EP2046528A1

EP2046528A1 - Method of grinding an indexable insert and grinding wheel for carrying out the grinding method

Info

Publication number: EP2046528A1
Application number: EP07787913A
Authority: EP
Inventors: Hubert Müller
Original assignee: Erwin Junker Maschinenfabrik GmbH
Current assignee: Erwin Junker Maschinenfabrik GmbH
Priority date: 2006-08-01
Filing date: 2007-07-25
Publication date: 2009-04-15
Anticipated expiration: 2027-07-25
Also published as: RU2432246C2; RU2009107227A; KR20090050050A; US20100062690A1; US8500518B2; IL196380A0; KR101442568B1; CN101495269A; IL196380A; WO2008015144A1; JP2009545458A; AU2007280484A1; DE102006035845A1; EP2046528B1

Abstract

In an indexable insert having the wide sides 10a, 10b, the inclined narrow sides 24 are to be ground, that is to say the grinding allowance 38 is to be removed. To this end, the indexable insert 10 is set in rotation about the driven axis of rotation 11 (C axis) between a clamping insert 6 and a thrust bolt 9. Serving for the grinding is a grinding wheel 18 which rotates about the rotation axis 19 and which has a circumferential surface 18a contoured in a circular shape and having the largest diameter 43 and is composed of a leading region 41 and a trailing region 42. The grinding wheel 18 is guided relative to the indexable insert 10 along the geometrical defining line 39 which is formed by the generating line of the finished narrow side 24 in the feed direction 44. The leading region 41 tapering forwards effects preliminary grinding of the narrow side 24 by longitudinal grinding, whereas the trailing region 42 effects finish grinding by linear contact with the narrow side 24. The grinding wheel 18 is held with the clamping flanges 40 on a grinding spindle. The grinding operation is effected with controlled movement of the driven axis of rotation 11 (C axis), a first displacement axis 3 (Z axis), a second displacement axis 15 (X axis) and a pivoting movement of the grinding wheel 18 relative to the indexable insert 10 according to double arrow B.

Description

METHOD FOR GRINDING A TIPPING PLATE AND GRINDING WHEEL FOR CARRYING OUT THE GRINDING PROCESS

The invention relates to a method for grinding an indexable insert, in which the narrow sides thereof are moved along the circular contoured circumferential surface of a rotating grinding surface and ground by the latter, with the following CNC-controlled, coordinated movements of the grinding process:

a) the indexable insert is driven for rotation about a plane perpendicular to its plane of rotation;

b) a grinding spindle which supports and drives the grinding wheel and the axis of rotation of the indexable insert are displaced relative to one another in two mutually perpendicular displacement axes, the displacement axes lying in parallel or identical planes;

c) the worm spindle and the indexable insert are pivoted relative to one another about a pivot axis which is perpendicular to the planes in which the displacement axes and the axis of rotation of the indexable insert lie,

according to the preambles of claims 1 to 3

Such a grinding method is known from DE 42 40 053 A1. The narrow sides of the indexable insert are ground in this known method with a narrow grinding wheel which has a cylindrical peripheral contour. The grinding wheel is driven by a grinding spindle, which is displaceable in two mutually perpendicular horizontal planes The indexable insert is located in a clamping device which is pivotable about a vertical axis. The clamping device has two Einspannstempel, which clamp the indexable insert on their broad sides between them and drive to rotate by the clamping device to the During the grinding process, the following four movements are constantly synchronized with each other CNC-controlled: The rotational movement of the indexable insert about its driven axis of rotation (C-axis), the movement of the worm spindle in the direction the first displacement axis (Z axis) and the second displacement axis (X axis) and the pivoting movement of the clamping device about the vertical pivot axis (B axis) In this way it is possible to sand flat sides with the desired clearance angle to the indexable insert.

With the known method according to DE 42 40 053 A1, hitherto usual grinding methods were to be improved, in which the narrow sides of the indexable insert are ground with cup-shaped grinding wheels. However, difficulties were encountered in realizing the grinding process with four axes of movement controlled by CNC interpolation. Therefore, in the known method according to DE 42 40 053 A1 also expressly prescribed that during the grinding of the narrow sides of the cylindrically contoured narrow grinding wheel in the axial direction superimposed on the controlled movement oscillating back and forth is moved, whereby the engagement of the individual abrasive grains The grinding wheel should be constantly corrected It has been shown in practice that the grinding results nevertheless did not lead to the hoped-for improvement. Excessively high grinding wheel wear and unsatisfactory precision in the grinding result, ie in the nature of the ground narrow sides, were found.

Presumably therefore, even after the proposal became known according to DE 42 40 053 A1, further suggestions for improvement were made for grinding with cup-shaped inserts, as shown for example in DE 43 01 214 A1. Although this would possibly improve the Schleϊfer- result again, but provided for this purpose cup-shaped grinding wheels were particularly complicated, namely built in several parts Since it is often necessary to grind bevels when grinding indexable inserts, at least two abrasive coatings of cylindrical shape were required, which lie in different planes. One edge of the indexable insert sanded the narrow sides of the indexable insert, while grinding the required bevels with the second one, which is located in another axial plane. Grinding with cup-shaped grinding wheels also causes difficulties with respect to the mutual accessibility of the grinding wheels Areas at the turnaround Cutting board Therefore, even the improved methods of grinding indexable inserts with cup-shaped grinding wheels could not be economically satisfactory

In a simple device for regrinding worn indexable inserts according to DE 295 14 702 IM, it is known to regrind the inserts with a grinding wheel, which has the profile of a double cone in cross-section. The device is turned off on the grinding of indexable inserts, the broad sides of a diamond-shaped contour The indexable inserts are mounted on a tool carrier Grinding wheel and tool carrier are movable relative to each other in two horizontal directions and vertically By raising or lowering the grinding wheels, a hollow grinding on the insert or a clearance angle can be formed The contour of the grinding wheel in the mold A double bevel serves to sharpen different narrow sides of the indexable insert one after the other on the one or the other conical surface of the grinding wheel. For this purpose, the clamped indexable insert must only be clamped on the tool This type of grinding is not to be compared with a grinding process which is to be carried out economically in the production of indexable inserts in mass production.

The invention is therefore based on the object to provide a grinding method of the initially mentioned type, with the inserts are produced in an economical mass production, in which the narrow sides even when using difficult to sinter materials sintered have a perfect condition and have the desired Dimensional and geometrical tolerances are met

A first solution to this problem is achieved with the entirety of the features of claim 1. Here, a grinding wheel is used, which has a forwardly tapering lead area and an adjoining cylindrical trailing area. The grinding process is carried out in such a way that the lead-in area, which forms a lead angle with respect to the contour of the indexable insert, performs a longitudinal grinding according to the principle of peel-shearing, thereby first passing over the narrow side of the indexable insert. The lead-in area causes roughing, for example roughing. The lead-in area removes most of the grinding allowance. By passing the lead-in area at the location of its largest diameter into the cylindrical caster area, an immediate transition from the lead Grinding performed on the regrinding on the surface of the narrow sides The two processes can thus take place simultaneously

It has been found that in the procedure according to the invention very good grinding results are achieved in conjunction with a significantly improved service life of the grinding wheels, ie the wear of the grinding wheels is significantly reduced. This is due to the fact that in peeling grinding with a longitudinal movement of the grinding wheels Grinding process forward tapered grinding wheel significantly improved Kuhlverhältnisse exist, whereby the grinding wheel is protected and in the workpiece in the grinding zone a minimum of heat is entered. The subsequent trailing edge is significantly shorter than the leading edge, eg only one third of the grinding wheel thickness can be used. When grinding with the trailing edge, the grinding wheel will make line contact with the narrow side of the indexable insert, white! the grinding wheel is perpendicular to the respective narrow side of the indexable insert. However, only relatively little material is removed here, and the contact length is short. Thus, the thermal stress on the grinding wheel and the workpiece is kept small Grinding the hard-to-machine carbide sintered materials of the indexable inserts has proven to be crucial. The service life of the grinding wheel could thus be significantly increased. In addition, cutting inserts made of ceramic materials can be machined using the grinding process

A second solution of the object underlying the invention is achieved by the entirety of the features of claim 2 The Applicant has found that a slight pivoting of the grinding wheel relative to the indexable insert can lead to similar good results as the orientation perpendicular to the respective contour of the narrow side Grinding according to the first solution If the procedure according to claim 2 is used, the grinding wheel forms a bleed angle in the feed area! This is also the case if the trailing area of the grinding wheel is cylindrically contoured as in the procedure according to claim 1. The grinding wheel is then only with the tapered feed area up to the largest grinding wheels - Diameter abrasive Effective lead angle and clearance angle lead to a further improvement of the cooling conditions The method according to claim 2 may also be carried out by peel grinding When particularly hard sintered materials u. U Perform pre-grinding and regrinding with two different grinding wheels If, however, the trailing region is likewise tapered starting from the largest diameter of the grinding wheel, a larger starting angle and a larger clearance angle result, without the grinding wheel having to be tilted or pivoted particularly strongly in relation to the turning cutting plate.

A third solution of the object on which the invention is based is given in claim 3. The Applicant has found that the trailing region can even be completely eliminated and that the procedure according to claim 2 can also be carried out with a grinding wheel which has a tapering, for example, has conical, contour and is guided with the small diameter first on the narrow sides of the insert. The advantage of this solution is based to a very special extent on the thereby improved cooling conditions on the surface of the grinding wheel and the indexable insert

For the three specified procedures, various embodiments are possible, which are specified in the dependent claims

If, in claims 1 and 2, the lead-in area is referred to as tapering forwards, this is based on a movement of the grinding wheel relative to an indexable insert which is stationary in the axial direction. However, basically only a relative movement between indexable insert and grinding wheel in the feed direction of the longitudinal loops required, so that the term "forward" is only an ordinance for the condition of the grinding wheel

Since indexable inserts with a free width have a larger and a smaller broadside, the question arises in which direction the grinding wheel should be moved relative to the indexable insert. Basically, both directions of movement are possible, ie moving the cutting plate from the small broad side to the larger width side and vice versa It has been found that it is better for hard sintered materials and high grinding performance, according to a first embodiment of the method according to the invention to guide the grinding wheels from the larger broad side of the indexable inserts over their narrow sides away to the smaller broadside. The reason for this is that When grinding from the larger broad side, the endangered cutting edge breaks down less easily in the area of the large transverse dimension than when this cutting edge reaches from the narrow side through the grinding wheel grinding pressure and thermal stress are then lower when grinding this cutting edge.

In the procedure according to claim 2 or 3, a Schäischleifen can also be carried out according to a further embodiment of the method

According to a further advantageous embodiment, it is provided that the taper of the leading area and / or the trailing area {claims 1 and 2) or the entire tapered contour of the rotating grinding wheel (claim 3) are formed as a conical shell Leading area, trailing area or grinding wheel are then straight lines. This is a particularly favorable production technology when dressing the grinding wheel. It must be mentioned, however, that there is no compulsion to do so in terms of grinding technology. Thus, the tapers can also be curved, for example as spherical surfaces or as fillets, whereby the special process control of the hard material materials to be ground is very important

In many cases, in particular in the procedure according to claim 1, it is sufficient to carry out the entire gradation of grinding, ie from roughing to fine grinding, through the leading and trailing areas of the grinding wheel. Even with the conical grinding wheel according to claim 3, a finishing by longitudinal and peeling grinding in one go is possible. However, in the case of particularly hard sintered materials and particularly high abrasive stress, it may also be necessary to distribute the grinding process to two grinding wheels. This is the subject matter of a further advantageous embodiment of the method according to the invention, wherein for grinding and finishing, successive grinding operations with different grinding wheel specifications but with the same basic principles Assembly takes place The grinding machines required for this purpose, for example with pivotable grinding headstocks, which carry two grinding spindles, belong to the state of the art.

Despite the leading and trailing areas (claims 1 and 2), the grinding wheels required to carry out the method according to the invention retain a relatively simple construction. Since the basically disc-shaped basic shape of the grinding wheel is maintained, the mutual accessibility of the indexable insert with the circular contoured circumferential surface, but also with the side surfaces of the grinding wheel, presents no difficulties. According to a further advantageous embodiment of the inventive method, it is therefore easily possible to grind also located between the narrow sides and the broad sides bevels of the indexable insert in the same clamping with the side surfaces of the rotating grinding wheel With one and the same grinding wheel can thus in one and the same clamping the narrow sides of the insert as well the bevels are ground, which are arranged between the individual flat narrow sides or between the narrow sides and the broad sides of the indexable insert

Finally, there is a particularly simple and thus advantageous possibility to carry out the method according to the invention when the indexable inserts do not have a free angle. The surfaces of the indexable inserts then run perpendicular to their broad sides, and the relative pivoting of the grinding spindle and indexable insert about a particular pivot axis can be dispensed with

The invention also relates to a special grinding wheel for carrying out the grinding method according to claim 1 or 2 and to these dependent claims 4 to 6 and 8 to 10; The grinding wheel according to the invention is specified in claim 11 of the application According to the different grinding operations to be performed by the leading and trailing area of the grinding wheel, which is located on the circular contoured peripheral surface of the grinding wheel cutting material, although in each case of diamond grains with ceramic or metallic bond; However, the grinding wheel specification is different in the leading and trailing areas. The cutting material and its bond can be adjusted to the requirements of roughing and in the trailing area to those of Schlich- tens in the lead, ie be performed finer example

A development of the grinding wheel according to the invention consists in that, for grinding the bevels, an abrasive coating is also provided on the side surfaces of the grinding wheel, which can then again have a grinding wheel specification that is different from that in the circular contoured peripheral surface of the grinding wheel

As has already been presented for the embodiment of the method, according to a further embodiment, the grinding wheel according to the invention, the taper of the lead-in area and / or the trailing area in the form of a conical shell on points, without it being necessary to specify them for reasons of grinding technology.

The invention will be explained in more detail in the drawings illustrated embodiments. The figures show the following:

Figure 1 shows a top view of the essential parts of a grinding machine, with which the inventive method is performed

Figure 2A is an end view and a partial section of an indexable insert to be ground

FIG. 2B indicates a detail from the partial section according to FIG. 2A.

FIG. 3 shows a longitudinal section and an end view in the region of the workpiece receptacle of the workpiece spindle of the grinding machine according to FIG. 1

FIG. 4 shows in a schematic representation the relevant influencing variables when grinding the narrow sides of an indexable insert

FIG. 5 illustrates the grinding engagement at the beginning of the longitudinal grinding

Figure 6 shows an advanced phase of the grinding process.

Figure 7 is a representation of a grinding phase at the end of regrinding.

FIG. 8 is the reproduction of a modified one of FIGS. 4 to 7

Grinding method, wherein the rotating grinding wheel is slightly tilted relative to the indexable insert

Figure 9 shows a representation corresponding to Figure 8, but with the rotating grinding wheel has a changed contour FIG. 10 illustrates how bevels with the same grinding wheel and the same clamping can be ground to the indexable cutting insert in the grinding method according to the invention.

Figure 11 is a view corresponding to Figure 10, wherein the chamfer is ground on the opposite side of the indexable insert

FIG. 12 illustrates a further variant of the method according to the invention, wherein the grinding wheel has a continuously tapering contour in its circumferential area

In Figure 1, a grinding machine is shown schematically in a view from above, as it corresponds to the usual universal round and -Unisundschleifmaschine Here, only the essential parts are shown on a machine bed 1, a grinding table 2 in the direction of a first displacement axis 3 is moved The displacement axis The grinding table 2 carries a workpiece headstock 4 with a receptacle 5 and a centering insert 6 At a distance from the workbench 4, the tailstock 7 is arranged with a centering receptacle 8 and a Druckbolzeπ 9. Workpiece headstock 4 and tailstock 7 can normally be moved against each other, but also together. At the centering insert 6, the indexable insert 10 to be ground can be fastened and centered and tightened by the pressure pin 9 of the tailstock 7

The indexable insert 10 can be driven in rotation by the workpiece spindle 4. During grinding, therefore, the indexable insert 10 rotates about the driven axis of rotation 11. In grinding machine construction, this is generally referred to as the C axis. In the distance to the grinding table 2, a wheel spindle 12 is arranged, which can be pivoted about a plane perpendicular to the drawing plane pivot axis 13. The pivot axis 13 is usually referred to as B axis means of a carriage 14, the wheel spindle 12 relative to the grinding table 2 in the direction of the second Displacement axis 15 are moved the second displacement axis 15 is commonly referred to in grinding machine construction as the X-axis.

The grinding headstock 12 carries a first grinding spindle 16 with a first grinding wheel 18 and a second grinding spindle 17 with a second grinding wheel 20. Each of the two grinding wheels 18, 20 has a circular contoured peripheral surface 18a. associated axes of rotation of the first and second grinding spindle 16, 17 and grinding wheel 18, 20 are designated 19 and 21

To the grinding machine also includes a dressing spindle 22 with a dressing wheel 23, to which the two grinding wheels 18 and 20 can be made to dress

The pivotability of the grinding spindle rod 12 about the pivot axis 13 serves once to selectively bring the first grinding wheel 18 or the second grinding wheel 20 into contact with the indexable insert 10 and secondly that the required pivoting movement of the grinding wheel during grinding can take place Pivoting movement of the grinding headstock 12 about the pivot axis 13 in this case is included in the CNC control of the entire grinding machine

In the grinding machine for carrying out the grinding method according to the invention, four possible movements are thus coordinated with one another in a CNC-controlled manner:

Rotation of the indexable insert 10 about the driven axis of rotation 11 (C-axis),

Moving the indexable insert 10 over the grinding table 2 in the direction of the first displacement axis 3 (Z-axis),

Moving the Schieifspϊndelstocks 12 relative to the grinding table 2 in the direction of the second displacement axis 15 (X-axis),

Swiveling the grinding spindle rod 12 about the pivot axis 13 (B axis)

The first and second displacement axis 3, 15 and the driven axis of rotation 10 lie in parallel planes; they can even all lie in the same plane The pivot axis 13 is perpendicular to these planes or this plane

The CNC-controlled adjustment of the four movement possibilities is achieved in the manner of a non-circular grinding process that the narrow sides of the indexable insert 10 get the desired contour In this case, generally flat surfaces with bevels in the transition from the narrow sides to the two broad sides are desired

In FIGS. 2A and 2B, the indexable insert 10 to be ground is shown with its details. Its broad sides 10a, b are already finished at the beginning of the grinding process. Indexable inserts are mostly made of cemented carbide or ceramic materials; Wide sides 10a, b can be produced with sufficient accuracy and fineness already by sintering. If higher accuracies are required, the broad sides are ground in a preceding operation. The indexable inserts are interchangeable and rotatable, for example by means of a mounting hole 26 in tool holders a free angle 27 so that their narrow sides 24 are inclined relative to the broad sides Therefore, the one broad side 10a is greater than the other broad side 10b The narrow sides 24 go into each other with chamfers 25 over chamfers 28 can also in the transition between the narrow sides 24 and the broad sides 10a For this purpose, a chamfer angle 29 is created in the edge region. In the broad sides 10a, 10b of the indexable inserts, depressions 30 may be located, or the board sides 10a, 10b may be formed by the depressions 30 in certain applications n the clearance angle 27 can be omitted, so that the narrow sides 24 are perpendicular to the broad sides 10a, b The individual angles depend on the intended use of the indexable insert 10, in particular after the Zerspanaufgabe and the material to be machined, which is to be machined with the indexable insert 10

FIG. 3 shows an enlarged view of details of the workpiece spindle stock. The already mentioned holder 5 is fastened with screws 32 to the receiving part 31 for the workpiece headstock 4. The receptacle 5 comprises the clamping insert 6, which is provided in its longitudinal direction with stepped holes. In this longitudinally movable is a centering pin 37 which is biased by a compression spring 34 in the direction of the tailstock 7 The compression spring 34 is supported with its inner end to a pressure plate 35 from the pressure plate 35 also serves to support the centering pin 37 with a nut 36 By rotation about the driven axis of rotation 1 1, the clamping insert 6 is driven for rotation The indexable insert 10 is attached to the centering pin 37 and at the same time supports itself on the shoulder of the clamping insert 6 Since the workpiece headstock 4 and tailstock 7 can be set against each other, the indexable insert becomes 10 clamped between the clamping insert 6 and the pressure pin 9 of the tailstock 7 and positively entrained for rotation while the illustrated Design also provided a fast, suitable for mass production replacement of the grinding indexable inserts The partial handling for loading and unloading is preferably carried out fully automatically in this or from the device

4 shows the grinding process schematically and with its basic influencing variables. The indexable insert 10 provided with a grinding allowance 38 is driven for rotation about the driven rotation axis 11. The extended surface of a narrow side 24 forms the geometrical determination line 39 for the grinding process narrow side

The grinding wheel 18 rotates about its axis of rotation 19, the actual grinding body being clamped between two clamping flanges 40 as usual. The rotating circumferential surface 18a of the grinding wheel 18 is contoured in a circular shape, ie in each radial plane of the grinding wheel a circular contour is present Grinding disc 18 in its Schieifwirksamen area but from a lead-in area 41 and a Nachiaufbereich 42 together The lead area 41 is performed in the axial direction of a tapering From a largest diameter 43 of the grinding wheel 18, it decreases to a smaller diameter of its front side surface The front side surface is doing defined by the feed direction 44, in which the relative movement of the

Grinding wheel 18 takes place relative to the indexable insert 10 along the geometrical lines of determination 39. In this case, the indexable insert 10 can be moved and the grinding wheel can be stopped in the axial direction or vice versa

In Figure 4, the contour of the lead-in area 41 is shown as a conical contour The apparent in Figure 4 surface line of the lead-41 is thus a straight line However, this is by no means mandatory, depending on the technological requirements of the cutting process, the surface line can also curved, z B convex or as a groove However, these shapes can also be freely determined depending on the shape of the work piece and the grinding. FIG. 4 also shows that the mutual movement between the grinding wheel 18 and the indexable insert 10 starts in the feed direction 44 at the larger broad side 10a and This is the generally preferred abrasive coating; because it reduces the risk that the peripheral edge of the indexable insert 10, which is located between the broad side 10a and the narrow side 24, breaks out during grinding. In principle, however, it is also possible lent to work with different grinding direction, so that the mutual movement attaches to the smaller broadside 10b

The lead-in region 41 is adjoined by a follow-up region 42, which in the present case has a cylindrical contour, so that the diameter of the wake region is also the largest diameter of the lead region

The grinding process is controlled in such a way that with the lead area 41 a peel grinding in the sense of pre-grinding and with the trailing area 42 a regrinding peel grinding is known, the grinding wheel 48 delivered so that the entire grinding allowance 38 is removed in a single longitudinal passage While When peeling grinding takes place with a tapering contour of the lead-in area, there is a line contact between the trailing area 42 and the narrow side 24 of the indexable insert 10 during regrinding

The grinding process is carried out on the basis of a longitudinal grinding, wherein the grinding wheel 18 is guided relative to the indexable insert 10, as illustrated in the figures also in Figures 1 to 7. FIGS. 5 to 7 show the enlarged detail U from FIG. 4, but in the advanced stages of the grinding process

The roughing and regrinding can be carried out as roughing and sizing. In certain application cases, ie with particularly difficult to machine sintered materials, it may be expedient, however, to distribute roughing and sizing to two different grinding wheels, as the grinding machine according to FIG The two grinding wheels 18 and 20 in this case have the same basic structure but different grinding wheel specifications

Although the machining process is basically based on longitudinal grinding, it must always be borne in mind that the four different movements listed above must always be adjusted in a CNC-controlled manner so that the desired result can be achieved

The progress of the longitudinal grinding is shown particularly clearly in FIGS. 4 to 7 in the context of FIG. 4, the grinding wheel 18 first reaches the indexable insert

10 introduced and touches the Schleϊfaufmaß 38 just with the flow area at the Position of the Larger Wide Side 10a In the phase of FIG. 5, a large part of the grinding allowance is already removed by the lead-in area 41, and the trailing area 42 is currently being used. According to FIG. 6, there is a complete line contact between the trailing area 42 and the pre-ground narrow side While the pre-grinding has not yet been completed, regrinding already starts with the entire axial extension of the trailing region 42. In FIG. 7, regrinding with the trailing region 42 is just ending, and the grinding process is so far completed the bevels 25 are mitgeschliffen between the individual narrow sides 24 in the course of the grinding process described here

A grinding process is described with reference to FIG. 8, which is modified in comparison to FIGS. 4 to 7

The reference numerals for the illustrated parts of the grinding machine and the indexable insert have remained unchanged. However, a new sequence of reference numerals for the rotating grinding wheel 48 is introduced because, although the latter has remained unchanged, it is moved in a changed pivotal position relative to the indexable insert 10 4, the grinding wheel 18 is perpendicular to the generatrix of the narrow sides 24, the grinding wheel 48 is pivoted in the illustration of Figure 8 forward by the tilt angle 47. This can be easily adjusted and maintained by means of the pivot axis 13. The grinding wheel 48 again has a forwardly tapering lead-in area 49 and a cylindrical trailing area

In this way, the circular contoured peripheral surface 48a in the feed region 49 forms a lead angle 45 with respect to the resulting narrow side 24 of the indexable insert 10 and a relief angle 46 in the lead region 50. The chip flanges of the rotating grinding wheel 48 are again denoted by 40 and their axis of rotation coincides

51 and her biggest diameter at 52

The grinding wheel 48 is guided relative to the indexable insert 10 in the feed direction 44 along a longitudinal grinding on the narrow side 24 of the indexable insert 10 along. In this case, peeling grinding is preferred.

In this case, there is no longer any line contact with the narrow side 24 of the indexable insert 10 in the trailing region 50, but instead only one point contact through the largest diameter 52. It has been shown, however, that in this way too Desired contours on the narrow sides 24 of the insert 10 are reliably herauszuarbeiten are Here, the entire processing can be done by peeling grinding If the abraded grinding 38 to be processed, however, higher, the grinding of the contour can be done in several steps; d. The grinding allowance is removed step by step. The clearance angle 46 in the trailing region 50 leads to improved cooling conditions because the line contact between the indexable insert 10 and the trailing region 50 is canceled

Figure 9 has a variant of the illustrated by the figure 8 process flow to the subject The contour of the caster region 50 is no longer cylindrical in this case, but opposite to the feed direction 44 of the longitudinal grinding, ie tapered towards the end of the grinding wheel 48 The contour of the taper can preferably With the modified shape of the grinding wheel according to FIG. 9, a larger lead angle 53 in the lead area and also a larger clearance angle 44 in the lead area 50 can be realized without the grinding wheel 48 facing the side surface 24 the indexable insert 10 has to be tilted even more. This shows very snowy! a comparison of the cutting angle 47 according to the figures 8 and 9. Also in the method according to Figure 9, a longitudinal grinding can be realized easily

Finally, FIGS. 10 and 11 show how bevels 28, which are located in the transition region between the broad sides 10a, b and the narrow sides 24, can be ground with the same grinding wheels 18, which serve for grinding the narrow sides 24. For this, the broad sides 55 are , 56 of the grinding wheel 18 are likewise provided with an abrasive coating and are made obliquely laterally against the transition region between the broad sides 10 a, b and the narrow sides 24 of the indexable inserts 10.

To carry out the previously described Schieifverfahren according to the invention thus grinding wheels are required, which have two different areas in the axial direction, namely a lead-in area 41, 49 and a trailing area 42, 50 During the lead-in area 41, 49 to the first side surface 55 of the grinding wheel 18th 48, the trailing region 42, 50 may be cylindrical or also tapering towards the second side surface 56 Since cutting inserts 10 consist of sintered hard metal or ceramic materials, the cutting material is made of diamond grains with ceramic or metallic Bonding The grinding wheel specification will generally be different in the lead area 41, 49 than in the trailing area 42, 50, because the lead area 41, 49 usually works in the sense of pre-grinding, thus removing larger amounts of material in comparison to the trailing area 42, 50 must and works coarser The tracking range 42, 50 can be set finer and softer in its grinding specification; because of the wake area above all the required surface finish must be achieved

The abrasive pads on the side surfaces 55, 56 of the grinding wheels 18, 48 are also formed of ceramic or metal-bonded diamond grains and will again have a different grinding wheel specification according to their task of grinding the chamfers 28 to the indexable insert 10 it is present in the lead region 41, 49 or in the wake region 42, 50

It has even been found that advantageous results can be achieved if the method is carried out with a grinding wheel which has no trailing area. The grinding wheel then consists practically only of the lead-in area, thus has a tapering in its peripheral area, in the simplest case tapered contour and is guided with the smaller diameter ahead on the narrow sides of the indexable inserts This case is shown in FIG 12

In FIG. 12, first the indexable insert 10 with its broad sides 10a, b and its narrow sides 24 is again shown. The reference numerals for this have remained unchanged as well as those for the workpiece support of the grinding machine and the four relevant axes of movement C, BX and Z deviating from the preceding illustrations the circular contoured circumferential surface 58 of the grinding wheel 57 here a continuous continuous bevelled contour, in the illustrated embodiment, that of a conical shell with rectilinear generatrices. However, the conical shape is not mandatory indexable insert 10 and grinding wheel 57 are again tilted around the tilt angle 60 against each other and are guided relative to each other in terms of longitudinal grinding Here, the formed on the larger side surface 63 of the grinding wheel 57 circumferential edge 61 is in sliding contact with the indexable insert 10, and the smaller side surface 62 of the grinding wheel faces forwardly in the feed direction 64 of the longitudinal grinding. It can be seen again that a leading angle 59 is formed between the peripheral surface 58 of the grinding wheel 57 and the narrow side 24 of the indexable insert 10 List of reference numbers

1 machine bed

2 grinding table

3 first displacement axis (Z-axis)

Workhead

5 recording

6 clamping insert

7 tailstock

8 centering

pushpin

10 indexable insert

10a, b broadside

1 1 driven rotary axis (C-axis)

12 wheelhead

13 pivot axis (B axis)

14 sleds

15 second displacement axis (X-axis)

16 first grinding spindle 7 second grinding spindle 8 first grinding wheel 8a circular contoured circumferential surface 9 first rotation axis 0 second grinding wheel 1 second rotation axis 2 dressing spindle 3 dressing wheel 4 narrow side 5 chamfer (narrow side) 6 mounting hole 7 clearance angle 8 chamfer (wide side) 9 chamfer angle 0 recess 1 receiving part Screw Compression spring Pressure plate Nut Centering pin Grinding allowance Geometric determination line Clamping flange Leading area Follow-up area Largest diameter Feed direction of longitudinal grinding Leading angle of lead-in area Clearance angle of lead-out area Tilting angle Grinding wheel Circular contoured peripheral surface Leading area Follow-up area Rotation axis Largest diameter Leading angle! of the lead-in area Free angle of the after-emergence area first side surface second side surface grinding wheel circular contoured circumferential surface starting angle tilting angle large peripheral edge small side surface large lateral surface feed direction of the longitudinal grinding

Claims

Claims. A method of grinding an indexable insert (10) in which the narrow sides (24) thereof are moved along and grinded by the circular contoured peripheral surface (18a) of a rotating grinding wheel (18) with the following CNC-controlled movements of the grinding operation: a ) the indexable insert (10) is driven to rotate about a perpendicular to its plane veriaufende axis of rotation (1 1) for rotation; b) a grinding spindle (18) overlapping and driving grinding spindle (16) and the axis of rotation (1 1) of the indexable insert (10) are displaced relative to each other in two mutually perpendicular displacement axes (3, 15), wherein the displacement axes (3, 15 ) and the axis of rotation (11) lie in parallel or identical planes; c) the grinding spindle (16) and the indexable insert (10) are pivoted relative to each other about a pivot axis (13) which is perpendicular to the planes in which the displacement axes (3, 15) and the axis of rotation (11) of the indexable insert

(10), characterized by the following procedure: d) the grinding process is based on a longitudinal grinding, wherein the circular contoured peripheral surface (18a) of the rotating grinding wheel (18) relative to the

Narrow sides (24) of the indexable insert (10) starting at the one broad side (10 a) to the other broad side (10 b) of the indexable insert (10) is guided; e) during longitudinal grinding on the grinding wheel (18) befindlicher, forward tapering lead area (41) is preceded, the loop by peeling in the sense of pre-grinding on the narrow sides (24) of the indexable insert (10) acts; f) adjoining the lead-in region (41) lying at the longitudinal grinding backward region (42) of the grinding wheel (18) is cylindrically shaped and acts by Linienberühruπg in the sense of regrinding on the narrow sides (24) of the indexable insert (10).

2 A method for grinding an indexable insert (10), wherein the narrow sides (24) along the circular contoured peripheral surface (48 a) of a rotating grinding wheel (48) moves and be ground by this, with the following CNC-coordinated movements of the grinding Vor- ganges: a) the indexable insert (10) is driven about a perpendicular to its plane extending axis of rotation (1 1) for rotation; b) a grinding spindle (48) overlapping and driving grinding spindle (16) and the axis of rotation (11) of the indexable insert (10) are displaced relative to each other in two mutually perpendicular displacement axes (3, 15), wherein the

Displacement axes (3, 15) and the axis of rotation (1 1) lie in parallel or identical planes; c) the grinding spindle (16) and the indexable insert (10) are pivoted relative to each other about a pivot axis (13) which is perpendicular to the planes in which the displacement axes (3, 15) and the axis of rotation (11) of the indexable insert

(10), characterized by the following Verfahrensfύhrung: d) the grinding process is based on a longitudinal grinding, wherein the circular contoured peripheral surface (48 a) of the rotating grinding wheel (48) relative to the narrow sides (24) of the indexable insert (10) starting at the one broadside

(10a) is guided to the other broad side (10b) of the indexable insert (10); e) during longitudinal grinding, a lead-in area (49) located on the grinding wheel (48) and leading to the front is advanced, which acts on the narrow sides (24) of the indexable insert (10) by peeling grinding in the sense of pre-grinding; f) the trailing area (50) of the grinding wheel (48), which adjoins the largest diameter (52) of the pre-emergence area (49), is cylindrical starting from this diameter (52) or tapering towards the end; g) the rotating grinding wheel (48) is guided in such a pivotal position relative to the narrow sides (24) of the indexable insert (10), that the lead-in area (49) has a lead angle (45, 53) and the after-running area (50) has a clearance angle (50). 46, 54) relative to the narrow sides (24) is formed and a punctiform Schleifberύhrung between the largest diameter (52) of the grinding wheel (48) and the narrow sides (24) of the indexable insert (10) comes about

3 A method for grinding an indexable insert (10), wherein the narrow sides (24) along the circular contoured peripheral surface (58) of a rotating grinding wheel (57) moves and be ground by this, with the following CNC-controlled coordinated movements of the grinding process: a) the indexable insert (10) is driven about a perpendicular to its plane extending axis of rotation (1 1) for rotation; b) one the grinding wheel (57) overlapping and driving Schleifspϊndel and the axis of rotation (1 1) of the indexable insert (10) are displaced relative to each other in two mutually perpendicular displacement axes (3, 15), wherein the displacement axes (3, 15) and Rotary axis (11) in parallel or identical

Layers lie; c) the grinding spindle and the indexable insert (10) are pivoted relative to each other about a pivot axis which is perpendicular to the planes in which the displacement axes (3, 15) and the axis of rotation (11) of the indexable insert are, characterized by the following Verfahrensfuhrung: d) the grinding process is based on a longitudinal grinding, wherein the circular contoured peripheral surface (58) of the rotating grinding wheel (57) relative to the narrow sides (24) of the indexable insert (10) starting at one broad side (10 a) to the other broad side (10 b) the indexable insert (10) is guided; e) the rotating grinding wheel (57) has a verjungende contour in its peripheral region and is guided with the smaller diameter first on the narrow sides (24) of the indexable insert (10); f) the rotating grinding wheel (57) is guided in such a Schwenksteliung with respect to the narrow sides (24) of the indexable insert (10) that their Umfangsflä- surface (58) forms a leading angle (59) relative to the narrow sides (24) and a point-like Schleifberuhrung between the largest diameter of the grinding wheel (57) and the narrow sides (24) of the indexable insert (10) comes about

4. The method according to any one of claims 1 to 3, characterized in that the relative movement between the rotating grinding wheel (18, 48) and the indexable insert (10) during longitudinal grinding at the larger broad side (10a) of the indexable insert (10) begins and in the smaller Broadside (10b) ends

5. The method according to claim 2 or 3, characterized in that the longitudinal grinding is carried out by peeling grinding

6. The method according to claim 1 or 2, characterized in that the taper of the flow area (41, 49) and / or the trailing area (50) is formed as a conical surface

7 A method according to claim 3, characterized in that the tapered contour of the rotating grinding wheel is shaped as a conical surface

8. The method according to any one of claims 1 to 7, characterized in that for roughing and finishing successive grinding operations with grinding wheels (18, 20) of different grinding wheel specification, but provided the same basic structure

Method according to one of claims 1 to 8, characterized in that between the narrow sides (24) and the broad sides (10a, b) located chamfers (28) of the indexable insert (10) in the same clamping with the side surfaces (55, 56) of the rotating Sanding disc (18) are sanded

10. The method according to any one of claims 1 to 3 and 5 to 9, characterized in that the relative pivotability of rotating grinding wheel and indexable insert about a particular pivot axis is eliminated when grinding of indexable inserts without undercut

1 . Grinding wheel for carrying out the grinding method according to claim 1 or 2 and to these dependent claims 4 to 6 and 8 to 10, having a circular contoured peripheral surface (18a, 48a), characterized by the following features: a) the grinding wheel (18, 48) has at least in its peripheral region in axial

Towards two different areas; b) starting from the largest diameter of the circular contoured peripheral surface (18a, 48a), the first region, which serves as a leading region (41, 49) during longitudinal grinding, is tapered towards a first side surface (55); c) the second region adjoining the largest diameter of the first region, which serves as a trailing region (42, 50) during longitudinal grinding, is cylindrical or tapering towards the second side surface (56); d) the cutting material consists of diamond grains, with ceramic or metallic bond, the grinding wheel specification in the lead (41, 49) and trailing (42, 50) is different.

Grinding wheel according to claim 11, characterized in that also at least one of its side surfaces (55, 56) is provided with an abrasive coating whose cutting material consists of ceramic or metallic bonded diamond grains and whose grinding wheel specification differs from that in the circular contoured peripheral surface (55). 18a, 48a) of the grinding wheel (18, 48).

Grinding wheel according to claim 1 1 or 12, characterized in that the taper of the lead-in region (41, 59) and / or the trailing region (42, 50) is formed as a conical surface