EP1080843A2 - Method and apparatus for CNC controlled dressing of the regulating wheel of a centerless grinding machine - Google Patents

Abstract

CNC controlled trimming of the regulating pulley (32) of a milling machine for centreless milling of a workpiece (38) in which the trimming tool for the regulating pulley is numerically controlled, in order to provide a desired circumferential profile to the regulating pulley. The procedure is achieved by entry of control parameters to the milling machine and measurement of workpiece parameters. The two sets of parameters are then transformed into a pre-set circumferential profile for the regulating pulley. The data are then converted to CNC control data and relative processing of regulating pulley and trimming tool using the CNC control data produces the desired circumferential profile on the pulley. Independent claims are made for a centreless milling procedure and a milling machine using the procedure.

Description

The invention relates to a method for CNC-controlled dressing a control wheel of a grinding machine for one centerless grinding process on a workpiece using a dressing 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 a Regulating wheel with a dressing tool before the grinding process for the regulating wheel under numerical control of its Movement engaged with and on the regulating wheel is guided along to a predetermined circumferential profile the control wheel.

The invention further relates to a device for CNC controlled Dressing 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 one Generate 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, a dressing tool for the regulating wheel before the grinding process under numerical control of their movement with the Control wheel can be brought into engagement and guided along it is to generate a predetermined circumferential profile of the regulating wheel.

The method, the device and the grinding machine of the aforementioned Kind are known.

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

These centerless grinders essentially exist from three main assemblies, namely a grinding wheel with associated 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 a 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 regulating wheel are adjustable on sledges. With a type with the so-called "movable center" is the support rail movable on a sled and e.g. the grinding wheel in one fixed storage arranged while the control disc also located on a sled.

Such grinding machines also include dressing tools for dressing the grinding wheel and the regulating wheel. The dressing tools can be used separately for these two Disks or provided as a common assembly for both disks his. The dressing tools are in the usual centerless Grinding machines, seen from the longitudinal median plane, arranged behind the grinding wheel or the regulating wheel. In the context of a parallel patent application by the same applicant on the same day (legal file 4828P100) described another design, in which the dressing tools are in the area of the longitudinal median plane.

Through the slides of the above-mentioned assemblies (grinding wheel, Regulating disc, support rail) become the usual feed axes or machine axes. Here are the sledges in a direction perpendicular to a longitudinal plane of the workpiece, namely along the so-called X-axis, movable, during at least one of the sledges, often both Slide, 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 Move the slide relative to each other in the required manner become. In this way, separate dressing axes, i.e. 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 median longitudinal plane 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 worried not only the support of the workpiece opposite 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 be placed one behind the other in the axial direction on the regulating wheel and Grinding wheel are conveyed past (so-called grinding).

The axes of the grinding wheel and regulating wheel are usually located 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 this Level, in exceptional cases also below.

It is known to pivot the regulating wheel about two axes, 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 horizontally 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 opposite the regulating wheel axis also slightly offset.

A swiveling of the regulating wheel around the A-axis creates one axial feed force that the workpieces during through grinding 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 their circumference are profiled in the form of a hyperboloid.

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

In the case of known centerless grinding machines, the regulating wheel is provided a circumferential profile to support the workpiece. The perimeter profile is in the grinding machine by a dressing or Turning process generated.

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

To the control wheel profile on the workpiece profile to be generated workpiece-specific templates used, which are changed mechanically. It is also known NC programs from the dressing tool to the grinding wheel use. With CNC-controlled dressing tools, this is workpiece-related Profile saved in an NC program. In this Program are the geometry parameters of the Workpiece already taken into account.

In known centerless grinding machines there is a technological one Optimization of the grinding process through a presetting 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.

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. A feed slide runs on the swivel slide along a first axis (X ₁ ) which is at a right angle to the longitudinal axis (Z) of the grinding machine if the swivel slide is not swiveled about the B axis. The feed slide also carries the support rail for the workpiece. A feed carriage (X ₂ ) runs in parallel on the feed carriage. The feed carriage carries the regulating disc housing. This can be pivoted about the horizontally directed A-axis (A ₁ ), so that the longitudinal axis of the regulating wheel can be inclined by an angle α to the horizontal. The dressing tool sits on the regulating disc housing, one axis (X ₃ ) of which runs essentially vertically and the other axis (Z ₃ ) of which runs 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 is usually pivoted along the other axis (Z ₃ ) relative to the axis of the regulating wheel 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. You can relative shifts or rotations between the regulating wheel and the path of the dressing tool in three dimensions Be space. For this purpose, the postforming template is in your Adjusted holder and / or the center height of the dressing tool. It is known the entire dressing tool around the A axis to incline relative to the control wheel axis. This setting takes place in connection with the inclination of the regulating wheel around the A axis.

The aforementioned adjustment work in this known procedure are extremely time-consuming and require suitable ones mechanical adjustment elements of complicated design. About that In addition, there is a high degree of "dexterity" with the user the grinder required, the one accordingly long experience in handling the grinding machine. The correction steps mentioned can also each can only be executed iteratively, i.e. several times in a row, so that the total amount of time is significant.

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

In the known method for a subsequent high-speed peeling process on a workpiece with 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 degree of coverage 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 Grinding wheel dimensioned an axial length of the secondary cutting surface.

This known method is for use only a grinding wheel for a grinding process between centers determines and leads depending on the process parameters 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 methods, the device and the grinding machine of the beginning mentioned type in that the above mentioned disadvantages can be avoided. In particular, according to the invention can be achieved on very simple, CNC-controlled Way an optimal installation of the regulating wheel on the Workpiece reached during a centerless grinding process , even with an iterative correction, the fine adjustment can be done via a numerical control. It So this adjustment and readjustment should no longer be necessary using complicated mechanical devices, 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 accomplished be that an integration of the methods and devices in a computer-controlled manufacturing (CIM) is possible.

a) Erfassen von vorbestimmten ersten, die Durchführung des Schleifprozesses bestimmenden Parametern der Schleifmaschine;

b) Erfassen von vorbestimmten zweiten, die Durchführung des Schleifprozesses bestimmenden Parametern des Werkstücks;

c) Transformieren der ersten und der zweiten Parameter in Daten für ein vorbestimmtes Umfangsprofil der Regelscheibe;

d) Umsetzen der Daten in CNC-Steuerdaten; und

e) Relatives Verfahren von Regelscheibe und Abrichtwerkzeug zueinander in Abhängigkeit von den CNC-Steuerdaten, derart, daß das Abrichtwerkzeug an der Regelscheibe das vorbestimmte Umfangsprofil erzeugt.

In the method mentioned above 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 parameters of the grinding machine which determine the execution of the grinding process;

b) detecting predetermined second parameters of the workpiece which determine the execution of the grinding process;

c) transforming the first and second parameters into data for a predetermined peripheral profile of the regulating wheel;

d) converting the data into CNC control data; and

e) Relative movement of the regulating wheel and the dressing tool to one another as a function of the CNC control data, such that the dressing tool generates the predetermined circumferential profile on the regulating wheel.

a) Erfassen von vorbestimmten ersten, die Durchführung des Schleifprozesses bestimmenden Parametern der Schleifmaschine;

b) Erfassen von vorbestimmten zweiten, die Durchführung des Schleifprozesses bestimmenden Parametern des Werkstücks;

c) Transformieren der ersten und der zweiten Parameter in Daten für ein vorbestimmtes Umfangsprofil der Regelscheibe;

d) Umsetzen der Daten in CNC-Steuerdaten;

e) Relatives Verfahren von Regelscheibe und Abrichtwerkzeug zueinander in Abhängigkeit von den CNC-Steuerdaten, derart, daß das Abrichtwerkzeug an der Regelscheibe das vorbestimmte Umfangsprofil erzeugt; und

f) Schleifen des Werkstücks, wobei die Regelscheibe mit dem Umfangsprofil an dem Werkstück anliegt.

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 parameters of the grinding machine which determine the execution of the grinding process;

b) detecting predetermined second parameters of the workpiece which determine the execution of the grinding process;

c) transforming the first and second parameters into data for a predetermined peripheral profile of the regulating wheel;

d) converting the data into CNC control data;

e) Relative movement of the regulating wheel and dressing tool to one another as a function of the CNC control data, such that the dressing tool on the regulating wheel generates the predetermined circumferential profile; and

f) grinding of the workpiece, the regulating wheel with the circumferential profile abutting the workpiece.

a) Mittel zum Erfassen von vorbestimmten ersten, die Durchführung des Schleifprozesses bestimmenden Parametern der Schleifmaschine;

b) Mittel zum Erfassen von vorbestimmten zweiten, die Durchführung des Schleifprozesses bestimmenden Parametern des Werkstücks;

c) Mittel zum Transformieren der ersten und der zweiten Parameter in Daten für ein vorbestimmtes Umfangsprofil der Regelscheibe;

d) Mittel zum Umsetzen der Daten in CNC-Steuerdaten; und

e) Mittel zum relativen Verfahren von Regelscheibe und Abrichtwerkzeug zueinander in Abhängigkeit von den CNC-Steuerdaten, derart, daß das Abrichtwerkzeug an der Regelscheibe das vorbestimmte Umfangsprofil erzeugt.

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

a) means for detecting predetermined first parameters of the grinding machine which determine the execution of the grinding process;

b) means for detecting predetermined second parameters of the workpiece which determine the execution of the grinding process;

c) means for transforming the first and second parameters into data for a predetermined circumferential profile of the regulating wheel;

d) means for converting the data into CNC control data; and

e) Means for the relative movement of the regulating wheel and dressing tool to one another in dependence on the CNC control data, such that the dressing tool generates the predetermined circumferential profile on the regulating wheel.

a) Mittel zum Erfassen von vorbestimmten ersten, die Durchführung des Schleifprozesses bestimmenden Parametern der Schleifmaschine;

b) Mittel zum Erfassen von vorbestimmten zweiten, die Durchführung des Schleifprozesses bestimmenden Parametern des Werkstücks;

c) Mittel zum Transformieren der ersten und der zweiten Parameter in Daten für ein vorbestimmtes Umfangsprofil der Regelscheibe;

d) Mittel zum Umsetzen der Daten in CNC-Steuerdaten;

e) Mittel zum relativen Verfahren von Regelscheibe und Abrichtwerkzeug zueinander in Abhängigkeit von den CNC-Steuerdaten, derart, daß das Abrichtwerkzeug an der Regelscheibe das vorbestimmte Umfangsprofil erzeugt; und

f) Mittel zum Schleifen des Werkstücks, wobei die Regelscheibe mit dem Umfangsprofil an dem Werkstück anliegt.

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 parameters of the grinding machine which determine the execution of the grinding process;

b) means for detecting predetermined second parameters of the workpiece which determine the execution of the grinding process;

c) means for transforming the first and second parameters into data for a predetermined circumferential profile of the regulating wheel;

d) means for converting the data into CNC control data;

e) means for the relative movement of the regulating wheel and the dressing tool in relation to one another depending on the CNC control data, such that the dressing tool generates the predetermined circumferential profile on the regulating wheel; and

f) means for grinding the workpiece, the regulating wheel with the circumferential profile abutting the workpiece.

The object underlying the invention is achieved in this way completely solved.

By including such parameters of the grinding wheel and the tool needed to carry out the grinding process are determining, 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 regulating wheel realized. So the user of the machine only needs still enter the predetermined parameters so that this is already in the first run to the desired perimeter 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 preferably 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 of the A axis and a target position of the B axis. The second parameter is essentially the predetermined one The diameter of the workpiece or its predetermined profile.

These measures have the advantage that for the grinding process important parameters of grinding wheel and workpiece to be considered.

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

f) Durchführen eines Schleifprozesses an einem Werkstück, wobei die Regelscheibe mit dem Umfangsprofil während des Schleifprozesses an dem Werkstück anliegt;

g) Vermessen des Werkstücks hinsichtlich der zweiten Parameter;

h) Vergleichen der gemessenen mit den vorbestimmten zweiten Parametern; und

i) Bilden einer Differenz zwischen den gemessenen und den vorbestimmten zweiten Parametern.

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

f) performing a grinding process on a workpiece, the regulating wheel with the peripheral profile abutting the workpiece during the grinding process;

g) measuring the workpiece with regard to the second parameters;

h) comparing the measured with the predetermined second parameters; and

i) forming a difference between the measured and the predetermined second parameters.

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

These measures have the advantage that they are also computer-based Determination of any correction values and subsequent CNC control set the required correction values and the circumferential profile of the regulating wheel is corrected accordingly when a first test workpiece after grinding is checked accordingly.

This ensures that the workpiece accuracy is even higher 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 his. 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 axes A and B can be omitted entirely, so that these axes are also mechanical much easier and therefore with lower manufacturing costs can be executed. 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 attached one Drawing.

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

Fig. 1

eine äußerst schematisierte Seitenansicht einer Schleifmaschine zum spitzenlosen Außenrundschleifen von Werkstücken;

Fig. 2

eine Draufsicht auf die Maschine gemäß Fig. 1;

Fig. 3A bis 3C

in stark vergrößertem Maßstab einen Ausschnitt aus den Figuren 1 und 2 in drei verschiedenen Ansichten;

Fig. 4

eine Variante zur Darstellung gemäß Fig. 3C zur weiteren Erläuterung der Erfindung; und

Fig. 5

ein Blockschaltbild zur Erläuterung einer Steuerung der Maschine gemäß Fig. 1 und 2.

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

Fig. 1

an extremely schematic side view of a grinding machine for centerless external cylindrical grinding of workpieces;

Fig. 2

a plan view of the machine of FIG. 1;

3A to 3C

on a greatly enlarged scale a section of Figures 1 and 2 in three different views;

Fig. 4

a variant of the representation of FIG 3C to further explain the invention. and

Fig. 5

2 shows a block diagram to explain a control of the machine according to FIGS. 1 and 2.

In Fig. 1, 10 designates a grinding machine for centerless external cylindrical grinding of workpieces. It understands yourself that this is only to be understood as an example, because the Invention also in such grinding machines for internal cylindrical grinding or for plunge grinding, especially oblique plunge grinding is usable.

The grinder 10 belongs in its configuration with respect the dressing tools located in the area of the longitudinal median plane not state of the art. In this respect, it is the subject the aforementioned parallel patent application Applicant on the same day (attorney file 4828P100). The However, the problems described below apply in a corresponding manner Way also for conventional grinding machines, in which the Grinding wheel and the regulating wheel are dressed from behind.

The grinder 10 includes a machine bed 12. On the machine bed 12 is a first one on the left in FIGS. 1 and 2 Sledge 14 can be seen, with an X-guide 16 as well a Z-guide 18 is provided, so in the manner of a cross slide is trained. The first carriage 14 is thus Can be moved along two mutually perpendicular axes.

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

1 and 2 is the first Carriage 14 on the left side indicated by 24 Longitudinal center plane of the grinding machine 10.

To the right of the longitudinal center plane 24 is a second slide 28 recognizable on the machine bed 12. The second slide 28 is only provided with a guide 30 in the X direction, so only adjustable in the direction of the first carriage 14.

The second carriage 28 carries a regulating wheel 32 with an associated one Drive (not shown). The regulating wheel 32 is around an also horizontally extending axis 34 rotatable.

Is located between grinding wheel 20 and control wheel 32 in Region of the longitudinal central plane 24 along the longitudinal central plane 24 extending support rail 36, the top of which in known Is designed obliquely to the horizontal.

The support rail 36 carries a workpiece 38, which is also extends along the longitudinal median plane 24.

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

This is the case with conventional centerless grinding machines Grinding wheel axis parallel to the workpiece axis. As part of another parallel patent application by the same applicant on the same day (legal file 4828P102), however, one centerless grinding machine described in which the grinding wheel axis runs inclined to the workpiece axis, so that in Sloping plunge process can be ground. When tilted The grinding wheel also extends to this extent Axis 34 inclined.

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

In FIG. 1 and FIG. 3A, as already indicated, there are two further axes drawn. At 44 is the so-called A axis designated. The A axis is horizontal and can be the axis 34 of the control wheel 32 cut or be offset to this. In grinding machine 10, regulating wheel 32 can rotate about the A axis be pivoted slightly.

Another axis 46 runs in a corresponding manner, the so-called B-axis, in the vertical direction, too offset to the axis 34 of the regulating wheel 32 and offset to the A axis. The regulating wheel 32 can also be in the grinding machine 10 can be pivoted slightly around the B axis. The above Offsets of the B axis to the regulating wheel axis 34 and to the A axis are relatively minor and are not shown in the drawing.

It has already been mentioned at the beginning that a swivel the regulating wheel 32 has an axial feed force about the A axis generated with which the workpiece 38 during through grinding in the axial direction, i.e. along the longitudinal median plane 24, is transported on the support rail 36. In the in the Plunge loops not shown in the figures, e.g. the The new type of oblique plunge grinding mentioned above, the workpiece 38, however, pressed against a stop by means of this force and held in a fixed position.

In contrast, the control disk 32 is pivoted about the B axis that a radial orientation of the workpiece 38 relative to the grinding wheel 20 takes place. That way the workpiece 38 in the desired manner conical or cylindrical processed.

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

It can also be seen in FIG. 2 that the first carriage 14 is provided with a first arm 50 which is pivotable about an axis 52 is. The axis 52 runs parallel to the axis of rotation 22 the grinding wheel 20. The first arm 50 carries on its front End of a first dressing tool 54 for the regulating wheel 32.

In the position shown in FIG. 2, the first arm 50 is in swung a dressing position to dress the regulating wheel 32. For this purpose, the first carriage 14 can initially be advanced along the X axis until the first dressing tool 54 engages with the outer circumference of the regulating wheel 32 reached. By then moving the first carriage 14 along the Z axis, the circumference of the regulating wheel 32 can now be trained. If the first carriage 14 by means of a suitable NC control during this process with respect to X and Z is moved accordingly, can on the circumference of the regulating disc 32 a predetermined profile can be generated.

The second carriage 28 is provided with a second arm 56, that in the example shown in the direction of an arrow 58 is movable in the X direction. The second arm 56 carries on it Front a second dressing tool 60 for dressing the Grinding wheel 20.

In the situation shown in FIG. 2, the second arm is 56 in its retracted position so that the second dressing tool 60 does not protrude beyond the outer circumference of the regulating wheel 32. When performing the dressing process described above there is then no risk of a collision on the regulating wheel 32.

It has already been mentioned that the second carriage 28 only is adjustable along the X axis.

Therefore, by means of the second dressing tool 60, the grinding wheel 20, (when the first arm is swung in 50) the second arm 56 is advanced. The required X-Y control can then by the X control of the second Carriage 28 or the X control of the first carriage 14 as well by the Z control of the first carriage 14.

The same can also be done when dressing the regulating wheel 32 the X motion component instead of the first Carriage 14 can be exercised by the second carriage 28.

In this respect, any combinatorial exchanges of the movement units possible. As already mentioned, in Within the scope of the present invention, the novel dressing of the The grinding wheel and the regulating wheel "from the front" are only examples to understand. 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 of course it is it is possible to arrange the dressing tools 54 and 60 fixed in space and the disks 20, 32 by appropriate path control on them to guide the stationary dressing tools.

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

In the context of the present invention, it is therefore i.a. possible, to arrange the dressing tools 54, 60 on the slides 14 and 28, so that separate dressing axes are saved and the Dressing processes with machine axes X and Z at the first Carriage 14 or Z on the second carriage 28 executed alone can be.

The above description related to a type of centerless grinding machine with "fixed center", i.e. With fixed support rail. However, it is more preferred that Invention also in another design with a "movable center" to use.

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 taken along by the feed carriage during the process. The feed slide is used to adjust the workpiece diameter and to compensate for 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 is also displaceable along this axis (X ₃ ) and adjustable 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 infeed 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 cylindrical shape of the workpiece during plunge grinding and the distribution of the grinding abrasion over the width of the grinding wheel during through grinding.

The dressing tool for the regulating wheel preferably engages from behind on the regulating wheel, as well as the dressing tool 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 train - which is hyperbole-like when looping through - is calculated (correspondingly when plunge-cutting). 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 transformation can by 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.

3A to 3C, this is the ideal case shown, in which the regulating wheel 32 is exactly cylindrical is trained and neither about the A-axis 44 nor B-axis 46 was pivoted. The height error ΔY is 0, see above that ideal conditions exist. In this case, the regulating disc lies 32 along a line of contact 64 on the workpiece 38 that is exactly straight.

These ideal relationships are lost when the regulating wheel 32 e.g. is rotated about the A axis 44. If the regulating wheel 32 then still has a cylindrical shape, it just lies still at one point on the cylindrical workpiece 38. Too in this case, a plant along a line of contact 64 reach, the regulating wheel 32 must be profiled on its outer circumference become. This is shown with a profile 66 in FIG. 4, where it can be clearly seen that the control disc 32 um the A-axis 44 is inclined, as indicated at 32 '. The representation in Fig. 4 is not to scale.

By a predetermined, ideally possible contact line 64 between One has to reach regulating wheel 32 and workpiece 38 the various settings (A-axis, B-axis, height adjustment ΔY) manually and iteratively in known grinding machines changed until an optimal grinding result revealed.

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

For this purpose, a control is used, such as Block diagram in Fig. 5 is indicated extremely schematically.

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 carriage 28, as indicated in FIG. 5 by X ₂ and Z ₂ , it being assumed here that the second carriage 28 also is controllable in both axes (which is not the case in the exemplary embodiment according to FIGS. 1 and 2).

Such come as input parameters for the input unit 70 Parameters in question that determine the grinding process. These are machine parameters, workpiece parameters and associated ones Setting variables.

As machine parameters, for example, the diameter D _{S of} the grinding wheel 20 and the diameter D _R of the regulating wheel 32 are considered. 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, the coordinates x, y, z _{(A) of} the normal position of the first dressing tool 54, from which the dressing process is based, can be taken into account.

In the case of workpiece parameters, the diameter D _{W of} the workpiece 38, for example, or a corresponding profile P _W is primarily to be taken into account.

Of the setting variables, it is particularly important to take into account, for example, 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 are to be understood as examples. You can in the above Overall combination or in sub-combinations or together with other parameters.

The aforementioned parameters are at the beginning of the invention Method or in the device according to the invention detected. The input unit 70 now transforms these parameters in a predetermined manner in data for a predetermined scope profile 66 of the regulating wheel 32. These data in turn become in the computing unit 74 CNC control data for the process of those Generates axes that dress the process on the control wheel 32 run. As explained in detail above, this sequence of movements can be carried out in many different ways depending on which elements along which axes are movable.

In the illustrated embodiment of Figures 1 and 2 it is for this, for example, only required the first sled 14 to be moved in a program-controlled manner along the Z and X axes.

After all of this has been done, a first trial workpiece is created 38 ground by the regulating wheel 32 with the circumferential profile 66 abuts the workpiece 38, previously in the manner described was generated by dressing the regulating wheel 32.

The test workpiece 38 ground in this way is now measured to determine deviations from target data.

The desired profile corrections are characterized 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 centerless grinding machines, the introduction of a targeted distortion additionally offers the possibility of specifically distorting the circumferential profile 66 of the regulating wheel 32 in order to achieve better grinding results. The distortion is described in the system with parameterizable basic shapes (e.g. slant or crowning) as well as by specifying support points and selecting an interpolation function (e.g. trigonometric functions, polynomials or spline functions).

As stated above, the idealized line of contact is a straight line between regulating wheel 32 and workpiece 38 (Line 64 in Fig. 4), even if the control wheel 32 around the A-axis 44 was pivoted. However, as mentioned, deviations, i.e. provide targeted distortions in the grinding gap, to achieve even better grinding results. So can the line of contact e.g. an inclined line, a convex line, be a concave line or a higher order polynomial.

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

Claims (27)

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 dressing tool (54) for the regulating wheel (32) under numerical control of its movement with the regulating wheel (32 ) is brought into engagement and guided along this in order to generate a predetermined circumferential profile of the regulating wheel (32), comprising the steps: 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 movement of the regulating wheel (32) and 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 circumferential profile (66). Method according to claim 1, characterized in that the first parameters comprise a diameter (D _S ) of the grinding wheel (20). Method according to claim 1 or 2, characterized in that the first parameters comprise a diameter (D _R ) of the regulating wheel (32). Method according to one or more of Claims 1 to 3, characterized in that the first parameters include a vertical distance (y _R ) between the axes (22, 34) of the grinding wheel (20) and regulating wheel (32). 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 desired position of the dressing tool (54). Method according to one or more of claims 1 to 5, characterized in that the first parameters include a vertical position (y _AS ) and / or an angle (αAS) for the workpiece (38) of a support (36) for the workpiece (38) . Method according to one or more of claims 1 to 6, characterized in that the first parameters are a Target position (A) of a first pivot axis (44) for the regulating disc (32) include the horizontal and below at a right angle to the axis (34) of the regulating wheel (32) runs. Method according to one or more of claims 1 to 7, characterized in that the first parameters are a Target position (B) of a second pivot axis (46) for the regulating disc (32) include the vertical and below at a right angle to the axis (34) of the regulating wheel (32) passed. 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). 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). Method according to one or more of claims 1 to 10, characterized by the further steps: f) performing a grinding process on a workpiece (38), the regulating wheel (32) with the peripheral profile (66) abutting the workpiece (38) during the grinding process; g) measuring the workpiece (38) with regard to the second parameters (D _W , P _W ); h) comparing the measured with the predetermined second parameters (D _W , P _W ); i) forming a difference between the measured and the predetermined second parameters (D _W , P _W ); k) introducing a correction quantity in step c) of the transformation; l) performing steps d) and e) after the corrected transformation. Method according to one or more of claims 1 to 10, characterized by the further steps: f) performing a grinding process on a workpiece (38), the regulating wheel (32) with the peripheral profile (66) abutting the workpiece (38) during the grinding process; g) measuring the workpiece (38) with regard to the second parameters (D _W , P _W ); h) comparing the measured with the predetermined second parameters (D _W , P _W ); i) forming a difference between the measured and the predetermined second parameters (D _W , P _W ); k) introducing a correction quantity in step d) of the conversion; l) Execution of step e) after the corrected implementation. Method according to one or more of claims 1 to 12, characterized in that in step e) the dressing tool (54) in the area of a longitudinal median plane (24) the grinding machine (10) engages with the regulating wheel (32) is brought. Method according to one or more of claims 1 to 12, characterized in that in step e) the dressing tool from that of the longitudinal center plane of the grinding machine brought into engagement with the regulating disc on the opposite side becomes. Method according to one or more of claims 1 to 14, characterized in that in step e) a slide (14) for the grinding wheel (20) Dressing tool (54) by moving the slide (14) is brought into engagement with the regulating wheel (32). A 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. A 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 carriage (14) along a second axis (Z) parallel to the axis (34) the regulating wheel (32) is moved. Method according to one or more of claims 1 to 14, characterized in that the dressing tool for the Control wheel arranged on the slide for the control wheel and with its own traversing axes relative to the regulating wheel is movable. Method according to one or more of claims 1 to 18, characterized in that in addition a peripheral profile of the grinding wheel (20) as a function of 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. 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 a dressing tool ( 54) for the regulating wheel (32) under numerical control of its movement in 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 steps: 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 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 circumferential profile (66); and f) grinding the workpiece (38), the regulating wheel (32) with the peripheral profile (66) abutting the workpiece (38). A method according to claim 20, characterized by the further steps: g) performing a grinding process on a workpiece (38), the regulating wheel (32) with the peripheral profile (66) abutting the workpiece (38) during the grinding process; h) measuring the workpiece (38) with regard to the second parameters (D _W , P _W ); i) comparing the measured with the predetermined second parameters (D _W , P _W ); k) forming a difference between the measured and the predetermined second parameters (D _W , P _W ); l) introducing a correction quantity in step c) of the transformation; m) performing steps d) to f) after the corrected transformation. Method according to claim 20 or 21, characterized by the further steps: g) performing a grinding process on a workpiece (38), the regulating wheel (32) with the peripheral profile (66) abutting the workpiece (38) during the grinding process; h) measuring the workpiece (38) with regard to the second parameters (D _W , P _W ); i) comparing the measured with the predetermined second parameters (D _W , P _W ); k) forming a difference between the measured and the predetermined second parameters (D _W , P _W ); l) introducing a correction variable in step d) of the conversion; m) performing steps e) and f) after the corrected implementation. Device 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 dressing tool (54) for the regulating wheel (32) under numerical control of its movement with the regulating wheel (32 ) can be brought into engagement and can be guided along this 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) which determine 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 the relative movement of the regulating wheel (32) and dressing tool (54) to one another depending on the CNC control data, such that the dressing tool (54) on the regulating wheel (32) generates the predetermined circumferential profile (66). Device according to claim 23, characterized by the further features: f) means for carrying out a grinding process on a workpiece (38), the regulating wheel (32) with the peripheral profile (66) abutting the workpiece (38) during the grinding process; g) means for measuring the workpiece (38) with regard to the second parameters (D _W , P _W ); h) means for comparing the measured with the predetermined second parameters (D _W , P _W ); and i) means for forming a difference between the measured and the predetermined second parameters (D _W , P _W ). Device according to claim 24, characterized by the further features: k) means for introducing a correction quantity in step c) of the transforming; l) performing steps d) and e) after the corrected transformation. Device according to claim 24, characterized by the further features: k) means for introducing a correction quantity in step d) of converting; l) performing step e) after the corrected conversion. 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 regulating wheel (32), in which a dressing tool (54) for the regulating wheel ( 32) can be brought into engagement with the regulating wheel (32) under numerical control of its movement and can be guided along this 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) which determine 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; e) means for moving the regulating wheel (32) and dressing tool (54) relative to one another in dependence on the CNC control data, such that the dressing tool (54) on the regulating wheel (32) generates the predetermined circumferential profile (66); and f) means for grinding the workpieces (38), the regulating wheel (32) with the circumferential profile (66) abutting the workpiece (38).

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