EP2353780B1 - Rotation finishing device and method for installating or operating same - Google Patents

Abstract

The device (10) has a finishing tool (46) designed in form of a cap washer that is rotatably driven by a tool-driving unit (16) around a tool shaft (48). A detecting unit i.e. camera, detects condition of processing lines on a workpiece surface (24) by the finishing tool. An elevating unit elevates the detected condition of the lines with respect of value of parameters that relates to characteristic curvature of course of the lines on the workpiece surface. A controlling unit controls adjusting units (28, 30, 51, 62) depending on the parameters value and target-values. An independent claim is also included for a method for equipping or operating a rotary finishing device.

Description

The invention relates to a Rotationsfinishvorrichtung, with a finishing tool in the form of a cup wheel, which is rotatably driven by a tool drive means about a tool axis, wherein the position of the tool axis is adjustable by means of an adjusting relative to a workpiece to be machined.

Rotational finishing devices of the aforementioned type are used to machine rotating workpiece surfaces, in particular rolling bearing surfaces, by bringing an effective surface of a cup wheel into engagement with the workpiece surface, wherein the cup wheel is driven to rotate about a workpiece axis.

In principle, rotary finishing allows high precision machining of workpiece surfaces. In practice, however, it takes a lot of time to equip rotary finishing devices for machining certain workpieces and to maintain a consistent quality of surface machining over a batch of multiple workpieces. In particular, to set up the rotation finishing device, a high degree of experience on the part of the operator is required. In addition, setting up a rotary finishing device to accommodate a new workpiece lot is often accompanied by the destruction of multiple sample workpieces.

From the EP 1 878 534 A1 is a device for aligning a tool spindle and attached to the tool spindle cup wheel known, with which the tool spindle and the cup wheel can be pivoted about an inclination angle and a guide angle.

On this basis, the present invention has the object to provide a Rotationsfinishvorrichtung, which allows short makeready times and easy control of the manufacturing quality.

This object is achieved by a Rotationsfinishvorrichtung with the features of claim 1.

The invention provides to detect an actual state of the workpiece surface and to determine on the basis of this actual state an actual value of at least one parameter which relates to a curvature property of the course of a machining track. This makes it possible, without the experience of a machine operator would need to be able to determine a deviation from a desired state and to create from this specifications for a change in the position of the tool axis.

The detection device is an optical system (for example a camera) which detects at least a section of the workpiece surface to be machined. It can be provided that the position and / or the position of the detection device is variable.

In particular, in cramped production conditions, it is advantageous if the detection device is designed in the form of an endoscope, so that as much space for the workpiece and the finishing tool remains as possible.

The use of scattered light measuring systems is also possible. With such a system, a workpiece surface to be machined is illuminated in sections, and the radiation scattered back from the workpiece surface is directed by a measuring optics onto a diode cell. Such systems are offered for example by the Optosurf GmbH in Ettlingen / Germany.

The position of the tool axis is adjustable relative to the workpiece to be machined by means of an adjustment. A control device is provided, by means of which the adjusting device can be controlled as a function of, in particular, a comparison of the at least one actual value and at least one desired value. This allows an automated adjustment of the position of the tool axis relative to the workpiece to be machined, which is particularly advantageous in terms of time-consuming setup operations.

In a preferred embodiment of the invention it is provided that the at least one parameter comprises the relative position of a machining track and an associated center of curvature. A center of curvature is understood to mean a reference point, from the viewpoint of which a machining track has a concave curvature. This makes it possible to determine whether the tool axis is arranged offset with respect to a centered desired position, in which direction there is an offset and in which direction a correction of the position of the tool axis should take place.

It is particularly preferred that at least one first parameter comprises the relative position of a first processing track and an associated first center of curvature, and that at least one second parameter comprises the relative position of a second processing track and an associated second center of curvature, wherein the first relative position and the second relative position opposite to each other are. This makes it possible to detect a cross-cut structure desired for rotational finish machining of a workpiece. Here, the first and second processing tracks are curved in opposite directions so as to intersect with each other.

In a further advantageous embodiment of the invention it is provided that the at least one parameter comprises an angle of a machining track relative to a reference plane or reference direction of the workpiece, in particular to a plane of rotation of the workpiece, a plane parallel to the plane of rotation or a direction perpendicular to the plane of rotation. This allows, for example, an undesirable offset the tool axis to determine in a direction parallel to the axis of rotation of the workpiece direction.

Furthermore, it is preferred if the at least one parameter comprises the existence of an angle between two intersecting machining tracks. If such an angle can not be determined, it can be concluded that intersecting machining tracks are not present and thus a change in the position of the workpiece axis is required.

In a further embodiment of the invention it is provided that the at least one parameter comprises the size of an angle between two intersecting machining tracks. This makes it possible in particular to check whether the ratio of the rotational speed of the finishing tool and the rotational speed of the workpiece to be machined is correct or whether a change of at least one rotational speed is required. After carrying out such a change, it can be checked whether the size of a processing line crossing between two corresponds to a predefinable setpoint value.

In particular, a change in a rotational speed of the finishing tool and / or a rotational speed of the workpiece to be machined is effected by means of a control unit which actuates a tool drive device and / or a workpiece drive device. This control unit can also be formed by a control device described below.

It is further preferred if a memory device for storing at least one desired value of the at least a parameter is provided. Preferably, the memory device is integrated into the evaluation device.

It is possible that the position of the tool axis relative to the workpiece to be machined is adjusted by changing the absolute position of the tool axis. Alternatively or additionally, it is possible that the absolute position of the workpiece is changed.

The drive device may additionally be designed to control a tool drive device and / or a workpiece drive device in order to specify a rotational speed of the finishing tool and / or a rotational speed of the workpiece to be machined.

The invention further relates to a method for establishing or operating a Rotationsfinishvorrichtung, with a finishing tool in the form of a cup wheel, which is rotatably driven by a tool drive means about the tool axis, wherein the position of the tool axis is adjustable by means of an adjustment.

Another object of the present invention is to provide a method which enables short setup times and easy control of the manufacturing quality of a rotary finishing device.

This object is achieved by a method having the features of claim 9.

Embodiments and advantages of the method according to the invention are already above in connection with the Embodiments and advantages of the Rotationsfinishvorrichtung invention have been explained.

The invention further relates to the use of a rotary finishing device described above for use in a method as described above.

Further features and advantages of the invention are the subject of the following description and the diagrammatic representation of a preferred embodiment.

Figur 1

eine perspektivische Ansicht einer Ausführungsform einer Rotationsfinishvorrichtung;

Figur 2

eine Seitenansicht der Rotationsfinishvorrichtung längs einer in Figur 3 mit II - II bezeichneten Schnittebene;

Figur 3

eine Draufsicht der Rotationsfinishvorrichtung;

Figur 4

eine Draufsicht von Teilen der Rotationsfinishvorrichtung;

Figur 5

eine Seitenansicht eines Ausschnitts der Rotationsfinishvorrichtung längs einer in Figur 4 mit V - V bezeichneten Schnittebene, mit einer Erfassungseinrichtung zur optischen Erfassung einer Werkstückoberfläche, wobei sich die Erfassungseinrichtung in einer ersten Position befindet;

Figur 6

eine der Figur 5 entsprechende Ansicht, wobei sich die Erfassungseinrichtung in einer zweiten Position befindet;

Figur 7

eine Draufsicht auf eine geschnitten dargestellte Topfscheibe der Rotationsfinishvorrichtung, welche sich in einer ersten, seitlichen versetzten Eingriffsposition mit einer Werkstückoberfläche befindet;

Figur 8

eine Seitenansicht auf die Werkstückoberfläche, welche mit der ersten Eingriffsposition korrespondierende erste Bearbeitungsspuren aufweist;

Figur 9

eine Seitenansicht auf eine Werkstückoberfläche, welche mit einer zweiten, seitlich versetzten Eingriffsposition korrespondierende zweite Bearbeitungsspuren aufweist;

Figur 10

eine Draufsicht auf die Topfscheibe, welche sich in einer bezogen auf eine Seitenrichtung zentrierten Eingriffsposition mit der Werkstückoberfläche befindet;

Figur 11

eine Seitenansicht auf die Werkstückoberfläche, welche mit der zentrierten Eingriffsposition korrespondierende erste und zweite Bearbeitungsspuren aufweist;

Figur 12

eine Seitenansicht der Topfscheibe, welche sich in einer höhenversetzten Eingriffsposition befindet;

Figur 13

eine Seitenansicht auf die Werkstückoberfläche, welche mit der höhenversetzten Eingriffsposition korrespondierende erste und zweite Bearbeitungsspuren aufweist; und

Figur 14

eine Seitenansicht der Topfscheibe, welche sich in einer bezogen auf eine Höhenrichtung zentrierten Eingriffsposition mit der Werkstückoberfläche befindet.

In the drawings show:

FIG. 1

a perspective view of an embodiment of a Rotationsfinishvorrichtung;

FIG. 2

a side view of the Rotationsfinishvorrichtung along a in FIG. 3 sectional plane designated II - II;

FIG. 3

a plan view of the Rotationsfinishvorrichtung;

FIG. 4

a plan view of parts of the Rotationsfinishvorrichtung;

FIG. 5

a side view of a section of the Rotationsfinishvorrichtung along a in FIG. 4 V - V designated cutting plane, with a detection device for optically detecting a workpiece surface, wherein the detection device is in a first position;

FIG. 6

one of the FIG. 5 corresponding view, wherein the detection device is in a second position;

FIG. 7

a plan view of a cut cup wheel of the Rotationsfinishvorrichtung, which is in a first, lateral offset engagement position with a workpiece surface;

FIG. 8

a side view of the workpiece surface, which has corresponding to the first engagement position corresponding first processing tracks;

FIG. 9

a side view of a workpiece surface having a second, laterally offset engagement position corresponding second processing tracks;

FIG. 10

a plan view of the cup wheel, which is located in a centered with respect to a lateral direction engagement position with the workpiece surface;

FIG. 11

a side view of the workpiece surface, which with the centered engagement position has corresponding first and second processing tracks;

FIG. 12

a side view of the cup wheel, which is in a height-offset engagement position;

FIG. 13

a side view of the workpiece surface, which has corresponding to the height-offset engagement position corresponding first and second processing tracks; and

FIG. 14

a side view of the cup wheel, which is located in a centered relative to a height direction engagement position with the workpiece surface.

One embodiment of a rotation finishing device is shown in FIG FIG. 1 generally designated by the reference numeral 10. The rotary finishing apparatus 10 includes a machine bed 12 for mounting a workpiece driver 14 and a tool driver 16.

The workpiece drive device 14 comprises a workpiece carrier 18 for supporting a workpiece 20, which can be driven to rotate about an axis of rotation 22 by means of the workpiece drive device 14.

The workpiece 20 is in particular annular and has a workpiece surface 24, which in particular points radially inward and is curved in itself. The workpiece 20 is in particular a bearing ring of a roller bearing.

The workpiece 20 is rotationally driven about the axis 22 and rotates within a plane of rotation 26. In order to fix the position of the workpiece 20 within the plane of rotation 26, a total of three adjustment devices 28, 30 and 32 (see also FIG FIG. 3 ) intended. The adjusting devices 28, 30 and 32 each have a pressure roller 34, 36, 38, which are adjustable relative to the workpiece axis 22 in radial directions in position. For this purpose, the adjustment means 28, 30, and 32 corresponding adjustment device drives 40, 42 and 44, respectively.

The tool drive device 16 serves to drive a finishing tool 46, which can be driven to rotate about a tool axis 48.

The tool drive device 16 comprises a carriage 50, which can be moved by means of an adjusting device 51 along a first travel axis 52 and is mounted on the machine bed 12 by means of a first guide device 55. The carriage 50 is used to arrange a drive motor 53, by means of which a drive wheel 54 is driven in rotation. The drive wheel 54 serves to drive a drive belt 56, which in turn serves to drive a driven gear 58. The output gear 58 is rotatably driven about the tool axis 48.

The tool drive device 16 can be moved along a second travel axis 60. For this purpose, an adjusting device 62 and a second guide device 64 are provided.

The first travel axis 52 and the second travel axis 60 are in particular perpendicular to each other. The first travel axis 52 is, for example, an X-axis For example, the second travel axis is a Z-axis of the rotation-finishing device 10.

The rotary finishing device preferably further comprises a pressing device, not shown (for reasons of clarity), which has pressure rollers which press on the upper edge 66 of the workpiece 20 in the drawing and thus the workpiece 20 against the workpiece carrier 18. Such a pressing device is known per se and becomes therefore not explained in detail. Alternatively or in addition to a pressing device and a magnetic workpiece carrier 18 may be provided, which is in particular designed as a magnetic disk.

With further reference to the FIG. 4 the tool 46 is designed in the form of a cup wheel 68, which has an annular active surface 70 for finishing machining of the workpiece surface 24.

The cup wheel 68 is rotatably connected to a spindle 72 which is mounted in a spindle housing 74. The spindle 72 is rotatably driven by means of the output gear 58 of the drive belt 56.

The rotation finishing device 10 further comprises a detection device 76, which is designed as an optical system and in particular in the form of a camera or an endoscope, and which serves to optically detect the actual state of the workpiece surface 24 to be processed. The optical data obtained thereby can be evaluated by means of an evaluation unit 78.

The detection device may alternatively or additionally to a camera or an endoscope also Scattering light measuring system include. With such a system, the workpiece surface 24 is illuminated in sections and the backscattered from the workpiece surface 24 radiation is directed by a measuring optics on a diode cell.

The evaluation unit 78 comprises a memory device 80 in which target values are stored. These are used for comparison with actual values obtained from the actual states of parameters explained below.

The evaluation unit 78 is coupled to a control device 82, which preferably serves to control at least one of the adjustment devices 28, 30, 32, 51 and 62, in particular of all adjustment devices 28, 30, 32, 51 and 62. Additionally or alternatively, the drive device 82 is used to control the workpiece drive device 14 and / or the tool drive device 16 for setting a rotational speed of the finishing tool 46 and / or the workpiece 20.

With further reference to the FIGS. 5 and 6 For example, the detection device 76 has an optical sensor 84 whose position relative to the workpiece surface 24 is adjustable in mutually perpendicular adjustment directions 86 and 88. This makes it possible to optically detect a respective section 90 of the workpiece surface 24.

In the rotation-finishing machining of the workpiece surface 24, the aim is for the active surface 70 to be in contact with the workpiece surface 24 that is as full-surface contact as possible. This is the case when the tool axis 48 and a radial direction 92 relative to the workpiece surface 24 (cf. FIG. 7 ) agree with each other. The radial direction 92 corresponds to the axis of a sphere, the workpiece surface 24 being part of the surface of this sphere.

In the FIG. 7 a case is shown in which the radial direction 92 and the tool axis 48 are offset relative to each other. As a result, the active surface 70 is only in operative engagement with the workpiece surface 24 with one partial section. At the in FIG. 7 illustrated constellation, the tool axis 48 is arranged to the right of the radial direction 92. As a result, only a right portion of the active surface 70, as viewed from a rearward perspective of the cup wheel 68, comes into engagement with the workpiece surface 24. This has the consequence that in FIG. 8 shown first processing tracks 94 are generated. These machining tracks are curved, in the direction of a center of curvature 96, which is arranged to the left of the machining tracks 94 relative to the machining tracks 94.

This in FIG. 8 illustrated micrograph is also referred to as "beam ground".

In the case that the radial direction 92 and the tool axis 48 relative to the in FIG. 7 shown arrangement having an opposite relative position, is a in FIG. 9 illustrated grinding pattern generated in which second processing tracks 98 are curved toward a second center of curvature 100. The second center of curvature 100 is arranged to the right of the processing track 98 relative to the second processing track 98.

Detector 76 now allows the FIGS. 8 and 9 be able to detect corresponding actual states of the workpiece surface 24. By means of the evaluation unit 78, the relative position between a processing track 94, 98 and a respective associated center of curvature 96, 100 are determined. This makes it possible to change the relative position between the tool axis 48 and the radial direction 92 of the workpiece 20 so that they are brought together in overlapping position. Practically, this is done by means of the drive means 82, which controls the adjustment means 30 and 32 so that the position of the workpiece 20 and thus the radial direction 92 is displaced. Alternatively or additionally, it is also possible to change the absolute position of the tool axis 48, for example by changing the position of the spindle housing 74.

In FIG. 10 a state is shown in which the tool axis 48 and the radial direction 92 of the workpiece 20 are brought into overlapping position with each other. As a result, the annular active surface 70 of the cup wheel 68 is in engagement with the workpiece surface 24 with a main cutting edge 70a and with a secondary cutting edge 70b. This will create an in FIG. 11 illustrated grinding pattern generated, which is referred to as "cross-cut". This microsection has first processing tracks 94 and oppositely curved second processing tracks 98. The processing tracks 94 and 98 intersect and enclose an angle 102 between them. The existence of such an angle is a parameter for whether the active surface 70 is in contact with the main cutting edge 70a and the minor cutting edge 70b with the workpiece surface 24. The size of the angle 102 is a parameter for determining whether the ratio of the rotational speeds of the cup wheel 68 (and thus the effective area 70) and the Workpiece 20 in a correct relationship to each other.

With further reference to FIG. 12 it is also possible that the tool axis 48 and the plane of rotation 26 of the workpiece 20 are offset relative to each other. This has an in FIG. 13 example shown grinding pattern result if the tool axis 48 and a radial direction 92 of the workpiece 20 coincide with each other. Although there are intersecting processing tracks 94 and 98, the respectively associated centers of curvature 96 and 100 lie in a plane which is displaced more than a predefinable or predetermined permissible dimension relative to the plane of rotation 26. This offset can be detected with the aid of the detection device 76 and with the aid of the evaluation unit 78.

Another possibility is to detect, at the level of the plane of rotation 26, an angle 103 which exists between a machining track 94 and the plane of rotation 26. The angle 103 is dependent on the ratio of a first movement speed of the active surface 70 of the cup wheel 68 and a second movement speed of the workpiece surface 24. The first movement speed is determined by the geometry of the active surface 70 and by the rotational speed of the cup wheel 68 about the tool axis 48. The second movement speed is determined by the geometry of the workpiece surface 24 and by the rotational speed of the workpiece 20 about the workpiece axis 22. For a high ratio of first to second movement speed (for example 10: 1 or greater), the angle 103 is approximately perpendicular. If the angle 103 deviates more than a predefinable or given measure from a vertical angle, can be closed to an undesirable height offset of the tool axis 48 and the rotation plane 26.

Another possibility is, in particular for the case that the workpiece 20 is mirror-symmetrical with respect to the plane of rotation 26, to compare angles 104 and 106 which are enclosed between a machining track 98 and a surface boundary 108 and 110, respectively. The surface boundaries 108 and 110 each extend in planes parallel to the plane of rotation. For a previously defined high ratio of first to second movement speed, the angles 104 and 106 are at least approximately equal. If the angles 104 and 106 deviate from one another by more than a predefinable or predefined measure, a height offset between the tool axis 48 and the plane of rotation 26 can be deduced. Alternatively or in addition to a comparison of the angles 104 and 106, the angles 104 and / or 106 can also be evaluated independently of one another.

Depending on the direction of the height offset takes place by means of the drive means 82, a control of the adjusting device 62 until the tool axis 48 is brought into covering position with the plane of rotation 26, compare FIG. 14 , In this position of the tool axis 48, an in FIG. 11 illustrated target grinding pattern generated.

Moreover, it is possible to compare at least one of the detected actual angles 102, 103, 104, 106 with at least one reference angle stored in the memory device 80 and, depending on the comparison, a rotational speed of the workpiece drive device 14 and / or the tool drive device 16 to change. Such a change can be performed by a control unit not shown in the drawing or by means of the drive 82.

Claims (15)

1. A rotation finishing device (10), having a finishing tool (46) in the form of a cup wheel (68), which is driven by a tool driving device (16) so as to rotate about a tool axis (48), whereby the position of the tool axis (48) is adjusted by an adjusting device (28, 30, 32, 51, 62) relative to a work piece (20) that is being processed, characterized by a detection device (76) in the form of an optical system for detecting the actual condition of at least one processing track (94, 98) that is or can be generated on a work piece surface (24) using the finishing tool (46); by an evaluating unit (78) for evaluating the detected actual condition with regard to the actual value of at least one parameter, which relates to the curvature property of at least one processing track (94, 98) on the work piece surface; and by the provision of a drive device (82), which can drive the adjusting device (28, 30, 32, 51, 62) as a function of the actual value and at least one nominal value.
2. The rotation finishing device (10) as recited in Claim 1, wherein the at least one parameter includes the relative position of a processing track (94, 98) and of an associated center of curvature (96, 100).
3. The rotation finishing device (10) as recited in any of the preceding claims, wherein at least one first parameter includes the relative position of a first processing track (94) and of an associated first center of curvature (96) and that at least one second parameter includes the relative position of a second processing track (98) and of an associated second center of curvature (100), whereby the first relative position and the second relative position are the reverse of each other.
4. The rotation finishing device (10) as recited in any of the preceding claims, wherein the at least one parameter includes an angle (103, 104, 106) of a processing track (94) relative to a reference plane or reference direction of the work piece (20), in particular to a rotational plane (26) of the work piece (20), a plane that is parallel to the rotational plane (26) or a direction that is perpendicular to the rotational plane (26).
5. The rotation finishing device (10) as recited in any of the preceding claims, wherein the at least one parameter includes the existence of an angle (102) between two intersecting processing tracks (94, 98).
6. The rotation finishing device (10) as recited in any of the preceding claims, wherein the at least one parameter includes the size of an angle (102) between two intersecting processing tracks (94, 98).
7. The rotation finishing device (10) as recited in any of the preceding claims, characterized by a storage device (80) for storing at least one nominal value of the at least one parameter.
8. The rotation finishing device (10) as recited in any of the preceding claims, wherein the adjusting device (28, 30, 32, 51, 62) is driven as a function of a comparison of the actual value and the at least one nominal value.
9. A method for installing or operating a rotation finishing device (10), having a finishing tool (46) in the form of a cup wheel (68), which can be driven by a tool driving device (16) so as to rotate about the tool axis (48), whereby the position of the tool axis (48) can be adjusted by an adjusting device (28, 30, 32, 51, 62) relative to a work piece (20) that is being processed, wherein an actual condition of at least one processing track (94, 98) that has been generated on a work piece surface (24) by the finishing tool (46) is optically detected; the detected actual condition is evaluated with respect to the actual value of at least one parameter, which relates to a curvature property of at least one processing track (94, 98) on the work piece surface (24); and the adjusting device (28, 30, 32, 51, 62) is driven as a function of the actual value and of a nominal value of the at least one parameter.
10. The method as recited in Claim 9, wherein the at least one parameter includes the relative position of a processing track (94, 98) and of an associated center of curvature (96, 100).
11. The method as recited in Claim 9 or 10, wherein at least one first parameter includes the relative position of a first processing track (94) and of an associated first center of curvature (96) and that at least one second parameter includes the relative position of a second processing track (98) and of an associated second center of curvature (100), whereby the first relative position and the second relative position are the reverse of each other.
12. The method as recited in any of Claims 9 to 11, wherein the at least one parameter includes an angle (103, 104, 106) of a processing track (94) relative to a reference plane or a reference direction of the work piece (20), in particular relative to a rotational plane (26) of the work piece (20), a plane that is parallel to the rotational plane (26), or a direction that is perpendicular to the rotational plane (26).
13. The method as recited in any of Claims 9 to 12, wherein the at least one parameter includes the existence of an angle (102) between two intersecting processing tracks (94, 98).
14. The method as recited in any of Claims 9 to 13, wherein the at least one parameter includes the size of an angle (102) between two intersecting processing tracks (94, 98).
15. A use of a rotation finishing device (10) as recited in any of Claims 1 to 8 for carrying out a method as recited in any of Claims 9 to 14.

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