Tool for surface finishing of workpieces

Abstract

The invention relates to a tool (1) for surface treatment of workpieces, wherein a surface (2) with a specific roughness can be produced. The invention is characterized in that at least two cutting edges (3) are provided which are arranged one behind the other in such a way that in the event of a defect of a first cutting edge (3a) a second cutting edge (3b) can take over the function of the first cutting edge (3a).

Description

[0001] The invention relates to a tool for surface treatment of workpieces.

[0002] Depending on the requirements and application of the workpieces, there are surface roughness requirements. In some cases, the surfaces must be as smooth as possible and may only have a defined roughness value or not exceed a defined roughness value.

[0003] For some requirements, the surface must not be too smooth and must instead exhibit a minimum roughness. It may also be the case that a minimum roughness, as well as a defined roughness, is required for specific areas of the workpiece surface.

[0004] From DE 10 2008 058 452 A1, a method for producing a cylindrical surface is known that has a surface structure with a predetermined geometry suitable for the application of material by thermal spraying. In this process, a geometrically defined groove structure is introduced onto the surface, with the groove cross-section being successively machined to a final dimension. The grooves are machined parallel to each other into the surface by a plurality of cutting edges. The different cutting edges each introduce different grooves into the structure.

[0005] DE 10 2012 021 089 A1 describes a component with a roughened surface designed for coating by thermal spraying. The surface features adjacent grooves, each with two undercuts. A raised section is formed at the bottom of the groove between the two undercuts. Different cutting edges are provided to form the different undercuts and the raised section. A first cutting edge can form a first undercut, and as the tool advances in the feed direction, a second cutting edge can form a second undercut in the groove.

[0006] DE 10 2012 025 725 B3 describes another tool designed for roughening a surface in preparation for coating by thermal spraying. As described in DE 10 2012 021 089 A1, this tool can be used to create a desired groove geometry.

[0007] For further prior art, reference can also be made to DE 10 2019 205 260 A1, which discloses a reamer. A cutter plate is provided on the tool head, with a roughening step located at a distance from the tool head. The tool has a grooved structure at the roughening step. When the reamer rotates, the surface can be machined by several cutter plates with such roughening steps arranged along the circumference of the reamer. Furthermore, reference can be made to DE 10 2016 216 926 A1, DE 10 2014 119 514 A1 and DE 10 2018 132 063 A1, which disclose rotary-driven tools with different cutting edges designed to produce a helical groove in a bore.

[0008] In current technology, turning and milling operations utilize tools with small cutting edges to achieve the required surface roughness values. For example, PCD tools (polycrystalline diamond reaming tools) with a defined cutting edge can be used.

[0009] A disadvantage of small cutting edges is their relative sensitivity, meaning that damage to the cutting edge is often not noticed or is noticed too late. A defect in the cutting edge can usually only be detected by checking the surface roughness. However, measuring the surface, i.e., the surface roughness, is rarely 100% accurate and is particularly time-consuming.

[0010] The object of the present invention is to provide a tool for surface treatment of workpieces which overcomes the aforementioned disadvantages.

[0011] According to the invention, this problem is solved by a tool having the features of claim 1, and in particular those of the characterizing part of claim 1. Advantageous embodiments and further developments are described in the dependent claims.

[0012] The core of the tool according to the invention comprises at least two cutting edges arranged one behind the other in a feed direction of the tool that does not involve rotation. This allows a second cutting edge to take over the function of the first cutting edge if one of the first is defective. All cutting edges lie on the same plane, ensuring that the same surface area can be machined by all cutting edges, and that the machining depth remains unchanged even if one cutting edge is defective. In particular, the cutting edges are of the same depth, so that the machining depth remains unchanged even if the first cutting edge is defective. This ensures process reliability and increases tool life. The tool is therefore designed with redundancy. Furthermore, surface and surface roughness checks are unnecessary, saving both time and money.

[0013] The tool is designed for surface finishing of workpieces, enabling the production of a surface with a specific roughness. In particular, a minimum roughness can be achieved. Furthermore, a surface with a defined target roughness value can be produced.

[0014] The cutting edges are arranged one behind the other, all lying on the same plane. "On the same plane" means, in particular, that with a feed direction that does not involve rotation, the cutting edges can machine the same surface area. This same surface area can be described as a "groove," with each cutting edge running in this groove. Each cutting edge can therefore replace any other cutting edge. In particular, flat surfaces can be machined with this tool.

[0015] Preferably, the tool should have at least three cutting edges. If the first cutting edge is defective, a second cutting edge can be used to machine the desired surface. If the second cutting edge is also defective, a third cutting edge is available, which can be used to selectively produce the desired surface. This delays the process until the tool needs to be replaced, thereby increasing the tool's service life and reducing machining time.

[0016] According to a highly advantageous refinement of this idea, it can be provided that all cutting edges run in an identical machining area at a defined feed rate. In other words, at the defined feed rate, each of the cutting edges can run in the "groove" of the first cutting edge. A machining step performed by the first cutting edge can also be carried out by the second cutting edge, the third cutting edge, or possibly further cutting edges. Therefore, more than three cutting edges can be arranged.

[0017] The tool is not comparable to a reamer, on which cutting plates are arranged at equal intervals around the circumference. In such a reamer, the tools are also designed to ensure that the reamer runs centered in a bore. In contrast, the tool according to the invention features a redundant arrangement of cutting edges, wherein a first cutting edge has, so to speak, substitute cutting edges that can take over the exact function of the first cutting edge.

[0018] In an advantageous embodiment, the cutting edges can be arranged parallel to each other. Consequently, during a tool feed, each subsequent cutting edge can assume the function of the first. The cutting edges can have the same width. Furthermore, the cutting edges can, for example, be arranged one behind the other at equal intervals. The cutting edges can, for example, be identical to each other.

[0019] According to a highly advantageous further development of the idea, it can be provided that the tool is a PCD (polycrystalline diamond) tool. Such tools are particularly advantageous when small cutting edges are to be used.

[0020] Further advantageous embodiments of the tool according to the invention also result from the exemplary embodiment, which is described in more detail below with reference to the figures.

[0021] This shows: Fig. 1 a sectional view through an embodiment of a tool; Fig. 2. A top view of a processing area.

[0022] In the presentation of the Fig. Figure 1 shows a possible embodiment of the tool 1 in a sectional view. In this embodiment, the tool 1 has three cutting edges 3a, 3b, and 3c. The cutting edges are arranged parallel to each other and one behind the other. In other words, the cutting edges are arranged one behind the other in a cut groove. In particular, the cutting edges 3a, 3b, and 3c are arranged with the same orientation relative to each other on the tool 1. The feed direction on the flat surface 2 is indicated by the arrow. When the tool 1 is moved across the surface 2 along the feed direction, the cutting edges 3a, 3b, and 3c are arranged one behind the other in such a way that they can machine the same area of ​​the surface 2.

[0023] Fig. Figure 2 shows a machining area 4 on surface 2. The feed direction is also indicated by the arrow in the illustration. Machining area 4 corresponds to the area over which the three cutting edges 3a, 3b, 3c extend. Fig. 1. The three cutting edges 3a, 3b, 3c run in the same groove, with the rear cutting edges 3b, 3c running in the groove of the first cutting edge 3a. The cutting edges are arranged redundantly one behind the other on the tool 2, whereby a defect in the first cutting edge 3a can be compensated for by the second cutting edge 3b. A defect in the second cutting edge 3b can, in turn, be compensated for by the cutting edge 3c. This ensures the reliability of the entire process and, in particular, increases the tool life.

Claims

[1] Tool (1) for surface treatment of workpieces, whereby a surface (2) with a certain roughness can be produced, characterized by that at least two cutting edges (3) are provided which are arranged one behind the other in a feed direction of the tool (1) which does not have rotation, that in the event of a defect in a first cutting edge (3a) a second cutting edge (3b) can take over the function of the first cutting edge (3a), wherein the cutting edges (3a, 3b) lie on the same plane so that the same surface area on the surface (2) can be machined by the cutting edges, wherein a machining depth remains unchanged in the event of a defect in a cutting edge. [2] Tool (1) according to claim 1, characterized by that at least three cutting edges (3a, 3b, 3c) are included. [3] Tool (1) according to claim 1 or 2, characterized by that all cutting edges (3a, 3b, 3c) run in an identical machining area (4) at a defined feed. [4] Tool (1) according to claim 1, 2 or 3, characterized by that the cutting edges (3a, 3b, 3c) are arranged parallel to each other. [5] Tool (1) according to one of claims 1 to 4, characterized by that it is a PCD tool.

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