CUTTING MECHANISM WITH MULTI-PART HEIGHT-ADJUSTABLE HOOP

Description

[0001] The present invention relates to a cutting unit for attachment to a harvesting machine according to the preamble of claim 1.

[0002] Whenever "front" and "rear" are mentioned in this description, these terms always refer to the working direction of the header. The working direction is the direction in which the header is moved to cut the crop.

[0003] From DE 10 2015 109 191 A1, a cutting unit is known which is composed of several frame parts, each extending over a partial working width and which are articulated to one another around an axis extending at least approximately in the working direction of the cutting unit. In the exemplary embodiment shown in this document, a central frame part is disclosed which is articulated to two lateral frame parts. The cutting unit disclosed in this document can have conveying surfaces formed by revolvingly driven conveyor belts of a draper cutting unit, which convey the cut crop from the respective intersection point on the cutter bar as a cutting element to a central and rearwardly arranged discharge point. In this way, the conveyor belts simultaneously form conveying elements, and the conveying surface and the upwardly facing surface of the conveying elements are located in an identical plane.Instead of conveyor belts, the cutting unit can also have a rigid sheet metal base as a cutting unit trough, which defines the conveying surface and over which the cut crop is conveyed away using a conveyor screw as the conveying element.

[0004] In particular, a three-part, height-adjustable reel is disclosed as a conveying device. The three reel parts are held by four reel support arms that are pivotably connected to the frame and act on them as adjustment motors for adjusting the height of the reel support arms and thus the reel parts in the vertical direction. To achieve synchronization during the height adjustment of the reel support arms, the hydraulic cylinders are interconnected in a hydraulic circuit in the manner disclosed therein. However, the hydraulic system as a whole is comparatively complex. One aim of the invention is to reduce the manufacturing costs for a cutting device of this type.

[0005] DE 10 2017 113 775 A1 also discloses a three-part cutting unit with a three-part reel. It is pointed out here that the conveyor screw in the outer frame section should be designed to be adjustable in length in the axial direction when an outer frame section pivots relative to the middle frame section, in order to achieve better conveying performance without a buildup of material in certain areas on the conveying surface. This document does not explain how a reel with multiple reel sections could be adapted to such pivoting movements without incurring excessive structural and financial expenditure.

[0006] It is the object of the present invention to increase the conveying capacity of the cutting unit at lower costs.

[0007] The problem is solved for a generic cutting device by the characterizing features of claim 1.

[0008] The torsion shaft connects at least two reel support arms in a rotationally fixed manner, so that the pivoting movement of these two reel support arms no longer needs to be coordinated. Using just a single adjustment drive, such as a hydraulic cylinder, the height of at least two reel support arms can be adjusted simultaneously. The reel section, which is held by these two reel support arms, always moves up and down with both ends in the same direction and by the same angular degrees. If the torsion shafts of adjacent reel sections are rotationally fixedly connected to one another, one adjustment drive can be sufficient to adjust the height of at least two reel sections. This is done by transferring the rotational movement of one torsion shaft to the other torsion shaft, thereby adjusting the height of the reel support arms that are rotationally fixedly connected to this torsion shaft in the same direction and by the same amount.The construction effort required to ensure synchronous running of the reel support arms carrying one or more reel parts can thus be eliminated or at least significantly reduced.

[0009] The axial bearing of a torsion shaft is problematic because the torsion shaft is positioned at a height at which it is vertically spaced from the axis around which adjacent frame sections of the cutting unit pivot relative to each other. Due to the vertical distance of the torsion shaft from the axis and the circular arc around which the frame section pivots relative to the adjacent frame section, relative length differences arise between the ends of the frame section and the end of the torsion shaft at different pivot positions if the torsion shaft is intended to follow the movements of the frame section and has a fixed bearing point on both sides in the axial direction of the torsion shaft.Because the torsion shaft has a fixed bearing point on a first side in the axial direction of the torsion shaft and is mounted in a plain bearing on a second side, the torsion shaft can move in the axial direction relative to the frame part to which the reel part is at least partially assigned. The plain bearing refers to a bearing that allows a sliding movement between the torsion shaft and the frame part on which the plain bearing is mounted. The plain bearing can consist of sliding surfaces that are at least partially adapted to the circumferential shape of the torsion shaft. For example, plastic shells can be used as plain bearings. However, roller or ball bearings can also be used, which allow relative movement between the torsion shaft and the frame part.The reel part is thus kept stress-free, regardless of the pivot position of the frame part relative to an adjacent frame part, and can therefore better adapt to pivoting movements of the associated frame part. The fixed bearing point on a first side in the axial direction of the torsion shaft can consist of a fixed bearing, a ball or universal joint, a gear, or the like. A ball or universal joint can connect the torsion shaft to an adjacent torsion shaft of an adjacent reel part.

[0010] According to one embodiment of the invention, one or more inner reel support arms carry several reel sections. For example, if a reel has two reel sections, the middle reel support arm carries the inward-facing shaft stubs of the reel shafts of the two reel sections; if there are three reel sections, the two inner reel support arms each carry the inward-facing shaft stub of the outer shaft sections as well as one of the two shaft stubs of the middle reel section. This makes it possible to reduce the number of reel support arms installed. By designing only the middle, one of the two middle reel support arms, or both middle reel support arms with an adjustment drive that is height adjustable, the height of two or three reel sections can be adjusted with just one or two adjustment drives. The number of hydraulic valves used and the pressure lines to be laid in the cutting unit, as well as their length, are considerably reduced.

[0011] According to one embodiment of the invention, an adjustment drive engages an internal reel support arm. The more internal arrangement of the adjustment drive reduces the load on the frame. An adjustment drive arranged on the outside of a cutting unit would load the cutting unit's mounting frame with a leverage force acting across half the cutting unit's working width, which could be further amplified by dynamic oscillations of the cutting unit. A further advantage is that the outer ends of the cutting unit offer more free space for drives and bearings of other cutting unit components, such as augers, belt conveyors, cutting elements, and the like.The adjustment drive may be located on the rear of the cutting unit and may engage a lug that projects beyond the circumference of the torsion shaft and is connected to the torsion shaft and / or the reel support arm.

[0012] According to one embodiment of the invention, one or more reel support arms are designed as an elastically spring-loaded element along the working width. Reel support arms are typically made of rigid and essentially inelastic tubes or profiles. By manufacturing the reel support arms as an elastically spring-loaded element, they can easily compensate for an axial offset along the working width of the cutting unit between the reel shaft of a reel section and the torsion shaft, to which the reel support arms are non-rotatably attached, through an elastic spring movement without permanent deformation in the offset direction. The elastically spring-loaded element is designed in terms of its component dimensions—material selection, material thickness, and web height—so that, with its elasticity, it can accommodate the possible offset paths of a reel section in relation to the associated frame part without permanent deformation.The elastically springy element builds up restoring forces, which cause the elastically springy element to return to its normal position when the axial offset between the torsion shaft and the reel shaft is eliminated. The elastically springy element is installed in the cutting unit in such a way that the flat surface of the elastically springy element faces the reel parts and the correspondingly thin material layer of the elastically springy element allows for lateral spring movement. The web of the elastically springy element is arranged in an at least approximately vertical orientation, so that the elastically springy element bears the weight of the reel parts it carries in the vertical direction without performing any major elastic spring movements.The elastically spring-loaded element can be made of a metallic material, such as spring steel, or a plastic, which can also be fiber-reinforced, that exhibits spring behavior that meets the requirements. In a reel with three reel sections, it may be sufficient to design only the two outer reel support arms as elastically spring-loaded elements, because the various adjustable height differences between the reel shaft and the torsion tube, in conjunction with the angling or sloping of the side frames, only lead to relative movement here.

[0013] According to one embodiment of the invention, the torsion shaft serves as a bracket for attaching the rear wall of the cutting unit. Since the torsion shaft extends at the rear of the cutting unit at a vertical distance from the conveying surface over a partial working width of the cutting unit, it is possible to use the torsion shaft to attach the rear wall of the cutting unit to it. The rear wall can be designed as a simple sheet metal that laterally limits the conveying path of the crop from the cutting elements to the discharge point and protects it against crop loss. The upper end of the rear wall of the cutting unit can be supported at the top on the torsion shaft. This eliminates the need for additional components and reduces the weight of the cutting unit.

[0014] According to one embodiment of the invention, the reel has three reel sections, of which the two outer reel sections are supported by a respective reel support structure. At least one of the two reel support structures is height-adjustable by an adjustment drive, and the two reel support structures are synchronized with each other in their adjustment movements via an intermediate shaft connected to them in a rotationally fixed manner. The intermediate shaft is a mechanically simple, yet highly resilient and cost-effective way of synchronizing the movements. The reel with all three reel sections then always moves in the same direction with the same stroke lengths. The rotationally fixed connection of the outer torsion shafts to the intermediate shaft can be achieved, for example, via cardan joints, so that the lateral frame sections can pivot up and down in relation to the central frame section in order to adapt to uneven ground contours.The torsion shafts can thus follow the pivoting movements of the frame parts. The universal joint then forms the pivot axis of the torsion shafts to the intermediate shaft.

[0015] According to one embodiment of the invention, the adjustment drive is designed as a hydraulic drive whose hydraulic circuit can be locked via hydraulic valves. Locking the hydraulic drive via the hydraulic circuit lock can be used as a protective measure against the risks posed by falling objects during maintenance work. Previously, to ensure maintenance work was carried out, it was necessary to move the reel with the reel support arms to the uppermost position and then engage mechanical locks on each individual reel support arm to secure the reel against accidental falling. Once maintenance work is completed, all mechanical locks must be removed. This is a considerable time-consuming process because the driver has to walk around the entire cutting unit several times, inserting and removing locks at various positions.Such maintenance work may be necessary several times a day, for example, to replace broken knife blades or clear blockages in the cutting unit. The considerable time required and the resulting loss of machine efficiency pose the risk that machine users will forgo the mechanical safety devices during maintenance work because they consider them too complex. The hydraulic locking system uses a hydraulic valve to block the hydraulic lines to and / or from the adjustment drive, which is a hydraulic cylinder. If the hydraulic lines and cylinders are blocked, a hydraulic adjustment drive can no longer move if the flow of hydraulic fluid has been blocked in the hydraulic valve.The hydraulic valves can be electrically controlled valves that, when the power supply is interrupted, are forced into a closed position by a mechanical spring return. The hydraulic valves can be disconnected from the power supply by activating a safety switch. This means that, to protect against risks from suspended loads, it is sufficient for the harvester driver to press the safety switch at the beginning of maintenance work. This cuts off the electrical supply and secures the reel against hazards from suspended loads. This saves the driver considerable time. The lock can be released by using the safety switch to restore power to the hydraulic valves. It is no longer necessary to go to each individual reel support arm and attach and remove mechanical safeguards.All it takes is a single safety switch, which can be done while passing by the machine if the switch is conveniently located. The quick and easy activation and deactivation of the safety switch makes it more likely that the safety switch will actually be activated when needed.

[0016] According to one embodiment of the invention, the adjustment drive is designed as a hydraulic drive in which a stroke limiter for one or more hydraulic cylinders can be activated by electrically controlling hydraulic valves that create the stroke limiter. A stroke limiter for the reel is useful to ensure that the reel tines attached to the reel do not come into the effective range of the knife blades of the cutter bar when the reel is lowered too low. Depending on how flexibly the cutter bar is mounted on the cutting unit, different distances can be useful. For example, with a rigidly mounted cutter bar, a distance of 50 mm between the reel tine tips and the cutter bar can be considered appropriate to eliminate the risk of the reel tine tips getting caught in the cutter bar and being cut off, or of the cutter blades breaking off.However, if the cutter bar is mounted on height-adjustable rockers to better adapt to the ground contours, a minimum distance of, for example, 200 mm may be appropriate. Depending on the mode in which the header is operated, the hydraulic valves can be electrically switched and controlled in accordance with the selected operating mode so that the stroke limit appropriate for the current operating mode is activated. The stroke limit can be automated via the machine's own or harvester-side software, or activated by operator input.

[0017] According to one embodiment of the invention, the adjustment drive comprises electrically or pneumatically operated actuators. As described above and in the following description, the adjustment drive may comprise hydraulic actuators, such as hydraulic cylinders, which are commonly used as motor drives in agricultural technology today. However, it is also possible to use electric or pneumatic drives instead of hydraulic drives.

[0018] Further features of the invention emerge from the claims, the figures, and the description of the figures. All features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective specified combination, but also in other combinations or even on their own.

[0019] The invention will now be explained in more detail using a preferred embodiment and with reference to the accompanying drawings.

[0020] They show: Fig. 1: a view from the front of a cutting unit, Fig. 2: a view from the front of a supporting structure without reel parts, Fig. 3: the Fig. 2 shown supporting structure without intermediate shaft from a different perspective, and Fig. 4: a detailed view of a side wall of the cutting unit.

[0021] In Fig. 1A frontal view of a cutting unit 2 is shown. The cutting unit 2 has a working width of 4. The cutting unit 2 consists of a frame 6 formed from three frame sections 8a, 8b, 8c. Each frame section 8a, 8b, 8c covers a corresponding partial working width 10a, 10b, 10c. The two outer frame sections 8a, 8c are pivotable relative to the central frame section 8b about the axes 12, which extend in the working direction A of the cutting unit 2.

[0022] Attached to the front of the cutting unit 2 is a cutter bar serving as a cutting element 14. The cutter bar is oscillatingly driven and has a number of knife blades that cut the standing crop in the field. As the harvester advances into the standing crop, the cut crop falls onto the conveyor surfaces 16 in the cutting unit 2. The crop is transported from the cutting elements 14 to the discharge point 20 by conveyor elements 18 – in the illustrated example, the two outer belt conveyors 18a, 18c, which transport the cut crop transversely to the working direction to the center of the cutting unit 2, and the belt conveyor 18b, which transports the crop accumulated in the central area of ​​the cutting unit 2 to the rear. At the discharge point 20, the cut crop is transferred to the harvester.

[0023] To ensure that the stalks of the harvested crop feed smoothly into the cutting element 14 during cutting, do not fall off to the side, and are deposited smoothly on the conveyor surface after cutting, a rotating reel 22 is located above the cutting element 14. In the illustrated embodiment, the reel 22 is divided into three parts: 24a, 24b, and 24c. The reel support arms 26b and 26c are located in the area of ​​the separation points between the reel parts 24a, 24b, and 24c. As it rotates, the reel 22 engages the grain stalks and throws them onto the conveyor surface 16 in the opposite direction of travel A.

[0024] The reel parts 24a, 24b, 24c are held by the reel support arms 26a, 26b, 26c, 26d. The centrally arranged reel part 24b is held by the reel support arms 26b, 26c, which also hold the inward-facing shaft stubs of the reel shafts of the outer reel parts 24a, 24c. The reel support arms 26b, 26c each support the shaft stubs of two reel parts, while the outer reel support arms 26a, 26d only support the outward-facing shaft stubs of the outer reel parts 24a, 24c. The reel support arms 26 are vertically adjustable in the direction of the double arrow, resulting in a different height position of the reel 22. The reel parts 24a, 24b, 24c are additionally adjustable in the horizontal direction, which is also indicated by a corresponding double arrow.

[0025] In Fig. 2is a diagonal front view of a cutting unit 2 without the frame 6, the reel parts 24a, 24b, 24c, and other components. In this reduced representation, it is clearly visible that the reel support arms 26a, 26b are adjustable via the adjustment drive 28a, and the reel support arms 26c, 26d are adjustable via the adjustment drive 28b. The reel support arms 26a, 26b are connected to one another via the torsion shaft 30a, while the reel support arms 26c, 26d are connected to one another via the torsion shaft 30b. An adjustment movement exerted by an adjustment drive 28a, 28b on a reel support arm 26b, 26c is also transmitted to the reel support arms 26a, 26d via the torsion shafts 30a, 30b. The reel support arms 26a, 26b with the torsion shaft 30a, as well as the reel support arms 26c, 26d with the torsion shaft 30d, each form a reel support structure to support the reel parts 24a and 24c. The reel support arms 26b, 26c can also support the middle reel part 24b.The middle reel part 24b is then pivoted together with the reel parts 24a, 24c, depending on how the reel support arms 24b, 24c move.

[0026] Since the frame parts 8a, 8d are pivotable about the axes 12 around the central frame part 8b, and since the torsion shafts 30a, 30b are arranged vertically spaced from the axes 12, corresponding pivoting movements result in length differences at the outer ends of the torsion shafts 30a, 30b relative to the outer ends of the associated frame parts 8a, 8c, which are indicated by the respective double arrows. The torsion shafts 30a, 30b are held and supported at fixed bearing points 34. In the exemplary embodiment, the fixed bearing points 34 are designed as universal joints, via which the torsion shafts 30a, 30b are connected to one another in a rotationally fixed manner via an intermediate shaft 36. In order to compensate for relative movements between the frame parts 8a, 8c and the torsion shafts 30a, 30b in the axial direction of the torsion shafts 30a, 30b, the torsion shafts 30a, 30b are connected at their outer ends to the frame parts 8a, 8c via plain bearings 38.The torsion shafts 30a, 30b can therefore slide in their axial direction in the plain bearings 38.

[0027] Out of Fig. 2 It can be seen that a rear wall 40, shown in dashed lines, can also be attached to the torsion shaft 30a.

[0028] In Fig. 3 is that in Fig. 2 simplified cutting unit 2 is shown with supporting structures 32, which are not connected by an intermediate shaft 36. In the Figure 3 However, the hydraulic cylinders 42 are visible in the view shown, which in the exemplary embodiment form the respective adjustment drives 28a, 28b. The hydraulic cylinders 42, together with the hydraulic lines 44, the hydraulic valve 46 and the hydraulic pump 48, form a hydraulic drive 50. In Fig. 3For reasons of graphic simplification, the hydraulic lines 44 are shown only as a single line. However, it is understood that the hydraulic lines 44 are designed in a hydraulic circuit with corresponding supply and return lines and correspondingly designed hydraulic valves 46.

[0029] The hydraulic circuit to the hydraulic cylinders 42 can be completely locked, for example, via a hydraulic valve 46. This is possible using a 2 / 2-way valve. In the closed position of the 2 / 2-way valve, it blocks any flow of hydraulic fluid, so that the hydraulic cylinders 42 are locked in their current extended position. The hydraulic circuit thus acts as a static safety device for the suspended load from the reel 22, under which maintenance work can then be carried out, such as replacing knife blades on the cutting element 14 or removing material buildup on the conveying surfaces 16 or on the conveying elements 18. The 2 / 2-way valve can be controlled electrically, for example, by an operating electronics unit 52.The operating electronics 52 can be designed as a switch with which a simple on / off switching is possible, or it can be a more complex operating electronics 52 in which software-supported operating inputs are possible via buttons or touch control surfaces on a control panel.

[0030] In Fig. 4 A detailed view of the outer end of the frame part 8c is shown. The reel support arm 26d is designed as a flat steel sheet, which forms an elastically springy element 54, which can elastically spring at its outer tip in the direction of the double arrow shown there, transverse to the working direction A. The elastically springy element 54 makes it possible for the reel part 24c as well as the torsion shaft 30d to change their position relative to the frame part 8c. The pivoting movement of the frame part 8c is in Fig. 4 also indicated by a double arrow.

[0031] The invention is not limited to the above embodiments. Those skilled in the art will have no difficulty modifying the embodiments in a manner they deem appropriate to adapt them to a specific application. List of reference numbers

[0032] 2 Cutting unit 4 Working width 6 Frame 8 Frame section 10 Partial working width 12 Axle 14 Cutting element 16 Conveyor surface 18 Conveyor element 20 Discharge point 22 Reel 24 Reel section 26 Reel support arm 28 Adjustment drive 30 Torsion shaft 32 Reel support structure 34 Bearing point 36 Intermediate shaft 38 Slide bearing 40 Rear wall 42 Hydraulic cylinder 44 Hydraulic line 46 Hydraulic valve 48 Pump 50 Hydraulic drive 52 Operating electronics 54 Elastic spring element

Claims

1. Cutting device (2) for attachment to a harvester with a frame (6) extending substantially over the working width (4) of the cutting device (2) and comprising several frame parts (8a, 8b, 8c) which each extend over a partial working width (10a, 10b, 10c) and which are connected to one another for articulated movement about an axis (12) extending at least approximately in the working direction (A) of the cutting device (2), with cutting elements (14) arranged on the front side of the cutting device (2) and connected to the frame (6), with conveying surfaces (16) and conveying members (18) for conveying the cut crop from the cutting elements (14) to a delivery point (20), at least one conveying member (18) is a multi-part reel (22) whose reel parts (24a, 24b, 24c) each extend transversely to the working direction (A) of the cutting device (2) over at least a partial working width (10a, 10b, 10c) of the cutting device (2), and the reel parts (24a, 24b, 24c) are held by reel support arms (26a, 26b, 26c, 26d) which are attached for pivotal movement on the frame (6) or frame parts (8a, 8b, 8c) and which are adjustable in height via adjustment drives for adjusting the height of the reel parts (24a, 24b, 24c), at least two reel support arms (26) supporting a reel part (24a, 24b, 24c) are connected rotationally secured to one another via a torsion shaft (30a, 30b), the reel support arms (26a, 26b, 26c, 26d) and the torsion shaft (30a, 30b) form a reel support unit (32), the reel support unit (32) is connected to an adjustment drive (28a, 28b) which engages on one or more reel support arms (26a, 26b, 26c, 26d) and / or the torsion shaft (30a, 30b) and during adjusting movements of the remote-controlled adjustment drive (28a, 28b) the associated the associated reel part (24a, 24b, 24c) is raised or lowered, characterized in that the torsion shaft (30a, 30b) on a first side has a fixed bearing point (34) in the axial direction of the torsion shaft (30a, 30b) which is formed as a universal joint, and on a second side is mounted in a plain bearing (38) which permits a pushing movement between the torsion shaft and the frame part so that the torsion shaft can move in the axial direction in relation to the frame part with which the reel part is associated at least in part.

2. Cutting device (2) according to Claim 1 characterized in that one of the inwardly placed reel support arms (26a, 26b, 26c, 26d) support several reel parts (24a, 24b, 24c).

3. Cutting device (2) according to Claim 1 or 2 characterized in that an adjustment drive (28a, 28b) engages on an inner reel support arm (26a, 26b, 26c, 26d).

4. Cutting device (2) according to one of the preceding claims characterized in that one or more reel support arms (26a, 26b, 26c, 26d) is / are designed as an elastically resilient element (54) along the working width (4).

5. Cutting device (2) according to one of the preceding claims characterized in that the torsion shaft (30, 30b) serves as a holder for attaching the back wall (40) of the cutting device.

6. Cutting device (2) according to one of the preceding claims characterized in that the reel has three reel parts (24a, 24b, 24c) of which the two outer reel parts (24a, 24c) are supported by a reel support unit (32), at least one of the two reel support units (32) is adjustable in height by an adjustment drive (28a, 28b), and the two reel support units (32) are synchronized in their adjusting movements relative to one another by way of an intermediate shaft (36) which is connected rotationally secured thereto.

7. Cutting device (2) according to one of the preceding claims characterized in that the adjustment drive (28a, 28b) is formed as a hydraulic drive (50) whose hydraulic circuit can be locked by means of hydraulic valves (4).

8. Cutting device (2) according to one of the preceding claims characterized in that the adjustment drive (28a, 28b) is formed as a hydraulic drive (50) wherein a stroke restriction of one or more hydraulic cylinders (42) can be activated by an electric control of hydraulic valves (46) providing the stroke restriction.

9. Cutting device (2) according to one of the preceding claims 1 to 6 characterized in that the adjustment drive (28a, 28b) has electrically or pneumatically operated servo motors.