CLEANING ASSEMBLY FOR A COMBINE HARVESTER

Description

[0001] The invention relates to a cleaning assembly for a combine harvester according to the preamble of claim 1. State of the art

[0002] Combine harvesters are used to harvest grain. The above-ground parts of plants, such as soybeans, wheat, or oats, are cut, collected, or stripped, or the seed heads of plants, such as corn or sunflowers, are separated and fed into a threshing and separating unit to separate the grain from the other components of the harvested crop. After the threshing and separating process, impurities such as straw particles and chaff remain in the grain. The mixture of grain and impurities obtained during threshing and separating is therefore conveyed to a cleaning system, which typically includes an upper and a lower sieve, and optionally a pre-sieve. A blower applies an airflow to the sieves from below. The sieves are also set in a reciprocating motion, moving back and forth and up and down along elliptical or circular paths.

[0003] Since the cleaning process relies at least partially on the effect of gravity and depends on the thickness of the mixture on the sieves, and a usable result is best achieved when the harvested material is homogeneously distributed across the width of the sieves, various arrangements have been proposed (in addition to sieves that swing back and forth laterally to even out the material distribution on the sieve) to distribute the harvested material as evenly as possible at the cleaning inlet.

[0004] GB 922 907 A describes a screw conveyor positioned before the discharge end of the conveying floor (which transports the mixture discharged from the threshing drum to the rear for cleaning). This conveyor is designed to move the crop to the left or right (uphill) if necessary, for example, when driving on a side slope, in order to ensure the cleaning unit is supplied with crop as homogeneously as possible across its width. Similar arrangements with screw conveyors at the discharge end of a conveying floor that transports the crop from the separator to the front for cleaning are described in US 3 581 746 A, EP 2 425 702 A1, and EP 3 501 259 A1. Conveyor belts positioned at this location for the transverse conveyance of the crop have also been proposed for this purpose (DE 24 54 315 A1, EP 2 425 702 A1).Another approach (US 5,338,257 A) involves arranging a chain around two sprockets with horizontal, forward-extending axes at the front end of a sieve. A number of fingers projecting rearward over the front of the sieve are attached to this chain. Depending on the lateral tilt of the combine harvester, the chain is set in motion to the left or right, with the fingers of the upper run moving uphill. The sieve is pressurized with air from below. DE 10 2008 017671 A1 discloses a cleaning assembly for a combine harvester. Task

[0005] It is evident from all of this that the existing transverse conveyors are located outside the airflow provided by the blower. They provide a certain conveying effect for the mixture in a lateral direction, which is based solely on mechanical action.

[0006] The present invention aims to achieve an improved cleaning effect. Solution

[0007] This problem is solved according to the invention by the teaching of claim 1, wherein further claims list features which advantageously develop the solution further.

[0008] A cleaning assembly for a combine harvester comprises a conveyor for transporting threshed and / or separated mixture of grain and impurities from a threshing and / or separating unit to an inlet of the cleaning assembly, screens for cleaning the mixture fed to the inlet of the cleaning assembly, which can be acted upon by a blower with an airflow, and a transverse conveyor arranged at the inlet of the cleaning assembly for evening the lateral distribution of the fed mixture. The transverse conveyor is of an open, air-permeable design and is arranged in an airflow supplied by the blower.

[0009] The air-permeable transverse conveyor is positioned within the airflow supplied by the blower. This offers the advantage that, firstly, devices located behind the transverse conveyor, such as louvers and / or finger rakes, can also be subjected to the airflow, thus achieving airflow-based separation of the mixture into particles and impurities right at the inlet of the cleaning assembly. Secondly, the open design of the transverse conveyor allows it to loosen and separate the mixture mechanically and through the airflow passing over the mixture at its top. Mixture passing through the spaces within the transverse conveyor is further separated by the airflow. This enhances the effectiveness of the cleaning assembly. Example of implementation

[0010] The drawings illustrate an embodiment of the invention, which is described in more detail below. It shows: Fig. 1 a schematic side view of a combine harvester, Fig. 2 a perspective view of the cleaning assembly of the combine harvester Figure 1 From left front and top, Fig. 3 a side view of the cleaning assembly, Fig. 4 an enlarged section from Figure 2 , and Fig. 5 a perspective view of the cross conveyor.

[0011] The Figure 1 Figure 1 shows a self-propelled harvesting machine in the form of a combine harvester 10 with a chassis 12, which is supported on the ground by driven front wheels 14 and steerable rear wheels 16 and is moved by these. The wheels 14 and 16 are set in motion by means of drive mechanisms (not shown) to move the combine harvester 10, for example, across a field to be harvested. In the following, directional terms such as front and rear refer to the direction of travel V of the combine harvester 10 during harvesting, which is shown in the Figure 1 runs to the left.

[0012] A detachable harvesting header 18, in the form of a cutting unit, is attached to the front end of the combine harvester 10. During harvesting, it harvests crops such as grain or other threshable cereals from the field and feeds them upwards and backwards through an inclined conveyor assembly 20 to an axial threshing unit 22. The mixture, containing grains and impurities, passes through threshing concaves and grates in the axial threshing unit 22 and enters a cleaning assembly 26. The cleaned grain is then conveyed by a grain auger to a grain elevator, which transports it into a grain tank 28. The cleaned grain from the grain tank 28 can be unloaded by a discharge system with a transverse auger 30 and a discharge conveyor 32. These systems are driven by an internal combustion engine and controlled by an operator from a driver's cab 34.The axial threshing unit 22 is only an embodiment and could be replaced by a tangential threshing unit with subsequent separation devices in the form of separator drums and / or straw shakers or axial separating rotors.

[0013] The cleaning assembly 26 comprises, in a manner known per se, an upper sieve 42 and a lower sieve 44, which are subjected to an airflow by a blower 40, with the airflow passing through the sieves 42 and 44 to the rear and upwards. The size of the sieve openings and the speed of the blower 40 can be changed in a manner known per se by an automatic cleaning setting or by the operator from the driver's cab 34.

[0014] The mixture of grain and impurities separated (threshed) from the crop in the front section of the axial threshing unit 22 is conveyed to the rear by a front conveyor 46, which thus serves to convey the threshed mixture. A rear conveyor 48 conveys the mixture separated (separated) in the rear section of the axial threshing unit 22 to the front.

[0015] At the discharge end of the front conveyor 46, a conveyor floor 56 is provided, followed to the rear by a transverse conveyor 50. Behind the transverse conveyor 50, a number of lamellae 52 are arranged one behind the other, extending transversely and diagonally upwards and backwards. Below the transverse conveyor 50 is another conveyor floor 54.

[0016] It will now be referred to as Figures 2 to 5Reference is made to the diagram. It can be seen that the front conveyor 46 comprises a number of augers 63 extending in the forward direction V and arranged laterally side by side. The conveyor floor 56, immediately following downstream, is located below the rear end of the front conveyor 46 and is offset forward at its front end. The conveyor floor 56 is equipped with transversely extending sawtooth profiles. Vertically extending partition plates 80 are arranged on the upper surface of the conveyor floor 56, positioned laterally centrally between two augers 63 of the front conveyor 46. These plates are intended to prevent the mixture from moving laterally on the conveyor floor 56, particularly when traversing a slope.

[0017] The rear conveyor 48 comprises a rear section with transversely extending sawtooth profiles 58 and a smooth front section 60 with vertically extending guide plates 62 that laterally merge the separated mixture. This mixture then enters the conveyor, as described in the Figure 3 As can be seen, on the cross conveyor 50. As in the Figure 2As shown, the front section 60 has a central cutout at its front end. The separated mixture is therefore fed to the transverse conveyor 50 primarily in its center. During operation, the rear conveyor 48 is set into a forward and backward as well as up and down oscillating motion, which applies analogously to the sieves 42, 44. For this purpose, the rear conveyor 48 can be suspended on swing arms and set into this motion by an eccentric drive. Depending on the position of the rear conveyor 48 and the lateral position of the material discharge, the harvested material discharged by the rear conveyor reaches the transverse conveyor 50 and / or the lamellae 52.

[0018] The conveyor floor 56, the cross conveyor 50 and to a certain extent also the lamellae 52 therefore form an inlet of the cleaning assembly 26.

[0019] Below the transverse conveyor 50, the further conveyor floor 54 is provided, which is equipped with transversely extending saw profiles. The transverse conveyor 50, together with the conveyor floor 56, the lamellae 52, and the rearward-extending finger racks 68 mounted behind the lamellae 52, forms an assembly that can be set into an oscillating motion, i.e., moves continuously forwards and backwards and up and down, analogous to the rear conveyor 48.

[0020] An upper outlet 74 of the blower 40, defined between an upper outlet wall 78 and a lower outlet wall 76, opens below the conveying floor 56. A lower outlet 94 of the blower 40 is directed towards the screens 42, 44.

[0021] The transverse conveyor 50 comprises a number of forward-extending carriers 64, each extending between two endless, internally toothed traction elements 84, which, as shown, are designed as belts but could also be designed as chains. The carriers 64 are designed as U-shaped profiles, which are attached to the traction elements 84 at their base, e.g., by bolting. The carriers 64 are chamfered at their front and rear ends. The two traction elements 84 each rotate around two front deflection pulleys 70 and two rear deflection pulleys 72, respectively. The deflection pulleys 70 and 72 are, in turn, rotatably mounted on brackets 90, which are themselves attached to a supporting frame of the aforementioned assembly consisting of the transverse conveyor 50, conveyor base 56, and slats 52. The two tensioning elements 84 can be tensioned by suitable means (such as springs and / or adjustable attachment to the brackets 90).

[0022] A drive arrangement comprising a motor 92, a shaft 88 coupled to it, and meshing bevel gears 85, 86 serves to drive the deflection wheels 70, 72 arranged on one side, which in turn drive the traction elements 84 by positive and / or non-positive engagement. The motor 92 can be driven electrically or hydraulically and connected to a drive energy source mounted on the chassis 12 via flexible lines guided in a loop. The associated chassis-side lines can be routed, in particular, in the cavity formed behind the outlet wall 76. Instead of a motor 92, a variable-speed and variable-direction (mechanical) drive train can also be used, which connects the shaft 88 to the internal combustion engine.

[0023] Support elements 96, extending across the width of the transverse conveyor 50 and bearing against the underside of the carriers 64 in front of and behind the upper runs of the traction elements 84, serve to support the traction elements 84 and prevent them from sagging or entering a vertical oscillating motion. A further support element 96 is located centrally below the center of the carriers 64 of the lower run of the transverse conveyor 50.

[0024] Based on the sensor-detected lateral tilt of the combine harvester 10 and / or a sensor-detected distribution of the material across the width of the cleaning assembly 26 and / or operator input via a suitable interface, the direction and speed of rotation of the motor 92 of the transverse conveyor 50 are automatically determined during harvesting in a manner known per se (see US 3,581,746 A, US 5,338,257 A, EP 3,501,259 A1) in order to even out the distribution of the harvested material at the inlet of the cleaning assembly 26. The upper run of the transverse conveyor 50 is driven in such a way that it moves towards the uphill side or towards the side where less of the mixture is present.

[0025] After all this, the following function of the cleaning assembly 26 results.

[0026] The threshed mixture, discharged from the rear end of the front conveyor 46, falls over a drop step onto the conveyor floor 56 and is conveyed from there to the rear, where it reaches the upper run of the transverse conveyor 50. The separated mixture discharged from the rear conveyor 48 also reaches this point.

[0027] The transverse conveyor 50 is supplied with an airflow from the front and bottom via the outlet 74 of the blower. This airflow flows rearward between the underside of the conveyor plate 56 and the top of the second conveyor plate 54. Due to its open design, with its carriers 64 suspended from endless tension members 84, the transverse conveyor 50, unlike a screw conveyor or a conveyor belt, is permeable to air in both the horizontal and vertical directions. This allows the airflow entering from the outlet 74 to pass through the mixture on the upper run and blow lighter impurities backward, while simultaneously allowing particles from the mixture conveyed above the upper run of the transverse conveyor 50 to fall downwards between the carriers 64.

[0028] From the top of the upper section of the transverse conveyor 50, the mixture is conveyed by the oscillating motion and the airflow to the following lamellae 52 and the finger racks 68. The lamellae 52 are also subjected to an airflow from the blower 40 from below, and a certain degree of separation occurs there as well for the mixture lying on them, which also applies analogously to the finger racks 68. The mixture then passes from the finger racks 68 onto the upper screen 44.

[0029] The grain and other components of the mixture, which fall downwards through the transverse conveyor 50 and between the lamellae 52, reach the further conveyor floor 54. This transports them to the rear discharge end, where they fall down a drop step and land on the lower sieve 42. This drop step is subjected to an airflow from the lower outlet 94 of the blower 40, which blows lighter impurities away to the rear.

[0030] In the event of uneven material distribution laterally within the cleaning assembly 26, the transverse conveyor 50 is activated by the motor 92. The upper section of the transverse conveyor 50 moves the threshed or separated incoming mixture to the side with less material. Due to the open design with endless traction elements 84 and carriers 64, material is gradually discharged across the entire width of the transverse conveyor 50. The operating speed of the motor 92 can be fixed or variable.

[0031] The start-up, direction of rotation, and speed of motor 92 can be controlled by operator input via a suitable interface in cabin 30. Additionally or alternatively, it would be conceivable to control them by an electronic control unit based on a sensor-measured material distribution on the screen or a representative parameter (i.e., based on feedback for the current material distribution value, so-called "closed-loop" control) and / or based on measured parameters that allow inferences about the current material distribution (i.e., without feedback, so-called "open-loop" control). The speed of motor 92 will increase with the greater the unevenness of the measured or expected material distribution.

[0032] For sensory detection of the current material distribution, the lateral distribution of the material on the sieve can be measured in a manner known per se (e.g. by means of a camera or a sensor that detects the airflow through the sieve) and / or the lateral distribution of the losses discharged at the rear end of the sieve and / or of the material entering a return conveyor, conveyed there to a secondary thresher or to the threshing unit, and / or of the grains separated by the sieve is detected (cf. EP 3 210 458 A1 or EP 3 482 624 A1).

[0033] To detect the expected material distribution using sensors, the lateral inclination of the combine harvester 10 can be detected by a sensor (not shown) or taken from a topographic map. Since the expected asymmetry in the material distribution increases with the steepness of the inclination and the throughput, the speed of the motor 92 will preferably depend on both input values ​​(inclination and throughput), e.g., be proportional to their product.

[0034] The lower section of the transverse conveyor 50 moves in the opposite direction, so there is a potential risk of it conveying material in the wrong direction. For this reason, the height of the lower section above the intermediate conveyor platform 54 is chosen such that, under normal operating conditions, the material on the intermediate conveyor platform 54 is located below the lower section of the transverse conveyor 50. Material falling from above onto the carriers 64 of the lower section will fall off the smooth surfaces of the carriers 64 on their sides adjacent to the endless traction elements 84 and will not be carried in the wrong direction, or at least not to a significant degree.

[0035] To prevent material from falling through the upper run onto the lower run and being conveyed in the undesired direction, a planar separating element 98 could be inserted in the middle plane of the transverse conveyor 50, as is done in the Figure 3 shown schematically.

[0036] The open design of the transverse conveyor 50 with endless traction elements 84 ensures that the airflow from the blower 40 can pass horizontally through the transverse conveyor 50 to the lamellae 52 and the finger racks 68. Furthermore, the transverse conveyor 50 enables a certain separation of grain and impurities and a gradual discharge of the conveyed material across the width of the cleaning device 26.

Claims

1. Cleaning assembly (26) for a combine harvester (10), comprising: a conveyor (46, 48) for transporting a threshed and / or separated mixture of grain and contaminants from a threshing and / or separating device (22) to an inlet of the cleaning assembly (26), screens (42, 44) for cleaning the mixture fed to the inlet of the cleaning assembly (26), which are able to be subjected to the action of an air flow by a fan (40), and a cross conveyor (50), arranged at the inlet of the cleaning assembly (26), for evening out the lateral distribution of the fed mixture, characterized in that the cross conveyor (50) is embodied with an open, air-permeable design and is arranged in an air flow provided by the fan (40).

2. Cleaning assembly (26) according to Claim 1, wherein the cross conveyor (50) comprises an endless traction means (84) having drivers (64) distributed in a spacedapart manner along the length of the traction means (84), wherein the traction means (84) circulates about deflection wheels (70, 72).

3. Cleaning assembly (26) according to Claim 2, wherein the cross conveyor (50) comprises two traction means (84) arranged one behind the other and the drivers (64) are each connected to both traction means (84).

4. Cleaning assembly (26) according to Claim 2 or 3, wherein the drivers (64) have a U-shaped profile which is upwardly open when the respective driver (64) is located on the upper strand of the cross conveyor (50).

5. Cleaning assembly (26) according to one of Claims 2 to 4, wherein the drivers (64) of the lower and / or upper strand of the cross conveyor (50) are supported on support elements (96) which extend in a lateral direction.

6. Cleaning assembly (26) according to one of the preceding claims, wherein the air flow flows against and through the cross conveyor (50) substantially horizontally.

7. Cleaning assembly (26) according to Claim 6, wherein a number of slats (52) are arranged to the rear of the cross conveyor (50), which are able to be flowed through by the air flow that has previously flowed through the cross conveyor (50).

8. Cleaning assembly (26) according to Claim 7, wherein a finger rake (68) is arranged to the rear of the slats (52), which is able to be flowed through by the air flow that has previously flowed through the cross conveyor (50).

9. Cleaning assembly (26) according to one of the preceding claims, wherein a conveyor floor (56) is mounted upstream of the cross conveyor (50), onto which conveyor floor a conveyor (46) dispenses a mixture from the threshing device via a drop step.

10. Cleaning assembly (26) according to one of Claims 7 to 9, wherein a further conveyor (54) is arranged beneath the cross conveyor (50) and the slats (52), said further conveyor conveying the material dropping onto it towards the rear and dispensing it onto the front region of a lower screen (42) via a drop step.

11. Cleaning assembly (26) according to Claim 10, wherein the lower strand of the cross conveyor (50) is arranged at a height above the further conveyor (54) that is measured such that the lower strand does not appreciably convey material located on the further conveyor (54) to the side.

12. Cleaning assembly (26) according to one of the preceding claims, wherein the cross conveyor (50) is able to be set into a vibrating motion, in particular together with the slats (52) and / or the finger rake (68) and / or the conveyor floor (56) and / or the further conveyor floor (54).

13. Cleaning assembly (26) according to one of the preceding claims, wherein a planar separating element (98) is fitted in the central plane of the cross conveyor (50) in order to prevent material dropping through the upper strand of the cross conveyor (50) onto the lower strand and being conveyed in the undesired direction.

14. Cleaning assembly (26) according to one of the preceding claims, wherein the direction and speed of rotation of a drive, in particular of a motor (92), of the cross conveyor (50) are able to be predefined on the basis of a lateral inclination, sensed by a sensor and / or taken from a topographical map, of the combine harvester (10) and / or a distribution, sensed directly or indirectly by a sensor, of the material across the width of the cleaning assembly (26) and / or an operator input via a suitable interface.

15. Combine harvester (10) having a cleaning assembly (26) according to one of the preceding claims.