Soil cultivation tool

Abstract

A soil cultivation tool with improved durability of a material-bonded connection between the share body / support body and the carbide inserts / tool ​​body is proposed. This is achieved by incorporating one or more drainage profiles into the tool body to allow air, gas, or liquid inclusions that could interfere with the bonding process to escape.

Description

[0001] The invention relates to a soil cultivation tool, according to the preamble of claim 1, and further to a manufacturing method for a corresponding soil cultivation tool.

[0002] Soil cultivation tools are used in agricultural equipment to cut, loosen, break up, or mix soil material or vegetation on the soil surface, such as weeds or plant residues. Naturally, soil cultivation tools are subject to abrasive wear as they move across the soil surface. To counteract abrasive wear and extend the service life of soil cultivation tools, particularly those geometries prone to wear, such as points and cutting edges, are armored with carbides or fitted with carbide, ceramic, or sintered plates.

[0003] Application EP923851A1 shows a loosening share for a soil cultivation implement with a carbide coating at the wear-prone areas. Furthermore, application DE102011102053A1 shows a share or share point with a carbide-tipped share body and a replaceable, additional guide element as a wear surface.

[0004] Patent DE102004034093B4 protects a method for applying hard metal plates to a share body and simultaneously combines a tempering of the share body.

[0005] It has been found that the durability of the bond between the share body and the carbide inserts is reduced by insufficient contact of an adhesive between the share body and the carbide inserts. This leads to premature breakage or peeling under localized stress on the carbide inserts and tips, such as that caused by unexpected contact with foreign objects in the soil. This results in the loss of the carbide inserts and, consequently, significant premature wear of the share body at the point of damage due to abrasive erosion.

[0006] The object of the invention is to avoid the above disadvantages by improving the contact of the joining agent and to improve the durability of the connection between the hard metal plates and the share body.

[0007] This problem is solved by the features of the characterizing part of claim 1 and the manufacturing method. Further advantages are discussed in the following claims.

[0008] A soil cultivation tool consists of at least a support body, for example, a share body, and at least one tool body, for example, a carbide insert. The support body and the tool body are bonded together by a joining process. The tool body has one or more drainage profiles to allow air, gas, or liquid inclusions that would interfere with the joining process to escape. This enables the controlled escape of air, gas, or liquids through the one or more drainage profiles, which could otherwise become trapped between the support body and the tool body during the joining process. As a consequence, these air, gas, or liquid inclusions would otherwise result in only partial contact of the bonded connection between the support body and the tool body.This would result in a weaker bond and premature breakage or loss of the tool body compared to a complete, continuous material bond. The material bond joining process is achieved, for example, by adding a joining agent such as solder or adhesive, and possibly fluxes or activators. Thermal assistance or application of heat during the joining process would otherwise lead to the detrimental formation of gas or vapor bubbles within the bond. The drainage profiles advantageously facilitate the removal and elimination of these disruptive air, gas, or liquid inclusions, thus improving the durability of the material bond between the support body and the tool body.

[0009] In an improved embodiment of the soil cultivation tool, the tool body has at least one main mating surface for a material-bonded connection between the support body and the tool body. The main mating surface is either the only one or the one with the largest surface area, forming at least a large part of the contact area between the support body and the tool body and serving to create the material-bonded connection. At least one drainage profile is designed as a recess or opening extending from the main mating surface through the tool body. The at least one recess or opening extends continuously from the main mating surface through the tool body to the side of the tool body opposite the main mating surface. The cross-sectional area of ​​the recess or opening, for example a bore, is preferably only a fraction of the thickness of the tool body.The thickness of the tool body is defined as the distance between the main joining surface and the opposing guide surface of the tool body in the area of ​​the recess. This fraction is preferably no more than half the thickness of the tool body, ideally no more than one-third. In the case of a single recess or opening in the tool body, it is preferably located at the centroid of the main joining surface or slightly adjacent to it. This allows air, gas, or liquid inclusions to escape via the shortest and therefore fastest path. If the main joining surface is a ruled surface such as a triangle or quadrilateral, the centroid is also the center point of the main joining surface.

[0010] In an improved embodiment of the soil cultivation tool, the tool body has at least one main interface surface for a material-bonded connection between the support body and the tool body. At least one drainage profile is designed as a recess or groove extending along the main interface surface. Preferably, the drainage profile extends from a first edge or corner of the main interface surface to an edge or corner of the main interface surface opposite the first. Here, too, the cross-sectional area of ​​the recess or groove is preferably only a fraction of the thickness of the tool body, more preferably no more than half the thickness of the tool body, and ideally also no more than one-third of the thickness of the tool body.

[0011] The main joining surface can be designed as a flat joining surface. This simplifies the production of the corresponding contact surface of the support body. Alternatively, the main joining surface can be curved. This results in a multi-axial stress transfer of shear, bending, or tensile stresses between the tool body, via the joining material, and onto the support body. These stresses arise from the action of cutting and breaking forces on the tool body, as occur during soil cultivation and the movement of the tillage tool through the soil, particularly when encountering foreign objects such as large stones. Instead of a curved main joining surface, it can also have an angle, particularly a roof-shaped one, or one or more steps. This enables a multi-shear material bond and thus also improved stress transfer between the tool body and the support body.

[0012] Advantageously, one or more tool bodies exhibit significantly higher wear resistance, tensile strength, or surface hardness than the support body. Conversely, the support body has significantly greater wall thicknesses, thicknesses, or generally a larger material volume subject to abrasive wear from soil contact than the tool bodies. This allows the support body, due to its shape, to absorb considerably greater cutting and breaking forces during feed through the soil surface and transfer them into a holder or tine attached to the frame of a soil cultivation implement. Since the tool body is preferably located in the cutting area of ​​the soil cultivation tool, it can, unlike the support body, be designed with a much thinner wall thickness or material thickness.The significantly higher wear resistance, tensile strength, and surface hardness compensate for the reduced wall thickness or material thickness. Overall, the combination of tool body and support body offers greater wear resistance and thus a longer service life before replacement is necessary. The tool body is preferably made of carbide or sintered metal.

[0013] In a particular embodiment of the soil cultivation tool, the tool body and the support body are spaced apart from each other by a gap, at least in the area of ​​the main joining surface. This defined gap allows for the application of a bonding agent, such as adhesive or solder, in a thin but uniform layer, which significantly improves the strength of the material bond. In the case of a soldered joint, the gap, defined by the specified gap, enables capillary action on the added solder, which melts into a liquid when the joint is heated and, through the gap and the existing capillary tension of the liquid solder, spreads itself into the gap.

[0014] In a further embodiment of the invention, the tool body or the support body has partial, preferably point- or knob-shaped, elevations or projections, at least in the area of ​​the main joining surface. These elevations, which preferably have a height of only a fraction of a millimeter, allow a defined joining gap to be maintained, which ensures the reproducible joining process with the aid of a joining material.

[0015] In another embodiment of the soil cultivation tool, the support body has positive locking elements or cavities for receiving one or more tool bodies. This allows the positioning of the tool body(s) on the support body to be predefined and precisely reproducibly maintained during the joining process.

[0016] Likewise, a method for manufacturing a soil cultivation tool, consisting of a support body and at least one tool body, advantageously comprises the following process steps: Shaping of the tool body, Inserting or attaching one or more drainage profiles into the tool body, hardening, tempering or sintering of the tool body, Arrangement of the tool body on the support body, Material-bonded joining process for connecting the support body and the tool body. Drainage profiles can be advantageously and easily attached to or inserted into the previously untreated tool body during or after its forming process. Only then is the tool body post-treated by hardening, tempering, flame cutting, or sintering. The now-finished tool body, equipped with drainage profiles, is then precisely positioned on the support body and firmly and permanently joined to it via a material-bonded joining process, with the previously inserted drainage profiles ensuring a reliable process.

[0017] In particular, the joining process for connecting the tool body and the support body is carried out by soldering or bonding. The previously known problems of flux evaporation during soldering are effectively and reliably avoided by the now improved process. Silver or copper solders have proven particularly suitable as joining materials for soldering. When using silver solder, the tool body and at least the adjacent area of ​​the support body must be heated to a soldering temperature below 1000 °C, ideally between 600 and 800 °C. Generally, the specified temperature ranges may vary depending on the alloying elements of the solders. When using copper solder, a soldering temperature above 1000 °C should be aimed for, ideally up to 1100 °C.In this temperature range, a process combining brazing with a simultaneous tempering process of the support body is also advantageous. The support body is made of a suitable material, particularly one containing carbon. After brazing, the soil cultivation tool, consisting of the support body and the tool body brazed to it, is quenched in a hardening bath or rapidly cooled. This rapid temperature reduction results in a structural change in the support body material that increases its strength and significantly improves its wear resistance. To further enhance the toughness of the support body and prevent brittle fractures, it can subsequently undergo a tempering process.

[0018] In bonding processes, liquid, usually viscous or pasty adhesives are used. These are difficult to apply in a constant, uniformly even layer thickness. Therefore, unwanted air inclusions form in the adhesive mass during joining. These are advantageously and harmlessly vented via the drainage profiles, preferably via the shortest possible route. Similarly, outgassing can occur during curing or thermal activation of the adhesive, which also causes unwanted bubble formation within the adhesive layer and thus weakens the bond. These gases are also effectively vented via the drainage profiles. When using a multi-component adhesive, the adhesive's hardener can also advantageously outgas through the drainage profiles.

[0019] Furthermore, the shaping and manufacturing of the tool body is advantageously carried out by the following process steps: Pre-pressing a tool body from a particulate and / or pasty tool body material, inserting or attaching one or more drainage profiles into the tool body, and sintering or firing the tool body. With extremely hard tool body materials such as sintered metal or ceramic compounds, it is extremely difficult to subsequently introduce holes or grooves as drainage profiles into the finished tool body. If the drainage profiles are pre-molded into the tool body blank, this now fully formed blank can then be easily subjected to a sintering or firing process at high temperatures.

[0020] Furthermore, the shaping and manufacturing of the tool body is improved and simplified by incorporating one or more drainage profiles through an embossing or pressing process. It has proven advantageous to integrate raised profiles or domes into a negative mold for forming and / or pre-pressing the tool body. These then act as drainage profiles, pressing into and / or penetrating the tool body. During the subsequent sintering or firing process, the drainage profiles exhibit minimal dimensional distortion, allowing the tool bodies to be manufactured in series and thus cost-effectively.

[0021] Further details and advantages of the invention will become apparent from the following description and the accompanying drawings, which illustrate an exemplary embodiment with the necessary details and components. The drawings show: Fig. 1 a soil cultivation tool in perspective, Fig. 2 a side view from Fig. 1 in sectional view, Fig. 3 a detail from Fig. 2 Fig. 4 a perspective of the tool body, Fig. 5 a bottom view of the tool body, Fig. 6 a side view of the tool body, Fig. 7 a detail from Fig. 6

[0022] The illustrations are essentially concrete embodiments. However, the invention is not limited to the illustrated embodiments, but can also be modified in a technically competent manner to adapt it to a specific application.

[0023] Fig. Figure 1 shows a soil cultivation tool 1, consisting of a support body 2 and a tool body 3. The tool body 3, along with further tool bodies 8, is bonded to the support body 2 at its front end, preferably by means of a soldered or adhesive bond. Further tool bodies 8 are arranged on both sides of the tool body 3 and are also bonded to the support body. Approximately in the middle of the support body 2, it has, as shown, at least one fastening area 7. This is, for example, designed or molded as a countersunk hole through which the support body 2, and thus the soil cultivation tool 1, can be screwed or otherwise fastened to a tine or holder of a soil cultivation implement. Several soil cultivation tools 1 are arranged laterally and / or offset from one another in the working or feed direction on the soil cultivation implement.The tool body 3 has a cutting edge 9 at its front, free end, which extends into a guide surface 10 in the upper region of the tool body 3. The soil material broken up by the cutting edge 9 slides over this guide surface 10 onto the upper surface of the support body 2, which connects to the rear end of the tool body 3. The tool body 3 is penetrated by a channel-shaped drainage profile 5, which extends from the guide surface 10 to the opposite, here concealed, main joining surface 4 of the tool body 3. The support body 2 has an L-shaped recess into which the tool body 3 is inserted and brazed with its main joining surface 4 and its rear side 12, opposite the cutting edge 9, to the surfaces of the L-shaped recess of the support body 2.Furthermore, the support body 2 has additional cavities 11 formed or removed to the right and left of the L-shaped recess. Additional tool bodies 8 are inserted into these cavities and also brazed in place. Analogous to the tool body 3, as described above, the tool bodies 8 can also have drainage profiles 5 which eliminate air, gas, or liquid inclusions by allowing air, gas, or liquid to escape from the brazing zone through one or more drainage profiles 5.

[0024] Fig. Figure 2 shows the soil cultivation tool 1. Fig. Figure 1 shows a lateral sectional view. The support body 2 has an L-shaped recess at its front end, into which the tool body 3 is inserted and bonded. The rear surface 12 of the tool body 3, opposite the cutting edge 9, is brazed to the short end, and the main joining surface 4 is brazed to the long end of the L-shaped recess. For this purpose, the surfaces to be brazed are, if necessary, wetted with flux, and both the tool body 3 and at least the front region of the support body 2 are heated to a sufficiently high brazing temperature. The added brazing material melts and penetrates, or spreads, into the area between the tool body and the support body, which is provided with a brazing gap or joining gap, by means of capillary action.Air, liquids, or residual gases displaced by the penetration and / or spread of the solder can be discharged from the joining area either to the boundary edges of the tool body 3 or through the drainage profile 5 into the surrounding environment. Similarly, in an adhesive bonding process, for example, with unevenly applied adhesive, air, liquids, vapors, or residual gases can be discharged through the drainage profile 5 into the surrounding environment during the joining of tool bodies and support bodies and the subsequent adhesive curing.

[0025] Fig. Figure 3 shows the front section of the soil cultivation tool 1. Fig. Figure 2 is shown in an enlarged view. The support body 2 and the tool body 3 are separated from each other by a joining gap with a gap dimension s. This creates a defined joining gap for the addition of an adhesive or solder. The gap dimension s can be precisely defined and maintained by point- or cam-shaped protrusions 13 or projections arranged on the main joining surface 4 of the tool body or opposite it on the support body 2. By arranging three protrusions 13 on the main joining surface outside the area of ​​the drainage profile 5, the position of the tool body 3 relative to the support body 2 is also geometrically stable. This eliminates further positioning errors, particularly with regard to maintaining a predetermined gap dimension s.The rear side of the tool body 3 also forms a joining gap with the support body, with a gap dimension s, which enables the previously described advantages for this area as well. The gap dimension s of the respective joining areas is preferably less than 1 mm, more preferably no more than 0.5 mm, and ideally selected to be in the range of 0.3 to 0.5 mm.

[0026] Fig. Figure 4 shows a tool body 3 in a perspective from a rear oblique angle. The guide surface 10 of the tool body 3 adjoins the front cutting edge 9 in the upper region, extending to its rear end. The guide surface 10 has a drainage profile 5, designed as a through-hole or recess, which extends to the main joining surface 4 of the tool body 3 opposite the guide surface 10. The main joining surface 4, together with the rear surface 12 of the tool body 3, forms a multi-section interface for a material-locking connection with the L-shaped recess of the support body 2.

[0027] Fig. Figure 5 shows the underside of the tool body 3. Fig. 4 with a view to the main joining surface 4 and the area of ​​the cutting edge 9 of the tool body 3 adjacent to it. In the central area of ​​the main joining surface 4, the previously in Fig. The recess described in section 4 or the opening of the drainage profile 5 through the tool body 3 is visible. Further drainage profiles 6, shaped like grooves or channels, open onto the drainage profile 5. These extend across the main joining surface 4 to its outer edge, preferably to its corners. More preferably, the drainage profiles 6 are arranged in a cross or star shape starting from the drainage profile 5 and divide the main joining surface 4 into several sub-areas. Air, liquid, or gas inclusions that form within these sub-areas can only be discharged to the outside or towards the tool body via the drainage profiles 6 and the drainage profile 5. The air, liquid, or gas inclusions that interfere with the joining process are thus released into the environment via the shortest possible route and thereby eliminated. Further protrusions 13 are arranged outside the area of ​​the drainage profiles 5, 6.The distance between the elevations 3 and the drainage profiles 6 and the respective adjacent edges of the main joining surface is preferably approximately the same.

[0028] Fig. Figure 6 shows a cross-section of the tool body 3. Fig. 4 and Fig. 5 as well Fig. Figure 7 shows an enlarged view of the drainage profile 5 into which the previously described drainage profiles 6 of the main joining surface 4 open. The cross-sectional area of ​​the drainage profile 5 at its largest point is preferably no more than half the mean thickness d of the tool body, ideally no more than one-third of the thickness d of the tool body. The drainage profiles 6 are preferably formed as trapezoidal, more preferably as semicircular or semi-ellipsoidal grooves or recesses and are either cut out of, formed into, or embossed in the main joining surface 4 of the tool body 3. The lateral cross-sectional area of ​​the drainage profiles 6 at their largest point, i.e., at the main joining surface 4, is preferably also no more than half the mean thickness d of the tool body, ideally no more than one-third of the thickness d of the tool body.The depth t of the drainage profiles 6 is preferably no more than the gap dimension s, which defines the joining gap, and preferably at least, but not more than, twice the amount of the gap dimension s. The mean thickness of the tool body 3 in the area of ​​the drainage profile 5 is represented by the dimension d. The in . Fig. The 6 visible protrusions 13, formed on the main joining surface 4 of the tool body 3, have a maximum distance s measured from the main joining surface 4, which defines the gap dimension to the opposite connecting surface of the support body 2 not shown. REFERENCE MARK LIST 1 soil cultivation tool 2 support structures 3 Tool bodies 4 Main joining surface 5 Drainage profile 6 Drainage profile 7 Mounting area 8 Tool bodies 9 cutting edge 10 Guide surface 11 Cavity 12 Back 13 Survey QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 923851A1

[0003] DE 102011102053A1

[0003] DE 102004034093B4

[0004]

Claims

[1] Soil cultivation tool (1) consisting of a support body (2) and at least tool body (3), wherein the support body (2) and the tool body (3) are joined together by a joining process in a materially bonded manner, characterized by , that the tool body (3) has one or more drainage profiles (5, 6) to allow air, gas or liquid inclusions that interfere with the joining process to escape. [2] Soil cultivation tool (1) according to claim 1, characterized by , that the tool body (3) has at least one main joining surface (4) for a material-bonded connection between the support body (2) and the tool body (3), wherein at least one drainage profile (5) is formed as a recess or opening extending from the main joining surface (4) through the tool body (3). [3] Soil cultivation tool (1) according to claim 1 or 2, characterized by, that the tool body (3) has at least one main joining surface (4) for a material-bonded connection between the support body (2) and the tool body (3), wherein at least one drainage profile (6) is formed as a recess or groove extending along the main joining surface (4). [4] Soil cultivation tool (1) according to any one of the preceding claims, characterized by , that the main joining surface (4) is designed as a flat, curved, angled or stepped joining surface. [5] Soil cultivation tool (1) according to the preceding claims, characterized by , that at least one tool body (4) has a higher wear resistance, tensile strength and / or surface hardness than the support body (3), in particular being designed as a hard metal or sintered metal body. [6] Soil cultivation tool (1) according to the preceding claims, characterized by, that the tool body (3) and the support body (2) are spaced apart from each other by a gap dimension (s) at least in the area of ​​the main joining surface (4). [7] Soil cultivation tool (1) according to the preceding claims, characterized by ,. that the tool body (3) or the support body (2) has partial, preferably point-shaped elevations (13) or projections at least in the area of ​​the main joining surface (4). [8] Soil cultivation tool (1) according to the preceding claims, characterized by that the support body (2) has positive locking elements or cavities for receiving one or more tool bodies (3) [9] Method for manufacturing a soil cultivation tool (1) comprising a support body (2) and at least one tool body (3), characterized by the procedural steps: Shaping of the tool body (3), Inserting or attaching one or more drainage profiles (5,6) into the tool body (3), Hardening, tempering or sintering of the tool body (3), arrangement of the tool body (3) on the support body (2) as well as material-bonded joining process for connecting the supporting body (2) and Tool body (3). [10] Method for manufacturing a soil cultivation tool (1) according to claim 9, characterized by that the joining process is carried out as a soldering or gluing process. [11] Method for manufacturing a soil cultivation tool (1) according to claim 9 or 10, characterized by , that the shaping and manufacture of the tool body (3) is carried out by the following process steps: Pre-pressing of a tool body (3) from a particulate and / or pasty tool body material, Inserting or attaching one or more drainage profiles (5,6) into the tool body (3), as well as Sintering or burning process of the tool body (3) [12] Method for manufacturing a soil cultivation tool (1) according to claim 11, characterized by , that the insertion or attachment of one or more drainage profiles (5, 6) is carried out by an embossing or pressing process.

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