the respective lever arm 24 can be screwed to a longitudinal end of the counter-blade carrier 23 by means of two screws 22.

[0051] The counter-blade 9 can be advanced onto the chopping blades 8 by means of the adjusting device 30, thereby adjusting a gap between the counter-blade 9 and the chopping blades 8 on the knife drum 7. The adjusting device 30 can be controlled by the control device 14. It is also conceivable for the adjusting device 30 to have a separate control device.

[0052] To protect the counterblade 9 from vibration during the chopping process, the adjusting device 30 also has a clamping device or braking device 31, which allows the counterblade 9 to be securely held and clamped during the chopping process while still allowing the counterblade 9 to be sensitively adjusted during an adjustment process. The clamping device or braking device 31 is preferably hydraulically actuated.

[0053] As in Fig. 1As indicated schematically, at least one distance sensor 32 is provided for detecting a distance between the counter-blade 9 and the drum housing 20. In particular, the at least one distance sensor 32 is arranged between the lever arm 24 and the drum housing 20 in the region of the counter-blade support 23. Preferably, a distance sensor 32 is also arranged on the opposite side of the drum housing 20 between the latter and the lever arm 24.

[0054] Furthermore, the chopping device 6 can be assigned a cleaning device 58, which serves to remove dust that arises during a regrinding process of the chopping blades 8 and the counter-blade 9. The cleaning device 58 can be designed in particular as a suction device or as a blower device. The cleaning device 58 can counteract the deposition of grinding dust, which can influence the measuring accuracy of the at least one distance sensor 32. In the illustrated embodiment, the cleaning device 58 is designed as a suction device and comprises two suction lines 59, wherein each suction line 59 is assigned to a distance sensor 32. Furthermore, the cleaning device 58 comprises at least one blower 60, to which the two suction lines 59 are connected.

[0055] The cleaning device 58 is controlled by the control device 14. The control device 14 can be configured to automatically control the cleaning device 58 depending on at least one parameter in order to remove the grinding dust generated by a grinding process. One possible parameter can be the result of a plausibility check, which can be performed by the control device 14, of the sensor values ​​generated by the at least one distance sensor 32. However, it is also conceivable for the cleaning device 58 to be controlled in conjunction with the execution of the grinding process in order to remove the grinding dust before, during, and / or after a grinding process.

[0056] The representation in Fig. 3 shows a detailed view of the drum housing 20 according to Fig. 2 . In Fig. 4 is the detailed view of the drum housing according to Fig. 3shown obliquely from behind. The at least one distance sensor 32 comprises at least two sensor components 33, 34, wherein one sensor component 33 is arranged directly on the drum housing 20 and the further sensor component 34 is assigned to the counter-blade carrier 23. The further sensor component 34 is arranged on the lever arm 24 adjacent to the sensor component 33 arranged on the drum housing 20. The further sensor component 34 is arranged on the inside of the lever arm 24. The inside arrangement of the further sensor component 34 is to be understood as the arrangement on the side of the lever arm 24 facing the drum housing 20. The further sensor component 34 can also be arranged on the counter-blade carrier 23 or on the pivot bearing 27.

[0057] According to the invention, the at least one distance sensor 32 operates without contact. Alternatively, the at least one distance sensor 32 can also operate with contact. It is advantageous that, by means of the at least one contactless distance sensor 32, sensor data is continuously generated even during the working process of the forage harvester 1, thereby enabling continuous monitoring of the gap dimension. According to the invention, the at least one distance sensor 32 is configured to determine an absolute position along a measuring path. The at least one distance sensor 32 is designed, in particular, as an absolute value sensor.

[0058] The at least one distance sensor 32 is preferably a magnetic tape sensor. The distance sensor 32, embodied as a magnetic tape sensor, comprises a read head forming the sensor component 33 arranged on the drum housing 20, and a magnetic tape forming the sensor component 34 arranged on the lever arm 24. Magnetoresistive sensors or Hall sensors can be located in the read head. Both sensor components 33, 34 can, for example, each have a protective device 61 that encloses the respective sensor component 33, 34 at least in sections. The protective device 61 can be embodied as a sheath made of plastic. The protective device 61 serves to protect the respective distance sensor 32 from grinding dust or other contaminants, or even from moisture.

[0059] By means of the at least one sensor 32, a change in the position of the counter-blade carrier 23 relative to the drum housing 20 is detected. More precisely, an adjustment path of the counter-blade carrier 23 relative to the drum housing 20 is determined, which is effected by controlling the actuators 21.

[0060] The method according to the invention for operating the forage harvester 1, in particular for adjusting the gap between the counterblade 9 and the chopping knives 8, is described below. The method according to the invention is based on the fact that the adjusting device 30, which comprises at least one distance sensor 32, detects a distance between the counterblade 9 and the drum housing 20, as already explained.

[0061] In Fig. 5A flowchart of an adjustment process for the counter-blade 9 is shown as an example. An operator of the forage harvester 1 selects the "adjust counter-blade" process using the input / output unit 18 in a first step 35 in order to automatically adjust the counter-blade 9.

[0062] In a subsequent step 36, the presence of at least one criterion is checked, which determines whether to branch to step 37 or step 38. To this end, in step 36, a check is made as to whether a previously set value for the gap size is stored in the memory unit 15 of the control device 14. If the answer is yes, the program proceeds to step 37. If the answer is no, the program proceeds to step 38.

[0063] In step 37, a "quick" adjustment process is executed. The "quick" adjustment process focuses on compensating for wear on the counterblade 9 through a regrinding process, followed by a simplified adjustment process. The simplified adjustment process involves the counterblade 9 approaching the cutting drum 7 until a chopping blade 8 first touches it, in order to then adjust the distance between the counterblade 9 and the chopping blades 8 to a predefined gap, for example, specified by the operator, by controlling the actuators 21 of the adjusting device 30. Contact between the counterblade 9 and the chopping blades 8 is detected in a known manner by knock sensors (not shown), which are preferably arranged on the counterblade support 23.In this context, a knock sensor is generally understood to be a sensor that detects a mechanical impulse between the counterblade 9 and the chopping blade 8, which is caused by the rotation of the knife drum 7 when the counterblade 9 is at maximum advance toward the chopping blade 8. In this respect, the term "knock sensor" is to be interpreted broadly. Here, and preferably, the knock sensor is a structure-borne sound sensor.

[0064] Preferably, only a limited number of repetitions of the selectable "Fast" setting method is provided. For this purpose, a counter is provided in step 37, which is incremented after each setting process performed according to the "Fast" setting method. If a maximum value for the number of repetitions according to the "Fast" setting method is reached, the system automatically proceeds to step 38 for the next setting process initiated by the operator.

[0065] In step 38, if the prerequisite checked in step 36 is met or if the maximum number of repetitions is exceeded according to the "Fast" setting method, a "Precise" setting method is executed. According to the "Precise" setting method, the adjustment process to be performed is characterized by high precision and therefore requires a longer execution time. In the "Precise" setting method, the smallest possible parallel gap between the counterblade 9 and the knife drum 7 is set, which is based on a specification by the operator or the control device 14. The adjustment process in the "Precise" setting method comprises contacting the counterblade 9 on both sides of the outer edge sections of the knife drum 7 until contact with one of the chopping knives 8 is detected by the knock sensors.This allows for geometric deviations on the cutting drum 7 or the chopping blades 8 and / or the counter-blade 9, which may be due, for example, to wear or damage caused by a foreign object, to be taken into account by averaging these geometric deviations during the subsequent parallel positioning of the counter-blade 9 with respect to the cutting drum 7 to set the smallest possible gap. The geometric deviations result from the differences in the adjustment paths determined by the two distance sensors 32 when the counter-blade 9 contacts the chopping blades 8 on both sides.

[0066] Following step 37 or 38, a step 39 is carried out, which involves checking the adjustment path of the counter-blade 9 covered during the respective adjustment process and detected by sensors by the control device 14.

[0067] In the subsequent step 40, the adjustment travel determined in step 39 is compared with a limit value x. If the limit value x for the adjustment travel is exceeded, the control device 14 generates a notification in step 41 indicating that the intervals for performing the regrinding process and / or the "Fast" or "Precise" adjustment methods should be shortened. The notification generated in step 41 is communicated to the operator via the input / output unit 18. If the result is negative, the adjustment process ends without notification to the operator.

[0068] The representation according to Fig. 6shows an example of a flow diagram for the detection of a geometric deviation of the counter-blade 9 and / or the knife drum 7 during the adjustment process according to the "Exact" adjustment method. During the automated execution of the "Exact" adjustment method, the gap shape, i.e., the contour of the counter-blade and the opposing chopping knives 8, can be monitored, as already explained above. A geometric deviation of the counter-blade 9 and / or the knife drum 7 or the chopping knives 8 can manifest itself in a convex shape. This convex shape can, for example,caused by increased wear in the outer area of ​​the chopping device 6 due to uneven material feed, in which larger quantities of crop are fed in at the edge than in the middle, or due to grinding processes in which the grinding stone at the edge of the knife drum 7 has longer exposure times and / or forces on the chopping knives 8 and / or the counter-blade 9 than in the middle of the chopping device 6.

[0069] In a first step 42, a counter in the memory unit 15 is set to the value zero. Then, in step 43, the counter blade 9 is moved with an outer edge, for example the right edge, towards the knife drum 7 until the knock sensors detect initial contact. In step 44, the counter blade 9 is retracted. In the subsequent step 45, the other outer edge, for example the left edge, is moved towards the knife drum 7 until the knock sensors again detect initial contact. In the following step 46, the counter blade 9 is retracted. The respective adjustment paths covered in steps 43 and 45 are recorded by the respective distance sensor 32 and transmitted to the control device 14 for evaluation. The adjustment paths of the left and right edges of the counter blade are averaged by the computing unit 16 in step 47.In step 48, the counter-blade 9 is advanced parallel to the knife drum 7 until contact is made that can be detected by the knock sensors.

[0070] In step 49, the adjustment path covered during parallel feeding is again detected by the distance sensors 32 and, after evaluation, stored in the memory unit 15. The adjustment path covered during parallel feeding is compared with the respective adjustment paths determined during probing in the preceding steps 43 and 45 in order to determine a difference value. In step 50, the difference value is compared with a threshold value for a maximum permissible difference stored in the memory unit 15 of the control device 14. The threshold value for a maximum permissible difference can be specified by the operator or can be a specification stored in the memory unit 15 by the manufacturer of the chopping device 6, the chopping blades 8 and / or the counterblade 9.

[0071] If it is determined in step 50 that the difference value is below the threshold for the maximum permissible difference, no action is derived and the procedure ends in step 54.

[0072] If it is determined in step 50 that the difference value exceeds the threshold value for the maximum permissible difference, the counter reading of the counter set in step 42 is checked in step 51 to determine whether it is greater than or equal to 1.

[0073] If the answer is yes, the procedure proceeds to step 52. In step 52, the control device 14 generates a message for the operator, indicating that the counterblade 9 should be checked for wear across its entire width. The procedure then ends in step 53.

[0074] If the answer is negative, the program proceeds from step 51 to step 55. In step 55, the control device 14 generates a notification indicating that the intervals for performing the regrinding process should be shortened. Following step 55, the regrinding of the counterblade 9 and / or the chopping blades 8 and the repetition of the adjustment process are performed automatically in step 56.

[0075] The counter is then incremented in the following step 57. The program then returns to step 43 to check the success of the action taken in step 56.

[0076] Furthermore, the control device 14 can be configured to continuously determine the position of the counter-blade carrier 23 during ongoing harvesting operations. This allows, for example, the function of the braking device 31 on the lever arms 24 of the adjusting device 30 to be monitored. Unintentional movements of the counter-blade 9 can be detected, which may be attributable to the release of one or both braking devices 31 on the lever arms 24. Likewise, the fit of the counter-blade 9 on the counter-blade carrier 23 can be monitored. A further aspect can be that a change in the position of the counter-blade 9 relative to the counter-blade carrier 23 due to foreign bodies that have penetrated the chopping device 6 can be detected.

[0077] The output of instructions takes place here and preferably by means of the input / output unit 18.

[0078] Further preferably, the control device 14 can be configured to determine and output, after a restart of at least the chopping device 6, in particular the main drive train of the forage harvester 1, a deviation from the value for the gap dimension last set before the restart by means of the at least one distance sensor 32. In this way, undesired displacements can be detected. In addition, the control device 14 can be configured to output an indication of a detected displacement. In particular, this indication can be associated with an instruction to readjust the counter-blade 9 according to one of the adjustment methods stored in the control device 14.

[0079] Furthermore, the control device 14 can be configured to detect a change in the distance between the chopping drum 7 and the counterblade 9 compared to a distance determined before the change after a change of an attachment 2, and to initiate a measure upon detection of a change in distance. The measure to be initiated can be a warning or an instruction to be issued. Thus, the measure can be the issuance of a warning and / or the execution of an adjustment process for the counterblade 9.

[0080] Preferably, the control device 14 can be configured to determine wear data of the chopping knives 8 and / or the counterblade 9 as a function of a traveled adjustment path of the counterblade carrier 23 and to output this data by means of the input / output unit 18. The adjustment path covered during the respective adjustment process is recorded and summed up. If a predeterminable limit value for a total adjustment path is exceeded, the control device 14 outputs an indication by means of the input / output unit 18 that the end of the service life has been reached. This is intended to inform the operator that the service life of at least the counterblade 9 has ended. In particular, the drum radius, i.e. the envelope radius of the chopping knives 8, can be automatically calculated by the control device 14 based on the adjustment path of the counterblade 9 covered during an adjustment process, whereby the knife condition is automatically determined.

[0081] Preferably, the control device 14 can be configured to automatically move the counter-blade 9 into a parking position and / or a calibration position. Using the input / output unit 18, the operator can trigger a control command and transmit it to the control device 14 in order to move the counter-blade 9 into the parking position and / or the calibration position by controlling the at least one actuator 21. In the parking position and / or the calibration position, the counter-blade 9 assumes a defined absolute position relative to the drum housing 20. In the parking position, the counter-blade 9 can be made accessible by pivoting the feed housing open. Thus, for example, the counter-blade 9 can be aligned with respect to a reference point on the drum housing 20 after disassembly due to a crop-type-related or wear-related change or after rotation on the counter-blade carrier 23.The alignment of the counter blade 9 with respect to the reference point on the drum housing 20 can be done manually using a gauge. List of reference symbols

[0082] 1 forage harvester 34 Sensor component 2 Attachment 35 Step 3 Feeding device 36 Step 4 Upper feed roller 37 Step 5 Lower feed roller 38 Step 6 Chopping device 39 Step 7 Knife drum 40 Step 8 chopping knife 41 Step 9 Counter blade 42 Step 10 Ejection chute 43 Step 11 Post-processing device 44 Step 12 Post-accelerator 45 Step 13 discharge spout 46 Step 14 Control device 47 Step 15 memory 58 Step 16 Computing unit 49 Step 17 Driver's cab 50 Step 18 Input-output unit 51 Step 19 drive motor 52 Step 20 Drum housing 53 Step 21 Actuator 54 Step 22 screw connection 55 Step 23 Counterblade holder 56 Step 24 lever arm 57 Step 25 side wall 58 Cleaning device 26 base 59 Suction line 27 swivel bearing 60 fan 28 Swivel axis 61 protective device 29 axis of rotation 30 Adjusting device 31 braking device 32 Distance sensor 33 Sensor component

Claims

1. A forage harvester (1), comprising a chopping device (6) with a knife drum (7) with chopping knives (8) disposed thereon, wherein the knife drum (7) is sectionally surrounded by a drum housing (20), as well as with a counter cutter (9) which cooperates with the chopping knives (8) and which is detachably fastened to a counter cutter carrier (23), wherein a control device (14) and a positioning device (30) having at least one actuator (21) are provided, by means of which the counter cutter (9) can be advanced towards the chopping knives (8), whereupon a clearance between the counter cutter (9) and the chopping knives (8) is set, and wherein the positioning device (30) comprises at least one distance sensor (32) for detecting a distance between the counter cutter (9) and the drum housing (20) which operates in a contacting or contactless manner and is connected by a wireless or wired communication means to the control device (14) which is configured to analyse the sensor data, characterized in that the at least one distance sensor (32) is configured to determine the position of the counter cutter carrier (23) relative to the drum housing (20) and comprises at least two sensor components (33, 34), wherein one sensor component (33, 34) is disposed on the drum housing (20) and the other sensor component (33, 34) is associated with the counter cutter carrier (23).

2. The forage harvester (1) according to claim 1, characterized in that the counter cutter carrier (23) is pivotally mounted on pivot bearings (27) disposed with axes parallel to the axis of rotation (29) of the knife drum (7), wherein two mutually opposing crank arms (24) are attached to the ends of the counter cutter carrier (23) and extend substantially in the vertical direction to the counter cutter carrier (23).

3. The forage harvester (1) according to claim 2, characterized in that the other sensor component (33, 34) is disposed on the crank arm (24) adjacent to the sensor component (33, 34) disposed on the drum housing (20) or on the adjacent pivot bearing (27).

4. The forage harvester (1) according to one of the preceding claims, characterized in that the at least one distance sensor (32) has at least one protection means (61) which at least sectionally surrounds at least one of the sensor components (33, 34).

5. The forage harvester (1) according to claim 4, characterized in that the protection means (61) is configured as a covering or enclosure produced from a plastic.

6. The forage harvester (1) according to claim 4 or claim 5, characterized in that the protection means (61) is configured as a frame element or a brush.

7. The forage harvester (1) according to one of the preceding claims, characterized in that a cleaning device (58) which is configured to keep the sensor components (33, 34) substantially free from dust produced during a sharpening procedure is associated with the at least one distance sensor (32).

8. The forage harvester (1) according to claim 7, characterized in that the control device (14) is configured to control the cleaning device (58) automatically as a function of at least one parameter in order to remove dust produced by a sharpening procedure.

9. The forage harvester (1) according to one of the preceding claims, characterized in that the control device (14) comprises an input / output unit (18) which is configured for inputting a value for the clearance to be complied with, which can be checked by the at least one distance sensor (32).

10. The forage harvester (1) according to one of the preceding claims, characterized in that the control device (14) comprises a processing unit (16) and a memory unit (15) in which at least two selectable adjustment methods which will be executed by the processing unit (16) are stored for automatically executing an adjustment procedure for setting the counter cutter (9).

11. The forage harvester (1) according to claim 10, characterized in that a "Quick" method, a "Precise" method, a "Wear Optimisation" method and / or a "Manual" method are stored in the memory unit (15) as the selectable adjustment method.

12. The forage harvester (1) according to claim 11, characterized in that the control device (14) is configured to control the positioning device (30) in the "Precise" adjustment method in a manner such that a smallest possible parallel clearance between the counter cutter (9) and the knife drum (7) is set which is based on a specification, in particular by an operator or the control device (14).

13. The forage harvester (1) according to claim 11 or claim 12, characterized in that the control device (14) is configured, in the "Quick" adjustment method, to control the positioning device (30) in a manner such that a simplified adjustment procedure follows a procedure for re-sharpening the chopping knives (8) and / or the counter cutter (9), wherein, during the simplified adjustment procedure, an approach of the counter cutter (9) to the knife drum (7) up to an initial contact of a chopping knife (8) occurs, in order to thereupon set the distance between the counter cutter (9) and the chopping knives (8) to a pre-defined clearance, in particular specified by the operator, by controlling the positioning device (30).

14. The forage harvester (1) according to one of claims 11 to 13, characterized in that the control device (14) is configured, in the "Manual" adjustment method, to control the positioning device (30) in a manner such that a manual adjustment of the counter cutter (9) can be carried out by means of a gauge or a tool.

15. The forage harvester (1) according to one of the preceding claims, characterized in that the control device (14) is configured to carry out a pre-adjustment of the counter cutter (9) as a function of the type of harvested material and / or when a change of front attachment is carried out.

16. The forage harvester (1) according to one of the preceding claims, characterized in that the control device (14) is configured to carry out the determination of the position of the counter cutter carrier (23) continuously during the ongoing harvesting operation.

17. The forage harvester (1) according to claim 16, characterized in that the control device (14) is configured to derive an action to be executed as a function of the position of the counter cutter carrier (23) determined during the ongoing harvesting operation.

18. The forage harvester (1) according to claim 17, characterized in that the action to be executed is an output of a warning, or stopping the knife drum (7).

19. The forage harvester (1) according to one of the preceding claims, characterized in that the control device (14) is configured, after a restart of at least the chopping device (6), in particular of the forage harvester (1), to determine and output a deviation from the last set value for the clearance prior to the restart by means of the at least one distance sensor (32).

20. The forage harvester (1) according to one of the preceding claims, characterized in that the control device (14) is configured, after a change of a front attachment for picking up harvested material, to detect a variation in the distance between the chopping drum (7) and the counter cutter (9) compared with a distance determined prior to the change and to derive an action upon detection of a variation in the distance.

21. The forage harvester (1) according to claim 20, characterized in that the action is an output of a warning and / or carrying out a procedure for adjusting the counter cutter (9).

22. The forage harvester (1) according to one of the preceding claims, characterized in that the control device (14) is configured to determine and output wear data for the chopping knives (8) and / or the counter cutter (9) as a function of an adjustment path of the counter cutter carrier (23) which is travelled.

23. The forage harvester (1) according to one of claims 10 to 22, characterized in that in the context of the automatic execution of an adjustment procedure, the control device (14) is configured to determine a geometric deviation, in particular camber, in the shape of the counter cutter (9) or the shape of the chopping knife which exceeds a threshold value provided for this purpose.

24. The forage harvester (1) according to one of the preceding claims, characterized in that the control device (14) is configured to determine a change of chopping knives (8) and / or counter cutter (9) and / or a manual change in the adjustment of the clearance and / or the disposition of the chopping knives (8) and / or counter cutter (9).

25. The forage harvester (1) according to one of the preceding claims, characterized in that the control device (14) is configured so as to move the counter cutter (9) automatically into a park position and / or a calibration position.

26. A method for operating a forage harvester (1), comprising a chopping device (6) with a knife drum (7) with chopping knives (8) disposed thereon, wherein the knife drum (7) is sectionally surrounded by a drum housing (20), as well as with a counter cutter (9) which cooperates with the chopping knives (8) and which is detachably fastened to a counter cutter carrier (23), wherein a positioning device (30) having a control device (14) and at least one actuator (21) is provided, by means of which the counter cutter (9) is advanced towards the chopping knives (8), whereupon a clearance between the counter cutter (9) and the chopping knives (8) is set, and wherein the positioning device (30) comprises at least one distance sensor (32), by means of which a distance between the counter cutter (9) and the drum housing (20) is detected, which operates in a contacting or contactless manner and is connected by a wireless or wired communication means to the control device (14) which is configured to analyse the sensor data, characterized in that the at least one distance sensor (32) is configured to determine the position of the counter cutter carrier (23) relative to the drum housing (20) and comprises at least two sensor components (33, 34), wherein one sensor component (33, 34) is disposed on the drum housing (20) and the other sensor component (33, 34) is associated with the counter cutter carrier (23).