DE202021004060U1 - honing tool - Google Patents

Abstract

Honing tool (10; 50) for producing a highly precise contour of curved sealing, clamping or bearing surfaces such as spherical or conical surfaces (4; 5) or other convex or concave surfaces in a component (2; 3), comprising:
- a tool shank (12) which is designed to hold the honing tool (10) in a tool holder,
- A rotationally symmetrical guide body (13) adjoining one end of the tool shank (12) and having a friction working surface (20) which allows the contour (4; 5) to be produced in a component (2; 3) to be machined and which additionally has at least one spiral groove (16) introduced on this friction working surface (20).

Description

technical field

The present invention relates generally to rotary honing tools for producing a highly precise contour of curved sealing, clamping or bearing surfaces such as spherical or conical surfaces or other convex or concave surfaces in a component in one operation.

background

• a) Oberflächenrauheit der Bauteile Ra < 0.5 µm
• b) maximale Profilabweichungen Bauteil Pt = max. 3 µm
• c) maximale Profilabweichungen Werkzeug Pt = max. 1.6 µm

The production of spatially curved, high-precision surfaces in components is particularly necessary in the machine tool and automotive industries as well as in engine production. Spatially curved surfaces that have at least one of the following surface properties often have to be created for sealing, clamping or bearing surfaces such as in combustion engines or valves:

• a) Surface roughness of the components Ra < 0.5 µm
• b) maximum profile deviations component Pt = max. 3 µm
• c) maximum profile deviation tool Pt = max. 1.6 µm

Honing tools are used to produce such high-precision surfaces. A desired contour with a very high surface quality is to be produced in the workpiece—often in a single operation—by means of such honing or forming tools. As standard, honing tools can be made of solid carbide or high-speed steel or of a guide body with CVD thick film or a guide body with brazed cutting edges made of hard material (CVD, PCD, hard metal, CBN). Likewise, the honing tools can have a number of very different cutting edges.

A first category of honing tools includes a removing and forming tool without defined cutting edges, but with a specific surface roughness in order to machine the surface of the component without significant and defined chip removal. Such honing tools produce a compacted surface by pressing on the surface and level existing roughness. Due to the loads, extremely hard cutting materials made of CBN or diamond are used here. If the contour production is not precise enough, this becomes visible on the component surface by means of grooves and traces.

A second category of honing tools has at least one defined cutting edge in order to process the surface of the component by means of a defined chip removal. In particular, this includes reamers with two or more cutting edges. The reamers are mainly used where, due to component contours, shoulders or diameters have to match and the application is not limited to just one sealing surface. As a result, coated tools are predominantly used here.

Such honing tools move both in the longitudinal axis and in rotation. Therefore, a honed surface can usually be recognized by the cross-hatch (cross line). This cross-cut is characteristic of the honing process, which is also referred to as "pulling". It improves the sliding and emergency running properties, as oil can collect in the small furrows. In addition, the roundness of the machined workpiece is significantly improved.

Components that are manufactured with such honing tools usually have a very small tolerance band with regard to shape and position tolerances, which is why precise adjustment of the mold is necessary. In the case of sealing seats, clamping or bearing surfaces, which can be represented by radius shapes, drafts or other convex or concave surfaces on components, both an extremely good surface quality and highly precise shape and position tolerances are important for the subsequent function of the component to be manufactured using the mold necessary.

In the present case, both categories of tools mentioned are to be subsumed under the term honing tool, i.e. in particular reamers are special honing tools within the meaning of this disclosure.

the JP 2011 235429 A shows a tool on which diamond chips are spirally applied. The spirals on this tool are said to be 0.1 to 2.0mm apart. Here the diamond chips are applied in a spiral. A friction working surface cannot be seen.

the CN 203936 761 discloses a tool with spirals, but how these spirals were created is unclear.

the DE 10 2016 216464 A1 teaches a roughening tool for roughening a cylindrical surface. A variety of peripheral cutting tools are available here.

From the CN 103 567 850 A a machining method for cylindrical surfaces is disclosed.

the U.S. 2011/273397 A1 shows a process for honing surfaces.

the U.S. 2002/173228 A1 describes a tool that is continuously coated with CBN or diamond particles. A spiral groove is introduced using a laser. In particular, the ejection of chips should be improved. A processing of curved surfaces is probably not intended, since the work surfaces are cylindrical.

the DE 43 16 012 A1 discloses a method for finishing workpiece surfaces. Here, scores and grooves are created in the workpiece surface by means of steel treatment. Laser beams are preferably used to process the workpiece surfaces.

From the EP 2 868 413 B1 a hard-coated cutting tool is known which has a defined cutting edge. The defined cutting edge has a flank face and a rake face. A hard coating is present on the flank face side and on the rake face side in the vicinity of the cutting edge in a cross section perpendicular to the cutting edge in a range that is less than or equal to 0.3 times the tool diameter, in the axial direction from the tip of the Tool specially trained.

From the JP 2008 229 838 A a diamond cutting tool is known in which a cutting tip is formed with periodic structures of 5 nm to 3000 nm by means of ultra-short pulsed laser beams in order to increase the service life of the cutting tip.

A method for influencing the chip flow behavior of tool surfaces in the area of cutting edges in chip-producing tools with a geometrically defined cutting edge is from DE 197 24 319 C1 known. Here, with the help of laser irradiation, at least the chip faces at a short distance from the cutting edge are provided with a pattern that changes the surface structure. According to one embodiment, the pattern can consist of a series of lines and/or dots, for example a strip or a track of lines and/or dots, which runs at a distance from the cutting edge. The laser irradiation is such that remelting and possibly oxidation are produced on the surface of the substrate material, which is said to result in increased surface roughness, which has an influence on the cutting speed. Not only the flow speed but also the flow direction can be influenced by the specific direction of the markings forming the pattern.

In the WO 2012 032286 A1 describes a drilling cutting tool in which a plurality of pits are formed in the cutting surface of the tool substrate and the coating also fills these pits.

From the JP 03196976A and JP 10113878 A grinding wheels with a plurality of radial fine grooves are known, which are introduced into the grinding wheel by means of a laser, for example.

A method for laser-based generation of a structure on a rake face of a cutting tool is from DE 2018 102 108 B4 known. Here, at least one structure is formed by means of lines, with the lines being generated at a maximum distance of 400 μm with a laser beam at least in regions within a predetermined contour on at least one cutting face of the cutting tool. The orientation or course of the structure-forming lines is based on a profile of at least one cutting edge of the at least one chip face.

Finally shows the JP 11156714A a dressing tool set with diamonds. A groove is formed parallel to the axis of rotation by means of laser beams or electron beams. This is intended to improve the dressing sharpness.

Honing tools of the type of interest here are given the desired contour by means of grinding or lasering, in order to produce a sharp cutting edge and shape with precise contours. However, it was found that a sharp cutting edge or - in the case of pure friction work surfaces - a surface that is too smooth on the tool contour is not ideal for sealing surfaces. By creating a surface that is too smooth on the component, the smallest deviations in the shape of the component lead to leaks and the component becomes unusable.

The present invention is therefore based on the technical problem of providing a honing tool that reduces one or more of the aforementioned deficiencies.

Summary of Revelation

This technical problem is solved by a honing tool for generating a high-precision contour of curved sealing, clamping or bearing surfaces such as spherical or conical surfaces or other convex or concave surfaces in a component, which has a tool shank, which is used to hold the honing tool in a Tool holder is formed, and an adjoining at one end of the tool shank, comprises a rotationally symmetrical guide body. The guide body has a friction working surface, which allows the machining of the contour to be produced in a component, and which additionally has at least one spiral groove introduced into this friction working surface.

The present invention is based on the idea of improving the working result of the previously existing friction working surface of such a tool, which can be designed with or without cutting edge(s), by additionally introducing at least one spiral groove in such a way that a kind of "scraping" along the to be produced Surface contour in the workpiece causes a smoothing of the workpiece surface. In particular with sealing or valve seats, a surface roughness can be achieved which, in combination with the previous form tolerance, enables the workpiece to be sealed.

It should be noted that the at least one spiral groove additionally applied to the working surface of the tool does not necessarily have to be continuous. It can also have interruptions, so that one spiral groove is formed only in sections on the circumference of the working surface, ie it has interruptions. In an exemplary embodiment of a honing tool according to the invention, the friction working surface of the guide body has a roughness Ra=0.02 μm to 0.4 μm with Pt<3.2 μm.

The spiral groove can, for example, have a depth t=0.3 μm to 8 μm, in particular 0.8 μm to 2.5 μm, and a spiral width b=2 μm to 40 μm, in particular 5 μm to 15 μm.

In a further exemplary embodiment of a honing tool according to the invention, the at least one spiral has a pitch s=0.8 μm to 200 μm, in particular 5 μm to 50 μm, relative to the axis of rotation of the honing tool.

In an exemplary embodiment of a honing tool according to the invention, the at least one spiral or its respective spiral sections is formed on a chamfer surface with a straight cross section at the tip of the honing tool head. Viewed in cross section, the bevel preferably encloses an angle of 87.5°+/−0.2° or 120°+/−0.2°. The included angle is to be selected depending on the workpiece to be machined. Furthermore, the spiral sections of the spiral introduced on the bevel assume an angle of between 10° and 20°, preferably between 15° and 20°. More preferably, the angle is between 14.5° and 15.5° and in particular 15°-15.5°. The spiral sections should also have a groove spacing of 25 ±5 µm (e.g. when measuring according to 13 ). With this configuration, it has been found that the desired roughnesses as indicated above are achievable. It has been found that if the spiral is too fine, i.e. the groove spacing and groove depth on the tool is smaller than previously specified, a good surface can still be achieved, but the desired dimensional accuracy may not be achieved or the tool may be damaged prematurely due to excessive working pressure becomes .

With regard to the measurement of the above values, the following should also be noted: The tool is aligned on the measuring device in such a way that the chamfer surface is in a horizontal position and the measurement is taken perpendicular to the chamfer surface. A vertical reference line is then added, this can be done directly be tangential to the edge of the chamfer surface to the face of the tool tip or be shifted parallel to this tangent. The spiral or its spiral sections, measured perpendicularly to the bevel surface, should then meet the specified values, see also esp. 10 onwards

In particular, it can be advantageous that, in an exemplary embodiment of a honing tool according to the invention, at least two spiral grooves are offset from one another in the direction of the axis of rotation.

The at least two spirals preferably have the same pitch and run parallel to one another.

Alternatively, the at least two spirals have the same or different pitches, but run in opposite directions to one another.

In a further exemplary embodiment of a honing tool according to the invention, the depth and/or pitch of the spiral groove changes along the friction working surface contour as viewed in the direction of the axis of rotation.

Honing tools according to the invention preferably consist of the materials that are already well known in this technical field, ie solid carbide or high-speed steel.

• a) Vollhartmetall mit einem 7 - 12 µm CVD-Dickfilm
• b) Vollhartmetall mit aufgelötetem CBN
• c) Vollhartmetall mit aufgelötetem PKD
• d) Vollhartmetall mit aufgelötetem CVD

In an exemplary embodiment, the guide body consists of a hard material comprising:

• a) Solid carbide with a 7 - 12 µm CVD thick film
• b) Solid carbide with brazed CBN
• c) Solid carbide with soldered PCD
• d) Solid carbide with brazed CVD

The friction working surface of the guide body is preferably provided with a CVD thick film into which at least one spiral is introduced. Alternatively, the guide body is provided with soldered cutting edges made of hard material such as CVD, PCD, hard metal, CBN). Here, too, the at least one spiral is then additionally introduced onto the surface of the functional area.

A configuration according to the invention with an additional spiral in the functional or working area of the honing tool can also be useful for tools with cutting edges. However, due to application-technical conditions and the chip formation properties, these tools can possibly produce poorer component surfaces compared to a reaming tool without cutting edges.

As is known from previous honing tools, the friction working surface of the guide body can also be provided with polycrystalline diamond in an exemplary embodiment of a honing tool according to the invention and the at least one spiral groove can be introduced therein.

Finally, it should be emphasized that the shape and/or contour of the friction working surface can be of any shape, depending on the intended use. The friction working surface of the guide body preferably has a (partial) spherical or conical shape.

• - Bereitstellen eines an sich bekannten Honwerkzeugs mit einem Werkzeugschaft, der zum Aufnehmen des Honwerkzeugs in einer Werkzeugaufnahme ausgebildet ist. An dem einen Ende des Werkzeugschaftes schließt sich ein rotationssymmetrischer Führungskörper an, der eine Reibarbeitsfläche aufweist, die es erlaubt, die in einem Bauteil herzustellende Kontur hochgenau herzustellen.
• - Erfindungsgemäß wird wenigstens eine Spiralnut in die Reibarbeitsfläche des Führungskörpers eingebracht, beispielsweise mittels Laser.

A method for producing a rotating honing tool according to the invention, with which a highly precise contour of curved sealing, clamping or bearing surfaces such as spherical or conical surfaces or other convex or concave surfaces can be produced in a component, includes the following process steps, for example:

• - Providing a known honing tool with a tool shank, which is designed to accommodate the honing tool in a tool holder. A rotationally symmetrical guide body is connected to one end of the tool shank, which has a friction working surface that allows the contour to be produced in a component to be produced with high precision.
• - According to the invention, at least one spiral groove is introduced into the friction working surface of the guide body, for example by means of a laser.

In principle, the manufacturing process works both for honing tools with a pure reaming surface and for reamers with a defined cutting edge. For the process, it is irrelevant whether and how many cutting edges are on the tool. Contours along the circumference are to be reworked here and can be adjusted to the desired roughness. Contours and cutting edges on the face of the tools may only be able to be produced to a limited extent.

wobei für beispielhafte Ausführungsformen gilt:

• Laserleistung 13 - 17 kW;
• Kontaktzeit 0,025- 1 s/mm;
• Schneidstofffaktor 0,7-1,1,
• insbesondere z.B. für PKD = 0,8 - 1,1, für CVD = 0.97, für CBN = 1,05, für CVD-Dickfilm = 1.

In an exemplary embodiment of the method, the at least one spiral groove is made with a laser factor of 0.3 kWs/mm to 16.2 kWs/mm. The laser factor consists of the contact time of the laser with the guide body, the laser power used and the cutting material to be processed. The following applies: $$\begin{array}{l}\text{laser factor}=\text{contact time}\left[\text{s}/\text{mm}\right]*\text{laser power}\left[\text{kW}\right]*\\ \text{cutting material factor},\end{array}$$

where the following applies to exemplary embodiments:

• laser power 13 - 17 kW;
• contact time 0.025-1 s/mm;
• cutting material factor 0.7-1.1,
• in particular, for example, for PCD = 0.8 - 1.1, for CVD = 0.97, for CBN = 1.05, for CVD thick film = 1.

A simple and effective introduction of the spiral groove is possible in an exemplary embodiment of the method in that the laser beam is introduced tangentially along the friction work surface of the at least one spiral groove.

The at least one spiral is preferably produced by means of a stationarily arranged laser and simultaneously rotating and translationally moving guide body in the direction of the axis of rotation of the honing tool, with the gradient being adjusted as a function of the rotation rate and the translational speed. The gradient s is preferably 0.8 μm to 200 μm and in particular in the ranges otherwise disclosed herein.

Depending on the desired roughness and surface quality on the component, in an exemplary embodiment of the method, the depth and/or pitch of the spiral, viewed in the direction of the axis of rotation, is changed along the contour of the friction work surface.

character list

• 1 eine schematische Querschnittsansicht eines ersten Werkstücks mit kalottenförmiger Ventilsitzfläche, die mittels eines erfindungsgemäßen Honwerkzeugs hochgenau herzustellen ist,
• 2 eine schematische Querschnittsansicht eines weiteren Werkstücks mit einer Kegelsitzfläche, die mittels eines erfindungsgemäßen Honwerkzeugs hochgenau herzustellen ist,
• 3 eine schematische Seitenansicht eines erfindungsgemäßen Werkzeugs,
• 4 eine schematische Detailansicht der Spitze des Werkzeugs gemäß 3,
• 5 eine Seitenansicht eines erfindungsgemäßen Werkzeugs mit teilkugelförmiger Bearbeitungsfläche,
• 6 ein Detail der Spitze des Werkzeugs gemäß 5,
• 7 eine schematische Seitenansicht eines weiteren erfindungsgemäßen Werkzeugs mit definierten Werkzeugschneiden und in diesem Bereich aufgebrachter zusätzlicher Spirale gemäß der vorliegenden Erfindung,
• 8 eine schematische Draufsicht auf eine Vorrichtung zur Herstellung einer Spiralnut auf einem Honwerkzeug,
• 9 eine weitere schematische Seitenansicht auf die Vorrichtung nach 8,
• 10 eine schematische Seitenansicht der in 9 gezeigten Anordnung,
• 11 eine schematische Seitenansicht auf ein erfindungsgemäßes Honwerkzeug und dessen Anordnung zur Vermessung,
• 12 eine Draufsicht auf die Fasenfläche und die darin eingebrachten Spiralnuten eines erfindungsgemäßen Honwerkzeugs,
• 13 eine Fotografie der Fasenfläche gemäß 12.

Exemplary embodiments of the present invention are described and explained in more detail below with reference to the accompanying drawings. Show it:

• 1 a schematic cross-sectional view of a first workpiece with a dome-shaped valve seat surface, which is to be produced with high precision using a honing tool according to the invention,
• 2 a schematic cross-sectional view of another workpiece with a conical seat surface, which is to be produced with high precision using a honing tool according to the invention,
• 3 a schematic side view of a tool according to the invention,
• 4 a schematic detail view of the tip of the tool according to FIG 3 ,
• 5 a side view of a tool according to the invention with a part-spherical machining surface,
• 6 a detail according to the tip of the tool 5 ,
• 7 a schematic side view of another tool according to the invention with defined tool cutting edges and an additional spiral applied in this area according to the present invention,
• 8th a schematic plan view of a device for producing a spiral groove on a honing tool,
• 9 a further schematic side view of the device 8th ,
• 10 a schematic side view of in 9 shown arrangement,
• 11 a schematic side view of a honing tool according to the invention and its arrangement for measurement,
• 12 a top view of the chamfer surface and the spiral grooves introduced therein of a honing tool according to the invention,
• 13 a photograph of the bevel surface according to 12 .

Detailed description

the 1 shows a schematic sectional view of a component 2 with a highly precisely ground valve surface 4, which in the present case corresponds to part of a spherical surface. Such surfaces and contours are particularly necessary in engine construction.

Another exemplary embodiment of a component 3 with a high-precision conical seat surface 5 is shown in FIG 2 shown. Such surfaces that are flat in cross-section, seen spatially here as frustoconical surfaces 5, must also be machined with high precision, depending on the application. As already explained in the introduction, such surfaces must preferably have at least one of the following surface properties, ie surface roughness of the components Ra < 0.5 µm, maximum profile deviations of component Pt = max. 3 µm and maximum profile deviations of tool Pt = max. 1.6 µm.

The in the 1 and 2 Surfaces 4, 5 shown are nowadays produced with honing tools that have very special friction surfaces in order to create highly precise surface structures.

An exemplary schematic side view of such a honing tool is shown in FIG 3 shown. This honing tool 10 includes a tool shank 12 to which a guide body 14 is connected. The entire honing tool 10 is designed to rotate about the X axis of rotation.

The guide body 14 comprises a cylindrical guide part 18 and a frustoconical part 17 at the tip. The guide body 14 with the partial surfaces 17, 18 is provided with a coating 20 here. The surface 17 provided with the at least one spiral is, for example, a straight chamfered surface viewed in cross section, see in particular 11-13 . The coating 20 can be, for example, a CVD thick film or a diamond coating of conventional construction.

Such tools are known per se, but have the problem that the desired high-precision surfaces 4, 5 can only be achieved to a limited extent.

An addition to such a known tool 10 according to the present invention is shown in FIG 4 shown schematically. Thus, the guide body 14 and the friction surfaces 17, 18 provided thereon are provided with at least one spiral groove 16, which has a pitch s. The gradient relative to the axis of rotation of the honing tool is preferably s=0.8 μm to 200 μm.

The gradient is selected to be lower the fewer structures are desired on a subsequent component and the smaller the laser beam diameter selected at the focal point on the machine. For tools with a coarse surface structure, the gradient is selected to be larger.

For example, gradients of <50 µm are used for Ra values of up to 0.2 µm. For a laser beam diameter of up to 0.2 mm, gradients of less than 50 μm are preferably used. A larger laser beam diameter allows a larger pitch.

In an exemplary embodiment of a honing tool according to the invention, the friction working surface of the guide body has a roughness Ra=0.015 μm to 0.4 μm with Pt<3.2 μm.

The spiral groove can, for example, have a depth t=0.3 μm to 8 μm, in particular up to 2.5 μm, and a spiral width b=2 μm to 40 μm, in particular 2.5 μm to 25 μm.

The width and depth of a spiral groove is determined by the laser beam diameter and the radial infeed by the tangential positioning on the diameter of the friction surface. The selection of the corresponding values is preferably based on the smallest inner radius on the tool contour, but is usually at least 0.03 mm.

The cutting material on the tool is also relevant. Highly absorbent materials, such as PCD with a low binder content, are machined with a smaller diameter in order to focus the energy density and to be able to remove the material better. In the case of tools with a coarse surface structure, the pitch and thus also the width are selected to be larger.

For Ra values of up to 0.2 µm, for example, widths of less than 50 µm are usually specified. The depth then results from the selected width and the laser diameter.

In this exemplary embodiment, the spiral groove 16 extends both over the planar cylindrical part 18 and into the truncated cone-shaped tip 16 and is introduced into the coating 18 by means of a laser.

It should be noted here only as an example that the spiral 16 does not have to extend continuously over the guide body or the friction surface; the spiral groove 16 can also only partially extend over the friction surface. For example, it is possible that the spiral groove 16 is repeatedly interrupted; in the present case, the coating would therefore not be deepened in small sections by the spiral groove.

Furthermore, it should be emphasized that one or more spiral grooves can be present in parallel or in opposite directions to one another. Furthermore, the width and/or depth of the spiral grooves 16 can change over their direction of extension in the direction of the X-axis. Furthermore, it is also possible not always to keep the gradient constant, but to increase or decrease it in certain areas.

the 5 shows a known VHM grinding pin 10, in the area of its friction working surface 20, ie in the tip area, which extends over the length l ₃ , with a spiral according to the 4 is provided.

The solid carbide mounted point 10 comprises a tool shank 12 and an adjoining guide body 13. The tool shank 12 has a diameter d ₂ which is larger than the diameter d ₁ of the guide body 13. As a transition between tool shank l ₂ and guide body 13 is a provided conical training, which has an angle α, here 60 °. The exemplary mounted point 10 has an overall length l ₁ . The actual guide body 13 has a length l ₂ .

As previously noted, the tip of the guide body 13 has a friction working surface 20 which extends to the flattened tip with a length l ₃ . The friction working surface 20 has a cylindrical area and an adjoining dome-shaped area with the radius r ₁ . A flat surface with the diameter d ₃ is again provided at the tip.

The design of the tip of this solid carbide grinding pin 10 is even better in the 6 evident. Here the spiral groove 16 with a pitch s=, a depth t= and a width b= has been introduced into the friction working surface 20 by means of a laser.

the 7 shows a schematic side view of another honing tool 50 according to the invention, which is equipped with defined cutting surfaces in the usual way. Here the entire guide body 52 extends over a length l _s2 . The blades 54 extend over a smaller length l _s3 . This friction surface area with cutting edges has a diameter d _s1 . This diameter d _s1 is smaller than the diameter of the tool shank d _s2 . Again, a spiral groove 54 is introduced by means of a laser on the friction working surface. That is, the spiral groove 54 extends over the length l _s3 to the flattened tip. Again, the spiral groove 54 may have the same dimensions as previously discussed.

Another exemplary embodiment of a honing tool according to the invention in the form of a mounted point 100 is shown in FIG 8th shown; here the grinding pin 100 is only provided with a cylindrical friction working surface 115 . Again, the friction working surface has a spiral groove with the aforementioned dimensions.

• - Oberflächengüte: Rz = 0,3 -1,2, insbesondere 0,6 - 1,2
• - Formtoleranz „Rundheit“ beträgt vorzugsweise 2 µm -5, insbesondere 4 µm.

Another exemplary embodiment of a honing tool or mounted point 10 according to the invention is shown in FIGS 11 and 12 shown. Here the honing tool or grinding pin 10 has a chamfer at the tip of the tool. Viewed in cross section, the chamfer surface 16 is rectilinear and encloses an angle of 120°+/-0.2°. The surface preferably meets the following conditions:

• - Surface quality: Rz = 0.3 -1.2, especially 0.6 - 1.2
• - Shape tolerance "roundness" is preferably 2 µm -5, in particular 4 µm.

From the 11 and 12 In particular, it can also be seen how the measurement of the spiral sections 16, which were introduced into the diamond coating on the bevel surface 17, takes place. So in a plan view according to 11 a reference line is placed on the chamfer surface 17 tangentially to the inner edge of the chamfer surface 17 . The angles of the spiral sections 16 are then measured against this reference line on the inner edge of the chamfer surface 17 . The angle should be at least 15°, in particular 15°-20°.

A top view of a chamfer surface 17 according to FIGS 11 and 12 of an actual mounted point according to the present invention is disclosed in US Pat 13 shown. In this top view, the reference line for measuring the angle of the spiral groove sections 16 is drawn in and the introduced spiral groove sections 16 can be seen. The angle of attack of the spiral sections 16 relative to the reference line is 15° to 20° here. The groove spacing of the individual spiral sections 16 is preferably 25 +/- 5 μm. It should be noted that the limit wavelength λc of the profile filter for the optical measurement of the spiral sections 16 is 0.025 mm in the present case. It should be noted that the profile filter determines which wavelengths are associated with roughness and which with waviness.

Commercial Applicability

Based on the 9 and 10 shown device, the production of the spiral groove on a friction work surface 20 of a honing tool 10 of the type described above will now be explained.

A honing tool 10, as described above, is clamped on the tool shank 12 in a rotatable clamping receptacle 300. A laser 200 generates a laser beam 205 which is aligned tangentially to the frictional working surface 20 such that a working point 210 is generated on the frictional working surface 20 . A spiral groove 16 with the aforementioned dimensions is thus produced in the friction working surface by simultaneous rotation and translatory movement of the clamped honing tool 10 . The laser factor is between 0.3 and 16.2 kWs/mm.

Machining is carried out as follows on the example tool with a friction surface made of CVD thick layer:

Based on the required surface quality of Pt < 1.6, a radial oversize on the tool of 0.02 mm and a selected laser diameter of 0.055 mm, a necessary gradient of 0.010 mm is calculated. The machine parameters speed and feed for producing the spiral-shaped surface can be determined using this: pitch = feed/speed, here e.g. 0.01mm/rev = 2mm/min / 200 rev/min.

The contact time of the laser beam per mm can be determined via the unwound length of the spiral along the friction surface, i.e. tool circumference * processing length, and the feed rate. This should be between 0.025 s/mm and 1.0 s/mm.

Materials such as PCD (with a low binder content) and CBN require contact times greater than 0.2 s.

CVD layers and CVD should preferably be processed with contact times of less than 0.1s. In addition, the necessary contact time decreases the smaller the laser diameter is selected. If the contact time is too long, the material is damaged and the material removal is too great. If the contact time is too short, the material removal is not sufficient. In the tool shown, the contact time is 0.037s/mm

The laser power for a finish process is CVD with a value of 0.83 at 16kW laser power.

An ns laser (nanosecond laser), for example, can be used to make the spiral groove. This is an ND-YAG solid-state laser as was installed as standard in the Rollomatic Lasersmart 500 machine type in the production batch from 2014.

The machine is controlled via the machine's own "LaserSmart" control system. The "LaserSuite" PC application, also from Rollomatic, is used to manage and set the laser parameters.

The tool is clamped in the workhead of the machine, consisting of a rotating C-axis with a corresponding clamping fixture. After probing the tool with a ball and surface probe to record the length and diameter, processing begins. Depending on the machine, concentricity and dimensional accuracy of <0.003 µm can also be reliably reproduced.

After measuring, the tool is positioned via the corresponding axes and the laser optics open to start processing. The C-axis starts rotating counter-clockwise. The emerging laser beam is now guided tangentially along the tool contour. As a rule, the cylindrical diameter surfaces are machined first, preferably starting at the tip of the tool in the direction of the shank.

In a second step, the convex or concave surfaces are processed. The processing sequence has primarily an economic background. When setting up a new product on the machine, settings must be made as with other machines so that temperature fluctuations and other external influences can be eliminated. The maximum removal for processing the surface and applying the spiral is e.g. 8 µm. The diameter is therefore set first to reduce rejects. The diameter is easier to measure than a radius or cone contour. The contour is then machined, which can be machined without any further effort thanks to the very good positioning and repeat accuracy of the machine.

After completion of the laser processing, finishing is carried out by vibratory grinding, in this case a cutting edge is rounded off in order to remove loose deposits that are still adhering to the laser process and thus to obtain a clean and even contour.

Honing tools 10, 50, 100 of the type described above are usually used to produce high-precision surfaces in components. However, the production results are better than with previously known honing tools, which can be attributed to the at least one spiral groove 16 additionally introduced.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• JP2011235429A [0009]
• CN203936761 [0010]
• DE 102016216464 A1 [0011]
• CN 103567850A [0012]
• US2011273397A1 [0013]
• US2002173228A1 [0014]
• DE 4316012 A1 [0015]
• EP 2868413 B1 [0016]
• JP2008229838A [0017]
• DE 19724319 C1 [0018]
• WO 2012032286 A1 [0019]
• JP03196976A [0020]
• JP10113878A [0020]
• DE 2018102108 B4 [0021]
• JP11156714A [0022]

Claims (15)

Honing tool (10; 50) for producing a highly precise contour of curved sealing, clamping or bearing surfaces such as spherical or conical surfaces (4; 5) or other convex or concave surfaces in a component (2; 3), comprising: - a tool shank (12) which is designed to hold the honing tool (10) in a tool holder, - A rotationally symmetrical guide body (13) adjoining one end of the tool shank (12) and having a friction working surface (20) which allows the contour (4; 5) to be produced in a component (2; 3) to be machined and which additionally has at least one spiral groove (16) introduced on this friction working surface (20). honing tool (10; 50). claim 1 , in which the friction working surface (20) of the guide body (13) has a roughness Ra = 0.015 µm to 0.4 µm at Pt <3.2 µm and the spiral groove has a depth of 0.3 µm to 8 µm and/or a width from 2 µm to 40 µm. Honing tool (10; 50) according to one of the preceding claims, in which the at least one spiral groove (16) has a pitch (s) of 0.8 µm to 200 µm relative to the axis of rotation (X) of the honing tool (10; 50). Honing tool (10; 50) according to one of the preceding claims, in which the friction working surface is designed as a chamfer surface (17) which, seen in cross section, has an angle of 80°-140°, preferably 87.5°+/-0.2° and 120° +/- 0.2°. honing tool (10; 50). claim 4 , in which the chamfer surface (17) is provided with a diamond coating and spiral groove sections (16) are introduced therein which, in a top view of the chamfer surface (17), form an angle of 10°-20° to a tangent to the inner edge of the chamfer surface (17). °, in particular at least 15 °. Honing tool (10; 50) according to one of the preceding claims, in which at least two spiral grooves are offset from one another in the direction of the axis of rotation (X). honing tool (10; 50). claim 6 , in which the at least two spiral grooves have the same pitch and run parallel to one another. honing tool (10; 50). claim 6 , in which the at least two spiral grooves have the same pitch and run in opposite directions to one another. Honing tool (10; 50) according to one of the preceding claims, in which the depth (t) and/or pitch (s) of the spiral groove (16) changes along the friction working surface contour (20) as seen in the direction of the axis of rotation (X). Honing tool (10; 50) according to one of Claims 1 - 9 In which the frictional working surface (20) of the guide body (13) is formed from a CVD thick film (18) into which at least one spiral groove (16) is introduced. Honing tool (10; 50) according to one of Claims 1 - 9 , in which the friction working surface (20) of the guide body (13) is provided with polycrystalline diamond, in which the at least one spiral groove (16) is introduced. Honing tool (10; 50) according to one of the preceding claims, in which the at least one spiral groove (16) is introduced into the friction working surface (20) of the guide body (13) by means of a laser, in particular with a laser factor of 0.3 kWs/mm to 16.2 kWs /mm, where: $$\text{laser factor}=\text{contact time}\left[\text{s}/\text{mm}\right]*\text{laser power}\left[\text{kW}\right]*\text{cutting material factor}.$$

Honing tool (10; 50) according to one of the preceding claims, in which the at least one spiral groove (16) is cut by means of a stationarily arranged laser (200) and a laser (200) which is simultaneously rotating and moving translationally in the direction of the axis of rotation (X) of the honing tool (10; 50). Guide body (13) has a pitch (s) of 5 µm to 200 µm. Honing tool (10; 50) according to one of the preceding claims, in which the at least one spiral groove is introduced into a chamfer surface (17) which is straight in cross-section such that in a plan view of the chamfer surface (17) the angle of the spiral groove sections (16) is 10° -20°, preferably at least 15°. Honing tool (10; 50) according to one of the preceding claims, in which the spacing of the spiral groove sections (16) in the plan view of the chamfer surface (17) along a perpendicular to the tangent to the chamfer surface inner edge is 25 +/-5 µm.

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