DE19940686A1 - Method and device for CNC-controlled dressing of a regulating wheel of a grinding machine for a centerless grinding process on a workpiece, method for centerless grinding and a grinding machine - Google Patents

Abstract

A method and a device for the CNC-controlled dressing of a regulating wheel of a grinding machine for a centerless grinding process on a workpiece are described, as well as a method and a device for centerless grinding of a workpiece. A dressing tool for the regulating wheel is brought into engagement with the regulating wheel under numerical control of its movement and guided along it in order to generate a predetermined peripheral profile of the regulating wheel. There are predetermined first parameters that determine the execution of the grinding process (DS, DR, YR, x, y, z (A), Y AS, A, B) of the grinding machine and predetermined second parameters that determine the execution of the grinding process (DW, PW ) of the workpiece. These are transformed into data for a predetermined circumferential profile of the regulating wheel and converted into CNC control data. The regulating wheel and dressing tool are then moved relative to one another in dependence on the CNC control data, in such a way that the dressing tool generates the predetermined circumferential profile on the regulating wheel. The workpiece is then ground against the regulating wheel. This process is preferably carried out iteratively, in that, after a first grinding process, contour errors of the workpiece which have been ascertained are used for correction during the transformation or implementation (FIG. 5).

Description

The invention relates to a method for CNC-controlled Ab straightening a regulating wheel of a grinding machine for one centerless grinding process on a workpiece in which an ab Straightening tool for the regulating wheel under numerical control engaged in their movement with the regulating wheel and on this is guided along to a predetermined circumferential profile the control wheel.  

The invention further relates to a method for centerless Grinding a workpiece on a grinding machine with a Support for the workpiece, with a grinding wheel and with an egg ner regulating wheel, in which a dressing before the grinding process Tool for the regulating wheel under numerical control of your Engaged movement with the regulating wheel and to the water is guided along to a predetermined circumferential profile the control wheel.

The invention further relates to a device for CNC controlled dressing of a regulating wheel of a grinding machine for a centerless grinding process on a workpiece, at which is a dressing tool for the regulating wheel under numerical Control their movement with the control wheel engaged can be brought and guided along this to a predetermined to generate the circumferential profile of the regulating wheel.

Finally, the invention relates to a grinding machine for centerless grinding of a workpiece with a support for the workpiece, with a grinding wheel and a regulating wheel, in which a dressing tool for the re gel disc under numerical control of its movement with the Control wheel can be brought into engagement and guided along it is to a predetermined circumferential profile of the regulating wheel testify.

The method, the device and the grinder of the front mentioned type are known.  

Grinding machines for centerless grinding of workpieces are usually used for external cylindrical grinding or also for in cylindrical grinding used.

These centerless grinders essentially exist from three main assemblies, namely a grinding wheel with too appropriate storage, a regulating wheel with associated storage and a support rail for the workpiece to be machined. The grinding wheel, the regulating wheel and the support rail can be in different kinematic arrangement relative to each other and arranged relative to the fixed machine bed his. In the case of a design with a so-called "fixed center", the Support rail fixed in space, and the grinding wheel and the Re gel discs are adjustable on sledges. With a type with the so-called "movable center" is the support rail a carriage movable and z. B. the grinding wheel in one fixed storage arranged while the control disc also located on a sled.

Furthermore, grinding machines of this type also include a dressing unit witness for dressing the grinding wheel and the regulating wheel. The dressing tools can be used separately for these two Disks or as a common assembly for both disks be seen. The dressing tools are in the usual spit Zenless grinding machines, seen from the longitudinal median plane hen, arranged behind the grinding wheel or the regulating wheel net. In the context of a parallel patent application of the same An same day registrant (attorney file 4828P100) described another design, in which the dressing unit are located in the area of the median longitudinal plane.  

Through the slides of the above-mentioned assemblies (grinding wheel, Regulating disc, support rail) are the usual feed axes or machine axes. Here are the Schlit ten in a direction perpendicular to a longitudinal plane of the work piece, namely along the so-called X-axis, movable, during at least one of the sledges, often both Sledge, also parallel to the longitudinal plane of the grinding machine, namely movable along the so-called Z-axis are.

The corresponding traversing axes for the dressing tools or the dressing tool can be designed as separate axes However, it is also known that the dressing tools on the Arrange the slide of the grinding wheel or the regulating wheel and perform the dressing process in that the two Sled relative to each other in the required manner will drive. In this way, separate dressing axes, d. H. separate adjustment devices for the dressing tools, saved.

The workpiece is used for centerless grinding of the workpiece placed on the support rail. The support rail defines an imaginary longitudinal center plane of the grinding machine.

The slides for the grinding wheel and the regulating wheel are usually on opposite sides of the longitudinal means level arranged. As a result, the workpiece is between the two disks on opposite sides of the Support the workpiece in a defined manner. The regulating wheel be not only provides support for the workpiece the grinding wheel, it usually also takes care of the axial one  Feed the workpiece on the support rail relative to Grinding wheel. In this way, several workpieces can go one behind the other in the axial direction on the regulating wheel and Grinding wheel are conveyed past (so-called through grind).

The axes of the grinding wheel and regulating wheel are more common wise at the same height, they run approximately parallel to each other and thereby define a horizontal plane. The The axis of the workpiece is usually slightly above that level, in exceptional cases also below.

It is known to pivot the regulating wheel around two axes ken, so that the control wheel axis and the grinding wheel axis in strict observation, they are slightly skewed to each other. A first axis, the so-called A axis, runs in horizon taler direction and is usually to the control wheel axis transferred. A second axis, the so-called B axis, runs perpendicular to it, that is vertical and is opposite to the rule also slightly offset.

A swiveling of the regulating wheel around the A-axis creates one axial feed force that the workpieces during through grinding fen axially through the grinding gap between grinding wheel and Control wheel transported. When plunge grinding, the Workpieces pressed against a stop by this force and held in a fixed position. If the control wheel around the A-axis is pivoted, but still along a line to be in contact with a cylindrical workpiece be profiled in their scope, in the form of a hyper boloids.  

The pivoting around the B axis serves to make the workpieces radial to the grinding wheel and thereby a desired Zy Lindricity or conicity.

In the case of known centerless grinding machines, the rule is maintained slice a circumferential profile to support the workpiece. The order profile is grinded in the grinding machine by a or turning process generated.

With known centerless grinding machines, the dressing is tool for the regulating wheel on the regulating wheel housing orderly. It is therefore when swiveling around the B axis and when Tilted around the A-axis of the regulating wheel. The Ab Straightening tool is a post-forming tool with templates or designed as a CNC-controlled tool.

To the regulating wheel profile on the respective work to be created To coordinate the piece profile are workpiece-related templates used, which are changed mechanically. It is also knows, NC programs from the dressing tool to the grinding wheel use. When it comes to CNC-controlled dressing tools, this is the factory Piece-related profile saved in an NC program. In the his program are the geometry parameters of the Workpiece already taken into account.

In known centerless grinding machines there is a tech ecological optimization of the grinding process through a preliminary position of the inclination of the regulating wheel (A-axis) and below through a fine adjustment by swiveling the entire Regulating wheel (B axis). Does this fine adjustment not lead to  Success, the inclination of the regulating wheel (A-axis) is corrected again rigged.

In these known centerless grinding machines, a pin protrudes vertically upwards from the machine bed in order to implement the B axis. A swivel carriage can be swiveled around the pin in a horizontal plane. On the swivel carriage, a feed carriage runs along a first axis (X ₁ ), which takes a right angle to the longitudinal axis (Z) of the grinding machine if the swivel carriage is not pivoted about the B axis. The feed slide also carries the support rail for the workpiece. A feed slide (X ₂ ) runs in parallel on the feed slide. The feed carriage carries the regulating disc housing. It is pivotable about the horizontally directed A-axis (A ₁ ), so that the longitudinal axis of the regulating wheel can be inclined at an angle α to the horizontal. On the regulating disc housing the dressing tool sits, one axis (X ₃ ) of which is substantially vertical and the other axis (Z ₃ ) of which is essentially parallel to the longitudinal axis (Z) of the grinding machine.

Since the entire dressing arrangement sits on the regulating wheel housing, it is pivoted together with the latter when the regulating wheel is pivoted about the A axis (A ₁ ). To compensate for this pivoting, the guide of the dressing tool along the other axis (Z ₃ ) is pivoted relative to the axis of the control disk about an axis (A ₂ ) which coincides with the vertical axis (Z ₃ ) of the dressing tool.

Around the regulating wheel profile then on this grinding technology the required setting values will be additionally  Fine adjustments of the dressing tool made. This can NEN relative shifts or relative rotations between the regulating wheel and the path of the dressing tool in the dreidi be dimensional space. For this purpose, the postforming template in ih rem holder and / or the center height of the dressing tool poses. It is known that the entire dressing tool around the A- Tilt axis relative to the control wheel axis. This setting is done in connection with the inclination of the regulating wheel around the A axis.

The aforementioned adjustment work in this known Vorge hens are extremely time-consuming and require ge suitable mechanical adjustment elements of complicated design. Dar In addition, there is a high degree of "dexterity" when loading user of the grinding machine required that one accordingly long experience in handling the grinding machine. The correction steps mentioned can also each are only executed iteratively, d. H. several times in a row, so that the total amount of time is significant.

DE 38 43 046 describes a method for generating the order catch profile of a grinding wheel, the workpiece is clamped between peaks.

In the known method for a subsequent high speed peeling process on a workpiece inclined grinding wheel a dressing roller by means of a numerically controlled multi-coordinate movement unit along moving a raw surface of the grinding wheel in Dependence on process parameters, especially the coverage degree of a secondary cutting surface of the grinding wheel  Rotation of the workpiece, the ratio of the peripheral speed of grinding wheel and workpiece, the diameter of the Workpiece, the axial feed speed of the workpiece relative to the grinding wheel and the peripheral speed of the Dimen the grinding wheel an axial length of the secondary cutting surface based.

This known method is for use only a grinding wheel for a grinding process between squares determines and leads depending on the process pa mentioned only for the axial dimensioning of a secondary cutting surface. The area of the minor cutting surface is at an inclined grinding wheel exactly conical, so that a three-dimensional, irregular shape, as in Installation of inclined cylindrical or conical bodies arises during centerless grinding, not taken into account here must become. Correction steps are also not provided.

The invention is based on the object, the Ver drive, the device and the grinding machine of the beginning mentioned type in that the above mentioned disadvantages can be avoided. In particular, inventions can be achieved according to the invention that on very simple, CNC controlled way an optimal system of the regulating wheel to the Workpiece reached during a centerless grinding process even with an iterative correction the fine can be set using a numerical control. It So this adjustment and readjustment should no longer be necessary work through complicated mechanical devices men, so that also a longer professional experience of the user is no longer required. Above all, the time spent on  such work can be drastically reduced, and it should be enough that an integration of the procedures and Vorrich into computer-controlled manufacturing (CIM).

In the method mentioned at the beginning for CNC-controlled dressing of a regulating wheel of a grinding machine, this object is achieved according to the invention by the following steps:

• a) detecting predetermined first, the implementation of the Grinding process determining parameters of the grinding machine;
• b) detecting predetermined second, the implementation of the Parameters determining the grinding process of the workpiece;
• c) transforming the first and second parameters into Data for a predetermined scope profile of the rule disc;
• d) converting the data into CNC control data; and
• e) Relative procedure of regulating wheel and dressing tool to each other depending on the CNC control data, the art that the dressing tool on the regulating wheel before certain circumferential profile is generated.

The object is also achieved according to the method mentioned above for centerless grinding of a workpiece by the following steps:

• a) detecting predetermined first, the implementation of the Grinding process determining parameters of the grinding machine;
• b) detecting predetermined second, the implementation of the Parameters determining the grinding process of the workpiece;
• c) transforming the first and second parameters into Data for a predetermined scope profile of the rule disc;
• d) converting the data into CNC control data;
• e) Relative procedure of regulating wheel and dressing tool to each other depending on the CNC control data, the art that the dressing tool on the regulating wheel before generates certain circumferential profile; and
• f) grinding the workpiece, the control disc with the Circumferential profile rests on the workpiece.

The task is further solved according to the above-mentioned device for CNC-controlled dressing of a regulating wheel of a grinding machine by the following features:

• a) means for detecting predetermined first, by management of the parameters determining the grinding process Grinding machine;  
• b) means for detecting predetermined second, the through management of the parameters determining the grinding process Workpiece;
• c) means for transforming the first and second Pa parameters in data for a predetermined scope profile Regulating wheel;
• d) means for converting the data into CNC control data; and
• e) Means for the relative movement of the regulating wheel and Ab straightening tool to each other depending on the CNC Control data, such that the dressing tool on the Re gel disc generates the predetermined circumferential profile.

Finally, the object is achieved according to the invention according to a grinding machine of the type mentioned at the beginning by the following features:

• a) means for detecting predetermined first, by management of the parameters determining the grinding process Grinding machine;
• b) means for detecting predetermined second, the through management of the parameters determining the grinding process Workpiece;
• c) means for transforming the first and second Pa parameters in data for a predetermined scope profile Regulating wheel;  
• d) means for converting the data into CNC control data;
• e) Means for the relative movement of the regulating wheel and Ab straightening tool to each other depending on the CNC Control data, such that the dressing tool on the Re gel disc generates the predetermined circumferential profile; and
• f) means for grinding the workpiece, the rule disc rests on the workpiece with the peripheral profile.

The object of the invention is based on this Wei se completely solved.

By including such parameters of the grinding wheel be and the tool needed to carry out the grinding are decisive for the process, a target profile for the regulating wheel is determined and this is then controlled by CNC Path guidance of the associated dressing tool on the rule disc realized. So the user of the machine only needs still enter the predetermined parameters so that this be in the first run to the desired circumferential profile Control wheel for the respective workpiece leads.

The user of the machine does not need anything special to have long experience because that for each Grinding process optimal circumferential profile of the regulating wheel through the Control itself is generated and executed.

The first parameters of the grinding machine are preferred the diameter of the grinding wheel, the diameter of the Regulating wheel, the vertical distance between the parallel ones  and horizontal axes of the grinding wheel and regulating wheel, Spatial coordinates of a target position of the dressing tool, a Vertical position of the support for the workpiece, a target position development of the A axis and a target position of the B axis. The second parameter is essentially the predetermined one Diameter of the workpiece or its predetermined profile to deliver.

These measures have the advantage that for the grinding process most important parameters of grinding wheel and workpiece take into account.

In particularly preferred embodiments of the invention a subsequent correction process to compensate for about existing residual errors made.

In the process for CNC-controlled dressing of a regulating wheel initially mentioned at the beginning, this correction process comprises the further steps:

• a) performing a grinding process on a workpiece where for the regulating wheel with the circumferential profile during the Grinding process on the workpiece;
• b) measuring the workpiece with respect to the second parameter ter;
• c) comparing the measured with the predetermined second Parameters; and  
• d) forming a difference between the measured and the predetermined second parameters.

This difference formed can then be used for targeted correction al ternatively used to complete the step mentioned above c) transforming or the step d) mentioned at the beginning implementation by introducing an appropriate correction adjust size, whereupon the following steps connect te.

These measures have the advantage that also under calculator supported determination of any correction values and connect the required correction values are set on the CNC control and the circumferential profile of the regulating wheel is cor is rigged when a first test workpiece after grinding is checked accordingly.

This ensures that an even higher work piece accuracy can be achieved with shorter idle times, and thus a much higher productivity. As part of the Invention would have to be used for the centerless Grinding machines axes A and B are not designed as NC axes leads. Rather, it is sufficient to do this once in one Fixed basic setting. According to the state of the Technically required fine adjustment of the settings of the ach Sen A and B can be omitted completely, so that these axes also me chanically much easier and therefore at lower her service costs can be carried out. With appropriate The procedure according to the invention can be refined to a of the axes, namely the B axis, can even be dispensed with entirely.  

Further advantages result from the description and the at added drawing.

It is understood that the above and the following standing features to be explained not only in each specified combination, but also in other combinations or can be used alone, without the scope of to leave the present invention.

Embodiments of the invention are in the drawing are shown and are described in more detail in the following description explained. Show it:

Figure 1 is an extremely schematic side view of a grinding machine for centerless external cylindrical grinding of workpieces.

FIG. 2 shows a plan view of the machine according to FIG. 1;

Figs. 3A to 3C, in a greatly enlarged scale a detail of Figs 1 and 2 in three different views.

Fig. 4 shows a variant of the representation of FIG 3C to Wei further explanation of the invention. and

Fig. 5 is a block diagram for explaining a control of the machine according to Fig. 1 and 2.

In Fig. 1, 10 designates a grinding machine for centerless external cylindrical grinding of workpieces. It goes without saying that this is only to be understood as an example, because the invention can also be used with internal grinding machines of this type for internal rounding or for plunge grinding, in particular oblique plunge grinding.

In its configuration, the grinding machine 10 does not belong to the prior art with regard to the dressing tools located in the region of the longitudinal center plane. To that extent, it is the subject of the aforementioned parallel patent application by the same applicant on the same day (attorney file 4828P100). However, the problems explained below apply in the same way to conventional grinding machines in which the grinding wheel and the regulating wheel are dressed from behind.

The grinding machine 10 comprises a machine bed 12 . On the machine bed 12 is in Fig. 1 and 2 on the left side he st carriage 14 can be seen, which is provided with an X-guide 16 and a Z-guide 18 , that is designed in the manner of a cross slide. The first carriage 14 is thus movable along two mutually perpendicular axes.

The first carriage 14 carries a grinding wheel 20 with associated drive (not shown). The grinding wheel 20 is rotatable about a horizontal axis 22 .

In the illustration according to FIGS. 1 and 2 is the first carriage 14 on the left side of an indicated with 24 longitudinal center plane of the grinding machine 10.

A second slide 28 on the machine bed 12 can be seen to the right of the longitudinal center plane 24 . The second carriage 28 is only provided with a guide 30 in the X direction, that is to say it can only be adjusted in the direction of the first carriage 14 .

The second carriage 28 carries a control disk 32 with associated drive (not shown). The regulating wheel 32 can be rotated about an axis 34 which also extends horizontally.

Between grinding wheel 20 and control disc 32 is located in the region of the longitudinal center plane 24 is a plane along the longitudinal centerline 24 extending supporting rail 36, the upper side in known manner be designed obliquely to the horizontal.

The support rail 36 carries a workpiece 38 , which just extends if along the longitudinal central plane 24 .

As can be seen from FIG. 1 and in more detail from FIG. 3A, the axes 22 and 34 of grinding wheel 20 and regulating wheel 32 lie in the same horizontal plane 40 . They run approximately parallel to each other in the illustrated embodiment. If the regulating wheel is pivoted about one or two axes in the manner described below, the grinding wheel axis and the regulating wheel axis are slightly skewed to one another.

In conventional centerless grinding machines, the grinding wheel axis is parallel to the workpiece axis. In the context of a further parallel patent application by the same applicant on the same day (law file 4828P102), however, a centerless grinding machine is described in which the grinding wheel axis is inclined to the workpiece axis, so that grinding can be carried out using the oblique plunge method. When the grinding wheel is inclined, the axis 22 is inclined to the axis 34 .

In contrast, the longitudinal axis of the workpiece 38 is in a plane 42 which lies above the plane 40 . The distance between these planes is designated h in Fig. 3A. There is a possible vertical position error of the axis 34 of the re gel disc 32 marked relative to the horizontal plane 40 marked with ΔY. There are also designs of centerless grinding machines in which the workpiece axis is below this level.

Two more axes in Fig. 1 and Fig. 3A Further, as already indicated, located. With 44 the so-called A-axis is designated. The A-axis runs horizontally and can intersect or be offset from the axis 34 of the regulating wheel 32 . In the grinding machine 10 , the regulating wheel 32 can be pivoted slightly about the A axis.

In a corresponding manner, a further axis 46 , the so-called B axis, runs in the vertical direction, specifically also offset to the axis 34 of the regulating wheel 32 and offset to the A axis. In the grinding machine 10 , the regulating wheel 32 can also be pivoted slightly about the B axis. The above-mentioned offsets of the B axis to the regulating wheel axis 34 and to the A axis are relatively slight and are not shown in the drawing.

It has already been mentioned at the outset that a pivoting movement of the regulating wheel 32 about the A axis generates an axial feed force with which the workpiece 38 is conveyed on the support rail 36 when grinding through in the axial direction, ie along the longitudinal central plane 24 . In the plunge grinding not shown in the figures, that is, for. B. the aforementioned novel oblique plunge grinding, the work piece 38, however, is pressed by means of this force against a stop ge and held in a fixed position.

In contrast, a pivoting of the control wheel 32 about the B-axis causes a radial alignment of the workpiece 38 takes place relative to the grinding wheel 20 . In this way, the workpiece 38 is machined conically or cylin drically in the desired manner.

The pivoting or inclination of the regulating wheel 32 about the A-axis 44 is indicated in FIG. 3C with ΔA, while the corresponding adjustment about the B-axis 46 is shown in FIG. 3B with ΔB.

In Fig. 2 it can also be seen that the first carriage 14 is provided with a first arm 50 which is pivotable ver about an axis 52 . The axis 52 runs parallel to the axis of rotation 22 of the grinding wheel 20 . The first arm 50 carries a first dressing tool 54 for the regulating wheel 32 at its front end.

In the position shown in FIG. 2, the first arm 50 is swung forward into a dressing position in order to dress the regulating wheel 32 . For this purpose, the first carriage 14 can first be advanced along the X axis until the first dressing tool 54 comes into engagement with the outer circumference of the regulating wheel 32 . The circumference of the regulating wheel 32 can now be dressed by subsequently moving the first slide 14 along the Z axis. If the first slide 14 is moved accordingly with respect to X and Z by means of a suitable NC control during this process, a predetermined profile can be generated on the circumference of the regulating wheel 32 .

The second carriage 28 is provided with a second arm 56 which, in the example shown, can be moved in the direction of an arrow 58 in the X direction. The second arm 56 carries on its front side a second dressing tool 60 for dressing the grinding wheel 20 .

In the situation shown in FIG. 2, the second arm 56 is in its retracted position, so that the second dressing tool 60 does not project over the outer circumference of the regulating wheel 32 . When executing the Abrichtvorgan ges described above on the regulating wheel 32 , no collision is then to be feared.

It has already been mentioned that the second slide 28 can only be adjusted along the X axis.

In order to dress the grinding wheel 20 by means of the second dressing tool 60 , the second arm 56 is advanced (with the first arm 50 pivoted in). The required XY control can then take place by the X control of the second slide 28 or the X control of the first slide 14 as well as by the Z control of the first slide 14 .

In a corresponding manner, the X movement component can also be exerted by the second carriage 28 instead of by the first carriage 14 when dressing the control wheel 32 .

In this respect, any combinatorial swaps of the Be movement units possible. As already mentioned, in Within the scope of the present invention, the novel dressing of the Grinding wheel and the regulating wheel "from the front" only example understandable. It is of course also possible, and under certain conditions also more advantageous for the purposes the present invention in a conventional manner "from behind" to dress.

It should be mentioned at this point that it is of course also possible to arrange the dressing tools 54 and 60 fixed in space and to guide the disks 20 , 32 past these fixed dressing tools by suitable path control.

Alternatively, the dressing tools can also be used separately movable carriage or on separate travel units order to perform the dressing operations.

In the context of the present invention, it is therefore possible, among other things, to arrange the dressing tools 54 , 60 on the slide 14 and 28 , so that separate dressing axes are saved and the dressing processes with the machine axes X and Z for the first slide 14 and Z for the second slide 28 can be carried out alone.

The above description related to a type of centerless grinder with "fixed center", d. H. With  fixed support rail. However, it is more preferred that Invention also in another design with "movable Zen trum ".

With this, the grinding wheel with storage and drive is firmly arranged on the fixed machine bed. The machine bed has a vertically protruding pin that forms the B axis. A swivel carriage can be rotated about the B axis in a horizontal plane. A feed carriage can be moved on the swivel slide as the first X slide (X ₁ ). The feed carriage performs the feed movement during plunge grinding.

The feed carriage carries the support rail at its front end. An infeed slide runs as a second X slide (X ₄ ) on the feed slide in a direction parallel to this. Both elements are consequently entrained by the feed slide process. The feed slide is used to adjust the workpiece diameter and to compensate the dressing amount on the regulating wheel. The infeed carriage in turn holds the horizontal regulating wheel bearing, which can be pivoted about the horizontal A-axis relative to the infeed carriage. The dressing unit sits on the regulating wheel bearing and can be rotated about a vertical axis (A ₂ ). The dressing tool can also be moved along this axis (X ₃ ) and adjusted perpendicular to it.

The dressing tool can consequently be pivoted relative to the bearing housing about the vertical axis (A ₂ ). The regulating wheel profile is distorted by swiveling the guide (Z ₃ ) of the dressing tool. If a template or an NC program controls the delivery along the guide (Z ₃ ), this results in a profile distortion in the form of a hyperboloid. This shape determines the position of the swiveled regulating wheel on the workpiece. It influences the cylindricity of the workpiece during plunge grinding and the distribution of grinding abrasion across the grinding wheel width during through grinding.

The dressing tool for the regulating wheel preferably engages from behind on the regulating wheel, as well as the dressing unit stuff for the grinding wheel in this case preferably on the Back of the grinding wheel is engaged.

While in conventional grinding machines the axes B and A _{2 were} iteratively adjusted in order to compensate for shape errors on the workpiece, this is done according to the invention by a first transformation to eliminate the A ₂ axis and a second transformation to eliminate the B axis.

In the A ₂ transformation, the contour line - which is hyper-like when grinding through - is calculated (correspondingly when plunge grinding). It should be noted that, depending on the ratio of the radii of the regulating wheel and workpiece, the contour to be applied to the regulating wheel only corresponds to a hyperbola to a first approximation.

The B transformation is used to specifically change the Grinding gap geometry, which was previously a rotation around the Swivel carriage axis has been realized. This transfor mation can be achieved through an exact 3D transformation or a realistic 2D transformation in the control wheel contour  be replicated. The 3D transformation corresponds to this a return to a more general A1 transformation.

As one can now appreciate from FIGS. 3A to 3C, there is shown the Ide alfall in which the regulating wheel 32 is trued exactly zylin thresh and has been pivoted to either the A-axis 44 or about the B-axle 46. The height error ΔY is 0, so that ideal conditions exist. In this case, the control disk 32 rests on the workpiece 38 along a line of contact 64 which is exactly straight.

These ideal conditions are lost when the control wheel 32 z. B. is rotated about the A-axis 44 . If the regulating wheel 32 still has a cylindrical shape, it only bears against the cylindrical workpiece 38 at one point. In order to achieve a system along a line of contact 64 in this case as well, the regulating wheel 32 must be profi lated on its outer circumference. This is shown with a profile 66 in Fig. 4 Darge, where it can be clearly seen that the control disk 32 is inclined about the A-axis 44 , as indicated by 32 '. The Dar position in Fig. 4 is not to scale.

In order to achieve a predetermined, ideal possible contact line 64 between rule wheel 32 and workpiece 38 , the various settings (A-axis, B-axis, height setting ΔY) in known grinding machines have been changed manually and iteratively until one changes optimal grinding result.

According to the invention, it is now provided to provide the regulating wheel 32 by numerical control of the dressing tool 54 with such a circumferential profile 66 that an optimal result is achieved, taking into account the parameters of grinding machine and workpiece that determine the grinding process.

For this purpose, a controller is used, as is indicated extremely schematically as a block diagram in FIG. 5.

An input unit 70 can be seen in FIG. 5, to which various parameters can be fed, which will be explained below as an example. The input unit 70 transforms these input parameters into data for a predetermined circumferential profile 66 of the regulating wheel 32 . This data is fed via a data line 72 to a computing unit 74 , which converts this data into CNC control data. The CNC data thus generated are fed to a first control unit 78 via a further data line 76 . The first control unit 78 controls the X axis and the Z axis of the first carriage 14 , as indicated by X ₁ and Z ₁ .

Further CNC data are fed via a further data line 80 to a second control unit 82 , which controls the corresponding axes of the second slide 28 , as indicated in FIG. 5 by X ₂ and Z ₂ , it being assumed here that the second slide 28 can also be controlled in both axes (which is not the case in the exemplary embodiment according to FIGS. 1 and 2).

As input parameters for the input unit 70 , such parameters come into question which are decisive for the grinding process. These are machine parameters, workpiece parameters and associated setting parameters.

As machine parameters come first z. B. the diameter D _{S of} the grinding wheel 20 and the diameter D _R of the regulating wheel 32 into consideration. Furthermore, the vertical setting y _{R of} the regulating wheel 32 is important because errors (ΔY in FIG. 3A) when the regulating wheel 32 is pivoted (B-axis 24 ) have the effect of an axial profile shift.

Furthermore, e.g. B. the coordinates x, y, z _{(A) of} the normal position of the first dressing tool 54 are taken into account, from which the dressing process starts.

On workpiece parameters is primarily z. B. the diameter D _{w of} the workpiece 38 or a corresponding profile P _w .

Of the setting variables, it applies here in particular. B. the height position y _{AS of} the support rail 36 and of course the pivoting A of the regulating wheel 32 about the A-axis 44 and B about the B-axis 46 .

It is understood that the above parameters each because they are to be understood as examples. You can in the genann total combination or in sub-combinations or together with other parameters.

The aforementioned parameters are recorded at the beginning of the method according to the invention or in the device according to the invention. The input unit 70 transforms these parameters in a predetermined manner into data for a predetermined circumferential profile 66 of the regulating wheel 32 . From this data, in turn, CNC control data are generated in the arithmetic unit 74 for the movement of those axes which perform the dressing process on the control wheel 32 . As explained in detail above, this sequence of movements can be carried out in a variety of ways, depending on which elements can be moved along which axes.

In the illustrated embodiment of FIGS. 1 and 2, it is only necessary for this, for example, to process the first carriage 14 along the Z and X axes.

After all this has happened, a first test workpiece 38 is ground by the regulating wheel 32 with the peripheral profile 66 resting on the workpiece 38 , which was previously generated in the described manner by dressing the regulating wheel 32 .

The test workpiece 38 ground in this way is now measured in order to determine deviations from target data. The desired profile corrections are shown in FIG. 5 by a displacement X _d in the vertical direction and by a pivoting A _d around the A axis 44 and B _d around the B axis 46 . A targeted distortion V _z can also be taken into account in this way. This data can either be entered manually or also generated by the system itself.

While the sizes Y _d , A _d and B _d reflect the fine adjustments familiar from conventional pointless, loose grinding machines, the introduction of targeted distortion additionally offers the possibility of specifically distorting the peripheral profile 66 of the regulating wheel 32 in order to achieve better grinding results. The distortion is described in the system both with parameterizable basic shapes (e.g. slant or balance) as well as by specifying support points and a selection of an interpolation function (e.g. trigonometric functions, polynomials or spline functions).

As stated above, the idealized Berüh is approximate line between the control disc 32 and the workpiece 38 is a Gera de (line 64 in FIG. 4), even if the control disc has been pivoted around the A-axis 44 32. However, as mentioned, deviations, ie targeted distortions in the grinding gap, can be provided in order to achieve even better grinding results. So the line of contact z. B. an inclined line, a convex Li never, a concave line or a higher order polynomial.

In further embodiments of the invention, the second dressing tool 60 for dressing the grinding wheel 20 can also be CNC-controlled in such a way that the grinding wheel 20 is lent a predetermined circumferential profile, as is known per se from DE 38 43 046 C2 . In this measure there is an additional possibility of intervention in order to achieve an optimal workpiece contour.

Claims (27)

1. A method for the CNC-controlled dressing of a regulating wheel ( 32 ) of a grinding machine ( 10 ) for a centerless grinding process on a workpiece ( 38 ), in which a straightening tool ( 54 ) for the regulating wheel ( 32 ) with numerical control of its movement is the regulating wheel (32) engaged and guided along the latter, to produce a predetermined circumferential profile of the regulating wheel (32), comprising the steps of:

• a) detecting predetermined first parameters determining the execution of the grinding process (D _S , D _R , y _R , x, y, z _(A) , y _AS , A, B) of the grinding machine ( 10 );
• b) detecting predetermined second parameters (D _W , P _W ) of the workpiece ( 38 ) which determine the execution of the grinding process;
• c) transforming the first (D _S , D _R , y _R , x, y, z _(A) , y _AS , A, B) and the second (D _W , P _W ) parameters into data for a predetermined perimeter profile ( 66 ) the regulating wheel ( 32 );
• d) converting the data into CNC control data; and
• e) Relative method of the regulating wheel ( 32 ) and from the dressing tool ( 54 ) to one another as a function of the CNC control data, such that the dressing tool ( 54 ) on the regulating wheel ( 32 ) generates the predetermined order profile ( 66 ).

2. The method according to claim 1, characterized in that the first parameters comprise a diameter (D _S ) of the grinding wheel ( 20 ). 3. The method according to claim 1 or 2, characterized in that the first parameters comprise a diameter (D _R ) of the control disc ( 32 ). 4. The method according to one or more of claims 1 to 3, characterized in that the first parameters include a vertical distance (y _R ) of the axes ( 22 , 34 ) of the grinding wheel ( 20 ) and regulating wheel ( 32 ). 5. The method according to one or more of claims 1 to 4, characterized in that the first parameters include spatial coordinates (x, y, z _(A) ) of a target position of the dressing tool ( 54 ). 6. The method according to one or more of claims 1 to 5, characterized in that the first parameters a vertical position (y _AS ) and / or an angle (αAS) for the workpiece ( 38 ) of a support ( 36 ) for the workpiece ( 38 ) include. 7. The method according to one or more of claims 1 to 6, characterized in that the first parameters include a target position (A) of a first pivot axis ( 44 ) for the regulating wheel ( 32 ) which is horizontal and at a right angle to the axis ( 34 ) of the regulating wheel ( 32 ). 8. The method according to one or more of claims 1 to 7, characterized in that the first parameters comprise a target position (B) of a second pivot axis ( 46 ) for the regulating wheel ( 32 ), which is vertical and at a right angle to the axis ( 34 ) of the regulating wheel ( 32 ). 9. The method according to one or more of claims 1 to 8, characterized in that the second parameters comprise a predetermined diameter (D _W ) of the workpiece ( 38 ). 10. The method according to one or more of claims 1 to 8, characterized in that the second parameters comprise a predetermined profile (P _W ) of the workpiece ( 38 ). 11. The method according to one or more of claims 1 to 10, characterized by the further steps:

• a) performing a grinding process on a workpiece ( 38 ), the regulating wheel ( 32 ) with the circumferential profile ( 66 ) abutting the workpiece ( 38 ) during the grinding process;
• b) measuring the workpiece ( 38 ) with respect to the two th parameters (D _W , P _W );
• c) comparing the measured with the predetermined second parameters (D _W , P _W );
• d) forming a difference between the measured and the predetermined second parameters (D _W , P _W );
• e) introducing a correction quantity in step c) of the transformation;
• f) performing steps d) and e) after the corrected transformation.

12. The method according to one or more of claims 1 to 10, characterized by the further steps:

• a) performing a grinding process on a workpiece ( 38 ), the regulating wheel ( 32 ) with the circumferential profile ( 66 ) abutting the workpiece ( 38 ) during the grinding process;
• b) measuring the workpiece ( 38 ) with respect to the two th parameters (D _W , P _W );
• c) comparing the measured with the predetermined second parameters (D _W , P _W );
• d) forming a difference between the measured and the predetermined second parameters (D _W , P _W );
• e) introducing a correction quantity in step d) of the conversion;
• f) performing step e) after the corrected implementation.

13. The method according to one or more of claims 1 to 12, characterized in that in step e) the straightening tool ( 54 ) in the region of a longitudinal center plane ( 24 ) of the grinding machine ( 10 ) is brought into engagement with the regulating wheel ( 32 ). 14. The method according to one or more of claims 1 to 12, characterized in that in step e) the dressing unit testimony of the longitudinal center plane of the grinding machine opposite side engages with the regulating wheel ge is brought. 15. The method according to one or more of claims 1 to 14, characterized in that in step e) on a carriage ( 14 ) for the grinding wheel ( 20 ) angeord Nete dressing tool ( 54 ) by moving the carriage ( 14 ) in engagement with the control disc ( 32 ) is brought. 16. The method according to claim 15, characterized in that the carriage ( 14 ) in step e) along a first axis (X) perpendicular to the axis ( 34 ) of the regulating wheel ( 32 ) and along a second axis (Z) parallel to the axis ( 34 ) the regulating wheel ( 32 ) is moved. 17. The method according to claim 15, characterized in that in step e) the regulating wheel ( 32 ) along a first axis (X) perpendicular to its axis ( 34 ) and the slide ( 14 ) along a second axis (Z) parallel to the axis ( 34 ) the regulating wheel ( 32 ) is moved. 18. The method according to one or more of claims 1 to 14, characterized in that the dressing tool for the Control wheel on the slide for the control wheel arranges and with its own traversing axes relative to the Re gel disk is movable. 19. The method according to one or more of claims 1 to 18, characterized in that in addition a circumferential profile of the grinding wheel ( 20 ) in dependence on the predetermined first (D _S , D _R , y _R , x, y, z _(A) , y _AS , A, B) and / or the second (D _W , P _W ) parameters is dressed. 20. Method for centerless grinding of a workpiece ( 38 ) on a grinding machine ( 10 ) with a support ( 36 ) for the workpiece ( 38 ), with a grinding wheel ( 20 ) and with a regulating wheel ( 32 ), in which before the grinding process dressing tool (54) for the control disc (32) under numerical control of their movement with the control disc (32) engaged and guided along the latter by a predetermined order to generate catch profile of the regulating wheel (32), comprising the steps of:

• a) detecting predetermined first parameters determining the execution of the grinding process (D _S , D _R , y _R , x, y, z _(A) , y _AS , A, B) of the grinding machine ( 10 );
• b) detecting predetermined second parameters (D _W , P _W ) of the workpiece ( 38 ) which determine the execution of the grinding process;
• c) transforming the first (D _S , D _R , y _R , x, y, z _(A) , y _AS , A, B) and the second (D _W , P _W ) parameters into data for a predetermined perimeter profile ( 66 ) the regulating wheel ( 32 );
• d) converting the data into CNC control data;
• e) Relative movement of the regulating wheel ( 32 ) and the dressing tool ( 54 ) to one another as a function of the CNC control data, such that the dressing tool ( 54 ) on the regulating wheel ( 32 ) generates the predetermined order profile ( 66 ); and
• f) grinding of the workpiece ( 38 ), the control disc ( 32 ) with the peripheral profile ( 66 ) abutting the workpiece ( 38 ).

21. The method according to claim 20, characterized by the further steps:

• a) performing a grinding process on a workpiece ( 38 ), the regulating wheel ( 32 ) with the circumferential profile ( 66 ) abutting the workpiece ( 38 ) during the grinding process;
• b) measuring the workpiece ( 38 ) with respect to the two th parameters (D _W , P _W );
• c) comparing the measured with the predetermined second parameters (D _W , P _W );
• d) forming a difference between the measured and the predetermined second parameters (D _W , P _W );
• e) introducing a correction quantity in step c) of the transformation;
• f) performing steps d) to f) after the corrected transformation.

22. The method according to claim 20 or 21, characterized by the further steps:

• a) performing a grinding process on a workpiece ( 38 ), the regulating wheel ( 32 ) with the circumferential profile ( 66 ) abutting the workpiece ( 38 ) during the grinding process;
• b) measuring the workpiece ( 38 ) with respect to the two th parameters (D _W , P _W );
• c) comparing the measured with the predetermined second parameters (D _W , P _W )
• d) forming a difference between the measured and the predetermined second parameters (D _W , P _W );
• e) introducing a correction quantity in step d) of the conversion;
• f) performing steps e) and f) after the corrected implementation.

23. Device for CNC-controlled dressing of a control wheel ( 32 ) of a grinding machine ( 10 ) for a centerless grinding process on a workpiece ( 38 ), in which a dressing tool ( 54 ) for the control wheel ( 32 ) with numerical control of its movement the regulating wheel ( 32 ) can be brought into engagement and can be guided along this in order to produce a predetermined circumferential profile of the regulating wheel ( 32 ), comprising the features:

• a) means for detecting predetermined first parameters determining the execution of the grinding process (D _S , D _R , y _R , x, y, z _(A) , y _AS , A, B) of the grinding machine ( 10 );
• b) means for detecting predetermined second parameters (D _W , P _W ) of the workpiece ( 38 ) determining the execution of the grinding process;
• c) means for transforming the first (D _S , D _R , y _R , x, y, z _(A) , y _AS , A, B) and the second (D _W , P _W ) parameters into data for a predetermined perimeter profile ( 66 ) the regulating wheel ( 32 );
• d) means for converting the data into CNC control data; and
• e) means for relatively method of regulating disc (32) and dressing tool (54) agreed with each other as a function of the CNC-control data, such that the dressing tool (54) on the regulating disc (32) the vorbe generates peripheral profile (66).

24. The device according to claim 23, characterized by the further features:

• a) means for performing a grinding process on a workpiece ( 38 ), wherein the regulating wheel ( 32 ) with the peripheral profile ( 66 ) abuts the workpiece ( 38 ) during the grinding process;
• b) means for measuring the workpiece ( 38 ) with regard to the second parameters (D _W , P _W );
• c) means for comparing the measured with the predetermined second parameters (D _W , P _W ); and
• d) means for forming a difference between the measured and the predetermined second parameters (D _W , P _W ).

25. The device according to claim 24, characterized by the further features:

• a) means for introducing a correction quantity in step c) of transforming;
• b) performing steps d) and e) after the corrected transformation.

26. The apparatus according to claim 24, characterized by the further features:

• a) means for introducing a correction quantity in step d) of converting;
• b) performing step e) after the corrected conversion.

27. Grinding machine for centerless grinding of a workpiece ( 38 ) with a support ( 36 ) for the workpiece ( 38 ), with a grinding wheel ( 20 ) and with a control wheel ( 32 ), in which a dressing tool before the grinding process ( 54 ) for the regulating wheel ( 32 ) under numerical control of its movement can be brought into engagement with the regulating wheel ( 32 ) and guided along it in order to generate a predetermined circumferential profile of the regulating wheel ( 32 ), comprising the features:

• a) means for detecting predetermined first parameters determining the execution of the grinding process (D _S , D _R , y _R , x, y, z _(A) , y _AS , A, B) of the grinding machine ( 10 );
• b) means for detecting predetermined second parameters (D _W , P _W ) of the workpiece ( 38 ) determining the execution of the grinding process;
• c) means for transforming the first (D _S , D _R , y _R , x, y, z _(A) , y _AS , A, B) and the second (D _W , P _W ) parameters into data for a predetermined perimeter profile ( 66 ) the regulating wheel ( 32 );
• d) means for converting the data into CNC control data;
• to each other that the dressing tool (agreed that readied on the control disc (32) generates e) means for relatively method of regulating disc (32) and dressing tool (54) in response to the CNC-control data, in such a way, 54) peripheral profile (66); and
• f) means for grinding the workpiece ( 38 ), the regulating wheel ( 32 ) with the peripheral profile ( 66 ) abutting the workpiece ( 38 ).