WO2014131823A1

WO2014131823A1 - Method for producing contours which are curved once or multiple times, and a corresponding tool

Info

Publication number: WO2014131823A1
Application number: PCT/EP2014/053807
Authority: WO
Inventors: Wolfgang Hintze; Christian Klingelhöller; Oliver Langhof
Original assignee: Tutech Innovations Gmbh; Technische Universität Hamburg-Harburg
Priority date: 2013-02-27
Filing date: 2014-02-27
Publication date: 2014-09-04
Also published as: DE102013003233B4; DE102013003233A1

Abstract

The invention relates to a method for producing contours which are curved once or multiple times in a workpiece with a rigid disk-shaped tool which has a main part with two flat opposing faces and a circumferential surface, said surface having a cutting surface and a defined width in the axial direction. A transition region is provided on at least one of the flat faces starting from the circumferential surface in an annular radius region of the tool, said transition region tapering in the axial direction and being at least partly provided with a cutting surface.

Description

Method for producing single or multiple curved contours and a corresponding tool

The invention relates to a method for producing single or multiple curved contours in a workpiece. Likewise, the invention relates to a tool which is suitable for producing single or multiple curved contours in a workpiece.

The present invention relates to machining processes for the production of gelmimmten contours in flat or shell-like workpieces, such as body parts or assemblies in the wind energy industry. When producing such contours, edge quality is an important aspect of the quality of the machining process.

From DE 37 20 169 C2 a sawing device for sawing squared timbers or logs is known, in which the saw blade cuts a notch via its cutting elements. The thickness of the cutting elements is greater than the thickness of the saw blade, so that there is always a minimum lateral distance between the saw blade and the cut edge. The lateral distance allows a radius of curvature for the cutting contour, whereby a lateral distance is maintained even when cutting the curved contour.

From DE 298 14 668 Ul a saw blade for circular saws or gang saws is known in which the individual cutting teeth have a U-shaped coating on their cutting edge. The cutting teeth are formed as separate components and are attached to the main body of the saw blade. From JP 2011-148008 A a saw blade for cutting along curved cutting lines is known. The saw blade is designed bendable and can be bent convexly or concavely via an axial pressing device.

From JP 2010-0127280 a device for cutting rectilinear and arbitrarily curved contours is known. A rotatably mounted between two conical holders saw blade can be bent according to the desired contour.

From US 2007/0266841 a circular saw blade has become known in which the saw blade in the radial direction on the outside has differently shaped, annular regions which give the saw blade elasticity in the axial direction.

From US 3,919,752 a circular milling head is known, which is provided for milling curved recesses of constant radius, wherein the cutting edges lie on a conical surface whose longitudinal axis coincides with the axis of rotation of the milling cutter.

From DE 88 15 942 Ul a circular saw blade has become known, which has a cone-segment-shaped or a spherical shell segment-shaped training to allow circular cuts in a plane safely.

From GB 211,642 a saw with a circular saw blade has become known, wherein the saw blade is convexly curved to cut contours of a given radius.

From US 4,602,434 a circular saw blade has become known in which the saw blade is convexly curved to cut a sheet. When producing contours in flat or shell-shaped workpieces, if the selected geometry of the inserted disk-shaped tool is not adapted to the radius of curvature of the contour, extreme friction between tool and workpiece, high tool wear, impermissible vibrations, noise and / or damage to the generated Component edge, ie an unstable process and a poor edge quality.

There is therefore a need to provide a method and a tool for the production of one or more curved contours that allows simple means with a good quality machining the cutting of different radii of curvature.

According to the invention the object is achieved by a method having the features of claim 1. Advantageous embodiments form the subject of the dependent claims.

The inventive method is provided and determined to produce single or multiple curved contours in a workpiece. The method uses a disc-shaped, rigid tool which has a base body with two opposite flat sides and a circumferential peripheral surface with a defined width. The method is preferably provided for the full cut, ie, two mutually opposite cut surfaces are simultaneously produced by the tool in the workpiece. At least one of the flat sides tapers in a transition region starting from the width of the peripheral surface in an annular radius region of the tool. The largest width of the peripheral surface in the tool cross-section defines the limits to the two flat sides. The areas of the flat sides of the tool cross-section largest width to the tool cross section of smaller width are called transition area. As a result, the disk has an axial projection w of the cutting area on the circumference of the disk with respect to the workpiece cross-section with a smaller width on the flat side. The cutting surface of the tool is arranged on the peripheral surface and at least partially in the transition region to the flat sides. The cutting surface extends at least partially into the transition region and may cover it partially or completely and extend beyond the transition region on the remaining flat side. The method provides as a method step to start a predetermined contour through the workpiece with a rotating tool. When the contour is traversed, a caster angle β is set, depending on the track radius of the worn contour. The caster angle β is defined as the angle of the rotational axis of the tool projected onto the workpiece surface to the connecting line from the instantaneous pole of the tool to the center of rotation of the tool projected onto the workpiece surface. The axial projection w and / or the setting of the caster angle ß allow to run contours with a variable track radius. Depending on the size of the track radius, a caster angle on the tool is set accordingly, so that there is always a good edge quality and a stable process. If a non-zero caster angle is set in the method according to the invention, the situation arises that the cutting surface arranged in the transition region also contributes to contour formation and thus cuts the contour into the workpiece together with the peripheral surface.

In a preferred embodiment of the method according to the invention, a minimum contour radius dependent on the depth of penetration of the tool into the workpiece, the tool radius r and the caster angle β is provided. The minimum Contour radius corresponds to the track radius, which can just be moved without one of the flat sides coming into contact with the desired workpiece edge. This means that the tool cuts on the peripheral surface and touches the cutting edge with at least one outer point of the peripheral surface. In the method according to the invention is preferably carried out with a caster angle of zero when the associated minimum contour radius is smaller than the track radius. At a caster angle of β = 0, the transition region participates exclusively in a change between different radii in the cutting process. Otherwise, only the peripheral surface will cut at a constant radius.

In the inventive method, a non-zero caster angle is selected when the track radius is smaller than the minimum contour radius resulting for a caster angle of zero. This means that the tool cuts on the peripheral surface and touches the cutting edge facing the tool axis with the outer points A and / or B as well as the workpiece surface facing away from the tool axis with the corresponding points A 'and / or B'. At a non-zero caster angle, machining of the workpiece additionally occurs due to the cutting surface arranged on one of the flat sides with the transition region. For each track radius smaller than the minimum contour radius, a negative or a positive caster angle can be selected, in which case the flat side facing the curvature or the curvature facing away from the curvature with its cutting surface is involved in the separation process.

In a further preferred embodiment, the caster angle is adjusted or adjusted along the feed path, that not only along the path the desired contour radii are maintained, but also the width of sliced groove influenced. Basically, it is to distinguish between the width of the cut groove on the upper and the lower workpiece surface. For thin-walled (shell) components, this difference is small and can be tolerated in a preferred embodiment.

In a preferred embodiment, the leading point of one edge of the peripheral surface and the trailing point of the other edge are guided on a respective one of the cut edges of the groove, which have the desired width to each other. In this way, slits of desired width can be produced on thin-walled components.

In a further preferred embodiment, the flat side of the tool in the region of the immersion depth h ₁ over the transition region is tapered so far that the contact surface of the tool on the flat side with the convex cut surface of the workpiece is reduced or avoided. This advantageously has the effect that, with curved contours, the groove width can be reduced in relation to the width in a straight cut.

In the method according to the invention, a track correction angle α can additionally be provided for the rotating tool. With the toe correction angle α, the tool is inclined about an axis which runs through the intersections of the workpiece surface, which faces the tool axis, with the edge of the peripheral region, which faces the instantaneous pole of the contour. The tool is then inclined by the angle α around the imaginary connecting line. By such an inclination by the angle α, the geometric configuration of the cut surface is changed. The cut surface adjoins the upper and lower workpiece surfaces via the cut edges. In a preferred embodiment, the track corrector angle α is set according to a desired contour angle γ. The contour angle γ is defined for any point on the upper cut edge between the surface normal to the cut surface and the surface normal to the component surface. Without trace correction angle α, there is a contour angle γ different for curved contours, since the intersections of the edge of the peripheral surface with the convex workpiece contour on the workpiece top side (points A and B) are not at the same radius with respect to the instantaneous pole. like the intersections on the underside of the workpiece (points A 'and B'). The distance of the radii in the direction of the tool axis is referred to as tracking error s. The toe correction angle α must be adapted during production of a desired contour angle γ during contour radius transitions, since, depending on the contour radius, different tracking errors occur between the lower and upper workpiece surface edges.

In the case of thin-walled (shell) components, a contour angle deviating from the target in a preferred embodiment can be tolerated by the method. By adjusting the toe angle α, the contour angle can be kept constant even at curved contours to a desired value.

The inventive object is also achieved by a tool for producing single and multiple curved contours according to claim 7. Advantageous embodiments form the subject matter of the dependent claims dependent thereon.

The tool according to the invention is provided and intended for the production of single or multiple curved contours. The tool has a disc-shaped, rigid body with a cutting surface. Of the 14 053807

- 8th -

Basic body has two opposite flat sides and a peripheral peripheral surface with a defined width. At least one of the flat sides tapers in width in the transition region, wherein the taper, starting from the width of the peripheral surface in an annular radius region of the tool is formed. The largest width of the peripheral surface in the tool cross-section defines the boundaries to the two flat sides. The areas of the flat sides of the tool cross-section largest width to the tool cross section of smaller width are called transition area. The cutting surface is arranged along the peripheral surface. According to the invention, the cutting surface additionally extends at least partially from the peripheral surface to the transition region of the flat side. The cutting surface may extend beyond the transition region on the flat side. The cutting surface on the transition region cooperates in the production of curved contours with the arranged on the peripheral surface cutting surface of the tool. The cutting surface extending on at least one transition region allows the tool to work with a non-zero caster angle. As a result, the tool can also be used to cut curve radii which are smaller than the minimum contour radius present at a caster angle of zero. The tool according to the invention can be used both on machine tools and industrial robots as well as portable handsets. For a caster angle of zero, at least the cuttable transition region is used in order to be able to process transitions between different radii of the cut edge.

In a preferred embodiment, the cutting surface consists of geometrically undefined cutting edges, in particular abrasive grains. In the embodiment of the cutting surface with geometrically undefined cutting, the tool can be regarded as a kind of cutting disc. In particular, in the embodiment as Cutting disc can be provided that the cutting surface extends to one, and only one, flat side of the tool.

In a further preferred refinement, the cutting surface has a main cutting edge pointing radially outwards on the peripheral surface and a secondary cutting edge arranged on the flat side in the transition region. In this embodiment, the tool serves as a saw whose main and minor cutting edge each have one or more cutting edges.

In a preferred development, the main cutting edge and the secondary cutting edge have mutually oppositely oriented cutting edges.

In a preferred refinement, the tool has a radius-projection ratio (RUV), which is defined as the quotient of tool radius r and axial projection w of the peripheral region over the flat side of smaller width, of a maximum of 30 (RUV r / w, see FIG. 5). Preferably, the RÜV is a maximum of 20, more preferably the RÜV assumes a maximum value of 10. The radius to supernatant ratio is a geometric quantity that is very important in the determination of the disk stiffness and the determination of the minimum contour radius.

A preferred embodiment of the tool according to the invention and of the method according to the invention is explained in more detail below with reference to exemplary embodiments. Show it:

FIGS. 1.1 u. 1.2 is a perspective view of a device according to the invention

Cutting disc when producing a curved contour, FIGS. 2.1 u. 2.2 is a view from the side of the cutting disc in Figs. 1.1 u. 1.2

Fig. 3 is a sectional view taken along the line A-A of Fig. 2.1 or

2.2

4 is a side view with geometric guides,

5 is a section along the line A-A of FIG. 4,

Fig. 6 is a schematic view of the tool at a

Caster angle of ß = 0,

Fig. 7.1 is a section along the line D-D of Fig. 6 at a

Caster angle of ß = 0 and in the case that point A and point B are on the convex cut edge,

Fig. 7.2 shows a section along the line DD of FIG. 6 by an extremely asymmetric tool at a caster angle of ß = 0 and in the event that point A and point B lie on the convex cut edge, a perspective view of the tool of the side at a positive caster angle,

Fig. 9.1 is a section along the line E-E of Fig. 8 at a

Caster angle ß> 0 and in the case that point A lies on the convex cut edge, a section along the line EE of Fig. 8 by an extremely asymmetric tool at a caster angle of ß> 0 and in the event that point A is on the convex cut edge and the axial plane of the tool flat side is directed away from the convex contour edge, a section along the line EE of Fig. 8 by an extremely asymmetric tool at a caster angle of ß> 0 and in the event that point A lies on the convex cutting edge and the axial plane of the tool flat side of the convex Konrurkaten facing, a perspective view of the Tool from the side at a negative caster angle, a section of the line FF of Figure 10 at a caster angle of ß <0 and in the event that point B is on the convex cut edge and cuts the flat side of the tool between B and B *, a section along the line FF of Fig. 10 at a caster angle of ß <0 and in the event that point B on the convex cut edge and the flat side of the tool cuts the workpiece between B and B * in two areas, 11.3 shows a section along the line FF from FIG. 10 through an extremely asymmetric tool at a caster angle of β <0 and in the case that point B lies on the convex cut edge,

12 shows the sectional view along the line B-B from FIG. 4 with and without track correction angle a, FIG.

Fig. 13 shows an example of a fiction, executed according to

cutting disc,

Fig. 14 is a section along the line C-C of Fig. 13 and

FIGS. 15 - 18 show the cutting process of various tools in the

View of the section D-D from FIG. 6.

Fig. 1.1 shows in a perspective view how a plate-shaped workpiece 10 along a curved contour 14 is separated by a cutting wheel 12. The cutting wheel 12 is driven by a motor, wherein the tool drive 16 can be adjusted with the cutting wheel 12 in its position relative to the workpiece 10. The tool drive is coaxially connected via a connecting element 35 with the tool and has a larger diameter than the tool itself.

FIG. 1.2 shows in a perspective view how a plate-shaped workpiece 10 is separated along a curved contour 14 by a cutting disk 12. The cutting disk 12 is driven by a motor, wherein the tool drive 16 is adjusted with the cutting disk 12 in its position relative to the workpiece 10 can be. The tool drive is orthogonal via an angle unit 36 connected to the tool.

FIG. 2.1 shows a view from the side onto the workpiece 10. It can be clearly seen that due to the curved contour 14, the tool 12 is offset with its circumferential surface in relation to the original opening 14. Furthermore, it can be seen in FIG. 2.1 that the tool 12 is inclined about the so-called axis. As a result, as will be explained below, the contour of the workpiece is corrected on the basis of the curved track. It can be seen that processing preferably takes place in the vicinity of the blank edge 37, since otherwise a collision of workpiece 10 and tool drive 16 would occur.

2.2 shows a view from the side of the workpiece 10. It can be clearly seen that due to the curved contour 14, the tool 12 is offset with its peripheral surface relative to the original opening 14. Furthermore, it can be seen in FIG. 2.2 that the tool 12 is inclined about the so-called a-axis. As a result, as will be explained below, the contour of the workpiece is corrected on the basis of the curved track. It can be seen that in the case of flat workpieces by using an angle unit 36, in contrast to the situation from FIG. 2.1, the machining can also take place remotely from the blank edge 37.

3 shows a sectional view along the line AA from FIG. 2.1 or FIG. 2.2 onto the workpiece 10. In the sectional view according to FIG. 3, it can be clearly seen that the curved contour 14 is cut on the one hand with the peripheral surface 16 of the tool. Based on the feed direction, the contour 14 is cut in the rear part of the disk by a radially inner transition region 18 of the flat side starting from point D. Transition region 18 shows the transition region actively involved in the section. As shown in Fig. 3 and will be explained below, the position of the tool 12 corresponds to a positive caster angle ß, which creates the possibility to cut in the contour 14 tighter radii than the geometry of the tool 12 allows without using the NacMaufwinkels.

The tool 12 has a radius r and is moved in the feed direction and rotates about its center M. Feed direction and direction of rotation can work in phase or in phase opposition depending on the design of the tool used.

In the snapshot illustrated in FIG. 4, the contact points of the tool with the side of the workpiece 10 facing the midpoint M of the tool 12 lie at A, B. For this purpose, the tool is immersed in the workpiece up to a height hu. The distance from the workpiece axis to the side of the workpiece facing away from the tool axis is designated by h ₂ . On the side of the workpiece 10 facing away from the center M of the tool 12, the points A 'and B' occur corresponding to the points A, B '. The workpiece has a thickness of t in the example shown. M 'represents the projection of the tool center on the workpiece surface, which faces the center of the tool. F describes half the distance between the points A and B. Using the known tool radius r and the set immersion depth hi, the length F can be determined via the geometric relationship F ² = r ² -hi ² .

Fig. 5 shows a section along the line AA through the tool. In the case of a gel-bladed contour, it can be seen that the points A, B lie on the upper side of the workpiece 10 along a circular arc having the radius Rs _pur . Due to the thickness t of the workpiece, the corresponding points A 'and B' are not located on the contour line A, B, but further inside. This smaller radius is marked with R '. The tracking error s and the resulting inclination of the cut surface will be explained in more detail with reference to FIG. 12.

Important to FIG. 5 is that a minimum contour radius RKmm is provided, which is defined by the points A, B and the tangent point T of the upper cut edge with the flat side of the tool 12. For β = 0, the minimum contour radius RKminCβ ⁼ 0) can be calculated from the ratio of F and w through the geometric relationship

2 2 2

Kmin ⁼ (Ri min - w) + F are determined. The associated circular arc 20 is shown in dotted lines in FIG. As can be seen in FIG. 5, the instantaneous pole MR of the contour 14 and the center of the minimum contour radius RKmin lie on the rotation axis RA projected onto the workpiece surface, so that in FIG. 5 the caster angle is 0. Furthermore, it can be seen that the minimum contour radius Kmin is significantly smaller than the radius Rs _pur , so that the contour 14 can be cut without special measures. By tilting the disk about the axis through the points A and B with the toe correction angle, the point A 'shifts to the tracking error s to a larger radius, which corresponds in the illustrated case, the radius of the points A and B. The advanced point is with

characterized.

FIG. 6 shows, for a caster angle β = 0, a section line D-D through the tool 12 which lies on the upper side of the workpiece 10.

Fig. 7.1 shows the section along the line DD, in which, in contrast to the sectional view in Fig. 5, the section lies in a plane through the points A, B and is orthogonal to the tool level WM. In Fig. 7.1 again the minimum contour radius RKmin is drawn, which by the points A, B and the Tangent point T is clamped. The track radius 22 is greater than the minimum contour radius R-Kmin 21, so that the cut surface does not drag on the tool 12.

As can be seen in Fig. 7.1, the tool 12 has two opposing flat sides 24, 26 and a peripheral surface 28. The peripheral surface has a width extending from point A to C. The flat sides 24 and 26 have a smaller width, which results from the distance of the flat side 24 from a tool level WM and the distance of the flat side 26 from the tool level WM. The flat sides include transition areas 30 which connect the peripheral surface 28 with the flat sides 24 and 26. The transition regions 30 are in the exemplary embodiment of FIGS. 7.1- 7.2, 9.1- 9.3 11.1 - 11.3 shown as a straight connection. As can be seen in FIG. 14, curved transition regions can also be provided. As can already be seen in FIG. 3, the cutting surface on the tool is arranged not only along the peripheral region 28, but also extends at least partially into a transition region from a flat side. In the exemplary embodiment of FIGS. 7.1 - 7.2, 9.1 - 9.3, 11.1 - 11.3, the peripheral surface 28 and at least one transition region 30 of the flat sides 24 and 26 are capable of being cut.

Fig. 7.2 shows again the section along the line D-D. In this case by a tool that is designed asymmetrically.

Fig. 8 shows the tool 12 with a positive caster angle ß. Relative to the feed direction of the tool 12, with which a movement of point B in the direction of point A, this means that the rear in the feed direction peripheral surface 28 is rotated away from the convex workpiece contour and thus becomes visible. Fig. 9.1 shows a section along the line EE of Fig. 8. In the cutting tool, a part of the groove is cut by the peripheral surface 28 between the points A and C. The further part is generated by the cutting surface between the points D and D *. As can be seen in FIG. 9.1, the region 30 (the outer flat side of the tool) cuts the region 32 into the workpiece. Important in Fig. 9.1 is that the sectional area of the contour is cut through the boundary area at point A and point D.

The trailing cutting in the area 32 is geometrically formed by the trailing angle β, which is defined by the rotational axis of the tool projected onto the workpiece surface to the connecting line from the instantaneous pole MR of the contour to the center of rotation of the tool projected onto the workpiece surface, designated M ' , For this case, a minimum contour radius Ri min results for β> 0, which is smaller than the minimum contour radius RKmin for β = 0. It is defined by ß, the tangent to the edge region of the peripheral surface at point A and the tangent to the flat side 24. The minimum contour radius RKmin (ß> 0) can be for ß> 0 by knowing the lengths F, the axial supernatant w and of the contact angle β via the geometric relationship RKmin ^{2 =} (RKmin - w) ² + (F - RKmin tan (| β |)) ² . Furthermore, the tool must be able to be cut in the region of the flat side and of the transitional region which the region 32 encounters due to the tool feed motion. The track radius, in the exemplary embodiment in Fig. 9.1 less than the minimum radius for the contour of NacUaufwinkel ß = 0. By selecting a caster angle different from 0 thus contours with a smaller track radius Rs can be run _neat.

Fig. 9.2 shows again the section along the line EE. In this case by a tool that is designed asymmetrically. The convex cut surface is defined by the Edge region of the peripheral surface cut at point A. In addition, the range D to D * cuts. The axial projection, which faces the convex workpiece contour, is zero in FIG. 9.2. In this case, the minimum contour radius is to be determined by the cutting capability on the flat side facing away from the convex contour and, for the illustrated case, must extend at least over the range from D to D *.

Fig. 9.3 again shows the section along the line EE of Fig. 8, in this case by a tool which is designed asymmetrically and wherein the directed to the convex contour edge tool side has an axial projection greater than zero. The minimum contour radius for ß> 0 is over the length F, the axial projection w and the caster angle ß on the geometric relationship R-Kmin ² - (Riimin - w) ² + (F - RKmin tan (| ß [)) ² and determines the cutting ability on the convex contour facing away from the tool side. In the illustrated case, the tool must be capable of being cut between A and C and between D and D *.

In addition to the case of a positive caster angle, the case of a negative caster angle is also possible. As shown in FIG. 10, a plan view of the peripheral surface 28 in the region of the tool 12, which lies in the direction of advance from B to A in the front, then results. The front in the feed direction of the peripheral surface 28 is rotated away from the convex contour.

It can be clearly seen that, on the one hand, the groove is cut along the circumferential surface 28 between the points A and C and, on the other hand, on the inner flat side with the cutting surface 30 between the points B * and B. Important in Fig. 11.1 is that the cut surfaces of the contour are cut by the edge portions of the peripheral surface at points B, C and only the transition region EP2014 / 053807

- 19 - cutting the flat sides. The track radius shown in FIG. 11.1 is in this case larger than the miriametric contour radius R-Kmin for β <0, which coincides with the length F, the axial projection w and the caster angle β via the geometric relationship Rs min ^{2 =} (R Kmin - w) ² + (F - Ri mm tan (| ß |)) ² . In addition, in the areas where the material 31 not cut from the peripheral area 28 meets the tool, the tool must be capable of being cut. In the case shown, the tool must be able to be cut at least in the region B to B *.

Fig. 11.2 also shows the section along the line F-F, in which, in contrast to Fig. 11.1 parts of the flat side 24 intersect. The track radius is greater than the minimum contour radius for set β <0. In the illustrated example, the cutting surface extends at the depth of penetration to the projected center on the flat side.

Fig. 11.3 again shows the section along the line F-F. In this case by a tool that is designed asymmetrically. The convex cut surface is cut by the edge portion of the peripheral surface at point B. In addition, the area A to C and parts of the flat side to the point B * cuts.

In addition to the ability to cut multiple radii, it is also possible to influence the geometry of the cut surface. It can clearly be seen in FIG. 5 that the points A and A 'do not have the same distance to the instantaneous pole MR. In a straight-line movement of the tool, the difference caused by the workpiece thickness t and the radius of the tool does not occur. In a curved movement of the tool creates a contour in which the point A 'is offset by the track error s against the track. This is in Fig. 5 and in Fig. 12, which shows the section along the line BB of Fig. 4, to detect. The correction of the tracking error s is effected by adjusting the toe correction angle α, the angle a, as shown in FIG. 12, resulting essentially from the inclination angle of the tool 12 about the a-axis. The inclination by the angle a causes the lower point A 'to be shifted and the correction angle γ to reach a desired value. Depending on the configuration of the cutting surface and its geometry, the cut surface may have a defined crown.

The Fign. 13 and 14 show an exemplary embodiment of the inventive tool. The tool 12 is designed as a cutting disc having two differently recessed flat sides 24 and 25 and a peripheral surface 28. The peripheral surface has on its outer side a cutting surface consisting of abrasive grains. The cutting surface continues over the edge of the peripheral surface 28 to the flat sides 24 and 25 with their transition regions 30 and 33. In contrast to the embodiment of FIGS. 1 to 13, the transition between peripheral surface 28 and recessed flat side 24 is rounded here. The Fign. FIGS. 15 to 18 show the sectional profile of various tools in the view of the section D-D from FIG. 6.

FIGS. Figs. 15 and 16 show contours cut by a conventional tool without annular concave transition areas. In FIG. 15, a caster angle β> 0 ensures that the convex cut edge can be produced in the desired shape. In this case, the edge region intersects the convex edge at point A and the concave edge at point D at the edge region. In contrast, in Fig. 16, the desired convex contour is generated by a caster angle β <0. In this case, the edge area at point B intersects the convex and the edge area at point C intersects the concave cut edge. In both Cases it comes to an increase in the contour width and therefore to a larger chip volume and larger cutting forces.

In Fig. 17, the same convex cut edge is cut by an inventive tool with annular taper at β = 0. The convex cut surface is cut from the edge portion of the peripheral surface at points A and B, and the concave cut surface is cut from the edge portion at points C and D. In this embodiment, the contour width is reduced. In the transition from the curve to the straight line, the transitional area at point D on the trailing side intersects the contour since the track width of the disc between B and D, which is related to the feed direction, is greater than the track width between A and C at the contour position itself.

To achieve a constant contour width, a caster angle ß 0 can be set. In Fig. 18, the cutting path for tracking angle ß> 0 is shown, which is controlled so that the contour width is constant. In this case, the edge region intersects the convex edge at point A and the concave edge at point D at the edge region.

In summary, it can be stated that a rigid saw blade or a bending-resistant cutting disc offset with abrasive grains is used to produce curved contours on shell-shaped structures, in particular of fiber composite materials. The cutting disk consists of a rigid basic body whose width, starting from a peripheral surface toward the center, decreases at least on one side in an annular region. The cutting disc can, as shown in FIGS. 7.2. 9.2, 9.3, 11.3, 13 and 14, asymmetrically with a recessed flat side on one side or both sides of the tool or symmetrically with recessed flat sides on both sides of the tool Cutting disc be provided. The cutting disc is equipped with a cutting-capable inside, which allows over or under turning of the cutting disc in the cutting gap to the caster angle ß. As a result, the edge quality can be specifically influenced and the minimum radius of contour to be machined can be further reduced.

Claims

claims

1. A method for producing single or multiple curved contours in a workpiece with a disc-shaped, rigid tool having a base body with two opposite flat sides and a circumferential, a cutting surface bearing peripheral surface having a defined width in the axial direction, starting from the Circumferential surface is provided in an annular radius region of the tool, a transition region on at least one of the flat sides, which tapers in the axial direction and is at least partially provided with a cutting surface, the method comprising the steps of

Traversing a predetermined contour through the workpiece with a rotating tool, wherein the leading and / or trailing edge of the peripheral region to the transition region, which is directed to the instantaneous pole of the convex cut surface, generates the desired contour cutting surface,

Adjusting a spin correction angle a which is changed, in particular during contour radii transitions, so that a desired angle γ is generated between the cutting surface and the workpiece surface, the tracking curvature α corresponding to a rotational angle about an axis passing through the intersections of the workpiece with the convex cutting surface and the setting of a caster angle β, depending on the track radius of the worn contour, wherein the caster angle ß between the axis of rotation projected onto the workpiece surface of the tool and the connecting line from the instantaneous center of the tool (MR) to the workpiece surface projected center of rotation of the tool (Μ ') is located.

2. The method according to claim 1, characterized in that a minimum contour radius RKmin is provided by the axial projection w of the peripheral region over the flat side of smaller width, the half distance between the points A and B, which is denoted by F and on the Geometric relationship F ² = r ² - hi ² is linked to the tool radius r and the depth of penetration, and by the caster angle ß on the geometric relationship Rfcmin ^{2 =} (Rt min - w) ² + (F - RKmin tan (| ß |) ) ^{2 is} determined.

3. The method according to claim 1, characterized in that when the track radius is smaller than the minimum contour radius at ß of zero, the caster angle ß is different from zero.

4. The method according to claim 3, characterized in that the caster angle ß is increased in terms of amount, so that the width of the cut groove is increased or reduced in amount, so that the groove width is reduced, in particular along the contour to vary the groove width or constant to keep.

5. The method of claim 1 to 4, characterized in that areas of the flat side, in particular at the trailing taper, for ß ^ 0 or ß = 0 involved in contour radii transitions on the separation process.

6. Tool for the production of single or multiple curved contours, which has a disc-shaped, rigid body with a cutting surface, wherein the main body has two opposing flat sides and a circumferential, a cutting surface bearing peripheral surface with a defined width in the axial direction, wherein starting from the peripheral surface in an annular radius region a transition region is provided on at least one of the flat sides, which tapers in the axial direction, characterized in that the cutting surface extends from the peripheral surface at least partially on the transition region and when creating the curved contour with the arranged on the peripheral surface and the transition region cutting surface can edit the workpiece.

7. Tool according to claim 6, characterized in that the cutting surface is occupied by geometrically undefined cutting edges, in particular abrasive grains.

8. Tool according to claim 7, characterized in that the cutting surface extends to a flat side of the tool.

9. Tool according to one of claims 6 to 8, characterized in that the cutting surface has a radially outwardly facing main cutting edge and arranged in the transition region secondary cutting edge.

10. Tool according to claim 9, characterized in that the main cutting edge and the secondary cutting edge have working cutting edges in opposite cutting directions.

11. Tool according to one of claims 6 to 10, characterized in that that a radius-projection ratio (RÜV), defined as the quotient of tool radius and axial projection of the peripheral region over the flat side of smaller width, a maximum of 30, preferably a maximum of 20 and in particular maximum 10, is.