EP2810739A1 - Tool for processing materials - Google Patents

Abstract

The invention relates to a tool for processing materials, in particular a grinding wheel with an axis of rotation substantially cylindrically symmetrical outer geometry, an inner hub (5) through the center of which the axis of rotation extends centrally, a concentric to this outer jacket body (4), and at least a carrier body (1) which is arranged between the hub and the jacket body and which is preferably integral with the hub (A) and / or the jacket body, wherein the carrier body (1) is designed with at least two feedthroughs (2) extending from the inside region of the body Carrier body towards the sheath body (4) extend, and wherein at least some of the bushings (2) on at least one of the two cylinder top surfaces of the carrier body (1) with at least one cover (10) are substantially completely covered, wherein the cover (10) at least in Interior of the carrier body and / or in the region of the hub with these positive, force and / or materially connected, and / or at least some of the bushings (2) are filled with a filling material (20), so that there is a closure of the respective bushings (2).

Description

The invention relates to a tool for processing materials. In particular, the invention relates to a tool for processing materials, preferably a grinding wheel, with a carrier body with bushings, wherein the tool has a hub for receiving a drive shaft, and means for covering the bushings and / or in which the bushings by suitable materials at least partially are closed.

Tools for processing materials with a carrier body with feedthroughs are known in the art. The US 4,004,378 shows a grinding wheel, the rotationally symmetrical support body is provided on its peripheral surface with an abrasive coating. The carrier body also has feedthroughs for achieving a substantially parallel to the axis of rotation of the carrier body extending air flow.

In addition, under the official file number 13 159 094.5 filed with the European Patent Office by the present applicant with the filing date of March 13, 2013, a European patent application discloses a tool for machining surfaces, which due to the specific design of the support body, and in particular the arranged therein, is particularly advantageous in terms of its grinding properties. On the one hand, the disclosed there devices are characterized by a particularly low weight, which has an advantageous effect on the development of vibration and handling when handling these abrasive tools, on the other hand, the inventive design of the bushings of the carrier body to a predetermined radial elasticity of the grinding tool, which a further damping of vibrations in grinding operation leads and thus to very good processing results.

It has now been found that in grinding operation of this grinding tool under certain production conditions in which there is a particularly high demand for coolant, so for example at high rotational and / or feed rates, an undesirable noise development takes place. Although this does not affect the sanding result, it does increase Noise level is a burden for the operating personnel on the processing machine, which is to be avoided in the interests of safety at work and for the prevention of diseases.

The present invention is therefore based on the object to provide a tool for processing materials of the type mentioned above, which overcomes the disadvantages of the prior art and in particular without sacrificing the machining result leads to a reduced noise in the grinding operation.

According to the invention, the above object is achieved by a tool for processing materials having the features of patent claim 1. Preferred embodiments are subject of the dependent claims.

Thereafter, the tool for machining materials, in particular a grinding wheel, with respect to a rotation axis substantially cylindrically symmetrical outer geometry, with an inner hub or axle through whose center the axis of rotation extends centrally, a concentric to this, outer shell body whose peripheral surface with an abrasive coating is provided, and a carrier body arranged between the hub and the jacket body, which is preferably integral with the hub and / or the jacket body. The carrier body is configured with at least two feedthroughs, which preferably extend from the inner region of the carrier body, ie from the edge region of the carrier body lying at the hub, in the direction of the outer edge of the carrier body, ie towards the jacket body, wherein, preferably in each sectional plane of the carrier body, the ratio A _D / A _{T is} greater than 1, preferably greater than 2, preferably greater than 3 and preferably greater than 4, from the sum of the areas A _D forming the lead body material and the area A _T forming the carrier body material. The areas forming the leadthroughs A _D are therefore greater in total than the surface of the material forming the support body A _T , and preferably significantly larger.

According to a first aspect of the invention, at least some of the feedthroughs and preferably all feedthroughs on at least one side of the tool are thus substantially completely covered on at least one of the two cylinder cover surfaces with at least one cover element. The cover is in this case at least in the inner region of the carrier body with this form, force and / or materially connected and concentric so on the cylinder top surface arranged the tool that a space for stretching or stretching of the cover is provided in the radial direction and equally a compression of the support body of the tool due to its radial elasticity does not lead to a tarnishing of the cover to the shell body and / or the abrasive coating.

In order to ensure or even promote a stretching or stretching of the cover element at high rotational speeds, it is possible to fix the cover element only in the interior region of the support body so that the cover element in areas of the support body lying further outward, ie in the direction of the direction is no longer connected to the outer edge of the carrier body with this but essentially only rests on this and can slide on it.

According to a second aspect of the invention, which can be used alternatively or in combination with the first aspect of the invention, at least some of the bushings are filled with a foamed filling material, so that with substantially constant low weight of the tool and also constant radial elasticity of the tool nevertheless there is a closure of the bushings.

In accordance with the invention it has been recognized that by closing the bushings of the generic tools even at high speeds and feed speeds, and in particular with it usually associated high coolant demand a significant reduction of noise during machining by means of the tool according to the invention can be achieved and thus at Consistent advantages of the generic tool a significant increase in the field of application is achieved.

In one embodiment of the invention, the least a cover element is made in the manner of a disc of a material which has a sufficiently high breaking strength, especially in the radial direction, that even at high speeds of the tool, although an elongation of the material can take place, but not for Material break is coming. It is advantageous in this context, the use of lightweight materials to keep the material load by the centrifugal forces during grinding operation low.

Preferably, the material of which the cover member is made is selected from a group including plastics, light metals, glass fiber or carbon fiber composites, fabrics and especially coated fabrics, films, fabric-reinforced composites, combinations of the foregoing materials and the like.

Depending on the application, preferred filling materials are selected from a group comprising foamed plastics and metals, in particular polyurethane foams, PVC foams or polystyrene foams, foamed aluminum and the like of similar materials.

In cases where the cover is made of a hard, self-supporting material, a positive, cohesive and / or cohesive connection of the cover in the interior of the carrier body or in the region of the hub, for example by a distortion of the cover against the support body and / or the hub by means of a clamping device and / or fasteners such as Screws, undercuts, clamping or clip means, be sufficient although application specific, alternatively or additionally thereto, also a substantially full-surface, cohesive connection of the cover with the carrier body and optionally also the filler can be beneficial.

In the use of non-self-supporting materials for the cover, it may also be advantageous to the cover substantially over the entire surface of the support body and optionally also of the filler cohesively with this to connect in the area above, optionally with the filler filled, implementations of the support body despite the use of such lightweight materials to create a sufficiently viable coverage of the bushings or the filling material.

In the cohesive connection of the covering element with the carrier body and / or the filling material, a permanently elastic connecting material with a relatively high modulus of elasticity is preferably used, such as, for example, adhesives based on resin, plastic or silicone.

By the above measures can be achieved that even at high speeds no entry of coolant or air in the bushings takes place whereby the noise during operation is significantly reduced. Nevertheless, the solution according to the invention is safe provided that the tool does not lose its radial elasticity, since the cover does not hinder radial deformation of the tool or at least predictably influenced and thus by the concrete geometry of the bushings or the remaining spoke material of the carrier body is compensated, so that achieved with the generic tools advantageous Grinding properties are preserved.

The carrier body may be made of a variety of materials, such as steel, aluminum, copper, bronze or the like, since the vibration is not carried out by the material properties themselves, but by the geometric configuration of the bushings of the carrier body. Thus, both a significant weight reduction can be achieved as a targeted vibration damping, especially in metallic support bodies, which have almost no radial elasticity in support bodies of solid material or support bodies with bushings of small geometric dimensions.

In a preferred embodiment of the invention, the thickness of the carrier body (in the direction of the axis of rotation) is smaller than that of the jacket body and / or the hub, so that the carrier body rebounds with respect to the jacket body or the cylindrical top surfaces defined by the latter and in this recess the cover is received.

In one embodiment of the carrier body, the bushings are executed in the base in the form of squares, wherein the long sides are preferably connected radially extending with the short sides and wherein the short sides are arranged on the inner or outer region of the carrier body. Although a straight course of the long sides of the bushings is preferred but not required. Likewise, a rounded design of the inner corners of the squares is preferred so that sharp-edged inner corners are present at the bushings.

In a development, at least one of the short sides in the plan view, that is to say when viewing a cutting plane arranged normally by the carrier body, can be at least partially circular-segment-shaped, for example concentric with the outer circumference of the lateral surface. Preferably, the two long sides of the respective bushing are designed to be of equal length, so that the bushings of the carrier body in this embodiment appear substantially annular segment-shaped.

To further improve the vibration damping properties of the tool in a preferred embodiment of the Tröägerkörpers the quadrangular passages are distorted or bent around a point outside the respective implementation point, so that the long sides of the bushings in plan view are substantially arcuate or preferably circular segment. The spokes emerging from the material of this embodiment remaining between adjacent feedthroughs are thus arcuately curved and preferably circularly curved and extend in the inner region of the carrier body, ie substantially initially radially outwardly from the hub or axle receptacle, and then by their curvature to experience a kind of asymptotic approach towards the scope of the tool. The degree or extent of the approach of the spokes to the circumference of the tool is different selectable and, as it were, an essential parameter for the radial elasticity of the tool.

Preferably, the long sides of adjacent bushings are substantially parallel, this equally applies to substantially radially extending long sides of the bushings as well as for curved or even circular segment running. Nevertheless, for example, those embodiments are preferred within the scope of the invention, in which a tapering of the spokes is carried out towards the outer region of the carrier body by a non-parallel course of the long sides of passages, whereby further influencing the radial elasticity and the weight of the tools according to the invention this Embodiment can be achieved.

In a further embodiment of the carrier body to achieve a particularly good vibration damping, the bushings of the carrier body from its opposite cylindrical top surfaces ago essentially incorporated to the middle in the material of the carrier body, for example by milling. It is particularly advantageous, the bushings, which are incorporated from the second side, so for example, the upper cylinder top surface of the carrier body ago by a predetermined rotation angle α about the axis of rotation rotates with respect to those of the first side of the carrier body, so for example the lower cylinder top surface will be incorporated to rotate. As a result, the spokes between adjacent passages of one side of the carrier body are thus substantially not congruent with the spokes between adjacent feedthroughs of the other side of the carrier body.

Preferred angles of rotation α lie between 0 ° and 90 °, in each case inclusive, preferably between 30 ° and 60 °, preferably at 45 °, and particularly preferably at half the angular pitch of the bushings, ie at an angle α = 360 ° / (2n ), where n is the number of feedthroughs in a plane normal to the axis of rotation.

It is preferred to reduce and at best to prevent imbalance of the tool according to the invention in its use could be provided in the carrier and / or sheath body at least one, as required, several balancing bores.

Preferably, the abrasive coating is applied by gluing or sintering or similar known methods on the outer peripheral surface of the sheath body and preferably selected from a group of diamond needles such as PCD, MKD, CVD, CBN needles, metal, plastic or ceramic bonded Diamonds, metal or plastic bonded boron nitride, in particular cubic boron nitride.

Fig. 1

gattungsgemäßes Werkzeug gemäß dem Stand der Technik;

Fig. 2

in einer Schnittansicht, eine schematische Ansicht eines ersten Ausführungsbeispiels eines erfindungsgemäßen Werkzeugs gemäß dem ersten Aspekt der Erfindung;

Fig. 3

in einer Schnittansicht, eine schematische Ansicht eines zweiten Ausführungsbeispiels eines erfindungsgemäßen Werkzeugs;

Fig. 4

in einer Schnittansicht, eine schematische Ansicht eines dritten Ausführungsbeispiels eines erfindungsgemäßen Werkzeugs gemäß dem zweiten Aspekt der Erfindung;

Fig. 5

in einer Schnittansicht, eine schematische Ansicht eines vierten Ausführungsbeispiels eines erfindungsgemäßen Werkzeugs gemäß einer Kombination des ersten und des zweiten Aspekts der Erfindung.

Further features of the present invention will become apparent from the following description of preferred embodiments of the tool according to the invention in conjunction with the drawings. It shows:

Fig. 1

generic tool according to the prior art;

Fig. 2

in a sectional view, a schematic view of a first embodiment of a tool according to the invention according to the first aspect of the invention;

Fig. 3

in a sectional view, a schematic view of a second embodiment of a tool according to the invention;

Fig. 4

in a sectional view, a schematic view of a third embodiment of a tool according to the invention according to the second aspect of the invention;

Fig. 5

in a sectional view, a schematic view of a fourth embodiment of a tool according to the invention according to a combination of the first and the second aspect of the invention.

The Fig. 1 shows a generic tool with a support body 1, a shell body 4 with an abrasive coating B and a hub or receptacle 5. The support body has a plurality of bushings 2 and lying between the passages 2 spokes 3, which in this case circular segment-shaped from the inner region of the support body to extend its outer region and approach in the direction of extension of the course of the shell body.

The Fig. 2 to 5 show schematic sectional views of grinding wheels according to the present invention, wherein for ease of explanation, the tools according to the invention along a section line that the section line XX of Fig. 1 corresponds, are cut. In all figures, like reference numerals designate corresponding elements or elements with corresponding functions.

This in Fig. 2 shown first embodiment according to the first aspect of the invention is derived from the generic embodiment of the Fig. 1 From here, the bushings 2 of the carrier body at the two cylinder top surfaces of the grinding wheel, each with an annular cover 10 are substantially completely covered. The cover 10 is located on both sides in a recess formed by the support body and extend radially with respect to the axis of rotation of the tool. The cover elements are presently made of light metal or carbon fiber reinforced plastics or ceramics, for example.

In the interior region of the carrier body, the cover elements 10 are connected to it by a material connection 11, whereas in the area of the carrier body lying further outside there is no material connection between the material of the carrier body and the cover elements 10. The cover 10 are on the support body in the outer region substantially only and there is a radial clearance 12 between the outer periphery of the cover 10 and the shell body 4 on both sides so that the cover 10 even at a high speed of the tool caused stretching or stretching of the Materials do not come on the jacket body 4 to the plant.

This ensures that the radial elasticity of the tool is not disturbed by the cover 10 and in particular the cover even at high speeds and equally high compression of the tool due to its high radial elasticity does not accumulate on the shell body and / or the abrasive coating and possibly interfere with the grinding process.

In the embodiment of the present invention according to Fig. 3 which of the Fig. 2 at least partially structurally corresponds and is omitted in this respect to a more detailed description to avoid repetition, no cohesive connection between the support body and the cover 10 is provided but rather a frictional connection in the region of the hub by a tensioning device A.

This can, as in Fig. 3 is shown, a slightly different from an exactly radial extent of the cover 10 deviating arrangement result, since in the region of the clamping device A compression of the material of the cover 10 can be made in the thickness direction.

In a similar manner as in the embodiment according to Fig. 3 is also preferred, the cover on both sides of the hub or the support body by screwing from the outside parallel to the direction of the axis of rotation with the support body or the hub to screw or brace.

Both in the case of the embodiments of Fig. 2 as well as the Fig. 3 a flat cohesive connection of the cover 10 with the support body or its spokes 3 would also be conceivable and application-specific if desired.

Fig. 4 shows an embodiment of the invention according to the second aspect, in which the bushings 2 are filled with a filling material 20, preferably a foamed plastic such as polyurethane or PVC foam. The filler material preferably terminates flush with the cylinder cover surfaces of the carrier body, so that they are substantially planar.

A development of the embodiment according to Fig. 4 is in Fig. 5 This embodiment advantageously combines the elements of both aspects of the present invention. Accordingly, the cylinder cover surfaces of the carrier body are in turn provided with cover elements 10, wherein these are substantially flat connected to the carrier body and in particular its spokes 3 and optionally also the surfaces of the filling material 20 cohesively. At the shown Embodiment, the cover 10 are made of a thin but tear-resistant fabric, so that by the full-surface cohesive connection of the fabric with the surface of the support body and optionally also of the filling material a durable, yet very light surface is formed by the cover 10. In particular, this is the case when the tissue is impregnated by the material used for the cohesive connection.

For further details reference is made to avoid repetition to the general description. Finally, it should be noted that the features described in the preceding embodiments, in the general description and the claims can be combined in any way. Further, features described in singular and plural are to be considered in their combinations with other features as singular and plural, respectively.

Claims (10)

Tool for processing materials, in particular a grinding wheel with an axis of rotation substantially cylindrically symmetrical outer geometry, an inner hub (5) through the center of which the axis of rotation extends centrally, a concentric outer jacket body (4), and at least one between the hub and the jacket body arranged support body (1), which is preferably integral with the hub (A) and / or the jacket body, wherein the carrier body (1) with at least two passages (2) is configured, which extends from the inner region of the carrier body to the jacket body (4) extend,
characterized in that
at least some of the passages (2) on at least one of the two cylinder top surfaces of the carrier body (1) with at least one cover (10) are substantially completely covered, wherein the cover (10) at least in the inner region of the support body and / or in the region of the hub with this is positively, positively and / or materially connected, and / or
at least some of the bushings (2) are filled with a filling material (20), so that there is a closure of the respective bushings (2). Tool according to claim 1, characterized in that the filling material (20) is a foam and is selected, in particular, from a group comprising foamed plastics and metals, in particular polyurethane foams, PVC foams or polystyrene foams, foamed aluminum and the like of similar materials. Tool according to claim 1 or 2, characterized in that the filling material (20) completely fills the passages (2) and is flush with the cylinder cover surfaces of the carrier body (1). A tool according to any of the preceding claims, characterized in that the cover member is made of a material selected from a group consisting of plastics, light metals, glass fiber or carbon fiber composites, fabrics and in particular coated fabrics, films, fabric-reinforced composites, combinations of the foregoing Materials and the like contains similar materials. Tool according to one of the preceding claims, characterized in that the cover element (10) is arranged concentrically on the cylinder top surface of the tool and the outer radius of the cover element (10) is smaller than the radius of the jacket body (4), so that between cover element (10). and sheath body (4) a radially extending free space (12) is defined. Tool according to one of the preceding claims, characterized in that the ratio A _D / A _T from the passages (2) forming surface A _D and the carrier body material forming surface A _T ≥ 1, preferably ≥ 2, preferably ≥ 3 and preferred ≥ 4. Tool according to one of the preceding claims, characterized in that all the passages (2) of the carrier body are completely covered by the cover element (10). Tool according to one of the preceding claims, characterized in that the connection of the cover element (10) with the carrier body (1) and / or the hub (5) by a distortion of the cover (10) against the carrier body (1) and / or the hub (5) and / or by fastening elements, in particular screws, engagement elements, clamping or clip means. Tool according to one of the preceding claims, characterized in that the cover element (10) is connected over the entire surface substantially cohesively with the carrier body (1) and, optionally, the filling material (20). Tool according to one of the preceding claims, characterized in that the material for producing the cohesive connection is an adhesive, preferably a permanently elastic adhesive and in particular a resin-based, plastic or silicone-based adhesive.

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