Soil-working device with reduced friction

Abstract

The invention relates to a soil-working device with reduced friction. The soil-working device has a surface which works the soil in a desired manner, e.g. turning, loosening, mixing, or the like, when working the soil, wherein the soil-working device has a surface with a plurality of openings which are designed to be substantially circular, oval, or polygonal and the largest diameter of which is less than 2.5 mm, preferably less than 1.5 mm, particularly less than 1 mm (e.g. 0.3 mm), and the openings lie at a desired angle relative to the surface, said angle ranging from 30 to 90°.

Description

[0001] Soil tillage equipment with reduced friction

[0002] The subject of this patent application is a soil tillage implement and associated components that are pulled over or through a field by a tractor or towing vehicle for agricultural use. The soil tillage implement consists of a power transmission structure and tools that interact with the soil, as well as a device for reducing friction. Friction reduction is achieved by partially or completely separating the soil to be loosened and turned from the soil tillage tools by a boundary layer. The boundary layer can consist of a gas, a liquid, or a mixture of both. Furthermore, coating materials can be used for tools that would previously have worn out too quickly due to the abrasive environment.The boundary layer is created, for example, when the fluid escapes from holes or gaps in the tool of the soil tillage device, thus causing a separation of the two solid bodies.

[0003] The goals of traditional soil cultivation are: optimal fuel consumption, optimal weed control, optimal soil structure for optimal root formation of the crop, and erosion protection; breaking up or avoiding harmful compaction (plough sole).

[0004] According to the understanding of the present application, the soil cultivation device is not only a classic soil cultivation device such as a plough or a cultivator, a seed drill or the like, but also an earth-moving machine, for example an excavator, caterpillar or a drill, with which the soil is worked in some way and in which a part of the machine is in frictional contact with the soil to be worked.

[0005] The fluid used can be compressed ambient air, liquids and chemicals carried by the tractor, steam generated from the aforementioned liquids, or combinations of the aforementioned components. To increase the efficiency of the soil tillage equipment, the boiling and dew points of the fluid can be chemically or physically influenced. The waste heat from the tractor can be used to evaporate the liquids. Previously uneconomical friction reduction technologies, such as electrically charging the soil tillage tool, vibrating the tool in the soil, special surface structures, and similar, can be used to further reduce friction.

[0006] In agricultural soil cultivation, various types of tools (ploughshares, cultivator tines, harrows, etc.) attached to a frame are usually pulled through the field by a tractor to turn, loosen, and aerate the soil. This requires the tractor to release large amounts of energy (diesel consumption 20-50 l / ha depending on the tillage depth and soil type). However, a large portion of this energy is not converted into useful work. In addition to losses due to the efficiency of the heat engine (approximately 60% power loss), only a portion of the available mechanical power is used for the soil cultivation necessary to increase yield. A significant portion of the mechanical power provided by the tractor is lost through friction losses (30-50% depending on soil type and soil moisture). (Schilling 1962)

[0007] The object of the invention to reduce friction between the soil cultivation device (tool for cultivating the soil) and the soil is achieved with a soil cultivation device having the feature of claim 1. Advantageous further developments are described in the further claims, which themselves

[0008] These friction losses arise primarily from the friction between the soil and the tillage tools. During tillage, the soil slides past / over the tool and rubs against it. To overcome this friction, the tractor must provide sufficient propulsion power. This increased power requirement is converted into heat energy through friction and thus does not contribute to increased agricultural yield. In addition to energy losses, this friction causes wear on the tillage tools. Reducing friction therefore results in reduced wear and energy savings. Reducing friction on the share itself reduces the formation of plow soles in the soil below the share. (Schilling 1962)

[0009] Any form of friction reduction on tillage tools leads to a reduction in the tractor's power requirements. To reduce friction between two solid bodies, intermediate media in liquid form (rarely gaseous media or special solids) are often introduced in technical applications. However, previous attempts to establish this for agricultural tillage have failed.

[0010] In the case of liquid intermediate media, this has previously been due to the fact that the medium had to be carried on the tractor before use, which, depending on consumption, may not be technically possible or impractical. With gaseous intermediate media, such as ambient air, compression often required more energy because no boundary layer in the technical sense was created; instead, a flow so strong that the tillage tool and soil were separated was generated. Depending on the technology used to separate the two media, other problems can also arise. However, it has already been proven that separating the solids can reduce friction and, as a result, lower the tractive power requirement of a tractor by more than 30%.The reduction in friction would also allow for a redesign of the soil tillage tool's shape, which could further reduce acceleration forces, increase travel speed, and enhance the effectiveness of the entire implement design. However, the resulting increase in productivity would only be associated with an actual reduction in the tractor's energy requirements if the separation of the solid bodies could be achieved using less power than the resulting power savings.

[0011] Furthermore, it should be mentioned that the boundary layer can not only contribute to reducing friction. Another effect of creating a boundary layer with the help of the holes in the soil cultivation tool is its contribution to loosening the soil. This not only reduces the power losses shown in Figure 1, but also allows the working fluid to perform deformation work. This allows tasks that previously had to be accomplished by the tool shape to be performed by the working fluid. It also prevents the soil layer, which is now guided by the boundary layer, from becoming smeared.

[0012] By using the soil tillage device according to the invention, it is also possible to ensure an active contribution to better soil aeration in order to better reduce any contamination present in the soil (for example through oxidation).

[0013] The use of solids that cause lower friction coefficients has so far failed primarily due to their low wear resistance. Despite good friction-reducing properties, such solid "lubricants" have not been successful because they wear out too quickly. (Qaisrani and Jianqiao 2016) An almost complete separation of the solids could reduce wear on the solids.

[0014] As early as the 1960s, experiments were conducted using plowshares with holes drilled into them, through which air was then forced to reduce friction. The patent-pending process used holes with a diameter of just over 1.5 mm, spaced approximately 2.5 cm apart. (Bertelsen 1965) Later experiments, however, showed that the compressor power, due to the high required flow rate, was too great to justify the friction reduction. (Wismer et al. 1968) Since Bertelsen's patent, no further field experiments have been conducted to separate the solid earth and tillage tools. Instead, it has been extensively demonstrated, for example by Wismer et al., that the technical implementation of such concepts is not energetically viable.Recent studies once again demonstrate that friction coefficients can be significantly reduced by blowing air into the gap between the soil and the solid. (Qin et al. 2022) However, Qin et al. do not consider fluids other than air and provide no information on hole geometry, required pressure in the gap, volume flow, or methods for providing the air with the least possible energy consumption.

[0015] The following describes how soil and tillage tools can be separated using a boundary layer. The fluid in the boundary layer is referred to as the working fluid. Regardless of the method of creating the boundary layer, the working fluid must be pressurized, as an excess pressure must be created between the tillage tool and soil compared to the ambient air. Therefore, a portion of the boundary layer will inevitably diffuse through the soil and out at the edges of the tillage tool and flow out. The greater this loss, the greater the volume flow of the working fluid must be.

[0016] The thickness of the boundary layer is therefore crucial for the required volume flow of the working fluid. The thicker the boundary layer, the greater the volume flow of working fluid that can escape at the edges of the soil tillage tool. At the same time, it must be taken into account that the friction reduction provided by a thicker boundary layer is only beneficial until the two solid bodies are just separated from each other. Once the soil and tool have separated, a further increase in the boundary layer hardly leads to any further savings. When creating the boundary layer, it is therefore essential to completely separate the two solid bodies from each other using the smallest possible thickness (boundary layer thickness). The smaller the thickness (boundary layer thickness) at which this separation is achieved, the lower the power required to create the boundary layer.

[0017] Figure 3 schematically illustrates the behavior of the boundary layer as a function of hole size and density. Reducing the hole size and the associated possibility of increasing hole density result in a smaller portion of the surface being "covered" with outflowing working fluid through a single hole. This can significantly reduce the outflow per hole.

[0018] At the same time, a higher density of holes leads to a more uniform boundary layer.

[0019] Pressure and velocity maxima and minima are closer together. This leads, on the one hand, to a lower volume flow required to "wet" the entire surface, allowing a thinner boundary layer to separate the solids. At the same time, deformations of the soil decrease, allowing the shape of the soil beam to better adapt to the shape of the tool, thus again reducing the required boundary layer thickness. Separating the solids opens up new possibilities in the context of the solid "lubricants" mentioned above. The lubricants tested so far (e.g., ultra-high molecular weight polyethylene, polytetrafluoroethylene, polyethylene, or ceramics) were able to reduce friction losses, but due to their lack of durability, they could not be used in the field (Qaisrani and Jianqiao 2016).However, an almost complete separation of the solids could make these materials relevant again for friction reduction, as the problem of wear now plays a subordinate role. This would make soil tillage tools made entirely of materials other than steel (plastics, ceramics, and coatings) possible. Likewise, complex surface geometries, some of which are of bionic origin, could exhibit longer durability and thus become relevant.

[0020] Using materials other than spring steel, which is commonly used for soil cultivation equipment, can also have a positive impact on the production of the holes. A soil cultivation tool made of plastic, such as polyethylene, polypropylene, or the like, could be machined more easily than spring steel or stainless steel. Thermal production is also conceivable.

[0021] Figure 4 breaks down the different layers that could make up a boundary layer. In order to reduce lateral leakage around the periphery of the plow body and increase the efficiency of the overall system, the number of exit holes is reduced at the edge or an additional bead is installed (see Figure 7). Forming fewer openings at the edge or where the bead forms can further improve the overall system, both in terms of its performance and by eliminating the need to create openings and supply them with working fluid. Since the friction behavior on the plow and the contact between soil and plow change, adjustments must be made to the plow itself. This can be done, for example, by adapting the pressure chambers already shown in the Bertelsen patent to the actual pressure profile on a plow. Figure 5 shows the numerically determined pressure profile (Formato et al.2005) and the original patent application (Bertelsen 1965) were compared. Dimensioning the pressure chambers according to the pressure profile of the plow on the right side would enable more effective lubricating film generation. To save material, the boundaries of the pressure chambers can be designed so that they can transfer shear stresses between the front and rear of the plow, thus contributing to the stability of the overall structure. This allows the front and rear of the plow to be made of thinner sheet metal and / or different materials (plastics) to be used.

[0022] In addition, similar to existing slatted ploughs, the plough can consist of several strips each equipped with strips in which a boundary layer is created. For example, existing ploughs can be retrofitted, or a simplified version of the plough can be designed in which a boundary layer is created on the slatted ploughs (see Figure 6). If necessary, significantly fewer holes than shown in Figure 6 can be used. Holes are also conceivable in and on the sides of the slatted plough blade.

[0023] In addition, the actual shape of the plough can be adjusted by making the ends of the moldboard, where the moldboard and the ground separate during cultivation, slightly more curved. If the shape of the plough is described mathematically, one can speak of an increase in Gaussian curvature or a decrease in the radius of curvature. This increases the contact pressure in these areas and the gap in the boundary layer becomes smaller, so that less working fluid can escape. To avoid a change in curvature and to enable simple production, additional material can also be welded (applied) just to the edges of the plough (to create the bead described above). The gradual opening of the holes for different working depths can be achieved with valves or taps that pressurize the corresponding pressure chambers, which could be automated in various ways.

[0024] In addition to the effects already described, the smaller radius of the holes can limit the flow of the working fluid. The maximum flow through a hole is determined by integrating the flow velocity over the hole area. Since the maximum flow velocity decreases with decreasing radius, the flow per hole area also decreases. (Rick 2013) Thus, not only the flow per hole is reduced, but also the total flow through all holes. This is particularly advantageous when no back pressure is generated by the earth bar (for example, at shallow working depths), thus reducing the losses of the freely flowing working fluid.

[0025] The effect can be further enhanced by a convergent-divergent design of the holes (see section on manufacturing technology).

[0026] In addition to this form of flow restriction by narrowing the cross-section, other forms of flow restriction can also be selected, which are shown as examples in Figure 8. Drawing (1) shows a hole narrowing by means of a screw connection, which allows the cross-section to be adjusted subsequently and thus represents an adjustable mechanism. Drawing (2) contains a movable wedge in the hole, which can move between internal and external pressure depending on the pressure conditions, so that, for example, if the counterpressure outside the pressure chamber disappears (soil tillage implement is not in the ground), the wedge closes the hole and can clear any blockage. An additional spring connected to the wedge is also conceivable. In this way, the pressure difference at which the wedge closes could be adjusted. Drawing (3) shows a flow restriction using centripetal forces.Here, a circular chamber is flowed tangentially, so that a rotating flow develops. At high flow velocities, the centrifugal forces slow the fluid flowing towards the center of the chamber, thus limiting the maximum flow. Drawing (4) shows a flow limitation using a convergent divergent nozzle. This nozzle shape is often also referred to as a Laval nozzle. The narrowest cross-section of the nozzle does not necessarily have to be in the center of the sheet, as shown here. A shift all the way to the edges is conceivable, resulting in either a convergent or divergent nozzle. Flow velocities and maximum flow rates can be determined by adjusting the individual cross-sections to one another.

[0027] These findings show that the studies of the 1960s, which were intended to demonstrate that reducing friction with air was not energetically viable, were not comprehensive enough. The technical data for a plow specified in US 3180432 were not capable of separating the two solids in an energetically viable manner. However, a significant reduction in the hole size changes a number of crucial physical variables. Modern manufacturing technology allows the production of holes that are significantly smaller than 1.5 mm (Bertelsen 1965). Laser or electron beam drilling can have diameters down to a few micrometers and can be produced at significantly higher speeds and densities than mechanical drilling in the 1960s. Increasing the hole density by a factor of 100 compared to the original patent would not require the full technical capabilities of modern drilling technologies to be exploited.Hole sizes in the range of 300pm would be sufficient for this and could easily be implemented in terms of production technology.

[0028] In contrast to the manufacturing limitations of the 1960s, it is now possible to drill holes not perpendicular to the surface, but at a specific angle to the surface. This allows for additional influence on the boundary layer. Modern manufacturing technology also allows for the production of convergent, divergent, or convergent-divergent holes. This allows for better control of the outflow behavior of the working fluid. Flow rate, flow velocity, pressure loss, etc., can be determined via the hole shape depending on the position of the hole on the tool. The surface roughness of the hole, which can also be influenced, also plays a role here.

[0029] Holes in the moldboard, however, do not have to be manufactured in a single production step, but can, for example, be assembled from several thin sheets (Figure 9), which are then joined after the holes have been drilled. This allows different manufacturing processes (mechanical, laser, electron beam-based drilling, etching, etc.) to be used for different sheet thicknesses. A finished moldboard can thus consist of sheets of different thicknesses and different hole sizes, manufactured using different manufacturing processes and later forming a single hole. Multiple manufacturing processes, or the same processes for different diameters, can also be used to machine a single sheet.

[0030] For example, a micrometer-thick sheet metal with a hole etched a few micrometers in diameter could be sandwiched between two sheets several millimeters thick and mechanically drilled, thus acting as a flow-limiting orifice. A combination of multiple manufacturing processes is also conceivable. This does not necessarily require the use of multiple sheets. Mechanical pre-drilling to a certain depth followed by laser drilling is also conceivable.

[0031] An alternative manufacturing process involves not drilling the holes directly into the sheet metal, but rather forming them in advance as openings in inserts and then creating cutouts in the sheet metal into which the perforated inserts are inserted with a form-fitting fit. These inserts have the advantage that, as relatively small workpieces, they can be manufactured more easily with suitable tools, and the openings created in them can be manufactured even more precisely than by drilling holes directly into the sheet metal.

[0032] Other material combinations would of course also be conceivable. A further advantage of this manufacturing method is that the inserts can be made of different metal materials or material combinations, which allow soil cultivation to be optimally adapted to the cultivation requirements using the holes provided in the inserts. For example, by using stainless steel for ploughshares or, for less demanding applications, a soft material such as aluminum or plastic, which is less difficult to drill than spring steel and enables problem-free drilling of small holes. Fig. 10 shows a brief diagrammatic overview of the most important tests that have been carried out to date on hole size and hole spacing. The hole size is plotted in mm on the y-axis and the hole spacing on the x-axis. In the rectangular area, tests for heavy, clayey soils are particularly useful.Hole spacings between 20mm and 30mm are possible, as well as hole sizes in the range of 0.5mm to 1mm.

[0033] - a. Bigsby had the problem that his holes were getting clogged. The proportion of holes in his experiments was so large that not all of them could be flowed through.

[0034] - b. Bertelsen created the effect, but required too much airflow. It can be assumed that the holes were too large at more than 1.5 mm, allowing air to escape too easily. - c. Kuan Quin focused more on ventilation and decontamination than on minimizing friction.

[0035] - d. The lines in the diagram indicate either lines of constant hole number or area. Figure 10 shows, with the hatched area, the hole diameter (of the opening) as well as the hole spacing to achieve the best possible result. The hole area refers to the open area of ​​the opening, the hole spacing of the (average) smallest distance between adjacent openings, for example, of the or another soil cultivation device, such as a (strip) plow.

[0036] Figures 11 and 12 show an alternative possibility for not directly drilling the holes into the sheet metal. Instead, the holes are created by targeted edge-fitting of sheet metal parts whose edges are provided with hole segments that are then completed to form complete holes when the sheet metal parts are joined together at the edges. The joining is carried out by welding or gluing, for example. Figure 11 shows several identical sheet metal strips each provided with semicircular hole segments at the same height on the edges. When the sheet metal strips are joined at the edges, the hole segments are combined to form round holes, the configuration of which must be fixed by joining the sheet metal parts at the edges, for example by welding or gluing. Whether this is a more viable, economically viable way to produce sheet metal with holes remains to be seen in practice.Figure 12 shows an alternative to the semicircular hole segments of Figure 11, which are combined into hexagonal holes by joining the sheet metal strips at the edges.

[0037] Cleaning the implement can be accomplished in a variety of ways, depending on the specific design. To prevent the holes from becoming clogged, the tillage implement should be cleaned regularly. This can be done during operation, during turning maneuvers at the end of the field, or at more irregular intervals. Integrated cleaning could be achieved by briefly increasing the pressure to blow out holes or by vacuuming in dirt by lowering the pressure below the external pressure. Depending on the hole shape, different methods may be advantageous.

[0038] In plows, impurities can be blown out, for example, by pulsating pressure, sudden pressure surges, or the individual switching on and off of shares or individual tools. Switching off individual shares increases the pressure or mass flow in the remaining shares, allowing impurities to be blown out.

[0039] By drawing in outside air, a negative pressure could be created in individual coulters using the same device that currently creates positive pressure, using a Venturi nozzle. As a result of the negative pressure in the coulter, air is drawn through the holes and can thus draw contaminants into the coulter.

[0040] In addition to creating a boundary layer above the surface of the soil tillage tool, the working fluid can also escape from a gap at an edge of the soil tillage tool, creating a boundary layer there. This can either be a gap machined into the solid material, for example, using a milling machine, laser cutter, or electron beam cutter, or a gap created between two components. The two components can be manufactured in such a way that, after assembly, a gap remains between them through which the working fluid can escape to separate the tool and soil or to cut the soil. A gap created by additive manufacturing is also conceivable. Like the holes described above, the gap can be divergent, convergent, or a combination of both.The size and stability of the gap can be further maintained at an exact level by inserting rods or pins into the gap, which have shaping and / or stabilizing effects.

[0041] This results in very little wear on the edges of the tillage tool. This not only saves fuel by reducing friction losses, but also keeps the tool sharp-edged over time, reducing the cost of wear parts and preventing worn edges from slowly increasing fuel consumption.

[0042] In the aforementioned 1962 patent from Bertelsen, outside air is compressed with the help of a compressor and forced through the holes in the plow to provide the working fluid. This has the disadvantage that the entire volume flow used must be compressed. Despite the already significantly higher efficiency of today's compressors compared to those available in 1962, the efficiency of providing the working fluid can still be significantly increased. For this purpose, existing components can be used instead of additional components, or the entire compression process can be thermodynamically optimized.

[0043] Existing components could be utilized, for example, by modifying the tractor engine's fan instead of an external compressor so that it can perform a dual function: providing the necessary airflow to cool the engine while simultaneously providing the airflow to minimize friction. This method can be combined with the thermodynamic optimization presented below.

[0044] Since the required compression power is proportional to the volume flow and the natural logarithm of the compression pressure ratio, the power requirement of a compressor / pump can be reduced if the volume flow or pressure increases after compression and is thus provided not by the compressor itself but by a downstream technical process. The following examines some systems that can utilize a tractor's waste heat to increase the volume flow of the working fluid.

[0045] As shown in Figure 13, in a modern diesel engine only about 40% of the energy of the diesel fuel is converted into drive power. The remaining energy is It is dissipated primarily through the exhaust gas and the radiator and is therefore unused heat energy. The heat flows leaving the engine occur at different temperature levels.

[0046] If the working fluid is heated using this waste heat following compression, the volume of the working fluid increases. This applies to both liquids and gases. The effect of volume increase after compression can be significantly increased if a liquid in the working fluid is evaporated. The first advantage of evaporation processes is the large increase in volume. Evaporating water increases its volume by a factor of over 1300 when it is evaporated at 1.2 bar. In addition, evaporation takes place at a specific temperature or within a narrow temperature range. This promotes heat transfer from exhaust gas or coolant to the working fluid. The actual use of waste heat to increase the volume flow or pressure can occur in many different ways, which vary greatly depending on the working fluid, outside temperature, soil conditions, plow used, etc.Examples can be found in the appendix. The basic concept is shown below. Depending on the temperature levels of the heat dissipation from the engine, the energy is gradually added to the working fluid.

[0047] The pipes or hoses used can be made entirely of stainless steel or other common materials for exhaust systems, or can be protected against corrosion by coatings such as Teflon or plastics.

[0048] The evaporated liquid can either be used directly in the process (see Fig. 14) or energy can be extracted from it in a cyclic process, which can then be used for compression (see Fig. 15). For both processes, water does not necessarily have to be used as the liquid medium. Other liquids or mixtures are conceivable.

[0049] Additives for the working fluid

[0050] Depending on the design of the compression and evaporation process and the machine selection, it may be beneficial to add different components to the working fluid. These components can fulfill different tasks: 1. Agricultural applications: a. Carbon farming b. Pesticides c. Different forms of fertilizer

[0051] 2, Corrosion protection of the various components of the machine

[0052] 3. Decalcification 4. Influence on the evaporation process and heat transfer a. Heat capacity b. Boiling temperature c. Dew point

[0053] In particular, influencing the boiling temperature can significantly improve the effectiveness of the process (see Fig. 16). For example, the cooling water temperatures of off-road

[0054] Heavy-duty diesel generators typically operate below 100°C and therefore, for example, can hardly contribute to water evaporation. Lowering the boiling point of water would make it possible to initiate heat transfer here as well. This could be achieved, for example, by adding ethanol or another organic chemical. Depending on the choice of working fluid, various additives can be used to increase the soil's carbon dioxide storage capacity and thus enhance humus formation.

[0055] Additionally, additional chemical additives can be added to the working fluid to minimize deposits in the heat exchangers. This can extend maintenance cycles or eliminate the need for maintenance altogether.

[0056] The first experiments were conducted 100 years ago to reduce friction on plows and other tillage implements. The tillage implement was electrically negatively charged. This caused water in capillaries in the soil to move toward the implement and create a lubricating film on the surface. The initial studies on this topic were not implemented because plows were not pulled by machines at that time that could have provided sufficient electrical power. (Crowther and Haines 1924)

[0057] However, studies conducted in the 1960s showed that the required electrical power is too high to justify the savings (Wismer et al. 1968). Furthermore, previous studies showed that the required voltage for conventional

[0058] Driving speeds would exceed 300V, which, in addition to the technical difficulties of providing this voltage, would pose a significant risk to humans and the environment (Mackson 1962). As a result of these studies, electrical friction reduction has not been able to gain widespread acceptance. Despite a 1995 publication (Larson and Clyma 1995) suggesting that the effects could be achieved with significantly lower voltages, the technology has not yet become established (see Fig. 17).

[0059] However, previous attempts in this area differ substantially from the patent application presented here. All previous attempts either position a

[0060] Anode (positively charged) near the tillage implement and electrically charge the tillage implement negatively (cathode) or provide the tillage implement with electrically charged elevations on which friction is reduced (Massah et al. 2021). As a result of the voltage between the two poles, an electric current flows between the two poles through the earth. The electric field between the two poles simultaneously ensures that the water flows towards the tillage tool and creates a lubricating film there. The electrical power requirement of this device is caused by the charge exchange, not by the electric field itself. An increase in the electrical resistance between the anode and cathode can therefore also lead to a reduction in the power requirement. Since it is a

[0061] The aim of this patent application is to separate the tillage tool from the soil. The electrical resistance also increases compared to conventional applications, which can reduce power requirements. Electrical friction reduction therefore becomes relevant again in combination with the patent presented here. These and other synergistic effects resulting from the combination of several technologies are shown in Figure

[0062] 18. The large rectangles show the friction minimization approaches in red, blue, and yellow. The corresponding colors and smaller rectangles contain the approaches to modernizing these processes. Synergy effects are shown in hexagonal boxes in a mixture of the three primary colors. The combination of electro-osmosis and liquid lubricants could result in two important synergy effects: Since, when liquid lubricants are used, a large portion of the lubricant diffuses into the soil and can no longer be used for lubrication, a combination with electro-osmosis could help reduce the proportion of diffusing lubricant. Electro-osmosis would ensure that the lubricant adheres to the surface of the soil tillage tool and can thus actually act as a lubricant. This can reduce the overall lubricant requirement.In a second step, electro-osmosis could even be used for lubricant recovery (see Fig. 18): For this, the lubricant would have to be bound to the tillage tool using electro-osmosis, as described above, so that only small particles diffuse into the soil and a significant portion of the lubricant flows along the tillage tool along with the soil. Upon reaching the end of the contact zone between the soil and the tillage tool, the lubricant would be collected again so that it could be reused in the process. For this purpose, anionic or cationic polymers, for example, could be used, which respond particularly well to the electric field. To simplify collection after use, liquids with extremely long molecular chains can be used, which have favorable absorption properties in this context (e.g. polyethylene glycol).Such a polymer could not only be reused, but the flow direction on the blade could also be influenced using the electric field. Similar to the combination of electro-osmosis and liquid lubricants, electro-osmosis can also be used with compressed air to make the lubricant more efficient. As the water flows through the capillaries, the soil layer in contact with the tillage tool becomes moister and less permeable to air. This allows less air to escape through the soil, and power losses can be reduced. The overall efficiency of the air lubrication increases.

[0063] At the same time, air lubrication can also contribute to further increasing the efficiency of electro-osmosis. Like most other lubrication methods, air lubrication results in the solids to be lubricated being almost completely separated from one another. In the special case of air lubrication, however, the air also acts as an insulator in addition to its lubricating properties. No, or only a very slow, charge exchange can take place across the air gap. This means that the charge exchange is concentrated in the soil-soil tillage tool contact zones. The effectiveness of electro-osmosis therefore increases precisely in those zones where lubricant is most needed. The use of air and liquid lubricants can be combined in various ways.Primarily, synergistic effects similar to those achieved by combining electro-osmosis and air can be achieved, with the high volume of air almost completely separating the solids from each other, and the liquid lubricant reducing friction losses in the remaining contact zones. Here, too, the mass requirements of both air and liquid lubricant can be reduced by combining the two processes.

[0064] The energy for the processes described here does not necessarily have to come from the engine power, but could, for example, be generated from the vibrations of the plow using piezoelectric elements. During soil cultivation, strong fluctuations in traction power occur (Borsa 1988), which lead to vibrations. These vibrations are usually converted into heat energy by the material. The use of piezoelectric elements enables conversion into electrical energy.

[0065] In addition to using the heat from the exhaust gas, the exhaust gas can also be fed into the tank of the working fluid. This can be done with any of the methods listed in the appendix.

[0066] Drawing can be performed additionally. This can have several advantages:

[0067] 1. On the one hand, the residual heat of the exhaust gas can be used to preheat the working fluid, allowing more working fluid to be evaporated overall.

[0068] 2. The exhaust gas can also be chemically cleaned. With the correct dosage, filtration using a working fluid can even replace the catalytic converter. Pollutants such as carbon monoxide, nitrogen oxides, soot particles, and the like can be filtered out. A significant reduction in the carbon dioxide content in the exhaust gas is also possible. For this purpose, the working fluid tank is equipped with a pH meter and an additional tank. The additional tank can be filled with a base (e.g., sodium bicarbonate) and, through the metered addition of the alkali, the pH of the working fluid can be regulated. This allows both the maximization of pollutant absorption and the influence of the soil pH. If the tillage equipment is additionally equipped with a soil pH tester, this can even be regulated locally (precision framing).In addition to reducing pollutant emissions, the nitrogen oxides in exhaust gases, which are particularly harmful to humans, are converted into nitrogen fertilizer and used to fertilize the soil. This saves on fertilizer. All of the chemicals used are also available in food-grade versions.

[0069] 3. The water present as steam in the exhaust gas can liquefy again when returned to the fluid tank, thus releasing energy and at the same time helping to ensure that less working fluid needs to be carried.

[0070] Since nitrogen oxides (carbon monoxide and dioxide) can be filtered, this invention can improve or even replace the tractor's entire exhaust aftertreatment system. Tractors that are primarily used in conjunction with implements that utilize the working fluid can thus dispense with expensive conventional catalysts. This can be particularly relevant for autonomous vehicles that are used exclusively for field work and are transported or towed to the field by another tractor.

[0071] The friction reduction measures described in previous chapters (particularly the interface between the tool and the soil) open up new possibilities for monitoring, documenting, and adjusting the operation of tillage equipment. For this purpose, technology already used in agriculture can be combined with the tillage equipment described here to achieve new synergy effects.

[0072] Since the external conditions in which a tillage implement is operated often vary within a field, it may be necessary to adjust the implement's settings while the implement is operating in the field. The following external data (data input) and implement data (data output) can be used for this purpose.

[0073] Data input: (old data georeferenced)

[0074] 1. Soil moisture map weekly DWD

[0075] 2. NDVI maps Sentinel 2 and other satellite or yield maps

[0076] 3. Soil maps 4. 3D model of the areas to be treated including the soil layers

[0077] 5. Optimal route on the plot with turns automatically planned

[0078] 6. Automatic turning process

[0079] 7. Pressure distribution on the tillage implement

[0080] Data output: (all data georeferenced) 1. Sensors on the plough / tillage implement / tractor

[0081] 2. Continuous tensile force measurement

[0082] 3. RGB and NIR sensor humidity and humus content (for map generation)

[0083] 4. Conductivity measurement between the plough bodies or cultivator tines (mapping) 5. Measurement of the working depth

[0084] 6. Mapping of the Earth’s gamma radiation Optimization related to:

[0085] 1 . Work result (plant cover as erosion control)

[0086] 2. Working depth

[0087] 3. Driving speed 4. Incorporation of plant residues / weeds

[0088] 5. based on all input and measured data

[0089] Optimization related to (for ploughs in particular):

[0090] 1. Automatic adjustment of the front furrow width of the traction point

[0091] 2. Transferring the plow weight and the earth bar to the tractor. Special sensors that can be used for friction-minimized tillage equipment include microphones on the back of the tillage tool, or light barriers, cameras, temperature, vibration, ultrasound, or pressure sensors in the tool. These sensors can be used to determine which areas have which type of contact between the tool and the soil. These measurements can be used to adjust the device to external conditions.

[0092] It would also be conceivable to have a camera inside the moldboard to control the boundary layer thickness and generate the soil map.

[0093] As described above, it is also possible to use not only normal air but also, for example, the (hot) exhaust gas from a tractor's exhaust as the working fluid. This is relatively easy to achieve, since the exhaust gas is available at overpressure and can be connected to the interior of the cavity and to the openings of the tillage implement via a suitably connected line or hose. (Figure 23)

[0094] Even if it has not yet been stated in the patent claims of the present disclosure, it is nevertheless the express aim of the present application to differentiate all individual features presented in the description and in the drawings from the prior art - if necessary.

[0095] Figure 19 shows a simple example in which a certain excess pressure can be delivered to the plow via the engine in a tractor (air supply) and / or water (water tank) via a corresponding device, such as a pump or compressor. A simpler version is shown in Figures 20 and 21.

[0096] Figure 22 shows, in sub-figures a) and b), how the expansion of the cavity, i.e., the two opposing plates in the cavity, can be prevented when an overpressure (p) develops between these two plates. Figure 22 b) shows that the opposing plates are connected to each other by means of rods or sheets, thus preventing the two plates forming the outside of the plough from expanding. The openings are not shown in Figure 22.

[0097] As shown in Figure 6 of the present application, the plough may not only be a forestry plough, but also a so-called strip plough, in which the plough body consists of individual metal strips into which the working fluid can penetrate and through which it can escape to the outside through openings in the body.

[0098] The plow body shown in Figure 2 is reinforced by its division into individual pressure chambers. These reinforcements (struts) can absorb tensile forces and thus reduce deformation caused by internal pressure, as well as counteract shear and compressive stresses and such external forces. The plow shown in Figure 2 is more resilient overall, and material savings can potentially be achieved in its design.

[0099] Figure 23 shows the direct use of the tractor engine's exhaust gas, whereby the exhaust gas or air is fed into the tillage implement as a working fluid. The working fluid then also has a predetermined high temperature, which improves the performance of the tillage implement.

[0100] If impurities settle in the openings of the soil tillage implement, they can be removed by supplying working fluid to the soil tillage implement or by pulsed pressure or by a pressure that is significantly higher than the pressure when the soil tillage implement is in use. In this case, the pressure of the working fluid is relatively slightly above the external pressure, for example 0.1 to 1.0 bar, preferably 0.1 to 0.5 bar above the pressure (atmospheric pressure). Any value between the prescribed intervals is suitable. Hole diameters and hole spacing in the soil tillage implement according to the invention also always depend on the soft environment in which the soil tillage implement is used. For example, a hole diameter in the order of 0.2 mm to 1.0 mm and a hole spacing in the range of 18.0 to 35.0 mm are well suited for heavy soils.For the cultivation of light or crumbly soils, both the.

[0101] Hole diameters and hole spacings can be selected to be smaller, for example 0.1 to 0.5 mm or a hole spacing of 5.0 to 20.0 mm, preferably 10.0 to 15.0 mm.

[0102] If the working fluid is routed from the tractor to the soil tillage implement, lines can be designed to transport the working fluid. This does not necessarily require a separate line; for example, if the soil tillage implement itself has a frame with a hollow tube, such as a square tube, the working fluid can also be routed through such a hollow tube within the frame. This has the advantage that the supply line is protected from external damage. The general state of the art is based on:

[0103] Bertelsen, William R. (1965): Plow. US19620221669. In: United States Patent Office A01 B15 / 02;A01 B17 / 00 (US3180432 (A)).

[0104] Borsa, Bela (1988): Testing the normality of the traction force distribution during plowing. In: Fundamentals of Agricultural Engineering 38 (5), pp. 158-167. Crowther, Edward M.; Haines, William B. (1924): An electrical method for the reduction of draught in plowing. In: J. Agric. Sci. 14 (2), pp. 221-231.

[0105] Formato, A.; Faugno, S.; Paolillo, G. (2005): Numerical Simulation of Soil-plow Mold-board Interaction. In: Biosystems Engineering 92 (3), pp. 309-316.

[0106] Gscheidle, Rolf (ed.) (2009): Automotive Engineering. 29th, revised edition. Haan-Gruiten: Publishers Europa-Lehrmittel Nourney Vollmer (European textbook series for automotive engineering).

[0107] Job, Georg; Rüffler, Regina (2021): Physical Chemistry. A New Conceptual Introduction with Numerous Experiments. 2nd edition. Wiesbaden, Heidelberg: Springer Spektrum (Textbook). Larson, DL; Clyma, HE (1995): Electro-osmosis Effectiveness in Reducing Tillage Draft Force and Energy Requirements. In: Transactions of the ASAE 38 (5), pp. 1281–1288.

[0108] Mackson, CJ (1962): The Effect of Electro-osmosis on Soil to Steel Sliding Friction as Influenced by Speed ​​Voltage and Soil Moisture. In: American Society of Agricultural Engineers. Massah, Jafar; Rahmani Fard, Mohsen; Aghel, Hassan (2021): An optimized bionic electro-osmotic soil-engaging implementation for soil adhesion reduction. In: Journal of Terramechanics 95 (3), pp. 1-6.

[0109] Qaisranl, Rashid; Jianqiao, Li (2016): Application of Bio-Inspired Surfaces in Reducing Adhesion to the Surfaces of Soil-Engaging Components of Agricultural and Earth-Moving Machinery. In: Eddie YK Ng and Yuehao Luo (eds.): Bio-Inspired Surfaces and Applications: WORLD SCIENTIFIC, pp. 485-553.

[0110] Qin, Kuan; Zhang, Yongzheng; Shen, Zhougao; Cao, Chengmao; Wu, Zhengmin; Ge, Jun et al. (2022): Investigating the Coupling Effect of High Pressure and Hot Air on External Friction Angle Based on Resistance Reduction Tests on Subsoiling Tillage Tools for Sandy

[0111] Clay Loam. In: Agronomy 12 (11), p. 2663.

[0112] Rick, Hans (2013): Gas Turbines and Aircraft Propulsion. Berlin, Heidelberg: Springer Berlin Heidelberg.

[0113] Schilling, Dr. Erich (1962): Agricultural Machinery. Textbook and Handbook for Agricultural Machinery Engineering. Machines and Equipment for Soil Cultivation. 2nd edition.

[0114] Wismer, R.D.; Wegscheid, EL; Luth, HJ; Romig, BE (1968): Energy Application in

[0115] Tillage and Earthmoving. In: SAE Transactions (77), last checked on 17.01.2022UTC.

Claims

Claims 1. Soil cultivation device with reduced friction, wherein the cultivation device has a surface which, during soil cultivation, cultivates the soil in the desired manner, e.g. turns, loosens, mixes or the like, wherein the soil cultivation device has a surface with a plurality of openings which are substantially circular, oval or polygonal and have the largest diameter of less than 2.5 mm, preferably less than 1.5 mm, particularly preferably less than 1 mm (e.g. 0.3 mm), and the openings are at a desired angle to the surface, wherein the angle is in the range of 30 to 90 °.

2. Soil cultivation device according to claim 1, characterized in that it has a supply line for a working fluid, for example air, (cold or hot liquid, for example water or the like), which is provided by the tractor of the soil cultivation device, wherein the working fluid penetrates out through the openings of the soil cultivation device in order to reduce the coefficient of friction of the soil cultivation device during the working process.

3. Soil cultivation device according to one of the preceding claims, characterized in that the working fluid is mixed with additives by which the boiling temperature is influenced, or a fertilizer is also added to the soil when the working fluid emerges.

4. Soil cultivation device according to one of the preceding claims, characterized in that the working fluid is subjected to a certain overpressure above the atmospheric pressure, preferably an overpressure of 0.01 to 0.5 bar, preferably 0.03 to 0.3 bar.

5. Soil cultivation device according to one of the preceding claims, characterized in that the tractor has a reservoir of the working fluid, which is designed and / or provided by means of a dispensing device, for example a pump, compressor or the like, via at least one line with the soil cultivation device for supplying the working fluid to the opening of the soil cultivation device, wherein the soil cultivation device has an internal cavity (Fig. 22) into which the working fluid can flow in order to then flow through the opening of the soil cultivation device to the surface of the soil cultivation device.

6. Soil cultivation device according to one of the preceding claims, characterized in that the hole diameter of the openings is in the range from 0.2 to 1.0 mm and the hole spacing is preferably in the range from 18 to 35 mm, preferably 20 to 30 mm (Figure 10) 7. Soil cultivation device according to one of the preceding claims, characterized in that the soil cultivation device can be compared to a plough, a cultivator, a seed drill, a drill or a strip plough.

8. Soil cultivation device according to one of the preceding claims, characterized in that for cleaning impurities that settle in the openings, a fluid is supplied to the soil cultivation device at an overpressure, for example up to 10 bar, wherein this overpressure is significantly higher than the overpressure during typical use of the soil cultivation device with the features according to claim 4.

9. Soil cultivation device according to one of the preceding claims, characterized in that the working fluid has a temperature of more than 50 degrees Celsius, preferably more than 100 degrees Celsius and, if the working fluid is a gas, for example air, the working fluid also has a temperature of 500 to 1000 degrees Celsius, preferably 800 degrees Celsius.

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