TOOL FOR A MULCHER FOR PROCESSING PLANT stubble IN A FIELD

Description

[0001] The invention relates to a mulching device for processing plant stubble in a field according to the preamble of claim 1. State of the art

[0002] In many cases, mulching devices are installed underneath harvesting attachments for grain or maize harvesting to shred and / or shred the plant stumps remaining in the field after harvesting, either to protect the tires of vehicles driving on the field, to improve the decomposition of plant residues or to destroy the overwintering area of ​​the European corn borer ( Ostrinia nubilalis ) .

[0003] The mulching devices comprise blunt or cutting tools that are rigidly or freely oscillatingly connected to a holder mounted on an at least approximately vertically extending, rotating shaft (cf. the generic embodiment according to Figure 10 of EP 3 272 199 A1). In practice, blunt tools have proven effective for shredding plant stumps, while cutting tools are typically used for shredding the upper parts of the plant stems that are discharged downwards by the picking rollers in corn headers (see DE 10 2016 213 919 A1).

[0004] In the prior art, blunt tools are solid, spherical or cigar-shaped bodies that are connected to the shaft rigidly or via flexible elements such as chains (EP 3 272 199 A1), or, according to the subsequently published DE 10 2019 216 223 A1, are cylindrically shaped and connected to a holder coupled to the shaft by means of self-aligning bearings. The rigid attachment to the shaft has the disadvantage that, in the event of a collision with a foreign object (stone) lying in the field, the tool is deformed to at least a greater extent than with a pendulum suspension (which allows the tool to deflect backward relative to the driving shaft). With a pendulum suspension, care must be taken to ensure that the tool is vertically symmetrical and does not generate a tilting moment on the self-aligning bearing, which would tend to tilt the tool from the direction perpendicular to the direction of rotation and lead to premature wear of the self-aligning bearing.This problem does not arise, or only to a limited extent, with the solid, cylindrical bodies used in the prior art, since these are essentially shaped symmetrically to the longitudinal center plane of the tool, which runs transversely to the axis of rotation. In the arrangement according to DE 10 2019 216 223 A1, any vertical asymmetry of the tool is compensated for by a spherical shape of the pendulum bearing, which allows movement of the tool relative to the holder about an axis oriented tangentially to the direction of rotation of the tool, but requires additional effort. However, the known tools require a relatively large amount of material, of which at least the upper half does not interact with the plant stumps, making the production of the tools expensive.

[0005] US 2017 / 0208741 A1 shows a mower with pendulum-mounted tools comprising a mounting area, a twisted transition area, and a semicircular working area whose leading edge is provided with a cutting edge, from which the working area extends upwards in a semicircle. In one embodiment, the center of mass of the tool lies in the plane of symmetry of the mounting area. This is intended to prevent the tool from swinging upwards and coming into contact with the upper cover plate of the mower. Task

[0006] The present invention aims to provide a mulching device that is improved over the prior art. Solution

[0007] This object is achieved according to the invention by the teaching of patent claim 1, wherein the further patent claims list features which further develop the solution in an advantageous manner.

[0008] A mulcher for cultivating stubble in a field, particularly suitable for attachment to a harvesting head, comprises a mount connected to a shaft and driven by the shaft to rotate. It also includes two tools mounted diametrically opposite each other on the mount. These tools are mounted on the mount so that they can freely swing by means of pendulum bearings with pendulum axes running parallel to the shaft's rotation axis. Of course, the mount could also be used to mount 3, 4, 5, or more tools arranged symmetrically to the shaft to prevent eccentricity during rotation.

[0009] A tool of the mulching device comprises a fastening area configured to be coupled to a holder in an oscillating manner about a rotation axis and through which an imaginary plane of symmetry oriented orthogonal to the rotation axis passes, and a working body configured to shred the plant stubble in a field and which is shaped asymmetrically with respect to the plane of symmetry—i.e., measured along the rotation axis. The tool is shaped such that its center of mass lies in the plane of symmetry. The working body has a blunt, leading surface, which serves to shred the plant stubble in a conventional manner.

[0010] In other words, the tool comprises a fastening area which can be coupled to a holder which is connected to a rotatable shaft and can swing freely around a rotational axis. An imaginary plane of symmetry runs through the fastening area and extends transversely to the rotational axis. This plane of symmetry runs exactly through the middle of the fastening area, i.e., at half its height measured along the rotational axis. The tool also comprises a working body which is shaped in such a way that, upon impact with the plant stubble in a field, it shreds or otherwise disintegrates it through (particularly blunt) impact. The working body is asymmetrically shaped in the direction of the rotational axis, i.e.It does not have to have a cross-section that is circular-cylindrical, rectangular or otherwise mirror-symmetrical to its longitudinal center plane or to the plane of symmetry over its entire radial dimension, in which the center of mass automatically and necessarily lies in the geometric plane of symmetry of the machining body, but can have any other shape, e.g. a U-shaped cross-section with a hollow or filled interior. This means that the center of mass of the machining body does not necessarily have to lie on its geometric plane of symmetry, but can be offset along the axis of rotation. In order to avoid the tilting moment on the pendulum bearing of the tool described above, which arises due to the asymmetry of the machining body, the tool - as a whole - is shaped in such a way that the center of mass of the entire tool still lies in the plane of symmetry.This allows any cross-section of the machining area to be selected that is more suitable (and less expensive to manufacture) than the familiar cylindrical cross-section without causing a tilting moment. The deviation of the machining area's shape from mirror symmetry with respect to the plane of symmetry is compensated for by the clever choice of the position of the mounting area.

[0011] In particular, the fastening area can be connected to the machining body by a bent connecting section in order to achieve the condition that the center of mass of the tool lies in the plane of symmetry. In this or another embodiment, however, this condition could also be achieved by additional balancing masses that compensate for an asymmetry of the machining body with respect to the plane of symmetry. In another embodiment, the plane of symmetry of the fastening area could simply be placed directly in the plane in which the center of mass of the (asymmetric) machining body lies. The features described in this paragraph could also be combined in any desired way.

[0012] In particular, the machining body may have a semicircular cross-section (solid or U-shaped), wherein an imaginary line connecting the ends of the two legs of the semicircle is oriented transversely or parallel to the axis of rotation or assumes an angle therebetween.

[0013] The machining body can be internally twisted in the section adjacent to the mounting area. This creates a smooth transition between the mounting area, which extends in the tool's plane of symmetry, and the outer section of the machining body, whose leading surface can extend more or less transversely to the tool's plane of symmetry and thus more parallel to the rotation axis.

[0014] Preferably, the tool is manufactured as a single piece, particularly by casting, forging, or pressing. However, it would also be conceivable to manufacture it as a welded or screwed assembly. Example

[0015] The drawings show an embodiment described in more detail below. They show: Fig. 1 is a side view of a harvesting machine with a harvesting header attached to which mulching devices are mounted, Fig. 2 is a perspective view of a mulching device from the front and below, Fig. 3 is an exploded view of the mulching device's mounting and tools, and Fig. 4a side view of a tool.

[0016] One in the Figure 1The agricultural harvesting machine 10 shown in the form of a self-propelled forage harvester is built on a frame 12 carried by front and rear wheels 14 and 16. The front wheels 14 serve as the main drive wheels, while the rear wheels 16 are steerable. The harvesting machine 10 is operated from a driver's cab 18, from which a harvesting attachment 20 is visible. Material picked up from the ground by the harvesting attachment 20, e.g., corn, is fed via an intake housing 30 to a chopper drum (not shown) inside the harvesting machine 10, which chops it into small pieces and feeds it to a conveyor device (also not shown). The crop leaves the harvesting machine 10 to a trailer traveling alongside via a discharge spout 28 that is rotatable about the vertical axis and adjustable in height. A secondary shredding device (not shown) can be arranged between the chopping drum and the conveyor device.Although the invention is illustrated here with a forage harvester, it can also be used on combine harvesters with associated harvesting attachments in the form of corn headers. In the following, directional references such as forward, rearward, sideways, and above refer to the forward direction of the harvesting machine 10 and the harvesting attachment 20, which are shown in the . Figure 1 runs to the left.

[0017] The harvesting attachment 20, which is attached in the forward direction to the front of the harvesting machine 10, serves to collect the harvested crop. In the embodiment shown, the harvesting attachment 20 is a known maize header, which comprises a central section 38 and two side sections 40 arranged to the left and right of the central section 38 (with respect to the forward direction of the harvesting machine 10). The side sections 40 are attached to the central section 38 so that they can be pivoted upwards for road transport and can be hydraulically pivoted down for harvesting so that they run parallel to the central section 38 during harvesting. They can then be pivoted up again. Figure 1shows the side parts 40 in the swung-up state. In the present embodiment, four harvesting units 32 with lower cutting discs for cutting the plants and upper conveyor discs for transporting the plants away are attached to the middle part 38, while two harvesting units 32 are attached to each of the two side parts 40. The harvesting header 20 is equipped in a conventional manner with stalk dividers 36, the harvesting units 32, dividing tips 34, cover plates, and conveyor means for feeding the harvested material to the chopper drum of the harvesting machine 10. During operation, the harvesting header 20 draws in the stalks of the crop in an upright position, cuts them off, and feeds them to the intake housing 30, from which they are conveyed to the chopper drum of the harvesting machine 10.

[0018] The harvesting header 20 comprises a support frame having a lower cross member 42 and an upper cross member 44. The lower cross member 42 extends at the bottom rear of the harvesting header 20 and comprises three segments, one of which is assigned to the central section 38 and one to each side section 40. Gear housings 46 are bolted to the front of the lower cross member 42, each of which serves to drive a harvesting unit 32. A drive shaft 48 for driving the harvesting units 32 via gears arranged in the gear housings 46, which also serves to drive the additional conveying means of the harvesting header 20 and is driven by an output shaft of the harvesting machine 10, extends laterally within the hollow lower cross member 42.

[0019] The upper cross member 44 extends laterally above the inlet of the feeder housing 30 across its width. It is connected to hook-shaped support elements, which are partially engaged by complementary support elements of the feeder housing 30 and serve to attach the harvesting header 20 to the harvester 10. It is connected to the lower cross member 42 by vertically extending supports and connecting plates. The support frame with the cross members 42, 44 and the vertically extending supports and connecting plates thus forms a skeleton of the harvesting header 20, which supports all other elements of the harvesting header 20.

[0020] A mulcher 50 is mounted behind each harvesting unit 32. The mulcher 50 is arranged with its axis of rotation laterally rearward of the axis of rotation of the associated harvesting unit 32. This is where the plants enter during normal harvesting. If a harvesting unit 32 harvests multiple rows of plants, it can be assigned several mulchers 50, whose axes of rotation are arranged rearward of the expected entry points of the rows of plants. It would also be conceivable to distribute the mulchers 50 seamlessly or with small gaps across the entire working width of the harvesting header 20.

[0021] It is now time to Figure 2 The mulching device 50 comprises two diametrically opposed tools 54, which are connected to a central holder 56 via pendulum bearings 58, oscillating around the vertical axis. The holder 56, in turn, is connected to a shaft 60 (see Figure 3), the axis of rotation of which extends parallel to the axes about which the tools are pivotally mounted by the pendulum bearings 58 on the holder 56.

[0022] The shaft 60 is connected at its lower end to the bracket 56 and at its upper end to a gear 62, which is driveably driven by the drive shaft 48. The shaft 60 is mounted so as to be freely pivotable about the axis of the drive shaft 48 relative to the drive shaft 48 and the lower cross member 42. A cover 64, which covers the mulching device to the rear and upwards behind the shaft 60, encloses the shaft 60 and moves with the shaft 60 and the mulching device 50 around the axis of the drive shaft 48, contouring the ground. Further details are described in EP 3 272 199 A1, the disclosure of which is incorporated by reference into the present documents.

[0023] The holder 56 comprises an upper part 68, which is connected to the shaft 60, and a lower part 66. The tools 54 are positioned between the two parts 66, 68. The two parts 66, 68 are connected to each other by the pendulum bearings 58.

[0024] The tools 54 each comprise a machining body 70 which extends radially outward from the pendulum bearings 58 (when the shaft 60 rotates and the tools 54 are pulled outward by centrifugal force and are not influenced by foreign bodies), and a fastening region 72 by which the pendulum bearings 58 are connected to the tool 54.

[0025] The two tools 54 are of identical construction and, in the assembled state, are rotated by 180° relative to each other with respect to an axis extending transversely to the longitudinal axis of the shaft 60, as shown in the Figures 2 and 3This eliminates the need for two different tools 54 for the mulching device 50, which simplifies spare parts management.

[0026] Based on the Figure 3 In the exploded view shown, it can be seen that the fastening areas 72 of the tools 54, which are centrally drilled to accommodate the bushings 74, are connected by bushings 74 to the upper part 68 and the lower part 66 of the holder 56. The bushings 74 are fixed by screws 78 and nuts 80. The lower part 66 of the holder 56 can be Figure 3 shown position, so that tabs formed thereon then form a stop which limits rotation of the tools 54 forwards.

[0027] It is now time to Figure 4 which shows a side view of a tool 54. In overall view with the Figures 2 and 3It can be seen that the fastening area 72 and the connecting area 74 are flat in themselves, although the latter is bent outwards and upwards. The machining body 70, on the other hand, has, for which reference is made in particular to the Figure 3 has an approximately U-shaped cross-section. The surface of the machining body 70 leading in the direction of rotation (during operation, the tools 54 rotate when they are Figure 3 The U-shaped section (viewed from above, clockwise) is thus convexly rounded to effectively shred the plant stubble. An imaginary line connecting the two outer ends of the U-shaped legs forms an angle of approximately 45° with the plane of the fastening area 72, although this angle could also be between 0 and 90°. Towards the inside, the leading section, which is in the Figure 3 The leg shown above slopes off and ends approximately at the beginning of the connecting area 74. The machining body 70 is, as can be seen in the Figure 3As can best be seen, it is twisted in its radially inner half. At the outer end, the machining body 70 is cut off at an angle, ie, it ends in a plane that forms an angle with the radius and with the plane of the fastening area 72.

[0028] From all of the above, it can be seen that the processing body 70 has a relatively complex shape, which enables optimal processing of the plant stubble with a given material expenditure and weight of the tool 54. The tool 54 can be manufactured, in particular, by casting, forging, or pressing. However, this asymmetrical shape relative to the horizontal longitudinal center plane of the tool 54 results in the center of mass 82 of the tool 54 (as a whole, see Figure 4) lies in a plane 86 which, without the offset 88 produced by the bent connection area 74 between the fastening area 72 and the machining body 70, would not lie in the plane of symmetry 90 which extends transversely to the axis of rotation 84 of the pendulum bearing and through the (in Figure 4 in the vertical direction) center of the fastening area 72.

[0029] By bending the connecting area 74, the center of mass 82 is located in the plane of symmetry 90 of the tool 54, so that no significant tilting moment results, which tends to keep the tool 54 in the plane of the drawing of the Figure 4 to twist and would have a detrimental effect on the service life of the self-aligning bearing. A crowned arrangement of the self-aligning bearing is therefore unnecessary.

Claims

1. Mulching apparatus (50) for working crop stubble in a field, wherein: the mulching apparatus (50) comprises a mounting (56) which is connected to a shaft (60) and can be set in rotation by the shaft (60), and two or more tools (54) for working the crop stubble, which are attached to the mounting (56) so as to be symmetrical to the shaft (60); and the tools (54) are mounted by pendulum mounts (58) so as to oscillate freely on the mounting (56), having pendulum axes that run parallel to the rotation axis of the shaft (60), have a fastening region (72) which is coupled to a mounting (56) so as to oscillate about a rotation axis (84) and through which, at half its height measured along the rotation axis (84), runs an imaginary symmetry plane (90) which is oriented orthogonally to the rotation axis (84), and comprise a working element (70) which is shaped to be asymmetrical in relation to the plane of symmetry (90) and has a blunt face which during operation extends in the rotating direction and is configured to shred the crop stubble in a field, characterized in that the tool (54) is shaped in such a manner that its centre of gravity (82) is in the plane of symmetry (90).

2. Mulching apparatus (50) according to Claim 1, wherein the fastening region (72) is connected to the working element (70) by way of a bent connecting portion (74) .

3. Mulching apparatus (50) according to Claim 1 or 2, wherein the working element (70) has a semicircular cross-section, and an imaginary line connecting the ends of the semicircle is oriented transversely or parallel to the rotation axis (84), or assumes an angle between them.

4. Mulching apparatus (50) according to one of Claims 1 to 3, wherein the working element (70) in its portion adjacent to the fastening region (72) is inherently twisted.

5. Mulching apparatus (50) according to one of Claims 1 to 4, wherein the tool (54) is manufactured in one piece, in particular by casting, forging or pressing.

6. Harvesting attachment (20) having a mulching apparatus (50) according to one of Claims 1 to 5.

7. Self-propelled harvesting machine (10) having a harvesting attachment (20) according to Claim 6.