EP2399706B9 - Finishing device for finishing the surfaces of workpieces - Google Patents

Description

The invention relates to a finishing device having the features of the preamble of patent claim 1.

From the DE 38 13 484 A1 a device for fine machining of the crankpin crankshaft is known, with a half-shell for guiding a Honbandes, which is guided on a guide body. The guide body has a rear support portion, which is integrally and resiliently connected to two circumferentially separated, segment-shaped sections.

The from the DE 38 13 484 A1 known device has the disadvantage that, due to the elastic connection of the segment-shaped portions with the support portion, the segment-shaped portions extend only over a relatively small circumferential angle. The actual available for a pressing system of the honing tape on the workpiece to be machined Guide surface is relatively small, so that a comparatively low material removal performance is achieved.

From the DE 196 02 974 a machine for the fine grinding of a cylindrical bearing surface on a shaft by means of an abrasive belt is known, which has three mutually angularly offset sanding shoes. Two sanding shoes are stationary; a third sanding pad is disposed on a movable Schleifschuharm. The Schleifschuharm can be pivoted so that a grinding station is made available for loading or emptying.

Also from the US 5,522,762 is a belt sander with three angularly offset shoes known.

On this basis, the present invention has the object to improve a finishing device of the type mentioned so that the introduction of a workpiece to be machined is simplified in the receiving area.

This object is achieved according to the invention in a finishing device of the type mentioned by the characterizing features of claim 1.

The guide device according to the invention allows independent movement of the guide body. As a result, the respective partial surfaces of the guide surface can be formed over a particularly large area. At the same time, the large-area partial surfaces seen along their course can act with uniformly distributed pressure forces on the finishing belt, so that the finishing tape along its course to the machining workpiece surface is pressed uniformly against the workpiece surface. Overall, therefore, an increase in the effective area ratio of the finishing strip is achieved at the same time increased contact pressure, so that the material removal rate can be increased.

It is envisaged that the guide body between a rest position and a working position are movable, wherein the guide surface extends in the rest position of the guide body between the finishing tape insertion end and the finishing tape performer over a first circumferential angle, which is an introduction of a workpiece to be machined in the Receiving area and an embodiment of a machined workpiece from the receiving area allowed, and wherein the guide surface extends in the working position of the guide body for machining a workpiece over a relatively larger to the first circumferential angle second circumferential angle. The first, smaller circumferential angle ensures that the workpiece is easier to insert into and out of the receiving area. The second, larger circumferential angle makes it possible to increase the effective finishing belt area, which achieves a particularly high material removal rate.

Further, a Kraftbeaufschlagungseinrichtung is provided, by means of which the guide body in its rest position are preserved. This has the advantage that - without the action of a workpiece - the guide body are held in their rest position, which is associated with the first, so smaller circumferential angle. As a result, the introduction of a workpiece to be machined in the receiving area is greatly simplified.

A particularly good handling of the finishing device results when the first circumferential angle is less than or equal to 180 °, so that a workpiece to be machined can be inserted undercut-free into and out of the receiving region.

Particular advantages also arise when the second circumferential angle is greater than 180 °. In particular, the second circumferential angle is more than about 200 °. As a result, a particularly large guide surface with a high wrap angle (equal to the second circumferential angle) can be provided, which is accompanied by a particularly high material removal rate. If, at the same time, the first circumferential angle is less than or equal to 180 °, workpieces can be inserted undercut-free into the receiving area, despite the high angle of wrap during machining.

With a wrap angle greater than 180 ° highest roundness requirements can be met. Moreover, it is possible to machine not only rotationally symmetrical, for example, cylindrical, workpiece surfaces, but also workpiece surfaces, which are seen in the circumferential direction only rotationally symmetrical segment. Such workpiece surfaces can be provided, for example, on balance shaft bearings, which, viewed along their circumference, have a part-cylindrical section and a flat section. Such workpiece surfaces may (as opposed to a full seat) also be referred to as half seat or partial seat. By wrapping such a workpiece surface with a second circumferential angle of greater than 180 °, an undesired emigration and / or tilting of such a workpiece surface with parts of the guide device is prevented.

In a preferred embodiment, exactly two mutually separate guide body are provided. These have mutually adjacent, but not interconnected partial surfaces, which extend, for example, in each case over a circumferential angle of greater than 90 °.

A particularly simple design of the guide device is obtained if at least one of the guide bodies is movably mounted on a guide body holder, in particular if all guide bodies of the guide device are movably mounted on the guide body holder.

A geometry which is particularly well suited for the machining of a workpiece, which is at least partially rotationally symmetrical, results when at least one of the guide bodies, preferably all guide bodies of the guide means, is or are pivotally mounted on the guide body holder. Here, the pivot axes are preferably oriented at least substantially parallel to a workpiece axis of a recorded in the receiving area workpiece.

A particularly uniform distribution of a pressing force results when a pivot axis of the at least one guide body is arranged such that a plane in which the pivot bearing axis and a workpiece axis parallel thereto in the receiving area when the workpiece is arranged extend at least the partial surface of the at least one guide body about halfway through.

Furthermore, it is preferred if the guide bodies can be transferred from the rest position into the working position, accompanied by the assembly of the receiving area with a workpiece, by means of the workpiece surface to be machined. This has the advantage that a conceivable in principle conceivable, but more complex drive for transferring the guide body from the rest position to the working position is unnecessary. Thus, the workpiece surface to be machined can be used to press this against the finishing belt, so that this in turn presses against the partial surfaces of the guide body, so that they are spent alone by a force applied by the workpiece actuating force from the rest position to the working position, if necessary contrary the effect of a Kraftbeaufschlagungseinrichtung described above.

A further advantageous embodiment of the invention provides that at least a part of the guide surface in the radial direction is resiliently deformable, so that a particularly gentle machining of a workpiece surface is made possible. The elastic compliance can, for example, be realized in that the partial surfaces of the guide surface are formed of an elastically deformable material, in particular of an elastomer.

In a further preferred embodiment it is provided that at least one of the guide body is mounted elastically yielding in the radial direction. This makes it possible to at least slightly adjust the spatial position of a bearing axis of a guide body, so that a particularly gentle and highly accurate machining of a workpiece surface is made possible.

The invention further relates to the use of a finishing device described above for finish machining a rotationally symmetrical workpiece surface, which is in particular cylindrical or spherical.

Furthermore, the invention relates to the use of a finishing device described above for finishing machining a circumferentially only segmentally rotationally symmetrical workpiece surface.

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 Seitenansicht einer Ausführungsform einer Finishvorrichtung mit einer schematisch dargestellten Führungseinrichtung;

Figur 2

eine perspektivische Ansicht der Führungseinrichtung gemäß Figur 1;

Figur 3

eine Draufsicht der Führungseinrichtung gemäß Figuren 1 und 2 längs einer in Figur 2 mit III-III markierten Schnittlinie; und

Figur 4

eine Seitenansicht einer weiteren Ausführungsform einer Führungseinrichtung.

In the drawings show:

FIG. 1

a side view of an embodiment of a finishing device with a guide device shown schematically;

FIG. 2

a perspective view of the guide device according to FIG. 1 ;

FIG. 3

a plan view of the guide device according to FIGS. 1 and 2 along a in FIG. 2 III-III labeled section line; and

FIG. 4

a side view of another embodiment of a guide device.

An embodiment of a finishing device is in FIG. 1 generally designated by the reference numeral 10. The finishing device 10 comprises a pressing device 12 with at least one first arm 14 and optionally with one second arm 16. The arms 14 and 16 are pivotally mounted so that they can be delivered towards a workpiece 18 having a central workpiece axis 20 (as in FIG FIG. 1 shown).

The workpiece 18 is, for example, a crankshaft whose central bearing or stroke bearing is to be machined finishend. The workpiece surfaces to be machined can be designed as a full seat with a workpiece surface that is completely cylindrical in the circumferential direction or as a partial seat with a workpiece surface that is cylindrical in the circumferential direction only.

The finishing device 10 further comprises a finishing belt 22, which in FIG. 1 dash-dotted lines is shown. The finishing belt 22 is provided by a finishing belt supply 24, fed to the workpiece 18 in an approximately radial direction, and brought into contact with a workpiece surface 28 of the workpiece 18 to be machined in the region of a finishing belt insertion end 26. The finishing belt 22 is guided, starting from the finish belt insertion end 26, between a guide device 30 shown in dashed lines and the workpiece surface 28 as far as a finishing belt performer 32. In the area of the finishing belt runner 32, the finishing belt 22 is led away from the workpiece surface 28 approximately radially outwards from the workpiece 18.

In its further course, the finishing belt 22 is guided by means of deflection rollers 34 and 36 and tensioned by means of a tensioning device 38. The tensioning device 38 has a clamping element 40 which acts on the finishing belt 22 and simultaneously serves as a deflecting element. The Clamping device 38 is fixedly connected to the first arm 14.

The guide device 30 is fixed to the first arm 14, in particular by means of a screw 42nd

During finishing machining of the workpiece 18, it is rotationally driven about the workpiece axis 20 by means of a drive device (not shown). Here, the finishing belt 22 can be fixed, or it is moved to increase the cutting speed during machining of the workpiece surface 28 in a feed direction 44. By means of the arm 14, a directed in the direction of the workpiece 18 pressing force is generated with which the guide means 30 presses on the finishing belt 22 and the finishing belt 22 on the workpiece surface 28.

The construction of the guide device 30 will be described below with reference to FIGS FIGS. 2 to 3 described.

The guide means 30 comprises a guide body holder 46, which is connectable to the first arm 14, for example using the in FIG. 1 shown screws 42 and / or using in FIG. 2 illustrated screws 48.

The guide body holder 46 is substantially C-shaped, for example, and includes a rear plate 50 from which two beams 52 and 54 protrude. The carrier 52 and 54 serve to receive further, described below components. On the carriers 52 and 54, pulleys 56 and 58, respectively, are fastened using one holder 60 each. In addition, the guide body holder 46 serves to specify pivot axes 62 and 64. The pivot axes 62 and 64 are in particular parallel to each other. They define the bearing axles for a respective guide body 66 or 68 pivotable about the pivot axes 62, 64. The guide bodies 66 and 68 each have a partial surface 70 or 72 of a guide surface 74 which extends between the finish belt insertion end 26 and the finish belt executor 32 extends. The partial surfaces 70 and 72 adjoin one another and are movable independently of one another.

To support the guide body 66 or 68 on the guide body holder 46 can be provided coaxially with the pivot axes 62 and 64 extending bearing pin 76 (see FIG. 3 ). The bearing bolts can be connected, for example, in a rotationally fixed manner to the carrier 52 of the guide body holder 46. A particularly low-friction bearing of the guide body results when used for the storage of the guide body 66 or 68 bearings, such as ball bearings 78th

The guide device 30 further comprises a force acting on the overall reference numeral 80 Kraftbeaufschlagungseinrichtung. In the simplest case, the force-applying device comprises at least one spring 82, which acts on the guide body 66 or 68 with a bias voltage. This allows the guide body 66 and 68 are held in a rest position. In the embodiment shown in the drawing, two springs 82 and 84 are provided, which are stationary with respect to the guide body holder 46 and articulated, for example, to a linkage 86.

The articulation 86 facing away from the ends of the springs 82 and 84 are each connected to one of the guide body 66 and 68, respectively. The force application device 80 generates a clamping force which causes the partial surfaces 70 and 72 to move toward one another, resulting in a first circumferential angle 88 enclosed by the partial surfaces 70 and 72. This is preferably at most about 180 °, in particular at most 180 °.

In FIG. 4 a further embodiment of a guide device 30 is shown. This is to the above with reference to FIGS. 2 and 3 described guide device 30 similar construction. It differs only in terms of the configuration of the bearing of the guide body 66 and 68, which are mounted by means of plain bearings 90 and 92 to the guide body holder 46. For example, the sliding bearings 90 and 92 each comprise a bearing pin 94, 96 which is rotatably connected to the guide body holder 46 and on which in each case a corresponding bearing surface of the guide body 66 and 68 slides, so that the guide body 66 and 68 about the pivot axes 62, 64 pivotally are. Optionally, the bearing pins 94, 96 may be guided in elastic bushings, which allow a radial mobility of the pivot axes 62, 64.

Incidentally, the structure and operation of the guide device 30 is according to FIGS. 2 and 3 identical to the structure and operation of the guide device 30 according to FIG. 4 , The following description therefore applies to both embodiments.

The guide surface 74 formed by the partial surfaces 70 and 72 defines a receiving region 98 (see FIG FIG. 2 ), in which the workpiece 18 (see FIG FIG. 4 ) can be arranged. The arrangement of the pivot axes 62 and 64 is selected so that an (imaginary) plane 100 or 102 in which each extend one of the pivot axes 62 and 64 and this at least approximately parallel workpiece axis 20, the sub-surfaces 70 and 72 cut through at least approximately half ,

In FIG. 4 the lower guide body 68 is shown in its rest position. In this case, the guide body 68 is inclined with its partial surface 72 in such a way that the receiving region 98 is enlarged and the introduction of a workpiece 18 into the receiving region 98 is facilitated. By introducing the workpiece 18 in the receiving area 98, the workpiece surface 28 comes into contact with the in the sake of clarity in the Figures 2 and 4 not shown finishing belt 22, whereby this in turn comes into contact with the partial surfaces 70 and 72 of the guide body 66 and 68, respectively. As a result, the guide body 66 and 68 are pivoted from its rest position to its working position. This job position will be in FIG. 4 illustrated by the upper guide body 66. In this working position, the partial surfaces 70 and 72 wrap around the workpiece 18 with a second circumferential angle 104 which is larger than the first circumferential angle 88 (cf. FIG. 3 ).

The second circumferential angle 104 is in particular greater than 180 °.

In the working position of the guide body 66 and 68, the workpiece surface 28 of the workpiece 18 is processed. The workpiece surface 28 may be completely rotationally symmetrical or only rotationally symmetric in segments and in an in FIG. 4 Dashed line indicated section 106 deviate from a rotationally symmetrical shape. In the machining of such, not completely rotationally symmetrical workpiece 18 allows the pivotal mounting of the guide body 66 and 68 that the guide body 66, 68 perform about the pivot axes 62, 64 oscillating movement, wherein the guide body 66, 68 alternately by action of a rotationally symmetrical sections Workpiece surface portion and by the action of the force application device 80 are pivoted back and forth.

Claims (12)

1. A finishing device (10) for finishing a workpiece surface (28), comprising a guide unit (30) for guiding a finishing belt (22), said guide unit (30) having a cup-shaped guide surface (74) which delimits a receiving zone (98) for a workpiece (18) and which has at least two separate partial surfaces (70, 72), wherein the finishing belt (22) is guided or guidable along the guide surface (74) between a finishing belt entry zone (26) and a finishing belt exit zone (32), wherein the guide unit (30) comprises at least two separate guide members (66, 68) which are not integrally built with each other, the guide members (66, 68) each providing one partial surface (70, 72) of the guide surface (74) and being movable relative to each other, characterized in that the guide members (66, 68) are movable between an idle position and an operative position, with the guide surface (74) extending in the idle position of the guide members (66, 68) between the finishing belt entry zone (26) and the finishing belt exit zone (32) over a first circumferential angle (88) which permits a workpiece (18) which is to be machined to be introduced into the receiving zone (98) and which permits to discharge a machined workpiece (18) from the receiving zone (98), and with the guide surface (74) extending in the operative position of the guide members (66, 68) for machining the workpiece (18) over a second circumferential angle (104) which is greater than the first circumferential angle (88), and characterized by a force-application unit for holding the guide members (66, 68) in their idle position without impact of the workpiece (18).
2. The finishing device (10) of claim 1, characterized in that the first circumferential angle (88) is equal to or smaller than 180°.
3. The finishing device (10) of claim 1 or 2, characterized in that the second circumferential angle (104) is greater than 180°.
4. The finishing device (10) of one of the preceding claims, characterized in that exactly two separate guide members (66, 68) are provided.
5. The finishing device (10) of one of the preceding claims, characterized in that at least one of the guide members (66, 68) is mounted movably at a guide member support (46).
6. The finishing device (10) of one of the preceding claims, characterized in that at least one of the guide members (66, 68) is mounted pivotably at the guide member support (46).
7. The finishing device (10) of claim 6, characterized in that a pivot axis (62, 64) of the at least one of the guide members is disposed such that a plane (100, 102) intersects at least in approximation in midsection the partial surface of the at least one of the guide members (66, 68), wherein the pivot axis (62, 64) extends in the plane (100, 102) and wherein a workpiece axis (20) of a workpiece (18) extends in the plane (100, 102) and is parallel to the pivot axis (62, 64) when the workpiece (18) is located in the receiving zone (98).
8. The finishing device (10) of one of claims 2 to 7, characterized in that the guide members (66, 68) are transferable from the idle position to the operative position by means of the workpiece surface (28) which is to be machined and when loading the workpiece (18) into the receiving zone (98).
9. The finishing device (10) of one of the preceding claims, characterized in that at least a portion of the guide surface (74) is deformable in an elastically resilient manner.
10. The finishing device (10) of one of the preceding claims, characterized in that at least one of the guide members (66, 68) is supported in a manner elastically resilient in a radial direction.
11. Use of the finishing device (10) of one of the preceding claims for finishing a rotationally symmetrical workpiece surface (28).
12. Use of the finishing device (10) of one of the preceding claims for finishing a workpiece surface (28) which as viewed in a circumferential direction includes a rotationally symmetrical segment or rotationally symmetrical segments only.

Images