Root crop harvester

Abstract

Root crop harvester (5) which has several vertical six-discs (20) running in the direction of travel of the harvester (5) which are designed to cut into the soil, wherein at least one of the six-discs (20) is rotatably mounted on at least one rocker arm (16) which is pivotably mounted on a frame (12) of the harvester (5), and wherein the rocker arm (16) is supported on the frame (12) via a spring element (22), characterized in that the spring element is formed by a pressure medium cylinder (22) whose pressure medium is connected to a pressure accumulator (28).

Description

[0001] The present invention relates to a tractor-driven or self-propelled or motorized harvesting machine for harvesting root crops, preferably potatoes. Such root crop harvesting machines have a plurality of vertically arranged coulter discs that cut into the soil for separating haulms that extend laterally beyond a receiving device of the harvesting machine before they are picked up by the receiving device. Such root crop harvesting machines can have both actively driven coulter discs and coulter discs whose rotation is generated by friction with the soil. At least one of the coulter discs, preferably all of the coulter discs, are rotatably mounted on rockers that are usually arranged on either side of the receiving device of the root crop harvesting machine. The rockers are pivotally mounted on a frame of the harvesting machine and are supported on the frame via a spring element.These spring elements are usually in the form of coil springs with a limited spring travel, which support the rocker on the frame and pre-tension the rocker and thus the coulter disc towards the ground. Due to the limited spring travel, the depth of the disc coulters must be pre-set using a spindle. A coil spring has a proportional and, due to the short spring travel in relation to the required spring travel, a steep force curve. This means that high forces can occur, especially on uneven soils such as those found in root crop ridges, when the coulter discs are pushed upwards on higher areas or when there are stones, and thus compress more strongly under great force. This puts strain on the entire mechanical system and impairs the depth control of the intake. It reduces the effectiveness and protects the crop from the harvester.

[0002] It is therefore an object of the present invention to provide a root crop harvester that enables more effective operation of the coulter discs. This object is achieved by a root crop harvester having the features of claim 1. Advantageous developments of the invention are the subject of the associated dependent claims. Advantageous developments of the invention are also described in the description and in the drawings.

[0003] According to the invention, the spring element, which supports the rocker arm on the frame and presses the coulter disc downward, is formed by a pressure cylinder whose pressure medium is connected to a pressure accumulator. The connection of the pressure cylinder to the pressure accumulator allows the pressure medium to flow into the pressure accumulator during compression. This pressure accumulator is preferably significantly larger than the working volume of the pressure cylinder. This results in a very flat, almost linear force curve in the working stroke of the pressure cylinder, depending on the size and design of the pressure accumulator.

[0004] This means that when the coulter disc is compressed further, the preload exerted by the coulter disc assembly on the soil barely increases, preventing the coulter disc from cutting too deeply into the soil and protecting the entire mechanism of the coulter discs and their bearings on the harvester frame. Especially with actively driven coulters, this also prevents overloading of the coulter disc rotation drive. This avoidance of force peaks when the rocker arm is compressed also reduces the propulsion force of the root crop harvester, regardless of whether it is tractor-driven or has its own drive, thus making the overall operation of the root crop harvester more efficient.

[0005] Furthermore, this means that the force acting on the coulter discs against the soil remains approximately constant throughout the entire spring travel of the individual coulter discs, which no longer requires pre-adjustment of the working depth via a spindle. The coulter discs are always pressed against the soil with the desired force, which is set by the pressure in the accumulator. The invention thus realizes automatic depth adjustment of the coulter discs.

[0006] For discs driven by friction, this ensures reliable drive and thus a safe flow of material even under difficult conditions.

[0007] In addition, a safe removal of the overhanging leaves of the root crops is ensured under all soil conditions, which is a prerequisite for effective harvesting.

[0008] Uniform force on the coulter discs also ensures that none of the disc coulters can negatively affect the depth control of the intake system in the event of excessive compression, thus ensuring a consistent harvesting depth. Consequently, damage to the crop caused by a harvesting share temporarily operating too shallowly can be ruled out.

[0009] Preferably, the pressure medium cylinder is a hydraulic cylinder and the pressure accumulator a diaphragm or bladder accumulator. The flat force curve depending on the compression travel of the hydraulic cylinder can be achieved if the pressure accumulator is a diaphragm or bladder accumulator. In a diaphragm or bladder accumulator, the hydraulic medium presses against a gas volume separated by a diaphragm or bladder. When the hydraulic medium flows into the diaphragm accumulator, this diaphragm or bladder gives way and thus allows the hydraulic cylinder to compress without the force increasing too much. In order to achieve the flattest and almost linear force curve possible, it is advantageous if the gas volume in the diaphragm or bladder accumulator is significantly larger than the working volume of the pressure medium cylinder.Oil is particularly suitable as a hydraulic medium, as all mechanical parts are subjected to enormous mechanical stress under the harsh operating conditions of a harvester. Using oil as the hydraulic medium significantly increases the service life and operational reliability of the root crop harvester.

[0010] In an advantageous development of the invention, the rocker arm is pivotally mounted on the frame of the harvester by means of a pivot bearing, and the pressure cylinder is articulated to the rocker arm in the area between the pivot bearing and the rotational bearing of the coulter disc or in the area of ​​the coulter disc's axle attachment. In this way, the actuation travel of the coulter disc can be greater relative to the actuation travel of the pressure cylinder. In contrast, if the pressure cylinder is articulated in the area of ​​the axle attachment, the force acting on the pressure cylinder is not increased by the lever ratio of the pivot bearing-rotational bearing to the pivot bearing-articulation of the pressure cylinder.

[0011] As already explained above, the accumulator should be larger than the pressure cylinder in order to achieve a flat force curve depending on the spring travel of the pressure cylinder. This is particularly achieved when the pressure accumulator is two to ten times the working volume of the pressure cylinder, in particular seven to ten times the volume of the pressure cylinder. In this case, there is plenty of space in the pressure accumulator to absorb the pressure medium flowing in when the pressure cylinder compresses. In addition, the pressure in the pressure accumulator can be precisely adjusted via the gas pressure, especially in the case of a diaphragm or bladder accumulator.

[0012] However, it may be advantageous to make the pressure accumulator even larger to ensure functionality at increased operating pressure.

[0013] The cylinders can only yield when the force acting on the pressure medium cylinders generates more pressure than the preset pressure in the accumulator. Accordingly, the fixed preset pressure in the accumulator must be adjusted so that pressure medium is drawn into the accumulator starting at the lowest desired release force.

[0014] If the user wishes to increase the release force, this can be achieved by pumping additional pressure fluid from the pressure fluid source into the system. The pressure increases, and with it the release force. However, this permanently reduces the pressure fluid supplied by the pressure fluid cylinders, as the additional pressure fluid pumped into the system takes up volume in the pressure accumulator. This has a detrimental effect on the pressure curve in the working range. This can be counteracted by further increasing the size of the pressure fluid accumulator. This advantageously allows the user to set a larger pressure range without significantly impairing the function of the evenly deflecting pressure fluid cylinders.

[0015] Preferably, the swing arm follows the direction of travel of the harvester so that the swing arm can always spring back even on rough uneven surfaces in the field without hindering the forward movement of the harvester.

[0016] The invention is particularly advantageous in potato harvesting machines where a large amount of haulm has to be separated before the potatoes are picked up by means of the picking device.

[0017] In an advantageous development of the invention, the multiple pressure cylinders are connected to a common pressure accumulator, which has the advantage that a separate pressure accumulator does not have to be provided for each pressure cylinder. This allows the entire spring device for the coulter disc rockers to be designed more compactly, and the force-displacement curve is the same for all coulter discs. This embodiment also allows for a large pressure accumulator to be arranged at any suitable location on the harvester outside the area of ​​the harvesting elements, ensuring that an identical, flat and almost linear force curve is achieved for all coulter discs depending on the spring travel.

[0018] As already explained above, the harvesting machine either has its own drive or is designed for traction operation in conjunction with a tractor, in particular a tractor.

[0019] In an advantageous development of the invention, the pressure cylinder is designed as a single-acting cylinder, which is structurally simpler. However, double-acting pressure cylinders can also be used.

[0020] The use of a central pressure accumulator also has the advantage that the spring force on the rockers on both sides of the intake system, and possibly also in the center of the intake system depending on the width of the intake system, is always applied with the same force. This ensures that the preload force of all coulter discs is identical regardless of their position relative to the intake system, which contributes to consistent depth control in multi-row intake systems. Of course, several small pressure accumulators can also be provided, either separately or connected to each other, to achieve a suitable total pressure accumulator capacity.

[0021] As already mentioned above, the harvester generally has a receiving device for the root crops, usually also connected to a digging share and a screening channel. The coulter discs, or the rockers for positioning the coulter discs, are arranged on either side of the receiving device to separate the haulms of the root crops on either side. In multi-row receiving devices, where two rows of root crops can be harvested simultaneously, rockers are also optionally arranged in each section between the rows of root crops to reliably separate overgrown haulms on both sides of each row of root crops in the field.

[0022] The following terms are used synonymously: coulter discs - disc coulters; pressure medium - pressure medium - hydraulic oil;

[0023] The invention is described below, for example, with reference to the schematic drawing, which shows: Fig. 1 is a schematic side view of a coulter disc arrangement of a root crop harvester, Fig. 2 the coulter disc arrangement Fig. 1 in operation and in interaction with a digging share and the sieve belt of a receiving device of the root crop harvester, Fig. 3 a schematic drawing of a hydraulic arrangement with a central pressure accumulator in connection with the pressure cylinders, and Fig. 4 a force-displacement diagram for comparing the force-displacement curve of a conventional coil spring compared to the force-displacement curve of a pressure accumulator-supported pressure medium cylinder according to the present invention.

[0024] Fig. Figure 1 shows a coulter disc assembly 10 of a root crop harvester 5, of which only a section of the frame 12 is shown here for reasons of clarity. A rocker arm 16 is pivotally mounted on the frame 12 by means of a pivot bearing 14. A rotary bearing 18 for a coulter disc 20 is arranged at the free end of the rocker arm 16, with the coulter disc 20 rotating either by friction with the soil or by its own rotary drive (not shown).

[0025] The rocker arm 16 is resiliently supported on the frame 12 via a pressure cylinder 22, with the spring travel being indicated by the letter DL. For this purpose, the pressure cylinder 22 is attached to the frame 12 by means of a first articulation point 24 and to the rocker arm 16 by means of a second articulation point 26. The second articulation point 26 is arranged significantly closer to the rotation bearing 18 of the coulter disc 20 than to the pivot bearing 14 of the rocker arm 16 on the frame. In this way, it is ensured that the deflection force of the coulter disc 20 in the direction of the spring travel DL does not become too great. A pressure accumulator 28 is arranged on the frame and is connected to the pressure cylinder 22 in a manner not shown, so that the pressure medium in the pressure cylinder, in particular hydraulic oil, can enter the pressure accumulator 28 and vice versa. The pressure accumulator 28 is preferably designed as a bladder accumulator or diaphragm accumulator.This arrangement ensures that the force curve of the coulter disc 20 is relatively flat, depending on its deflection. When the coulter disc 20 is fully compressed, the force exerted is not significantly greater than when it is slightly compressed. This results in the coulter disc's cutting depth into the soil remaining largely constant, thus enabling effective and energy-saving removal of the haulms of the root crop.

[0026] Fig. 2 shows the use of the coulter disc arrangement 10 from Fig. 1 in operation. In the figures, functionally identical or identical components are provided with identical reference numerals. Fig. 2 shows the operation of the harvesting machine 5 in the direction of travel x, wherein the rocker 16 trails in the direction of travel, whereby it is not able to hinder the travel of the harvesting machine depending on its spring state in conjunction with unevenness of the ground of a potato ridge 30 of a field. Fig. Figure 2 shows the root crops 32 to be harvested, the leaves of which are to be separated by the coulter disc 20. For harvesting the root crops themselves, the harvester has a digging share 34 as a receiving device, which, in conjunction with a sieve belt 36, transfers the harvested root crops into a receiving area of ​​the root crop harvester. Fig. 2 shows the potato ridge 30 with the potato plants 32 planted therein. The digging blade is designed like a rake and transfers the potato tubers arranged in the potato ridge 30 to the sieve belt 36.

[0027] The tops of the potato plants 32 are separated by coulter discs 20 on both sides of the potato ridge 30. Thus, a rocker arm 16 with a coulter disc 20 is arranged on each side of a potato ridge 30. As explained above, the flat force-displacement curve of the pressure cylinder 22 of the coulter disc arrangement 10 ensures a depth of penetration of the coulter disc into the soil that depends on the soil type, thus ensuring efficient operation of the root crop harvester that avoids force peaks.

[0028] Fig. Figure 3 shows in a very schematic way the interaction of the hydraulic components of the root crop harvester 5 from the Fig. 1 and Fig. 2. The pressure cylinders 22 on each rocker arm 16 are therefore connected via pressure lines 38 to the pressure accumulator 28, which is preferably designed as a bladder accumulator or diaphragm accumulator and is thus capable of receiving the hydraulic oil from the pressure cylinders 22. A pressure gauge 40 is arranged in connection with the pressure line 38 so that the operating pressure of the hydraulic oil in the pressure line 38 and thus the pressure in the pressure cylinders 22 can be measured. Such a pressure gauge 40 can of course also be an electronic pressure detection device that operates in conjunction with a central hydraulic control system. The hydraulic line 38 is further connected via a throttle valve 42 to a controlled hydraulic source 44, which is monitored and controlled in particular via a central hydraulic control system.This arrangement allows the preload pressure to be sensitively adjusted using the controlled pressure source. The pressure medium in the cylinders can interact with the accumulator at any time without resistance.

[0029] Fig.4 shows a travel-force diagram, where the spring travel of the pressure cylinder 22 is designated by ΔL and the associated deflection force by F. In diagram 50, the end stop of the hydraulic cylinder 22 in the fully extended state is designated by Lmin and the maximum permissible compression range by Lmax. Curve 52 shows the force-spring behavior of a conventional coil spring, which increases very sharply in a linear manner as a function of the compression. Curve 54 shows the inventive combination of pressure cylinder 22 and pressure accumulator 28, wherein, due to the size of the pressure accumulator 28, the pressure curve 56 in the working range of the pressure cylinder 22 between total extension Lmin and total compression Lmax can be kept very flat. As a result, the deflection force of the coulter disc hardly changes depending on its compression travel, which enables operation with much less wear and resistance.

[0030] The invention is not limited to the described embodiments, but can be varied within the scope of the appended claims. List of reference symbols: 5 root crop harvester 10 coulter disc arrangement 12 Root crop harvester frame 14 pivot bearings on the frame for a swing arm to hold the coulter discs 16 Swing arm for holding a coulter disc 18 rotation bearings on the swing arm for the rotating mounting of the coulter disc 20 coulter disc 22 pressure cylinders to support the swing arm on the frame 24 first linkage point of the pressure cylinder on the frame 26 second linkage point of the pressure cylinder on the swing arm 28 pressure accumulators arranged on the frame for the pressure cylinders 30 potato dams on a field 32 potato plants 34 harvesters at the root crop harvester 36 Sieve belt at the intake area of ​​the root crop harvester 38 Hydraulic line 40 pressure gauges 42 throttle valve 44 controlled hydraulic source 50 Force-Displacement diagram of the deflection force of the coulter disc depending on the deflection path 52 Force-displacement curve of the spring behavior of a conventional coil spring 54 Force-displacement curve of the inventive combination of pressure cylinder with pressure accumulator 56 In the force-displacement curve of the pressure cylinder, an almost linear flat area between minimum and maximum deflection DL compression travel or deflection of the spring element x Direction of travel

Claims

[1] Root crop harvesting machine (5) which has a plurality of vertical coulter discs (20) running in the direction of travel of the harvesting machine (5) and which are designed to cut into the ground, wherein at least one of the coulter discs (20) is rotatably received on at least one rocker (16) which is pivotally mounted on a frame (12) of the harvesting machine (5), and wherein the rocker (16) is supported on the frame (12) via a spring element (22), characterized by that the spring element is formed by a pressure medium cylinder (22), the pressure medium of which is connected to a pressure accumulator (28). [2] Harvesting machine (5) according to claim 1, characterized by that the pressure medium cylinder (22) is a hydraulic cylinder and that the pressure accumulator (28) is a diaphragm or bladder accumulator. [3] Harvesting machine (5) according to one of the preceding claims, characterized bythat the rocker (16) is pivotally mounted on the frame (12) by means of a pivot bearing (14), and that the pressure medium cylinder (22) is articulated on the rocker (16) in the region between the pivot bearing (14) and the rotation bearing (18) or in the region of the rotation bearing of the coulter disc (20). [4] Harvesting machine (5) according to one of the preceding claims, characterized by that the swing arm (16) runs in the direction of travel. [5] Harvesting machine (5) according to one of the preceding claims, characterized by that it is designed as a potato harvester (5). [6] Harvesting machine (5) according to one of the preceding claims, characterized by that several pressure medium cylinders (22) are connected to a common pressure accumulator (28). [7] Harvesting machine (5) according to one of the preceding claims, characterized by that the pressure accumulator (28) is larger than the working volume of the pressure cylinder (22). [8] Harvesting machine (5) according to claim 7, characterized by that the pressure accumulator (28) is two to ten times as large as the working volume of the pressure cylinder (22). [9] Harvesting machine (5) according to one of the preceding claims, characterized by that it has its own drive or is designed for train operation. [10] Harvesting machine (5) according to one of the preceding claims, characterized by that the pressure cylinder (22) is designed as a single-acting cylinder. [11] Harvesting machine (5) according to one of the preceding claims, characterized by that all coulter discs (20) of the harvesting machine (5) are mounted on at least one rocker (16). [12] Harvesting machine (5) according to one of the preceding claims, characterized by that each coulter disc (20) is mounted on a rocker (16). [13] Harvesting machine (5) according to one of the preceding claims, characterized bythat it has a receiving device for the root crops, and that the coulter discs (20) are arranged on both sides of the receiving device.

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