METHOD FOR THE MAINTENANCE OF A CHOPPERING DEVICE OF AN AGRICULTURAL MACHINE

Description

[0001] The present invention relates to a method for maintaining a chopping device of an agricultural machine, according to claim 1.

[0002] In agricultural harvesting machines, such as forage harvesters, it is common practice to collect and process crops by chopping them before transferring them to an accompanying vehicle, such as a trailer. A known type of chopping device features a rotating chopping drum with multiple knives that pass a stationary counter-blade. The crop is cut between each knife and counter-blade. For optimal results, a sharp cutting edge on the knife side and the smallest possible distance to the counter-blade are desirable. Increasing knife wear can be compensated for by adjusting the counter-blade towards the chopping drum to maintain a suitable distance. However, the adjustment range of the counter-blade is limited. It is also known to position the knife differently relative to the drum body of the chopping drum.For example, if the counter blade becomes heavily worn, it can be pulled out further if this wear can no longer be compensated for simply by adjusting the counter blade. However, even this extension is only possible to a certain extent. If the blade is already too worn, it must be replaced. It is possible not only to adjust the distance of the counter blade from the chopping drum, but also its angle relative to the chopping drum, for example, to compensate for any existing tilt of the blades. For this purpose, the opposite ends of the counter blade can be adjusted using individually controllable mechanisms. A grinding device can be used to sharpen the blades, in which a grinding head is adjustable along a grinding axis and can be positioned so that the blades pass by it while the chopping drum rotates.

[0003] If a blade needs to be removed or even replaced, a subsequent sharpening process is necessary to sharpen the blade and ensure correct alignment of the cutting edge. In the prior art, it is known to first run the blade along the counter blade against the chopping drum, i.e., to increase the distance to the chopping drum, and then to align the (removed or newly installed) blade against the counter blade before sharpening. To at least approximately maintain the angle of the counter blade during this process, the distances of the blade ends to the drum body are measured beforehand, determining any difference that would normally exist. During the process, distances are then set individually for each end, which again differ by the previously determined difference. This process is inherently prone to errors, primarily due to the manual measurement of the distances to the drum body.Therefore, the angle of the counter edge can only be reproduced imprecisely. Sharpening takes place after all the intended knives have been removed or replaced. Since the knives were aligned to the previously worn counter edge, their alignment before sharpening is also inaccurate, leading to significant losses during sharpening. Furthermore, manual measurement is time-consuming. After sharpening, the counter edge must be realigned to the sharpened knives, as its alignment generally does not match the newly sharpened cutting edge.

[0004] German patent DE 10 2020 128518 A1 discloses a method for grinding the chopping knives of a forage harvester. The process begins with grinding, followed by adjusting the position of the counter blade.

[0005] Further methods for grinding shredder knives are also known from DE 196 52 656 B4 and DE 689 02 669 T2.

[0006] The object of the invention is to optimize the maintenance of a shredding device.

[0007] The problem is solved by a method having the features of independent claim 1. Advantageous embodiments can be found in the dependent claims.

[0008] For this purpose, a method for maintaining a chopping device of an agricultural machine is provided, which chopping device has a chopping drum rotatable about an axial axis of rotation relative to a frame, with a drum body and a plurality of knives lockable thereto, a counter blade that interacts with the knives in the operating state and can be locked relative to the frame, having two axially spaced end regions, wherein radial end region distances from the axis of rotation are at least partially independently adjustable, and a grinding device that is configured to grind the knives along a grinding axis extending at least partially axially, wherein the method comprises at least the following steps: Grinding at least one knife using the grinding device; aligning the counter blade with at least one ground knife by adjusting the end-range distances; moving the counter blade away from the chopping drum in a parallel adjustment, whereby both end-range distances are increased by the same amount, which has been predetermined; rearranging at least one knife on the drum body, wherein the newly arranged knife is aligned with the counter blade and locked onto the drum body; and grinding the at least one newly arranged knife using the grinding device.

[0009] The agricultural machine in question could be a self-propelled forage harvester, but the method would also be applicable to other machines, such as trailed or stationary ones. The chopping unit is used to chop agricultural crops, for example, corn or straw. The frame can be considered part of the chopping unit. However, it can also be considered, wholly or partially, as a part of the agricultural machine that is not part of the chopping unit. It forms a stable, and in particular, rigid framework to which various moving parts can be mounted. These include the chopping drum of the chopping unit, which is rotatable around its axis of rotation. The axis of rotation, which is considered stationary with respect to the frame, defines an axial direction, a radial direction, and a tangential direction. The chopping drum is rotatably mounted on the frame.It can be coupled to a drive, at least temporarily, so that it can be driven around its axis of rotation. The drive itself can be located outside the actual shredding device, with power transmission to the shredding drum via a gearbox.

[0010] The shredding drum has a drum body. This can be rotationally symmetrical about the axis of rotation, for example, cylindrical. It can consist of several individual parts that are rigidly connected to each other during operation. Several knives can be locked onto the drum body. More precisely, the knives are locked onto the drum body during operation. They can be, for example, screwed on or clamped by means of locking screws. To avoid imbalances, the knives are advantageously arranged symmetrically with respect to the axis of rotation, for example, by being arranged in pairs opposite each other. For reasons of stability, both the drum body and the knives are preferably made of steel.

[0011] The counter blade interacts with the knives during operation. In this state, the counter blade is locked relative to the frame, and the knives are guided past the counter blade in accordance with the rotation of the chopping drum. Typically, the counter blade extends axially over at least 60% of the axial extent of the chopping drum. In particular, it should cover the entire area occupied by the knives in the axial direction. The counter blade can also be made of steel. Crop material that gets between the counter blade and the knives is cut. In connection with the method according to the invention, the "maintenance" of the chopping device refers in particular to restoring optimal knife sharpness and an optimal distance between the knives and the counter blade, which are essential prerequisites for optimal chopping results.

[0012] The counter-edge has two axially spaced end regions. These end regions can also be referred to as "ends." They are located opposite each other in the axial direction. Thus, the counter-edge extends in the axial direction, although it generally does not run exactly parallel to the axis of rotation. Each end region can be assigned a radial distance from the axis of rotation. The end-region distances can be equal, but they can also be different, so that the counter-edge is inclined towards the radial direction relative to the axial direction, even if only slightly. The end-region distances are at least partially adjustable independently of each other. This preferably refers to actuator-based adjustability. "Adjustable independently of each other" means, in particular, that the difference between the two end-region distances can be changed, and thus the inclination relative to the axial direction.The adjustability may not be completely independent. For example, the aforementioned difference, and thus the inclination, may be limited in magnitude for design reasons. It is also conceivable that two independent adjustment mechanisms are provided, one of which affects both end-range distances and the other only one. Adjusting an end-range distance does not necessarily require a movement parallel to the radial direction. The movement only needs to be partially radial and can, for example, also have a tangential component.

[0013] Furthermore, the shredding device includes a grinding unit. This unit is used to sharpen the blades, allowing for the sharpening of individual blades or multiple blades simultaneously. More precisely, the grinding unit is designed to sharpen the blades along a grinding axis that extends at least partially axially. This means that the grinding process creates a cutting edge on each blade, the path of which is determined by the grinding axis. It can, for example, be parallel to the grinding axis. However, this does not apply if the path of the cutting edge deviates from the axial-radial plane. If, however, only the inclination within the axial-radial plane is considered, the inclination of the grinding axis and that of the cutting edge after grinding will be the same.Advantageously, the grinding device is arranged tangentially to the counter-edge, so that the cutting process and the grinding of a knife take place in different positions.

[0014] The procedure comprises at least the following steps. These are preferably carried out in the order listed. However, at least one further procedure step can be carried out between any two of the listed procedure steps.

[0015] In one step, at least one blade is sharpened using the grinding device. As explained, the grinding process creates a cutting edge that is aligned with the grinding device and can, for example, run parallel to the grinding axis. Due to the rotation of the shredding drum, the cutting edge is generally only parallel to the grinding axis when the blade is close to the grinding device. This is only the case if the grinding axis runs exactly parallel to the axis of rotation. Otherwise, the inclination of the cutting edge relative to the grinding axis changes, with the cutting edge running along an imaginary conical surface during rotation. If only the axial-radial plane is considered, the inclination of the cutting edge relative to the axis of rotation does not change during rotation and corresponds, at least approximately, to the inclination of the grinding axis relative to the axis of rotation.Unless explicitly stated otherwise, the term "inclination" in the following always refers to the inclination within the axial-radial plane, i.e. any possible inclination relative to the axial direction in the tangential direction is disregarded.

[0016] In a further step, the counter-edge is aligned with at least one sharpened knife by adjusting the end-range distances. The "sharpened knife" is a knife that was sharpened in the previous step. This preferably ensures that both end ranges are equidistant from the sharpened knife. In this case, the inclination of the counter-edge can be said to be adapted to the inclination of the knife. Advantageously, the counter-edge is positioned radially adjacent to the knife by alignment, whereby the radial distance between the counter-edge and the cutting edge can be, for example, less than 0.5 mm, less than 0.2 mm, or less than 0.1 mm.

[0017] Furthermore, the counter blade is moved away from the chopping drum in a parallel adjustment, whereby both end-range distances are increased by the same amount. Instead of moving, one could also describe it as retracting. The counter blade is moved away from the chopping drum and thus from the axis of rotation. This occurs in a parallel adjustment. This means that after the parallel adjustment, the counter blade is aligned parallel to its position before the adjustment. Therefore, it retains the same inclination relative to the axis of rotation as the grinding axis. It is possible that a change in the inclination may occur temporarily during the parallel adjustment because the two end-range distances are not increased simultaneously and / or at the same speed. However, the difference between the two end-range distances is the same before and after the parallel adjustment.The amount by which the end-range distances are increased was predetermined, i.e., before the parallel adjustment. This ensures that both end-range distances are changed by the same amount. This contrasts with the prior art, where a change of the same amount could occur in individual cases, but would have been purely random.

[0018] In a further step, at least one knife is rearranged on the drum body, with the newly arranged knife being aligned with the counter-edge and locked onto the drum body. The term "rearrangement" generally means that the knife is positioned in a position in which it was not previously located. It is aligned with the counter-edge while the counter-edge remains stationary. This means that the end-range distances are kept constant. The cutting edge of the knife is preferably aligned so that its inclination matches that of the counter-edge. Depending on the embodiment of the invention, however, a certain deviation can also be accepted. Advantageously, the knife is arranged adjacent to the counter-edge, with the distance between the counter-edge and the cutting edge being, for example, less than 0.5 mm, less than 0.2 mm, or less than 0.1 mm.After alignment, the knife is locked onto the drum body. Since it has been aligned with the counter-edge, it now has an inclination relative to the axis of rotation that corresponds at least approximately to that of the grinding axis.

[0019] Furthermore, at least one newly positioned knife is sharpened using the grinding device. This also creates a cutting edge aligned with the grinding axis. Since the knife was aligned with the counter-edge, it exhibits, as already explained, an inclination that already corresponds approximately, or possibly exactly, to the inclination of the grinding axis. Therefore, the knife is sharpened very evenly, resulting in less unnecessary grinding waste.

[0020] A significant advantage of the inventive method is the avoidance of grinding losses and thus material savings. Each blade can be used for a longer period under the same stress, for example, with the same number of operating hours under comparable conditions. Blade replacement is necessary less frequently. Furthermore, the user is relieved of the tedious, time-consuming, and error-prone task of manually measuring the distances of the end sections from the drum body. The adjustment of the counter blade is based on a predetermined amount by which both end sections are moved.

[0021] The end-range distances can be adjusted in various ways. Generally, at least two independent drives are required. According to one embodiment, the end-range distances are adjusted by means of two actuators, each acting on one of the end ranges. Each actuator preferably has a motor that can act on the end range via power transmission means. For example, each end range can be connected to an actuating lever that pivots about a lever axis stationary on the frame. The actuating lever can be coupled to a connecting rod driven by the motor. For example, a rotary motor can act on the connecting rod via a spindle drive. Of course, other configurations of the actuating devices are also conceivable.

[0022] The grinding device can utilize different operating principles. According to an advantageous embodiment, the at least one blade is ground by guiding it past a grinding head of the grinding device while the chopping drum rotates. During grinding, the grinding head is adjusted along a grinding guide that is stationary relative to the frame and parallel to the grinding axis. The grinding guide can be implemented as a guide rail or the like, on which the grinding head is slidably mounted. The grinding head acts only on a portion of the respective blade at any given time, with this portion being shifted by adjusting the grinding head. The adjustment speed of the grinding head along the grinding guide can be lower than the blade's path speed during the rotation of the chopping drum.If the adjustment speed is significantly lower, the grinding head can be considered a quasi-stationary object with respect to the frame, past which the moving knife is guided.

[0023] Regarding the rearrangement of a knife, there are basically two possibilities. Firstly, the position of at least one knife on the drum body can be changed. This means the knife was already mounted on the drum body and is simply moved, or one could say pulled or removed. The knife's locking mechanism is released, although it can remain slidably connected to the drum body, and after the rearrangement, the knife is locked again. This method can be used when the knife has a relatively low degree of wear. Secondly, at least one knife can be removed from the drum body and replaced with another. The corresponding knife is therefore completely detached from the drum body. Subsequently, another, preferably new, knife is mounted on the drum body and locked in place.This method can be used particularly with a knife that is already so worn that it can no longer be extended.

[0024] It is conceivable to implement the process in which only a single knife is sharpened and rearranged. However, this is generally inefficient, to say the least. It is advantageous to sharpen and / or rearrange multiple knives, especially all knives. Sharpening individual knives is not possible, particularly with a grinding device that operates while the chopping drum is running. For example, all knives can be sharpened first. Then, multiple knives, especially all knives, can be rearranged. Finally, all knives can be sharpened again.

[0025] Preferably, after sharpening at least one newly arranged knife, the counter blade is realigned by adjusting the end-range distances to at least one newly arranged and sharpened knife. This takes into account the possibility that the counter blade is not optimally aligned after sharpening the knife(s). In particular, one or both end-range distances may be too large for optimal shredding results. Since the cutting edges of all previously sharpened knives have an identical orientation relative to the axis of rotation, it is generally possible to use only one knife or a plurality of knives to align the counter blade.

[0026] According to one embodiment of the method, when the counter-edge is realigned, the end-range distances are reduced by a predetermined amount in a parallel adjustment. This amount can generally differ from the amount by which the two end-range distances were previously increased. However, the parallel adjustment does not change the inclination of the counter-edge relative to the axial direction. This embodiment assumes that the inclination of the counter-edge still corresponds to that of the grinding axis and that the inclination of the grinding axis has remained constant. Optimal alignment may not be achieved with a single parallel adjustment. Multiple parallel adjustments can also be performed, whereby the end-range distances can also be increased, for example, if contact between the counter-edge and the knife is detected.

[0027] The assumptions mentioned above regarding the inclination of the counter-edge are at least approximately correct. However, due to any play or other factors, both the inclination of the counter-edge and that of the grinding axis can change, even if only slightly. To account for this possibility, an alternative design allows for individual adjustment of the end-range distances when realigning the counter-edge. Therefore, there is generally no parallel adjustment; instead, the inclination of the counter-edge can be changed to match that of the knife's cutting edge.

[0028] While when realigning the counter blade, a choice can be made between parallel adjustment and individual adjustment of the end area distances, it is advantageous to adjust the end area distances individually when initially aligning the counter blade.

[0029] Preferably, at least one parallel adjustment is performed automatically. This can involve increasing or decreasing the end-range distances. The end-range distances are changed by the respective amount without requiring manual control or monitoring from the user. The amount of the change can also be set automatically.

[0030] As previously explained, with parallel adjustment, the two end-range distances can be changed sequentially, i.e., increased or decreased. However, to maintain the inclination of the counter blade as precisely as possible, it can be advantageous to change the end-range distances simultaneously during parallel adjustment. This means that in the embodiment described above, where each end range has its own actuator, the actuators of both actuators are activated simultaneously.

[0031] One embodiment provides that, during at least one alignment of the counter blade, at least one end-area distance is reduced, contact between the counter blade and at least one knife is checked, and the at least one end-area distance is increased if contact is present. Both end-area distances can be reduced simultaneously, particularly when a parallel adjustment of the counter blade is performed. Alternatively, only one end-area distance can be reduced at a time. If contact between the counter blade and the knife is detected, this means that the end-area distance is already too small. Such contacts would damage the knife and, if applicable, the counter blade during operation. Accordingly, the at least one end-area distance is increased again. This can also apply to one or both end-area distances.If both end area distances were previously reduced, it may be useful to increase both end area distances upon contact.

[0032] Preferably, at least one alignment of the counter blade is performed while the chopping drum is rotating, and the presence of contact between the counter blade and at least one knife is checked using a vibration sensor. If contact occurs between the counter blade and the knife while the chopping drum is rotating, this results in deflection of both parts, which can be detected as vibration. This can be measured by a vibration sensor. The vibration sensor can be in contact with the counter blade or the knife, at least indirectly. Since the operation of the chopping drum also leads to vibrations even without such contact, it is normally necessary to calibrate the vibration sensor. During calibration, a certain intensity and / or frequency spectrum of vibrations is recognized as normal, so that a significant deviation from this can be interpreted as an indication of contact.Calibration can be performed before each alignment of the counter blade.

[0033] It can be designed so that, during parallel adjustment, the end-range distances are reduced in multiple steps, with contact checked after each step. A predetermined amount by which the end-range distances should be reduced can be specified; however, the reduction is not performed in a single step, but rather in multiple steps. For example, if a reduction of 0.8 mm is planned, a reduction of 0.02 mm or 0.01 mm can be made in each step. The reduction can be stopped or aborted if contact is detected after a step. This prevents more intensive contact between the counter blade and the knife, thus minimizing potential damage. The procedure described here can be used particularly when aligning the counter blade.

[0034] To prevent damage, it is advantageous that, if contact occurs, at least one end-range distance is increased until no further contact is detected. In principle, this could be sufficient to prevent further contact during operation of the shredding device. In practice, however, it has been shown that contact can sometimes occur due to various influences, such as thermal deformation, play between components, etc. Therefore, it is preferred that, after it has been determined that no further contact exists, both end-range distances are increased by the same safety margin in a parallel adjustment, which has been predetermined. This safety margin can be significantly smaller than the margin required when moving the counter blade as described above. For example, it could be a maximum of 20% or a maximum of 10%.When determining the safety margin, a balance can be struck between reliably preventing contact between the counter blade and the knife on the one hand, and cutting the harvested crop as effectively as possible on the other.

[0035] The invention is described below with reference to figures. The figures are merely exemplary and do not limit the general concept of the invention. They show Fig. 1 a perspective view of a first chopping device for use in a method according to the invention; Fig. 2 a perspective view of a chopping drum of the chopping device made of Fig. 1 ; Figs. 3A-3F schematic representations of the shredding device made of Fig.1 during various steps of a method according to the invention; and Fig. 4 a flowchart of a method according to the invention.

[0036] Fig. 1 Figure 1 shows a chopping device 1, which can, for example, be part of a self-propelled forage harvester. It can be used to shred crop material that has been picked up by the forage harvester's intake before it is passed on to downstream components. Most parts of the forage harvester, as well as the housing of the chopping device 1, have been omitted for clarity. A key element of the chopping device 1 is a chopping drum 2, which is located in Fig. 2 is shown separately. It has a drum body 3 which is rotatably mounted about a pivot axis D on a frame 25. The frame 25 is in Fig. 1 Only partially and in a simplified manner, it forms a rigid frame on which various parts of the shredding device 1 are arranged. A plurality of knives 4 are arranged on the drum body 3, each knife 4 sitting on a knife carrier (without reference numeral) and secured by means of a screw-on strip 7, which in turn is secured by locking screws 6. Fig. 2 The mounting strip 7 of one of the blades 4 is removed. The axis of rotation D defines an axial direction, a tangential direction, and a radial direction. When the chopping drum 2 is set in rotation by a drive (not shown), the blades 4 move in a tangential direction.

[0037] To shred the harvested crop, the knives 4 work together with a counter blade 10. The counter blade 10 can be locked relative to the frame 25, whereby, in the operating state, the cutting edges 5 of the knives 4 are guided close to the counter blade 10, so that the harvested crop is cut between them. The counter blade 10 is pivotably connected to the frame 25 via a lever axis 26, which in this example runs parallel to the axis of rotation D. A lever 17 of an actuating device 15 is attached to each of two opposite end sections 11, 12 of the counter blade 10. Each lever 17 can be deflected by means of an associated actuator 16. Thus, the two end sections 11, 12 can be pivoted independently of each other to a limited extent about the lever axis 26. Furthermore, the entire counter blade 10 can be pivoted by activating both actuators 16 simultaneously.The adjusting devices 15 allow the radial end-range distances A1, A2 of the two end ranges 11, 12, given with respect to the axis of rotation D, to be changed.

[0038] Furthermore, in Fig. 1 A grinding device 20 is discernible, which has a grinding guide 21 stationary and connected to the frame 25, running parallel to a grinding axis S. A grinding head 22 is adjustable along the grinding guide 21. It can be positioned so that the knives 4 are guided past it in grinding contact as the chopping drum 2 rotates, thereby grinding the cutting edge 5 according to the path of the grinding axis S. However, the cutting edge 5 does not run parallel to the grinding axis S. Rather, the grinding head 21, which is movable parallel to the grinding axis S, defines a straight line through its contact with the knives. Rotating this straight line around the axis of rotation D results in the lateral surface of a cone or cylinder. The cutting edge 5, in turn, runs along this lateral surface. In any case, the grinding process results in an inclination of the cutting edge 5 relative to the axis of rotation D, which corresponds to an inclination of the grinding axis S.This statement refers to the inclination within the axial-radial plane; that is, any inclination in the tangential direction also present in this example is disregarded. As in . Fig.3A-3F To exaggerate the point, the grinding axis S and the rotation axis D generally do not run exactly parallel to each other; that is, there is a non-zero inclination of the grinding axis S relative to the axial direction.

[0039] For optimal shredding results, the blades 4 must be sharp and maintain a small distance to the counter blade 10 along their entire length. For this to be achieved, the inclination of the counter blade 10 must also be adapted to the inclination of the cutting edges 5. To maintain the sharpness of the cutting edges 5, the blades 4 must be sharpened as needed. The sharpening process increases the distance to the counter blade, which can be compensated to a limited extent by reducing the radial end-range distances A1, A2. However, this is no longer sufficient once the blades 4 have become worn. In this case, a method according to the invention must be carried out, which is now described with reference to the flowchart in Fig. 4 as well as the Figuren 3A - 3F will be explained.

[0040] In a first step S100, all knives 4 are ground using the grinding device 20, so that defined cutting edges 5 are produced whose inclination corresponds to that of the grinding axis S. This process is shown schematically in Fig.3A as shown. Then, in step S110, the counter blade 10 is aligned with the previously sharpened knives 4, as shown in Fig.3B As indicated, the end-range distances A1 and A2 are individually reduced until contact between the blade 4 and the counter blade 10 is detected by a vibration sensor (not shown). After contact is detected, the respective end-range distance A1 and A2 can be increased again until no contact is detected. In this state, the inclination of the counter blade 10 corresponds at least approximately to the inclination of the grinding axis S. In a further step S120, the counter blade 10 is moved away from the chopping drum 2. This occurs in a Fig.3C The parallel adjustment shown involves increasing both end-range distances A1 and A2 by the same predetermined amount. The parallel adjustment maintains the inclination of the counter-blade 10.

[0041] In block S130, the blades 4 are rearranged. In step S140, it is decided whether the respective blade 4 can be extended, i.e., adjusted so that it projects further away from the drum body 3, considering its degree of wear. If this is affirmed, in step S150, the blade 4 is adjusted after loosening the locking screws 6, as shown in Fig.3D as indicated. In step S170, it is aligned with the counter blade 10 so that the inclination of its cutting edge 5 relative to the axis of rotation D approximately matches that of the counter blade 10. If it is decided in step S140 that the degree of wear is too high, the blade 4 is removed and replaced with a new blade 4, which is also aligned in step S170. In step S180, it is checked whether this was already the last blade 4. If not, the process returns to step S140, where the next blade 4 is checked. If so, the block S130 is exited and in step S190 the blades 4 are again sharpened with the grinding device 20 while the chopping drum 2 is rotating, which in Fig.3E This is shown. This allows for a precise adjustment of the inclination of their cutting edges 5.

[0042] In another block S200, the counter blade 10 is again aligned with the blades 4, as in Fig.3FAs indicated, assuming that the inclination of the counter blade 10 and that of the cutting edges 5 correspond with sufficient accuracy, a parallel adjustment can be performed in step S210, whereby the end-range distances A1, A2 are reduced by the same amount, which has been predetermined. The actual reduction can be carried out incrementally, with contact between the counter blade 10 and the knife 4 being checked after each step. However, no distinction is made between contact on the side of the first end-range 11 and contact on the side of the second end-range 12. If the agreement of the inclinations is questionable, the end-range distances A1, A2 can alternatively be adjusted individually in step S215. Here, too, an amount can be specified for each end-range 11, 12 by which the corresponding end-range distance A1, A2 is reduced.This can also be done step by step, with contact between counter blade 10 and knife 4 being checked after each step. In any case, if contact is present, the distance between at least one end area A1, A2 can be increased until no contact is present, after which it can be further increased by a safety margin. The procedure ends after block S200.

Claims

1. Method for maintaining a chopping device (1) of an agricultural machine, which chopping device (1) comprises a chopping drum (2), which can be rotated about an axial axis of rotation (D) relative to a frame (25) and has a drum body (3) and a plurality of cutters (4) which can be locked on said body, a counter blade (10), which interacts with the cutters (4) in the operating state, can be locked relative to the frame (25) and has two axially spaced end regions (11, 12), it being possible for radial end region distances (A1, A2) from the axis of rotation to be set independently of one another at least to some extent, and a sharpening device (20), which is configured to sharpen the cutters (4) along a sharpening axis (S) which extends at least partially axially, wherein the method comprises at least the following steps: - sharpening (S100) at least one cutter (4) by means of the sharpening device (20); - aligning (S110) the counter blade (10) with at least one sharpened cutter (4) by setting the end region distances (A1, A2); - moving (S120) the counter blade (10) away from the chopping drum (2) in a parallel adjustment, wherein the two end region distances (A1, A2) are increased by the same amount, which has been predetermined; - rearranging (S130) at least one cutter (4) on the drum body (3), wherein the rearranged cutter (4) is aligned (S170) with the counter blade (10) and locked on the drum body (3); and - sharpening (S190) the at least one rearranged cutter (4) by means of the sharpening device (20).

2. Method according to claim 1, characterized in that the end region distances (A1, A2) are set by means of two actuator positioning apparatuses (15), each of which acts on one of the end regions (11, 12).

3. Method according to either of the preceding claims, characterized in that the at least one cutter (4) is sharpened (S100, S190) by passing it past a sharpening head (22) of the sharpening device (20) while the chopping drum (10) is rotating, which sharpening head is adjusted along a sharpening guide (21), which is stationary with respect to the frame (25), in parallel with the sharpening axis (S) during the sharpening process.

4. Method according to any of the preceding claims, characterized in that in the rearrangement (S130), the position of at least one cutter (4) on the drum body (10) is changed (S150) and / or at least one cutter (4) is removed from the drum body (10) and replaced by another cutter (4) (S160).

5. Method according to any of the preceding claims, characterized in that a plurality of cutters (4), in particular all the cutters (4), are sharpened (S100, S190) and / or rearranged (S130).

6. Method according to any of the preceding claims, characterized in that after the at least one rearranged cutter (4) has been sharpened (S190) by setting the end region distances (A1, A2), the counter blade (10) is realigned (S200) on at least one rearranged and sharpened cutter (4).

7. Method according to any of the preceding claims, characterized in that when the counter blade (10) is realigned (S200), the end region distances (A1, A2) are reduced by an equal amount (S210), which has been predetermined, in a parallel adjustment.

8. Method according to any of the preceding claims, characterized in that when the counter blade (10) is realigned (S200), the end region distances (A1, A2) are set (S215) individually.

9. Method according to any of the preceding claims, characterized in that at least one parallel adjustment is performed automatically.

10. Method according to any of the preceding claims, characterized in that in the course of a parallel adjustment, the end region distances (A1, A2) are changed simultaneously.

11. Method according to any of the preceding claims, characterized in that at least one end region distance (A1, A2) is reduced in the course of at least one alignment (S110, S200) of the counter blade (10), contact between the counter blade (10) and at least one cutter (4) is checked, and if contact is present, the at least one end region distance (A1, A2) is increased.

12. Method according to any of the preceding claims, characterized in that the counter blade is aligned (S110, S200) while the chopping drum (2) is rotating, the presence of contact between the counter blade (10) and at least one cutter (4) being checked by means of a vibration sensor.

13. Method according to any of the preceding claims, characterized in that in the course of a parallel adjustment, the end region distances (A1, A2) are reduced in a plurality of steps, with contact being checked after each step.

14. Method according to any of the preceding claims, characterized in that if contact is present, the at least one end region distance (A1, A2) is increased until no contact is established any longer, and then the two end region distances (A1, A2) are increased by an equal safety amount, which has been predetermined.