CUTTING MACHINE FOR STRAIGHT-SHAPED AGRICULTURAL CROPPED CROPS

Description

[0001] The invention relates to a cutting device for straw-shaped agricultural crops according to the preamble of claim 1. State of the art

[0002] With crop harvesters such as balers and forage wagons (see US 2022 / 266437), there is often a need to cut the harvested crop into shorter pieces before storage. This is achieved using cutting units with a number of laterally arranged knives that extend into a channel through which the crop is conveyed by a rotor. Typically, the rotor operates undershot, and the knives extend into the channel from below, but the reverse arrangement is also possible.

[0003] In a common embodiment, the knives are each individually rotatably supported at their upstream ends about an axis extending horizontally and transversely to the flow direction of the crop and are held in their active position by a roller. The roller engages in a recess formed on the rear flank of the knife. The roller is pre-tensioned into the recess by the force of a spring. This allows the knives to deflect downwards in the event of an overload, for example, if a blockage or foreign object (stone, metal part, etc.) passes through the channel. The roller and spring automatically return the knives to their original position in the channel as soon as the overload is removed. Such cutting devices are described, for example, in DE 38 16 204 A1 and DE 43 02 199 A1.

[0004] The knives are held in a working position by the spring and the roller. A (first) actuator interacts with a lever holding the roller, allowing the lever to be rotated so that the roller disengages from the recess. Gravity or the flow of the harvested crop then moves the knife into its lower, inactive position. In this way, some or all of the knives can be moved into an inactive position, depending on the desired cutting length. As long as the tips of the knives in the working position do not contact the upper wall of the channel (DE 38 16 204 A1) or a scraper (EP 3 275 303 A1), they can also move upwards from the working position against the force of the spring by a certain angle, since the back wall of the knife below the recess has a convex shape (cf. DE 43 02 199 A1).For maintenance purposes or to facilitate the removal of blockages, embodiments of such cutting units are mounted on a frame (a so-called drop floor) which is pivotally mounted at its upstream end relative to the channel about a transverse axis (WO 2020 / 240427 A1). A (second) actuator allows the frame to be pivoted downwards, enabling maintenance work such as replacing or sharpening the blades and clearing blockages. US 7,404,284 B2 discloses a baler with a cutting device that can be lowered together with a guide surface and also moved transversely to the conveying direction. The cutting device is adjustable relative to the guide surface. Task

[0005] In the prior art, where the pivoting frame with the attached knives can be moved into a downward-pivoted maintenance position (see WO 2020 / 240427 A1), there is a risk that crop material will become jammed between, on the one hand, the rotor and / or the slots in the frame through which the knives extend upwards, and on the other hand, one or more of the knives. If the frame is then pivoted downwards from the operating position to the maintenance position by the (second) actuator, the knives are pulled even further upwards as they are held in place by the crop material. Even if the roller is pulled out of the recess by the (first) actuator, the jammed knives do not move downwards but remain in the aforementioned position, which is still raised compared to the working position.This has the disadvantageous consequence that the jammed blades strike the rotor when the frame is lifted, damaging both the rotor and themselves. If the roller is not pulled out of the recess by the actuator, it can even come into contact with the underside of the blade, locking the blade in the aforementioned position and causing further damage to the blade and rotor when the frame is lifted.

[0006] A movement of the knives from the working position to the aforementioned position, even further than in the working position from the position swung out of the channel, can occur, as long as this movement is not prevented by other means (DE 38 16 204 A1, EP 3 275 303 A1), which, however, entail additional effort and restrict the cross-section of the channel, even when the harvested material is conveyed backwards in the channel, e.g., to clear a blockage by reversing. In such cases, the knife can, for example, become jammed on a rotor.

[0007] The problem underlying the invention is seen as avoiding at least some of the aforementioned disadvantages. Solution

[0008] 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.

[0009] A cutting unit for straw-like agricultural crops thus comprises a number of knives arranged side by side transversely to a channel through which crop flows in one direction during normal operation. The knives are pivotally mounted on a frame of the cutting unit on their upstream side within the channel about a pivot axis extending transversely to the channel, allowing them to move between a working position and a position swung out of the channel. The movement of the knife from the working position into the channel (i.e., even further than in the working position from the position swung out of the channel) is limited by a stop rigidly connected to the frame, which interacts with an edge of the knife. The edge of the knife interacting with the stop is located on its upstream side and above the pivot axis.

[0010] The knives are associated with levers that are rotatably supported on the frame about an axis parallel to the pivot axis and are movable about the axis between a working position, in which they hold their assigned knife in an active position extending into the channel, and a disengaged position, in which they do not hold the knife in the active position. Springs are associated with the levers that bias the corresponding lever into the working position. The knives are provided with a recess on their rear edge, spaced away from the pivot axis, into which a roller coupled to the lever engages in the working position of the knives. The recess is shaped such that, when forces acting on the knife in the direction of flow exceed a defined threshold,from the working position, it can be moved out of the channel against the force of the spring, and when forces acting on the knife against the flow direction exceed a defined threshold, it can be moved from the working position into the channel against the force of the spring.

[0011] This easily prevents the knife from ending up in an unsuitable position, for example when reversing or swiveling the stand. This avoids or reduces the problems discussed earlier.

[0012] All or part of the levers can be moved by a first actuator into a position in which the roller is out of engagement with the associated recess.

[0013] Opposite the cutting unit, a conveying rotor can be arranged in the channel, between whose tines the knives of the cutting unit engage in the working position.

[0014] The frame can be movable relative to the channel between an operating position, where it is adjacent to the channel, and a maintenance position spaced away from the channel. In particular, the frame is pivotably mounted on a frame of the crop harvester on its upstream side relative to the channel. The frame can be moved between the operating and maintenance positions by a second actuator. The first and second actuators can be connected to a controller configured to, upon receiving an instruction to move the frame to the maintenance position, direct the first actuator to move the knives into the extended position and, in a predetermined temporal or spatial relationship (i.e., dependent on the respective position of the actuator or the frame or lever it moves), to direct the second actuator to move the frame to the maintenance position.

[0015] The cutting unit according to the invention can be used on any harvesting machine for harvesting straw. Examples include forage wagons and balers for round or rectangular bales. Example of implementation

[0016] 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 round baler with a cutting unit, Fig. 2 a side view of the cutting unit with the knife in the working position, Fig. 3 one view according to Fig. 2 , however with the cutting unit frame lowered, Fig. 4 an enlarged section from the Fig. 2 , Fig. 5 a view of the cutting mechanism with a knife moved upwards from the working position, resting against a front stop, and Fig. 6 an enlarged section from the Fig. 5 .

[0017] One in the Figure 1The baler 10 shown comprises a superstructure 12, a chassis 14, pressing elements 16, a pressing chamber 18, a pickup 20, a cross conveyor 22, and a conveying rotor 24. Here, the baler 10 represents any type of baler, i.e., a round baler with a fixed or variable pressing chamber volume, with belts, rollers, or chains, a square baler, used in agriculture, industry, or commerce, etc. In the conventional case, such a baler 10 is pulled across a field to pick up straw-like crops, e.g., straw, hay, or silage, from the ground and feed them into the pressing chamber 18 or the loading area of ​​a forage wagon, in order to form, for example, a bale 26 or to store the crop and unload it at a suitable location. The superstructure 12 contains walls and struts that rest on the chassis 14 and can be attached to a vehicle, e.g., a tractor, by means of a drawbar 28.The chassis 14 consists of an axle and wheels in a conventional manner.

[0018] In the illustrated embodiment, the pressing elements 16 are formed by belts that are guided over or combined with rollers 30. These pressing elements 16 leave a gap to form an inlet 32 ​​for the crop into the pressing chamber 18. The pressing elements 16 can rotate in both directions. In this embodiment, the pressing chamber 18 is of a constant size, but its dimensions can be customized.

[0019] The pickup 20, a so-called pick-up, collects crop from the ground, which is laid down in a swath of varying thickness and size and is gathered into a narrower swath on its way to the baling chamber 18. The pickup 20 operates with an overshot mechanism. The crop it collects is gathered by the transverse conveyor 22 located at its discharge end. This conveyor is a transverse screw conveyor consisting of a central tube and spirals wound around the tube. The transverse conveyor 22 then transfers the crop to the undershot conveying rotor 24, which has a central tube and attached carriers and conveys it into the inlet 32. Below the transverse conveyor 22 and the conveying rotor 24 is a rigid wall 34, along the top of which the crop is conveyed. A channel 36 is therefore located between the wall 34 and the conveying rotor 24, through which the crop is conveyed.

[0020] Optionally, knives 40 of a cutting unit 38 can be inserted into the channel 36 to cut the harvested crop into shorter pieces. The cutting unit 38 comprises several knives 40 arranged side by side (perpendicular to the flow direction of the harvested crop), of which a portion, all, or none can be inserted into the channel 36 by means of a mechanism known per se. When in their working position, the knives 40 each engage between two tines 82 of the conveying rotor 24.

[0021] In the Figure 2 The cutting unit 38 is shown in a situation where a knife 40 is in the working position, extending into the channel 36. The flow direction of the harvested crop in normal harvesting operation is shown in the Figures 2 to 6 directed to the right and in the Figure 1to the left. The knife 40 is pivotally supported at its upstream end, relative to the direction of flow of the crop indicated by arrow 42, about a pivot axis 44 on the frame 46 of the cutting unit 38. The pivot axis 44 extends horizontally and transversely to the forward direction of the baler 10 and thus transversely to the channel 36. The knife 40, which is approximately triangular in its overall shape, has a sharpened, serrated cutting edge 48 on its upper side, which extends into the channel 36 to cut the crop. At the lower end of its rear edge 50, the knife 40 has a recess 52.

[0022] A number of levers 54 corresponding to the number of knives 40 are individually rotatably supported on the frame or structure 12 of the baler 10 about an axis 56 running parallel to the pivot axis 44 and each lever comprises a first, upper arm 58 and a second, lower arm 60, between which the axis 54 is located. A roller 62 is rotatably attached to the upper end of the first arm 58 about an axis running parallel to the axis 54. Each lever 54 is also associated with a spring 64, which biases the roller 62 towards the rear edge 50 of the knife 40, so that the roller 62 is held in the recess 50. Contrary to the illustration, the spring 64 can push or pull the second arm 60 to the right or push the first arm 58 to the left.A number of levers 54 can be selectively moved into a disengaged position by a suitable mechanism with a pin 66, which interacts with the lever 54 and is attached to a rotatable bracket 86, by a first actuator 84, in which they and the associated blades 40 are located outside the channel 38, as shown by the lever 54' in the . Figure 2 as indicated. A suitable mechanism is also disclosed, for example, in EP 2 110 014 A1.

[0023] The cutting unit 38 comprises the frame 46, which is pivotally connected at its upstream end to a pivot axis 90 on the superstructure 12 of the baler 10 and supports the described components of the cutting unit 38. The pivot axis 90 extends horizontally and transversely to the channel 36 at the upstream end of the cutting unit 38 (relative to the flow direction of the harvested material during normal operation). A second actuator 92 is articulated to the superstructure 12 and the frame 46 and serves to pivot the frame 46 of the cutting unit 38 about the pivot axis 90, between which in Figure 2 shown operating position and the one in Figure 3 Maintenance position shown. A limiter 94, hinged to the frame 46 and the superstructure 12, with an elongated hole 96, limits the downward travel of the frame 46.

[0024] Actuators 84 and 92 are preferably designed as hydraulic cylinders. They can be controlled by a suitable electronic control system, which is, for example, mounted on a tractor pulling the baler 10, and by a suitable hydraulic system. The tractor operator can thus control the first actuator 84 via an operator interface to pivot the knives 40 in and out in order to vary the cutting length of the crop. The operator can also use the operator interface to instruct the second actuator 92 to move the frame 46 of the cutting unit 38 into the Figure 3The system moves the unit to the indicated maintenance position if maintenance work needs to be carried out or a crop jam needs to be cleared. In this case, the control system will first cause the first actuator 84 to pivot the knives 40 out of channel 36 and then (time- or position-controlled, i.e., by using a sensor to detect the position of the first actuator 84) activate the second actuator 92. The frame 46 is pivoted back into the channel 36 analogously in the reverse direction, and only then, if necessary, are the knives 40 pivoted into channel 36.

[0025] In the event of an overload, for example, if a foreign object or clogged crop flows through the channel 38, the knife 40 can deflect downwards against the force of the spring 64 and is automatically returned to the channel 36 by the spring 64 once the overload is no longer acting on the knife 40. During this movement, the roller 62 runs along the rear edge 50 of the knife 40 above the indentation 52. Below the indentation 52, the rear edge 50 is equipped with a lug 74 and an edge 76 extending obliquely forwards and downwards from it. The lug 74 and the edge 76, in conjunction with the roller 62, also allow the knife 40 to move upwards from its working position, as described in the Figure 4 shown.

[0026] It will now be referred to as Figure 4referenced, from which it can be seen that a front edge 68 of the knife 40, when it is in the working position, forms a certain gap 72 with a stop 70 formed by or connected to a front crossbar 80 of the frame 46.

[0027] If the knife 40 now moves out of the working position, as it is in the Figures 2 and 4 As shown, the rotor should deflect upwards, e.g., if the rotor 24 is reversed after a blockage and the blocked material pushes the rear edge 50 and / or an upper corner 78 of the knife 40 to the left and upwards, the situation arises as follows: Figure 4 This situation can also occur if the levers 54 are moved by the first actuator 84 into the dashed position of the Figure 2The blades 40 are moved from the working position to the retracted position, and the blades 40 are jammed by crop material with the rotor 24 or with a slot in the base 90 of the frame 46. Then, the frame 46 is lowered and raised again by the actuator 92. The roller 62 then rests against the edge 76, which extends obliquely forward and downward, and the front edge 68 of the blade 40 rests against the stop 70. In this way, the upward movement of the blade 40 into the channel 36 is limited by the stop 70 and the front edge 68, particularly when the frame 46 is moved from the maintenance position. Figure 3 back to the operating position after Figure 2The knife 40 is moved. Therefore, jamming of the knife 40 with the rotor 24 or striking the rotor 24 is no longer a concern. Resetting the knife 40 after the blockage or similar issue is resolved is possible if the lever 54 is moved to the out-of-service position. Then, the knife 40 can first move into the out-of-service position by gravity or the flow of harvested material and subsequently be moved back into the working position using the lever 54.

[0028] Based on the Figure 6 It is evident that the position and shape of the upper surface of the nose 74 defines the force or torque at which the knife 40 moves into the position after Figure 4 The edge 76, which extends straight and obliquely forward and downward from the nose 74, determines the force or torque with which the knife 74 rests against the stop 70.

[0029] In the illustrated embodiment, the knife 40 thus remains in the position after Figure 5 has been reached, in this position, until the levers 54 are again moved by the first actuator 84 into the Figure 2 The position shown with a dashed line is moved. If a conventional knife shape is used below the indentation 52, which is without a nose 74 and runs obliquely backwards and downwards below the indentation 52 (as in the Figure 2 (as shown in DE 43 02 199 A1), the knife can also be returned to its working position automatically by the force of spring 64 after the force rotating it upwards has ceased.

Claims

1. Cutting unit (38) for stalk-shaped agricultural crops, comprising a number of blades (40) which are arranged next to one another transversely with respect to a channel (36), through which crops can flow in a flow direction (42) in normal operation, and are articulated on a frame (46) of the cutting unit (38) on that side of the blades (40) located upstream in the channel (36) pivotably about a pivot axis (44) extending transversely with respect to the channel (36) between a working position and a position, in which they are swung out of the channel (36), and the cutting unit comprises levers (54) which are assigned to the blades (44) and are supported on the frame (46) rotatably about an axis (56) running parallel to the pivot axis (44) and are movable about the axis (56) between a working position, in which they hold the blade (40) assigned to them in an active position, in which it extends into the channel (36), and a non-operational position, in which they do not hold the blade (40) in the active position, and the cutting unit further comprises springs (64) which are assigned to the levers (52) and preload the assigned lever (52) into the working position, wherein that edge (68) of the blade (40) which interacts with the stop (70) is arranged on its upstream side and above the pivot axis (44), characterized in that the blades (40) are provided with a recess (52) on their rear edge (50) which is spaced apart from the pivot axis (44), into which recess a roller (62) coupled to the lever (54) engages in the working position of the blades (40), and the recess (52) is formed in such a way that the respective blade (40) can be moved, in the case of forces which act on the blade (40) in the flow direction and exceed a defined threshold value, from the working position counter to the force of the springs (64) out of the channel (36) and, in the case of forces which act on the blade (40) counter to the flow direction and exceed a defined threshold value, from the working position counter to the force of the springs (64) into the channel (36).

2. Cutting unit (38) according to Claim 1, wherein all or part of the levers (52) are movable by a first actuator (84) into a position, in which the roller (62) is out of engagement with the associated recess (62).

3. Cutting unit (38) according to either of the preceding claims, wherein a feed rotor (24) is arranged in the channel (36) so as to lie opposite the cutting unit (38), between the tines (82) of which feed rotor the blades (40) of the cutting unit (38) engage in the working position.

4. Cutting unit (38) according to one of the preceding claims, wherein the frame (46) is movable relative to the channel (36) between an operating position, in which it is adjacent to the channel (36), and a maintenance position, in which it is spaced apart from the channel (36).

5. Cutting unit (38) according to Claim 4, wherein the frame (46) is pivotable on its upstream side relative to the channel (36).

6. Cutting unit (38) according to Claim 4 or 5, wherein the frame (46) is movable by a second actuator (92) between the operating position and the maintenance position.

7. Cutting unit (38) according to Claim 6, when referring back to Claim 4, wherein the first actuator (84) and the second actuator (92) are connected to a controller which is configured to instruct the first actuator (84) to move the frame (46) into the maintenance position, to move the blades (40) into the swung-out position and, in a predetermined temporal or spatial context, to therefore instruct the second actuator (94) to move the frame (46) into the maintenance position.

8. Stalk crop harvester, in particular baler (10) or loading vehicle, having a cutting unit (38) according to one of Claims 1 to 7.