EP1859903B1 - Rotary tool for surface processing - Google Patents

Abstract

The tool has a rubber elastic disk (1) with an outer rim (2) equipped with a machining tooth (5) that is distanced from each other. The machining tooth exhibits imhomogenity forming hinge formed as a recess (8), where the hinge is formed in an area of a connecting rod (9) coupling the machining tooth in a foot sided manner. The machining tooth possesses a tapered surface (10) bent against a direction of rotation (D). The machining tooth exhibits an inclination of 10 to 12 degrees in relation to a radial direction.

Description

The invention relates to a rotary tool for surface processing, with a rubber-elastic disc whose outer rim is equipped with spaced apart processing teeth. Such a rotation tool is off DE 202 023 009 U known. - The machining teeth may be aligned in the radial direction or have a relation to the radial direction oblique arrangement. That is, the machining teeth are usually tilted, but can also extend radially.

A rotary tool of the embodiment described above is in the GB 456 985 described. In this case, the known rotary tool accesses a resilient rubber-elastic layer which carries the respective machining teeth. The machining teeth are manufactured separately, which in conjunction with the additional rubber-elastic layer leads to a relatively complicated structure.

Furthermore, the describes DE 202 023 009 U1 another rotary tool. This is essentially an improved abrasive wheel for removing adhesives from stickers or dirty objects from an object to be sanded. The grinding wheel in question can be made of soft rubber and can, for example, be rotationally driven by a hand tool. In this case, the grinding area can be equipped with a side which forms at least one bevelled surface.

A similar rotary tool with non-inclined machining teeth is the subject of DE 198 45 166 B4 , The rotary tool in question is also referred to as an eraser for removing adhesive residues and plastic films on metal surfaces. For this purpose, the outer surface of the annular disc is pressed onto the surface to be treated, so that the adhesive residues and foils, such as glued trims and advertising plastic film, softened and detached. This succeeds without damaging the relevant metal surfaces and in particular painted surfaces, as are customary in automobiles, for example.

In addition, a rotatable Abreibwerkzeug by the DE 39 20 972 B4 have become known, the abrasive elements are executed in the form of tufts of rigid plastic with embedded abrasive. A damage-free surface treatment can hardly be realized hereby.

The known rotation tools for surface treatment have proven themselves in principle, but come up against limits, where not only a gentle processing is required, but they should also go quickly and particularly effective. This is where the invention starts.

The invention is based on the technical problem of further developing a rotary tool of the embodiment described at the beginning in such a way that the efficiency is increased, that is to say the machining time is shortened compared to previous embodiments with unchanged gentle treatment of the surface.

To solve this technical problem, a generic rotary tool in the context of the invention is characterized in that the respective machining tooth has at least one hinge-forming inhomogeneity in the form of a recess.

In this inhomogeneity, which forms a hinge for the machining tooth in the context of the invention, it is basically an inhomogeneity, the deviations of the cross-sectional shape of the machining tooth of his essentially cuboidal design corresponds. For this purpose, the inhomogeneity is formed as a recess. In addition to deviations from the cross-sectional shape of the machining tooth and a variation of the material properties can be made.

In any case, the inhomogeneity in question ensures that the machining tooth in its longitudinal extent in the region of inhomogeneity undergoes a certain weakening and consequently a hinge is formed. This is achieved by the recess as inhomogeneity.

As a result of this hinge-forming recess or undercut, the machining tooth is consciously and (slightly) weakened in its longitudinal extension in terms of its material thickness in the region of the hinge in question. Of course, this reduction in the thickness of the material takes account of the loads occurring on the machining teeth as a whole and is dimensioned so that an outline of the machining teeth need not be feared. Rather, the formed hinge supports the inclination of the machining teeth in operation on the already existing and in the unloaded predetermined skew addition. The same applies if the machining teeth are radial. Because the hinge-forming recess supports in any case, the inclination and combines material compression.

As a result, the machining teeth attach almost to their entire leading machining edge and additionally with their surface to the object to be processed, so that a special effective grinding effect is achieved. In this context, it should be noted that the said leading machining edge of the respective machining tooth is inclined in this direction of rotation in comparison to the direction of rotation of the disk. A corresponding inclination counter to the direction of rotation also has the trailing processing edge on. That is, the alignment and mode of action of the individual processing teeth is comparable to the monofilaments of rigid plastic, as in the context of DE 39 20 972 B4 be used. In comparison, the surface to be machined becomes but spared and especially painted surfaces, as they are common for example in automobiles, are not damaged - similar to the DE 198 45 166 B4 described.

It has proven useful if the hinge-forming recess or undercut is provided only on one side of the machining tooth, namely at the respectively trailing machining edge. In addition, the described effect is particularly observed when the questionable hinge forming recess is formed at the foot side of the machining tooth. For this reason, as it were, the entire length of the machining tooth can be further pivoted by the formed hinge in the desired manner and in addition to the already predetermined inclination in operation and so ensure the almost full-surface contact of the leading edge machining with the surface to be machined.

In general, the leading and the trailing processing edge of the respective machining tooth are equipped with different inclination relative to the radial direction. This provides some compensation for the lack of material in the area of the hinge. For in this way, the respective machining tooth has a cross section in the form of a conical trunk or a trapezoidal cross-section with a broad foot and a narrower head.

The disc or annular disc is usually made of rubber or a rubber-elastic plastic, wherein in addition may be embedded in the peripheral processing teeth as a whole or primarily in the leading edge machining abrasive particles. In this case, for example, abrasive particles of corundum or even those of silicon carbide, boron carbide, boron nitride or diamond have proven. The grain size of the abrasive particles can move between extra-fine and very coarse.

That depends on the nature of the surface to be processed. For example, an extra-fine particle size or abrasive emulsion wetting of the leading processing edges will be used if, for example, adhesive residues and films on paint or metal surfaces are to be removed. In contrast, medium-fine or medium-coarse abrasive particles are recommended if, for example, the lacquer is to be removed from painted metal surfaces or other surfaces or a different surface finish is desired. Coarse or very coarse abrasive particles will be used if z. B. a rust removal of metal or steel surfaces is provided. In any case, depending on the selection of the abrasive particles and, where appropriate, the grinding emulsion, a vote can be made on the particular surface treatment to be carried out.

It is always achieved by the preferred rubber-elastic design of the disc that there is an observed in all three spatial directions large elasticity of the machining teeth due to the high polymer structure (elastic modulus between 1 and 500 N / mm ² ). In this way, with speeds of, for example, 3000 revolutions / min. and more driven rotary tool according to the invention or the Folienradierer also edit wavy surfaces and has a high concentricity due to the large-scale investment of the hinge-like pivoted during operation machining teeth on the surface to be machined.

As a result, it is possible on the one hand to work with low pressure forces, on the other hand a particularly high degree of efficiency and effective removal of adhesive residues, plastic films, etc. on metal or painted surfaces is achieved. In addition, due to the spaced machining teeth a ventilation effect, which for cooling the disc and for the discharge any abrasive particles or components removed from the surface.

It has proven useful if the hinge-forming recess is formed in each case in the region of a connecting web which connects the machining teeth on the foot side. In fact, the hinge-forming recess or the undercut and the connecting web taken together form a unit and are formed in total circular cross-section. As a result, both the hinge-forming recess and the connecting web can be defined in a machining step in the disk in which, for example, the disk equipped with the machining teeth is milled out at the foot end in the region of the hinge-forming recess and the connecting web.

In detail, the machining teeth have an inclination of 5 to 20 ° relative to the radial direction. In particular, values for the inclination of 5 to 15 ° and preferably those between about 10 ° and 12 ° have proven to be particularly favorable.

In addition, the disc is usually equipped with an inner ring with at least one receptacle for a disc holder for connection to a rotating machine tool. In principle, the disc can also be driven manually. However, in order to achieve the already mentioned rotational speeds, rotating machine tools are recommended, which provide the required speeds and the associated drive power available.

Finally, it has proved to be advantageous if the machining teeth additionally each have a beveled surface which the full surface area achieved by the inclination and hinge mobility Supporting the machining teeth on the surface to be machined supported. In fact, the surface is usually - as the leading and trailing edge of the respective machining tooth - inclined against the direction of rotation of the rotary tool. Have proven useful at this point angle of a few degrees, for example, 3 to 8 °. Due to the inclination of the respective surface of the machining teeth, the disk has a sawtooth-like circumferential profile on its outer rim, which supports the grinding performance.

As a result, a rotary tool is provided, the preferably rubber-elastic disc is equipped with specially trained and aligned machining teeth. Because in operation, these machining teeth put almost with their entire leading edge processing (and its surface) to the surface of the object to be processed and ensure an effective and full-surface removal of adhesive residues, films, advertising, etc., without the surface is damaged , Here are the main benefits.

In the following the invention will be explained in more detail with reference to a drawing showing only one exemplary embodiment. The single drawing shows the rotary tool according to the invention in section.

In the figure, a rotary tool for surface processing in the embodiment as a disc 1 or washer or Folienradierer is shown. The disc 1 in question consists of a rubber-elastic plastic, in this case made of polyurethane (PUR). But it is also possible that only an outer ring 2 is made of rubber-elastic plastic, while an inner ring 3 is made of thermoplastic material.

For processing, the disc 1 has the outer rim 2 and the inner rim 3, which is equipped for connection to a merely indicated rotatably driven disc holder 4. The outer ring 2 of the disc 1 has distributed over its circumference protruding bending elastic machining teeth 5, which are arranged distributed equally spaced over the outer rim 2.

The respective machining teeth 5 have a leading machining edge 6 and a trailing machining edge 7. It can be seen that the leading machining edge 6 and the trailing machining edge 7 have an oblique position predetermined by respective angles α, β with respect to a radial direction R.

In fact, the leading processing edge 6 (angle α) and the trailing processing edge 7 (angle β) are equipped with different inclinations relative to the radial direction R, because the angle α is about 11 in the embodiment, whereas β assumes values of about 8 °. As a result, the respective machining teeth 5 have a cross-sectionally truncated shape with a broad foot and a narrower head in contrast. The respective oblique position of the leading and trailing machining edges 6, 7 ensures that the machining teeth 5 are inclined overall with respect to the addressed radial direction R, against a direction of rotation D inclined.

Of particular importance for the invention is the fact that the respective machining tooth 5 has at least one hinge-forming inhomogeneity, which in the present case is designed as a hinge-forming recess 8 or undercut. It can be seen that the hinge-forming recess 8 is located in each case in the region of the trailing machining edge 7, namely on the foot side of the associated machining tooth 5. Im Incidentally, the hinge-forming recess 8 passes directly into a connecting web 9 which predetermines the spacing of the machining teeth 5. In fact, the hinge-forming recess 8 and the associated connecting web are each taken together in cross-section arcuately formed with the same radius. In this way, the connecting web 9 in question and the hinge-forming recess 8 are defined in one production step.

Furthermore, it can be seen that the respective machining teeth 5 have a bevelled surface 10. The associated angle γ of the inclination is located in the range of about 5 °, may be measured in total between 3 ° and 8 °. Like the leading machining edge 6 and also the trailing machining edge 7, the bevelled surface 10 of the respective machining tooth 5 is inclined counter to the direction of rotation D or working direction of the rotary tool. In this way it is achieved that the machining teeth 5 experience an additional oblique inclination in the state applied to the workpiece as a result of the hinge-forming recess 8, so that virtually all the leading machining edge 6 and the bevelled surface 10 on the surface in question and to be machined for machining Workpiece rest.

For this reason, abrasive particles 11 may be embedded at least in the leading machining edge 6 and / or the bevelled surface 10 of the respective machining teeth 5. These abrasive particles 11 may be those of fine particle size corundum.

For attachment of the disc holder 4 to the inner rim 3 of this inner ring 3 is equipped with slot-like receptacles 12, which may intervene in the webs of the disc holder 4. The disk holder 4 itself is acted upon by a rotationally working machine tool in the direction of rotation D.

Claims (10)

1. A rotary tool for surface machining, with a rubber-elastic disc (1), whose outer ring (2) is equipped with machining teeth (5), which are spaced apart from each other, characterised in that the respective machining tooth (5) has at least one inhomogeneity in the form of a cut-out (8), which forms a hinge.
2. The rotary tool according to Claim 1, characterised in that the inhomogeneity in the form of a cut-out (8), which forms a hinge, is realised at the foot of the respective machining tooth (5).
3. The rotary tool according to Claim 1 or 2, characterised in that the inhomogeneity in the form of a cut-out (8), which forms a hinge, is in each case configured in the region of a connecting web (9) which links the machining teeth (5) at the foot.
4. The rotary tool according to one of Claims 1 to 3, characterised in that the inhomogeneity in the form of a cut-out (8), which forms a hinge, and the connecting web (9) are configured to have an arc-shaped cross section as seen together.
5. The rotary tool according to one of Claims 1 to 4, characterised in that the respective machining tooth (5) has a sloped surface (10).
6. The rotary tool according to Claim 5, characterised in that the surface (10) is inclined counter to the direction of rotation (D).
7. The rotary tool according to one of Claims 1 to 6, characterised in that the respective machining teeth (5) have an inclined position (α) of 5 to 20°, in particular 5 to 15°, preferably approx. 10 to 12° with respect to the radial direction (R).
8. The rotary tool according to one of Claims 1 to 7, characterised in that the disc (1) is equipped with an inner ring (3) with receptacles (12) for a disc holder (5).
9. The rotary tool according to one of Claims 1 to 8, characterised in that the respective machining tooth (5) is configured to have a truncated-cone-shaped cross section.
10. The rotary tool according to one of Claims 1 to 9, characterised in that the respective machining tooth (5) has a leading machining edge (6) and a trailing machining edge (7) with different inclined positions (α, β) with respect to the radial direction (R).

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