Abrading – Precision device or process - or with condition responsive... – Computer controlled
Reexamination Certificate
1998-08-31
2001-03-20
Eley, Timothy V. (Department: 3723)
Abrading
Precision device or process - or with condition responsive...
Computer controlled
C451S011000, C451S024000, C451S051000, C451S221000, C451S385000
Reexamination Certificate
active
06203401
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a device for superfinishing treated, in particular finished or ground, surfaces of work pieces, having a clamping device for the workpiece, a finishing block as the tool, a holder for the finishing block, a multi-axis drive device for performing a multi-axis relative movement between the surface to be treated and the holder in a plane which is orthogonal with respect to the surface to be treated and is defined by the coordinates X and Y, as well as a control unit for controlling the drive device, wherein the control unit has input means for inputting the profile of the surface to be treated, as well as electronic calculating means.
BACKGROUND OF THE INVENTION
It is known that ground surfaces of workpieces, in particular of roller bearings, are finished in a further work step wherein, for one, the roughness of the surface is reduced, and furthermore accuracy as to shape and dimension is increased. As a rule, up to 6 &mgr;m of material are removed during this finishing process, in special cases even 50 &mgr;m and more. Flat surfaces are worked by means of a flat finishing block, which is used in the plane of the surface. Curved surfaces are also worked with a finishing block, wherein the work surfaces of the finishing block in this case are not flat, but matched to the curvature of the surface to be worked. The block is pivoted during the treatment, so that at all times it rests flat against the workpiece to be treated, or respectively on its surface to be treated. To this end the finishing block is clamped in a pivoting device, whose pivot axis is located in the center of curvature of the surface to be treated. It has been shown that only a limited number of workpieces can be treated by means of such devices. Workpieces with a slight curved surface, i.e. with surfaces whose radius of curvature is very large, cannot be treated with such devices, since as a rule the pivot arm for pivoting the finishing block is too short. This applies in particular to angularly adjustable movable bearings and large spherical roller bearings.
CNC treatment machines are furthermore known, by means of which treatment tools, for example drills, turning chisels, and the like can be displaced in space. However, such tools have point-shaped or line-shaped cutting surfaces, so that, although the angular position of the tool with respect to the workpiece is determined by the effective tool side rake, this effective tool side rake can be variable over relatively large ranges. Machines of this type are not suitable for tools which treat the workpiece not at points or along lines, but in a planar manner, namely by means of a finishing block. In relation to the tool, this finishing block must not only be exactly positioned in the X, Y plane, but also in its angular position, so that the cutting surface of the finishing block at all times rests flat on the surface of the workpiece to be treated.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to make a device available, by means of which such workpieces can also be relatively easily treated.
This object is attained by means of a finishing device of the species mentioned at the outset in that by means of a pivoting device the holder is seated pivotable around a virtual pivot axis which is orthogonal with respect to the X, Y plane, and that the pivot angle of the holder corresponding to the position of the finishing block can be determined by means of calculating means, and that the pivoting device can be controlled from the control unit.
By means of the device in accordance with the present invention the finishing block is not only displaced in the X, Y plane by means of the drive device, but is also pivoted in such a way that the finishing block rests at all times flat on the surface of the workpiece to be treated. The pivot angle corresponding to each position of the finishing block is calculated by the calculating means from the geometry of the surface to be treated, or respectively from the profile of the workpiece. As a rule, two points and the radius of curvature of the surface are required for this. The virtual pivot angle around which the finishing block is exclusively pivoted is calculated from this data. Because this virtual pivot angle can be at a very large distance from the surface to be treated, the finishing block is displaced in the X direction as well as the Y direction by means of the drive device, and is additionally pivoted around an actual pivot axis. This movement over the plane as well as pivoting around the actual pivot axis corresponds to pivoting around the virtual pivot axis. However, the actual pivot axis is located inside the finishing device, and in particular inside the pivoting device and is constituted by a pivot bearing. By means of the device in accordance with the present invention it is now possible to treat workpieces which have very large radii of curvature, or respectively have a flat surface to be treated (whose radius of curvature is infinite).
In accordance with a preferred exemplary embodiment, the pivoting device is integrated into the drive device. Thus, the finishing block is displaced in the X and Y direction by means of the drive device, which is accomplished in that the pivoting device on which the holder of the finishing block is provided is displaced by means of the drive device. In addition, the holder, and therefore also the finishing block, are pivoted by means of the pivoting device.
However, there is also the option that the pivoting device is fixed in place on the machine, and a drive device is provided in the pivoting device, which displaces the holder for the finishing block in two directions which are orthogonal with respect to each other.
In accordance with the present invention this pivoting device can be activated electrically, for example by means of servo motors or the like, electro-magnetically, hydraulically and/or pneumatically. In particular, this pivoting device has an oscillator, by means of which the holder can be oscillatingly moved.
The device in accordance with the present invention is suitable for working flat and curved surfaces, as well as concave and convex surfaces. In addition it is possible to work surfaces which are inclined, so that the virtual pivot axis is located outside of the plane of the component, which as a rule has a ring shape.
A further development provides that the holder and/or the drive device has a contact pressure device for the finishing block. This contact pressure device at all times keeps the finishing block on the surface to be treated and drives it with a predetermined force. The desired amount is removed and the wear of the finishing block is compensated in this manner. The contact pressure device can preferably be actuated pneumatically or hydraulically, but the finishing block can also be pressed against the surface to be worked by means of a spring force. A pneumatic device has the considerable advantage that the contact pressure can be maintained constant in a relatively simple manner.
One variant of the device in accordance with the present invention is embodied in such a way that the actual pivot axis is located in the tangent plane of the finishing block and the surface to be treated. In connection with a preferred exemplary embodiment the actual pivot axis is located between the tangent plane and the location of the virtual pivot axis. The position of the actual pivot axis is preferably displaceable with respect to the surface to be worked.
Further advantages, characteristics and details of the present invention ensue from the claims and the following description, in which a particularly preferred exemplary embodiment is described with reference to the drawings. It is possible here that the characteristics illustrated in the drawings and mentioned in the specification and claims are respectively important to the present invention both individually as well as in any arbitrary combination.
REFERENCES:
patent: 5031303 (1991-07-01), Orain
patent: 5097635 (1992-03-01), Beas
Berry Jr. Willie
Eley Timothy V.
Jones Tullar & Cooper P.C.
Supfina Grieshaber GmbH & Co.
LandOfFree
Device for superfinishing treated surfaces does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device for superfinishing treated surfaces, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for superfinishing treated surfaces will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2470538