Tool component and method for producing a tool component

Abstract

A tool component (1) of a machine tool comprises a functional body (2) having at least one functional surface (4) and a support body (3) which supports the functional body (2), wherein the functional body has at least one surface for fixing or guiding the tool component (1) within the machine tool, wherein the functional body (2) is formed at least partially from a solid material. The tool component (1) is characterised in that the structure of the support body (3) adjoins the structure of the functional body (2), the functional body (2) at least partially has a carrying structure having cavities, and the carrying structure is formed at least partially from a hard material, a hard metal or a hard alloy on a cobalt-chromium basis.

Description

[0001] Tool component and method for producing a tool component

[0002] The present invention relates to a tool component of a machine tool, comprising a functional body with at least one functional surface and a support body that supports the functional body. The functional body has at least one surface for securing or guiding the tool component within the machine tool. The functional body is formed at least partially from a solid material. The present invention further relates to a method for producing such a tool component.

[0003] DE 10 2016 108 507 A1 discloses a cutting tool with a rake face and flank faces, which has an internal cavity containing one or more lattice structures. These lattice structures are intended to enable a lightweight construction, thus also enabling more cost-effective production.

[0004] DE 10 2016 221 518 A1 discloses a tool holder for a metal-cutting machine, comprising a base body with a fixing area for fixing a tool holder in the metal-cutting machine and a receiving area for receiving and fixing a metal-cutting tool. This base body is intended to be formed at least partially from a supporting structure having cavities. The cavities can be shaped as a honeycomb structure, a spoke structure, a tubular structure, or in a variety of other ways.

[0005] EP 4 063 047 A1 also discloses such a tool holder for a cutting machine.

[0006] The object of the invention is to create a tool component with high wear resistance.

[0007] This problem is solved as stated in claim 1.

[0008] The invention also aims to provide a method for producing a tool component. This objective is achieved as defined in claim 8.

[0009] Advantageous further training results from the respective sub-claims.

[0010] According to the invention, hard metals or hard alloys based on cobalt-chromium are intended for use in the support body because they are characterized by their high hardness, as well as their toughness and wear resistance. Hard metals are metal matrix composite materials in which hard materials, present as small particles, are held together by a metal matrix. Tungsten carbide (WC) is most commonly used as the hard material, but it can also be titanium carbide (TiC), titanium nitride (TiN), niobium carbide, tantalum carbide, or vanadium carbide.

[0011] Due to their high wear resistance, hard metals and hard materials can be used in the manufacture of tools or tool parts for cutting, punching, forming, pressing, countersinking, and drawing tools. For example, they can also be used as parts of tools for the production of products made of metal and ceramic powders, for stamped parts in the automotive and electrical engineering industries, and for the drawing of metal containers and bricks. Due to their comparatively low wear, components made of hard metals, hard materials, or the alloys mentioned above are also gentle on machines, as hardly any abrasion is generated that enters the manufacturing machine.

[0012] According to the invention, the tool part comprises a functional body, which can be a solid block or a round or square rod, a ring, or a molded plate; in individual embodiments, bores or other recesses are also present in the functional body. A tool part within the meaning of the present invention also includes a machine part.

[0013] The functional body forms the working part of a tool or tool component, which only fulfils a functional or working task on its surface, while a component of the tool or tool component is connected to the functional body or forms a core of the tool or tool component, which only has a supporting and shape-preserving function and is therefore referred to below as the supporting body.

[0014] According to the invention, the supporting body is replaced by a honeycomb, cell or grid-shaped structure made of the same or a different material, instead of the compact structure of the core known from the prior art, which continues to assume the supporting function of the previously solid core.

[0015] The tool component according to the invention has a working part or a functional part made of a hard metal or a hard alloy. At least one side surface of the tool or tool component consists of the solid material, which does not preclude the support body from also having outer surfaces or parts made of a solid material.

[0016] The core of the support body is made of the same or a different material as the functional body and is characterized, for example, by a honeycomb or lattice-shaped structure.

[0017] The support body or the entire component is manufactured using additive manufacturing, particularly through 3D printing. Fused Deposition Modeling (FDM) or Fused Filament Fabrication (FFF) are particularly suitable manufacturing processes in the field of 3D printing; these processes allow a workpiece to be built up layer by layer from molten metal.

[0018] The partially hollow structure of the support body allows for a weight saving of at least 15% compared to solid material; the reduction in component weight conserves resources.

[0019] Advantageous further developments emerge from the dependent claims and the description, particularly in conjunction with the drawings. The tool component according to the invention preferably comprises a functional body that is annular, rectangular, cylindrical, or designed as a sliding block or as a blank.

[0020] According to an advantageous embodiment of the invention, it is provided that at least the support body is at least partially produced by an additive manufacturing process and that the support body, insofar as it is produced by the additive manufacturing process, has a support structure produced by the additive manufacturing process.

[0021] If the supporting structure of the support body has a textured structure, a honeycomb structure, a meandering structure, a gyroid structure, or a structure with at least substantially periodic or randomly repeated structural support elements, a weight reduction of at least 15% can be achieved compared to a solid body, thus saving valuable raw material. Despite the weight savings, the full functionality of the tool component is ensured.

[0022] Advantageously, it can be provided that the tool component has a support body with a closed-pore structure or with a structure comprising at least one channel.

[0023] In a further embodiment of the invention, the at least one channel serves as a temperature control channel, allowing the temperature range in which the tool operates to be adjusted over a wide range and reducing wear. Furthermore, an open-pore support structure can be used for the uniform or targeted distribution of a cooling, heating, or lubricating medium to control the temperature of the tool or machine part, or even to lubricate it.

[0024] In a method for producing a tool component, a tool, or a machine component, the functional body is produced by a casting process or an additive manufacturing process, while the support body, which builds on or adjoins the functional body, is always produced by an additive manufacturing process. Advantageously, the tool component is sintered during or after the manufacturing process.

[0025] It is also shown that the tool component produced according to the invention has an effective and adaptable damping behavior and a high stability while being easy to manufacture.

[0026] The tool component described above is intended, for example, for use in a forming machine. This could be a bending machine or a deep-drawing machine, for example.

[0027] The tool component comprises, for example, a shaft-, cylinder-, or ring-shaped functional or base body, by means of which the tool component can be fixed within a tool or moved along a contour, for example along a circular or oval contour. In such a case, the functional body has the shape of a piston that can be moved within a hollow cylinder. In another exemplary embodiment, a fixing region serves to fix the functional body of the tool component in a cutting machine. The fixing region is thus designed to be received by the cutting machine or fixed in the cutting machine, for example, to be clamped. The functional body is characterized in that it has at least one functional surface through which it acts on the part to be machined in the machine tool, for example, a metal surface to be formed.In addition, the functional body has, for example, at least one guide surface, over which it is guided within the tool. The functional body also has at least one surface via which it is connected to the support body. In one embodiment, the functional body and / or the support body are ring- or cylindrical-shaped. However, according to the invention, any contours of the functional body are possible, for example, even cuboid structures.

[0028] According to the invention, the support body is formed at least partially from a supporting structure having cavities. The support body is constructed, for example, from a supporting structure shaped in such a way that it has and encloses cavities; the support body is, for example, porous. A cavity is generally understood to be any hollow space defined by the supporting structure and thus surrounded and closed by it.

[0029] Because the support body is at least partially formed from a support structure with cavities, wherein the cavities are also filled with a fluid or a solid material, for example, a granular material, effective damping behavior can be achieved. This is particularly true compared to a body formed from a solid material, as is known from the prior art. In detail, the design of a support structure with cavities results in the weight or mass of the material filling the cavities of the support body exerting a certain inertia on the entire tool component. This inertia leads to the damping of the tool component.

[0030] Such a support body also offers the additional advantage of effective adaptability of the damping properties. This is because the damping behavior can be easily adapted to the desired application area by varying the fill quantity, the powdered material filled in, or the number and size of the cavities, i.e., the volume ratio of cavities to the supporting structure.

[0031] Furthermore, such a support body, due to the structure described above, offers a stability that is essentially comparable to that of a support body of a tool component made of a solid material.

[0032] Preferably, the support body is manufactured at least partially by an additive process. For example, the support body can be formed entirely by an additive process. Using an additive or generative process, such as selective laser melting, binder jetting (free-jet binder application), or FDM printing, a tool component with a comparatively complex structure can be manufactured quickly and precisely. In particular, the structure of the support body with a support structure and cavities can be created in a simple manner, something that was not possible, or at least not trivially possible, using conventional manufacturing technology.

[0033] The textured, honeycomb, lattice-like, or other structure comprising connecting struts, connecting tubes, or tubes arranged side by side creates a cavity with a very large surface area, which facilitates good heat transfer from the support body to a cooling fluid flowing through the cavity, making the support body well-suited for controlling the temperature of the functional body. A plurality of temperature control channels is particularly preferably provided. This can be advantageous for the functionality of the tool component, since it is often desirable or necessary to cool or heat the area where forming, machining, or other material processing takes place, for example, with a fluid that preferably serves as a heat transfer agent and also serves as a lubricant.For example, the tempering channel or the tempering channels running through the tool component can have one or more inlets through which the tempering channels can be connected to the machine tool, for example the forming or cutting machine.

[0034] It may further be preferred for the cavities in the support body to be formed in the form of a honeycomb structure. This should mean, in particular, that in a cross-section through the cavities, the support structure delimiting the cavities has a hexagonal honeycomb structure, roughly comparable to a honeycomb. In particular, this configuration can enable high stability even with a support structure formed from comparatively little material. This configuration can also make it possible, for example in an additive process such as laser sintering, to save a great deal of production time, which can make the manufacturing process particularly economical. Furthermore, a honeycomb structure can be advantageous because the areas or parts of the support structure are optimally interconnected inside, which can lead to high stability.

[0035] In addition to a honeycomb structure, which may be preferred, other structures or textures may also be preferred, in which the cavities have a tubular orientation or a tubular course and are shaped parallel. Examples include cylindrical structures or triangular structures in a cross-section through the cavities.

[0036] The process for manufacturing the tool component enables simple and economical manufacturing, as described in detail below.

[0037] For example, it may be preferred that the functional body is also formed at least partially and the support body is formed completely by an additive process, wherein the additive process using a hard metal or an alloy of hard metals or a hard alloy based on cobalt-chromium leads to very high strength and stability.

[0038] An additive or generative process can be understood in particular as a process in which a component is manufactured on the basis of digital 3D design data by depositing or building up material layer by layer. Examples of such processes include 3D printing, which is often also understood to mean FDM printing or the binder jetting process. An additive manufacturing process differs significantly from conventional, subtractive manufacturing methods. Instead of milling a workpiece out of a solid block, as is common with subtractive processes, the components in additive manufacturing are built up layer by layer from materials or raw materials, the starting material being a fine powder or filament.

[0039] For processing, such as melting the raw material, which is particularly in powder form, a laser such as a CO2 laser, an Nd:YAG laser or a fiber laser, or even an electron beam source is used.

[0040] Using an additive process offers the particular advantage that the base body can be created as a whole in a single manufacturing step. This allows for simple process sequences to be implemented, which can reduce manufacturing costs. Furthermore, an additive process can enable essentially any structure with cavities without increasing manufacturing costs, which can further improve adaptability with regard to stability and coolant utilization.

[0041] Using an additive process, the supporting structure can be easily formed in the raw material by melting it, while the remaining raw material can remain in the cavities. This allows for a simple process, since the remaining raw material is actually disadvantageous in conventional additive processes, as it must be removed in a subsequent process step. If no raw material remains in the cavities due to the use of an FDM process, this can be achieved using binder jetting. Binder jetting, also known as free-jet binder deposition, is an additive manufacturing process in which powdered starting material is combined with a liquid binder at selected locations to create workpieces.

[0042] As a result, the invention creates a component, in particular a tool part or a machine part, which consists at least partially of a hard material, a hard metal, or a hard alloy based on cobalt-chromium. A component according to the invention is suitable for replacing machine or tool parts (or tools) which, for wear reasons, were previously made of, for example, hardened tool steel, with the above-mentioned hard materials, hard metals, or hard alloys based on cobalt-chromium, whereby attention is paid to weight optimization while taking machine dynamics into account. Preferably, cavities are provided according to the invention which compensate for the higher weight of the metals or metal compounds used according to the invention or even enable a lower weight than achievable with conventional metals.

[0043] The advantages of the invention therefore include not only reducing wear on the functional surfaces but also weight optimization with the goal of generating components that are either equally heavy or lighter. Since, for example, hard metal has approximately twice the density of steel and, as a solid component, would result in disadvantages in machine dynamics regarding speed and increased vibrations, as well as increased wear in other areas and higher energy consumption, improved machine dynamics are achieved by the inventive introduction of cavities, in particular through honeycomb, lattice, or cell-shaped cavities, but also through other cavities provided according to the invention.

[0044] Laser sintering can be used for parts made of both hard metal and stellite-like alloys.

[0045] A preferred manufacturing process is the FDM or FFF process, in which a tool component body is built up layer by layer using a hard filament containing a thermoplastic binder. Afterward, a portion of the plastic is removed using solvent debinding in preparation for the sintering process, which only allows for limited maximum wall thicknesses. The gyroid structure is advantageous here because it is open-pored and therefore also allows for debinding from the inside, provided small holes are drilled to allow the solvent to penetrate.

[0046] According to the invention, the functional body assumes the primary function of guiding the component within the machine tool and ensures a uniform surface structure that is adapted to the conditions within the machine tool, such as the temperatures or the substances that touch or act on the functional body from the outside.

[0047] The support body performs secondary functions such as fastening, force transmission, bearing, and guidance functions. The filler structure is designed to perform the support function while simultaneously reducing weight compared to prior art structures. The filler structure performs special functions such as force transmission or, through channels incorporated within it, fluid guidance, temperature control, and / or lubrication. The support body is at least partially integrated into the functional body. The support body preferably differs from the functional body only in the transition to the support structure.

[0048] The invention is described in more detail below with reference to preferred embodiments. In the drawings: Fig. 1 a shows a side view of a first tool component,

[0049] Fig. 1 b is a horizontal sectional view of the first tool component along a section line A - A from Fig. 1 a,

[0050] Fig. 1 c is a vertical sectional view of the first tool component along a section line B - B from Fig. 1 b,

[0051] Fig. 2a is a side plan view of a support body of a second tool component,

[0052] Fig. 2b is a horizontal sectional view of the support body along a

[0053] Section line A - A from Fig. 2a,

[0054] Fig. 2c a vertical sectional view of the support body along a

[0055] Section line B - B from Fig. 2b,

[0056] Fig. 3a a side view of a third tool component,

[0057] Fig. 3b is a side view of the third tool component, partially sectioned along a section line A - A of Fig. 3a,

[0058] Fig. 3c is a horizontal sectional view of the third tool component along a section line B - B from Fig. 3a,

[0059] Fig. 3d is a vertical sectional view of the third tool component along a section line C - C from Fig. 3c,

[0060] Fig. 4a is a side view of a fourth tool component,

[0061] Fig. 4b is a side view of the third tool component, partially sectioned along a section line A - A of Fig. 4a, Fig. 4c is a horizontal sectional view of the third tool component along a section line B - B of Fig. 4a,

[0062] Fig. 4d is a vertical sectional view of the third tool component along a section line C - C from Fig. 4c,

[0063] Fig. 5a is a vertical sectional view through a schematically illustrated tool component with a punch that can be guided through a die to form a cylindrical hollow body together with a sheet metal blank to be machined by the tool before deformation and

[0064] Fig. 5b is a vertical sectional view of the tool component according to Fig. 5a after deformation of the sheet metal blank into the cylindrical hollow body, wherein the punch is guided through the die.

[0065] A tool component 1 (Figs. 1 a - 1 c) comprises a cylindrical functional body 2 and a support body 3, also cylindrical, shown above the functional body 2 and firmly connected to the functional body 2. The strength and stability of the functional body 2 are ensured by the functional layer 5 forming a functional surface 4. The functional layer 5 is connected on both sides to an outer wall 6 of the support body 3 and merges into it.

[0066] The functional body 2 and the support body 3 are preferably formed in their walls 5 and 6 (functional layer 5 and outer wall 6) from the same hard material, the same hard metal, or the same cobalt-chromium-based hard alloy. In another embodiment, the functional body 2 and the support body 3 have the same diameter. Instead of a circular cross-section, the functional body 2 and the support body 3 can have any other cross-sections, for example, elliptical cross-sections.

[0067] Internally, the functional body 2 and the support body 3 consist of the same support structure 7, which includes channels or cavities 8 and support walls 9 arranged between them. The support walls consist of a three-period minimal structure, which also includes the well-known gyroid shape. This open-pore 3D structure offers the advantages of easy printability with minimal material usage and high strength in all axial directions. Furthermore, the open porosity facilitates the further manufacturing process by reducing massive material thicknesses. Overall, the interior of the functional body 2 merges seamlessly into the interior of the support body 3 and is manufactured using the same additive manufacturing process.

[0068] Another, also cylindrical support body 10 (Figs. 2a - 2c) has a honeycomb structure 11 with honeycombs 12 within it. The honeycombs 12 have walls extending vertically. A functional body (not shown here) onto which the support body 10 is placed, for example, is also constructed in the same way as the support body 10, or it is made of solid material.

[0069] In a further embodiment, a tool component 15 (Figs. 3a - 3d) with a functional body 16 and a support body 17 is configured in its external structure like the tool component 1. In its interior, the functional body 16 and the support body 17 each have a square structure 18. The functional body 16 and the support body 17 have a common wall 19.

[0070] In another embodiment, a tool component 20 (Figs. 4a - 4d) with a functional body 21 and a support body 22 is designed in its external structure like the tool components 1 and 15. In its interior, the support body 22 has a spoke structure 23; the functional body 22, however, is formed from a solid material.

[0071] In a further exemplary embodiment (Figs. 5a, 5b), a punch 30 of a tool or tool component 31 for forming a hollow cylinder 32 from a sheet metal blank 33, i.e., a circular sheet, for example made of aluminum, has a functional body 34 which surrounds a support body 35 at least on the side facing the sheet metal blank 33, preferably also on its outer surface 36, preferably likewise on its upper side 37. In another embodiment of this exemplary embodiment, however, connections for the supply and discharge of fluids, for example for cooling, which are passed through the structure of the support body 35 can be provided on the upper side 37.

[0072] By pushing the punch 30 through a die 38 in the direction of an arrow 39 together with the sheet metal blank 33, the punch 30 deforms the sheet metal blank 33 into the hollow cylinder 32, which can be used to produce a closed cylindrical container.

[0073] The die 38 also comprises a functional body 40 and, within its interior, a support body 41. In an embodiment (not shown here), this can also be supplied with a fluid, for example, to cool the support body 41.

[0074] Alternatively, the support body and / or the functional body have a plurality of different structures, for example columns, which extend according to the longitudinal axis of the cylindrical shape of the support body and / or the functional body and which form the supporting structure.

Claims

Patent claims 1. Tool component (1, 15, 20; 31) of a machine tool, comprising a functional body (2, 16, 21; 34, 40) with at least one functional surface (4) and a support body (3, 17, 22; 35, 41) which carries the functional body (2, 16, 21; 34, 40), wherein the functional body (2, 16, 21; 34, 40) has at least one surface for fixing or for guiding the tool component (1, 15, 20; 31) within the machine tool, wherein the functional body (2, 16, 21; 34, 40) is formed at least partially from a solid material, characterized in that the structure of the support body (3, 17, 22; 35, 41) is adapted to the structure of the functional body (2, 16, 21; 34, 40) that the functional body (2, 16, 21; 34, 40) at least partially has a support structure having cavities and the support structure is at least partially formed from a hard material, a hard metal or a hard alloy based on cobalt-chromium.

2. Tool component (1, 15, 20; 31) according to claim 1, characterized in that the functional body (2, 16, 21; 34, 40) is annular, rectangular, cylindrical, designed as a sliding block or as a shaped blank.

3. Tool component (1, 15, 20; 31) according to claim 1 or 2, characterized in that at least the support body (3, 17, 22; 35, 41) is at least partially produced by an additive manufacturing process and that the support body (3, 17, 22; 35, 41), insofar as it is produced by the additive manufacturing process, has a support structure produced by the additive manufacturing process.

4. Tool component (1, 15, 20; 31) according to claim 3, characterized in that the support structure has a textured structure, a honeycomb structure, a spoke structure (23), a meandering structure or a structure comprising gyroids or a structure having at least substantially periodically or statistically scattered repeating structural support elements.

5. Tool component (1, 15, 20; 31) according to one of claims 1 to 4, characterized in that the support body (3, 17, 22; 35, 41) has a closed-pore structure or a structure comprising at least one channel.

6. Tool component (1, 15, 20; 31) according to claim 5, characterized in that the at least one channel serves as a cooling channel.

7. Tool component (1, 15, 20; 31) according to one of claims 3 to 6, characterized in that the support structure has cavities with a volume fraction of at least 15% of the total volume of the support body (3, 17, 22; 35, 41).

8. Method for producing a tool component (1, 15, 20; 31) according to one of claims 1 to 7, characterized in that the functional body (2, 16, 21; 34, 40) is produced by a casting process or by an additive manufacturing process and that the support body (3, 17, 22; 35, 41) is produced by an additive process on the functional body (2, 16, 21; 34, 40).

9. Method according to claim 8, characterized in that the tool component (1, 15, 20; 31) is sintered during or after the execution of the manufacturing process.

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