WO2020078563A1

WO2020078563A1 - Grinding tool and method for producing a grinding tool

Info

Publication number: WO2020078563A1
Application number: PCT/EP2018/078712
Authority: WO
Inventors: Thomas MOHN; Sascha RAUSCH; Achim Schmitz; Bernd Stuckenholz; Dominik Vogt
Original assignee: August Rüggeberg Gmbh & Co. Kg
Priority date: 2018-10-19
Filing date: 2018-10-19
Publication date: 2020-04-23
Also published as: SG11202103690PA; US20220143784A2; PT3867012T; EP3867012B1; US20210370471A1; EP3867012A1; CA3116449A1; BR112021006960A2; SI3867012T1; ES2907107T3; AU2018445669A1; PL3867012T3; MX2021004212A

Abstract

A grinding tool (1) has a main body (2) with at least one fiber ply (F₁, F₂) embedded in a binding agent (B). A grinding layer (3) is arranged on the main body (2). The at least one fiber ply (F₁, F₂) is arranged partially movably in the binding agent (B). In this way, within the main body (2) and within the at least one fiber ply (F₁, F₂), a relative movement is realized which ensures a high degree of vibration and noise damping.

Description

Abrasive tool and method of making an abrasive tool

The invention relates to a grinding tool and a method for producing a grinding tool.

A rough grinding wheel is known from EP 1 543 923 A1. The rough grinding wheel has two layers of bonded grinding grain, which are reinforced by external reinforcements and internal reinforcements. An annular separating layer is arranged between the inner reinforcements. The separating layer is formed by intermediate layers which lie against one another and which consist, for example, of paper or plastic film. The separating layer reduces the amplitude of the vibration when grinding, without softening the structure of the grinding compound bonded with a binder and increasing the abrasion.

The invention has for its object to provide an easy to manufacture and flexibly applicable grinding tool that has a high vibration and noise damping in conjunction with a high cutting performance and a long service life.

This object is achieved by a grinding tool with the features of claim 1. Characterized in that the at least one fiber layer is arranged to be partially movable in the binder, a free relative movement is achieved during the grinding within the at least one fiber layer, so that the base body achieves high vibration and noise damping. To achieve the free relative movement within the at least one fiber layer, on the one hand so much binder is used in the production of the base body that the base body has sufficient stability and on the other hand so little binder is used that the at least one fiber layer does not have a continuous and / or full-surface bond with the bandage has medium. The at least one fiber layer is embedded in the binder such that a first region of the at least one fiber layer is firmly connected to the binder and a second region of the at least one fiber layer is movable relative to the binder and the first region. The at least one fiber layer preferably has at least one thread. The at least one thread is arranged to be partially movable in the binder. The at least one thread preferably has a first thread section, which is arranged immovably in relation to the binding means, and at least one second thread section, which is connected to the binding element. tel is arranged movably. The second thread section is arranged, in particular, to be movable relative to the first thread section. The binder is preferably a resin and / or an adhesive. The binder is preferably a thermoset, in particular phenolic resin or epoxy resin.

The base body and thus the grinding tool can be produced in any shape, so that there is a high degree of flexibility when using the grinding tool. The vibration and noise-damping design of the base body does not have a disadvantageous effect on the grinding layer. The abrasive layer is arranged indirectly and / or directly on the base body, which ensures high stability and a long service life due to the at least one fiber layer. The grinding tool is also easy to manufacture.

The abrasive layer is formed depending on the intended use of the abrasive tool. The abrasive layer preferably comprises an abrasive grain layer which is applied electrostatically to the base body. The abrasive grains of the abrasive grain layer are attached to a surface of the base body in particular by means of an adhesive. The abrasive grains are in particular at least partially aligned with the base body and / or with one another. The abrasive grains have a geometrically determined and / or a geometrically undefined shape. The abrasive grains comprise at least one material which is selected from the group ceramic, comnd, in particular zirconcomnd, diamond, cubic crystalline bomitride (CBN), silicon carbide and tungsten carbide. The abrasive grains can be applied in one or more layers. If several abrasive grain layers are formed, an adhesive is applied to the underlying abrasive grain layer and the subsequent abrasive grain layer is applied. The abrasive grain layer is attached to the base body or to a support layer which is connected to the base body. The abrasive layer in particular comprises a bond, abrasive grain and a cover bond. The abrasive grains can be introduced at different basic bond heights or applied to the body.

The abrasive layer in particular comprises an abrasive fleece. The abrasive fleece is attached to a surface of the base body, for example, by means of an adhesive. Furthermore, the abrasive layer comprises, for example, a coated abrasive. The coated abrasive comprises in particular a base layer to which abrasive grains are attached. The coated abrasive is designed, for example, as a flap. The abrasive grains used, in particular diamond abrasive grains, can be used on a metallic base.

The base body preferably has a hub or a shaft for clamping and for rotating the grinding tool. The grinding tool is in particular a grinding wheel.

A grinding tool according to claim 2 ensures high vibration and noise damping. Due to the fact that the threads of the respective fiber layer are partially movable relative to one another and to the binding agent, a relative movement of the threads relative to one another and thus a relative movement within the respective fiber layer is achieved. The basic body preferably has a plurality of fiber layers, the respective threads of which are embedded in the binding agent in such a way that they can move in relation to one another.

A grinding tool according to claim 3 ensures high vibration and noise damping. The fiber layers are preferably embedded one above the other in the binder. The fact that the fiber layers are mutually movable in areas, on the one hand a relative movement within the respective fiber layer and on the other hand a relative movement between the fiber layers is achieved. Due to the multi-layer structure, the base body also has a high level of stability and strength and ensures a long service life of the grinding tool. The fiber layers comprise at least a first region which is fixedly connected to the binder and at least a second region which is movable relative to the binder and the at least one first region.

A grinding tool according to claim 4 ensures high vibration and noise damping. The fiber layers are in particular arranged one above the other. Because the threads are partially movable relative to one another and to the binding agent, a relative movement between the fiber layers and / or a relative movement within the respective fiber layer is achieved. A grinding tool according to claim 5 ensures high vibration and noise damping and a long service life. Due to the fact that the at least one fiber layer comprises at least one fabric and / or at least one fabric, a relative vibration and noise-damping movement is achieved within the base body. At the same time, the base body has a high stability and accordingly enables a long service life. The at least one fabric and / or the at least one scrim comprises at least one thread, in particular several threads. The at least one fabric in particular has warp threads and weft threads. The at least one thread comprises a first thread section which is immovable relative to the binding agent and at least a second thread section which is movable relative to the binding agent and relative to the first thread section. For example, the at least one fabric has a twill weave. The twill weave enables a simple shifting of the warp threads and / or the weft threads within the weave and thus a relative movement to achieve high vibration and noise damping. The at least one fabric and / or the at least one scrim is preferably made of glass fibers, carbon fibers, cotton and / or polyester.

A grinding tool according to claim 6 ensures high vibration and noise damping in conjunction with a long service life. The more fiber layers the base body comprises, the higher the degree of relative movement that can be achieved within the base body. Wei terhin increases the stability of the base body with the number of fiber layers, which ensures a long service life. Conversely, the manufacturing effort increases with the number of fiber layers, so that there is an optimal range for the number of fiber layers.

A grinding tool according to claim 7 ensures high vibration and noise damping in conjunction with a long service life. The following applies to the ratio M: M = m _β / m _F , where IU _B denotes the mass of the binder and IU _F the mass of the at least one fiber layer. The ratio M on the one hand ensures that the base body has sufficient stability and, in particular, does not delaminate or fold over in an undesirable manner during grinding. On the other hand, the ratio M ensures that the at least one fiber layer is not completely or completely connected to the binder and that there is no continuous bond with the binder, so that a sufficient relative movement is achieved within the base body. The degree of relative movement within the base body is all the more larger, the smaller the ratio M is. Conversely, the greater the ratio M, the greater the degree of stability.

A grinding tool according to claim 8 ensures high vibration and noise damping. The damping particles are incorporated into the base body as a damping additive during manufacture. On the one hand, the damping particles themselves have vibration and noise damping properties. On the other hand, the damping particles prevent the at least one fiber layer from being fully or completely connected to the binder.

A grinding tool according to claim 9 ensures high vibration and noise damping in conjunction with a long service life. The binder ensures the stiffening of the at least one fiber layer in some areas and preferably has self-damping properties. The binder is, for example, a mixture of phenolic resin and rubber.

A grinding tool according to claim 10 can be used flexibly and ensures high vibration and noise damping in connection with high cutting performance and a long service life. The base body is curved at least in sections in a work area. In the work area, the abrasive layer is arranged on the base body. The abrasive layer is curved in sections in the work area. Here, the grinding tool can be used flexibly, for example for fillet weld machining and / or for edge machining. The base body and / or the grinding layer is curved in particular in a radial direction and / or in a circumferential direction to an axis of rotation of the grinding tool. The curved formation is concave and / or convex. The abrasive layer preferably comprises an abrasive grain layer which is fastened directly to an upper surface of the base body by means of an adhesive. Due to the curved formation of the base body, forces occurring during grinding can be efficiently conducted into the base body and damped there, so that the grinding tool ensures high vibration and noise damping. Due to the fact that the curved base body enables the grinding layer to be curved, the machining performance is high in the most varied of applications. A grinding tool according to claim 11 can be used flexibly and ensures high vibration and noise damping in conjunction with high cutting performance and a long service life. The base layer serves as an intermediate layer between the base body and the abrasive layer and, depending on the desired application, has advantageous properties. The base layer is preferably connected monolithically to the base body. In particular, the base layer does not form any undercuts with the base body. The base layer for forming the grinding layer is preferably coated directly or directly with grinding grains. The abrasive grains are attached to a surface of the base layer, for example, by means of an adhesive. The abrasive grains are attached to the surface of the base layer, for example, by electrostatic application. The base layer is preferably formed from a metallic material.

A grinding tool according to claim 12 ensures flexible applicability in conjunction with a high cutting performance. The three-dimensional shape of the grinding layer depends on the desired application, so that a high cutting performance and a long service life are achieved for the desired application. The grinding layer is, for example, curved and / or aligned with one another in several planes, for example in planes running at an angle to one another. The grinding layer is preferably curved in two mutually perpendicular directions, for example in a radial direction and in a circumferential direction to an axis of rotation of the grinding tool. A curved design enables, for example, fillet weld machining and / or edge machining. Due to the inclined planes, the grinding layer forms a chamfer that enables roughing or flat machining. The abrasive layer is preferably attached directly to a surface of the base body or to a surface of a base layer which is connected to the base body by means of an adhesive. The grinding layer is produced in particular by electrostatic application of grinding grains.

The invention is also based on the object of providing a method for the simple manufacture of a flexibly applicable grinding tool with a high level of vibration and noise damping in conjunction with a high cutting performance and a long service life. This object is achieved by a method with the features of claim 13. The advantages of the method according to the invention correspond to the advantages of the grinding tool according to the invention already described. The method can in particular also be further developed with features of the grinding tool, in particular with a feature according to at least one of claims 1 to 12.

A method according to claim 14 ensures the manufacture of the grinding tool with a high level of vibration and noise damping combined with a long service life. The fibers were arranged one above the other and connected to one another by heating and then cooling the binder in such a way that the base body on the one hand has sufficient stability and strength and on the other hand a relative movement is achieved within the base body.

A method according to claim 15 ensures the manufacture of the grinding tool with a high level of vibration and noise damping combined with a long service life. Because the at least one fiber layer, preferably the plurality of fiber layers, is pressed together when the small amount of binder is heated, the binder is distributed to a sufficient extent so that the base body is sufficiently strong. Due to the small amount of binder, however, there is no continuous or full-area bond within the respective fiber layer and / or between the fiber layers, so that a relative movement is achieved within the base body during grinding. The binder is preferably also cooled under pressure.

A method according to claim 16 ensures the simple manufacture of the grinding tool with a high level of vibration and noise damping combined with a long service life. Because the at least one fiber layer is only provided on one side and / or only partially on two sides with the binder, there is no continuous or full-surface bond with the binder during the manufacture of the base body. The respective fiber layer is impregnated with the binder, for example. The impregnated fiber layer was produced, for example, in an upstream manufacturing step. Preferably, when the base body is produced, a plurality of fiber layers provided with binder and, if appropriate, at least one fiber layer without binder are arranged one above the other. A method according to claim 17 ensures the simple manufacture of the grinding tool with a high level of vibration and noise damping combined with a long service life. Because fiber layers with and without binders are arranged adjacent to each other, no continuous or full-surface bond with the binding agent is achieved when the base body is produced. This enables the desired relative movement within the base body. A plurality of first fiber layers and a plurality of second fiber layers are preferably arranged alternately one above the other. The respective second fiber layer is preferably provided on one side or on two sides with the binder. The respective second fiber layer is impregnated with the binder, for example.

A method according to claim 18 ensures simple manufacture of the grinding tool with a high level of vibration and noise damping combined with a long service life. When providing the at least one fiber layer has no binder. Because of the layer of binder arranged next to the at least one fiber layer, the base body receives the required strength on the one hand. On the other hand, the at least one fiber layer does not form a continuous or full-surface bond with the binder, so that the desired relative movement is achieved within the base body during grinding. The layer of binder is preferably designed as a binder film. A layer of binder, in particular a binder film, is preferably provided between two fiber layers without a binder. A fiber layer without binder and a layer of binder, in particular a binder film, are preferably provided alternately.

A method according to claim 19 ensures the manufacture of the grinding tool with a high level of vibration and noise damping in connection with a high cutting performance and a long service life. The base layer serves as an intermediate layer between the base body and the grinding layer. The base layer is formed depending on the desired application. The base layer is formed, for example, from a metallic material, a base fabric and / or from paper. The base layer is in particular monolithically connected to the base body. The abrasive layer is attached to the base layer or to a surface of the base layer. The abrasive layer can be arranged or attached to the base body on the base layer before and / or after the base layer has been arranged. A method according to claim 20 ensures the simple manufacture of the grinding tool with a flexible applicability in connection with a high cutting performance. The abrasive layer comprises an abrasive grain layer formed by the applied abrasive grains. Due to the electrostatic application of the abrasive grains, the abrasive grain layer is fastened directly to the base body or to a base layer arranged on the base body. The three-dimensional shape of the grinding layer is made possible in a simple manner by the electrostatic application, so that the grinding tool produced can be used flexibly. Furthermore, the electrostatic application enables a renewed coating or covering of the body or the base layer. After a grinding layer has been used up, the remaining grinding tool can be replaced by electrostatic application of a new grinding grain layer for repeated use. Due to the electrostatic coating, the abrasive grains are applied in a directed manner, in particular in accordance with the course of the electrostatic field lines. This achieves a high cutting performance, especially when using grinding grains with a geometrically defined shape. The abrasive grains are attached to the base body or the base layer in particular by means of an adhesive. The grinding layer is formed in particular by multiple electrostatic applications of grinding grains.

Further features, advantages and details of the invention result from the following description of several exemplary embodiments. Show it:

1 shows a sectional illustration of a grinding tool according to a first exemplary embodiment with a base body and an abrasive layer arranged thereon,

2 is an enlarged sectional view of the grinding tool in FIG. 1 to illustrate a structure of the base body with a binder and with fiber layers partially embedded in the binder,

3 shows a schematic illustration of the production of the base body according to a first method, 4 shows a schematic illustration of the production of the base body according to a second method,

5 shows a schematic illustration of the production of the base body according to a third method,

6 shows a schematic illustration of the production of the base body according to a fourth method,

7 shows a schematic illustration of the electrostatic application of abrasive grains to the base body,

8 shows a schematic sectional illustration of a grinding tool according to a second exemplary embodiment and

FIG. 9 shows a schematic illustration of the manufacture of the base body of the grinding tool in FIG. 8.

A first exemplary embodiment of the invention is described below with reference to FIGS. 1 to 7. A hand-held grinding machine (not shown in more detail) is used in operation to drive a grinding tool 1.

The grinding tool 1 is disc-shaped. The grinding tool 1 comprises a base body 2 and an abrasive layer 3 arranged thereon. The base body 2 has a circular opening 5 in a clamping area 4 for receiving a drive shaft of the grinding machine. The opening 5 defines an axis of rotation 6 of the grinding tool 1. As an alternative to the opening 5, the grinding tool 1 can have a shaft.

The grinding tool 1 comprises a working area 7 which surrounds the clamping area 4 in a ring shape. The grinding layer 3 is arranged on the base body 2 in the working area 7. The work area 7 is divided into an inner area 8 and an outer area 9. The inner area 8 is annular and surrounds the clamping area 4. In the inner area 8, the surface of the base body 2, on which the abrasive layer 3 is arranged, is essentially planar. The outer region 9 is annular and surrounds the inner region 8. In the outer region 9, the surface of the base body 2 on which the grinding layer 3 is arranged is curved. The base body 2 is curved in the outer region 9 relative to the axis of rotation 6 along a radial direction R and along a circumferential direction U. Due to the curvature of the base body 2, the grinding layer 3 is curved and three-dimensionally.

The base body 2 comprises a number N of fiber layers, the general rule being: 1 <N <12, in particular 2 <N <10, and in particular 4 <N <8. The fiber layers are denoted in detail by Fi, where i is a running index for the individual fiber layers and depends on the number N. The grinding tool 1 shown in FIG. 1 comprises, by way of example, four fiber layers, which are denoted in detail by Fi to F ₄ . The fiber layers Fi to F ₄ are shown only schematically in Fig. 1. The fiber layers Fi to F ₄ are designed as fabrics and / or scrims.

The base body 2 comprises a binder B, in which the fiber layers Fi to F ₄ are embedded in such a way that the fiber layers Fi to F _{4 are} partially firmly connected to the binder B and partially movable to the binder B and to each other. For this purpose, a mass m _{ß of} the binder B to a mass m _{F of} the fiber layers Fi to F _{4 is} comparatively small. For a ratio M = m _ß / m _{F of} the mass m _{ß of} the binder B to the mass m _{F of} the fiber layers Fi to F ₄ applies: 1/25 <M <1/2, in particular 1/20 <M <1/3 , in particular 1/15 <M <1/4, and in particular 1/12 <M <1/6. Binder B is an organic adhesive, in particular phenolic resin, epoxy resin and / or rubber.

2 shows the partially movable arrangement of the fiber layers Fi to F ₄ in the binder B. 2, the adjacent fiber layers Fi and F ₂ are shown as an example. The fiber layers Fi to F ₄ are designed, for example, as a fabric and each have a plurality of weft threads S and warp threads K running transversely thereto. FIG. 2 shows the weft threads Si and the warp threads Ki of the first fiber layer Fi and the weft threads S ₂ and the warp threads K _{2 of} the second fiber layer F ₂ . Due to the comparatively small amount of binding agent B 2 connection-free areas V are formed in the base body, in which the water layers Fi to F _{4 are} not connected to the binder B. In these connection-free rich V, the fiber layers Fi to F ₄ are intrinsically movable relative to the binder B. The fiber layers Fi to F ₄ embedded in the binder B are thus movable in themselves and / or relative to one another in some areas. In the connection-free areas V, for example, the weft threads Si, S ₂ and / or the warp threads Ki, K ₂ are movable relative to one another. The connection-free areas V allow a relative movement of the fiber layers Fi to F ₄ within the base body 2 in certain areas.

The abrasive layer 3 comprises abrasive grains 10 with a geometrically determined shape, which are attached to the base body 2 by means of an adhesive 11. The adhesive 11 is, for example, a resin, in particular a phenolic resin. The abrasive grains 10 are arranged relative to one another and relative to a surface of the base body 2. The abrasive grains 10 form an abrasive grain layer 12. On the Schleifkomschicht 12, a cover binding 13 and a cover layer 14 are arranged in a conventional manner. The cover weave 13 and / or the cover layer 14 preferably has abrasive fillers.

Because the fiber layers F 1 to F ₄ allow a relative movement in themselves and / or relative to one another, forces occurring during grinding are absorbed by the basic body 2, as a result of which a high level of vibration and noise damping is achieved. The base body 2 nevertheless has sufficient stability and strength so that the grinding tool 1 has a long service life. The basic body 2 is simple and can be produced with any geometric shape, so that the grinding tool 1 is flexible in use. The abrasive layer 3 is easy to apply to the shaped body 2 shaped in the desired manner, so that the abrasive layer 3 ensures high cutting performance of the grinding tool 1.

The production of the base body 2 is described below:

A first manufacturing method is illustrated in FIG. In the first manufacturing process, the fiber layers Fi to F ₄ are provided without a binder. Layers of binder B are arranged between the fiber layers Fi to F ₄ arranged one above the other. The layers of binder B are designed as binder films. The fiber layers Fi to F ₄ and the layers of binder B arranged between them are then pressed against a base body shape G under a pressure p and heated in such a way that the binder B is flowable becomes. The binder B connects the fiber layers Fi to F ₄ in the manner described. The base body 2 is formed by cooling the binder B.

4 shows a second production method of the base body 2. In the second production process, the fiber layers Fi and F _{4 are provided} without binder B and the fiber layers F ₂ and F ₃ with binder B. The fiber layers F ₂ and F ₃ are impregnated with the binder B on both sides. The fiber layers Fi to F ₄ are arranged one above the other and pressed against the base body shape G under a pressure p and heated in such a way that the binder B becomes flowable. The binder B connects the fiber layers Fi to F ₄ in the manner described. After the binder B has cooled, the base body 2 is formed.

5 illustrates a third production method for the base body 2. In the third production process, the fiber layers Fi to F _{4 are} impregnated on one side with the binder B. The fiber layers Fi to F ₄ are arranged one above the other and pressed against the base body shape G under a pressure p and heated in such a way that the binder B becomes flowable. The binder B connects the fiber layers Fi to F ₄ in the manner described. After cooling 4, the base body 2 is formed.

6 shows a fourth production method for the base body 2. In this manufacturing process, the fiber layers Fi to F _{4 provided are} each partially provided with the binder B on two sides. The fiber layers Fi to F ₄ are impregnated with the binder B in some areas. The fiber layers Fi to F ₄ are arranged one above the other under a pressure p pressed against the base body shape G and heated in such a way that the binder B becomes flowable. The binder B connects the fiber layers Fi to F ₄ in the manner described. After cooling, the connected fiber layers Fi to F _{4 form} the base body 2.

The production processes and the fiber layers Fi to F _{4 provided} can be combined with one another in the desired manner.

The formation of the grinding layer 3 on the base body 2 and the production of the grinding tool 1 are described below: The abrasive grains 10 are applied electrostatically to the base body 2 by means of an application device 15. The application device 15 comprises a handling device 16 for handling and positioning the base body 2, a first electrode 17 and an associated second electrode 18 for generating an electrostatic field E, a metering device 19 for feeding the grinding grains 10 to a conveyor device 20.

The conveyor device 20 comprises an endless conveyor belt 21 which is tensioned by means of two deflection rollers 22, 23. The deflection roller 22 is rotatably driven by means of an electric drive motor 24. A with respect to the gravity _G F above the guide rollers 22, 23 angeordne- ter part of the conveyor belt 21 forms a conveying range from 25 extending in a horizontal x- direction and a horizontal y-direction.

The metering device 19 is arranged in a conveying direction 26 in front of the electrodes 17, 18. The first electrode 17 is plate-shaped and arranged in the direction of gravity F _G below half of the upper part of the conveyor belt 21 or below the conveyor area 25. In contrast, the second electrode 18 is arranged with respect to the gravity F _G above the conveyor belt 21 or the conveyor area 25. The second electrode 18 is thus spaced in a vertical z-direction from the first electrode 17, so that the conveying region 25 extends between the electrodes 17, 18. The second electrode 18 is attached to the device 16 Griffungseinrich. The x, y and z directions form a Cartesian coordinate system.

The second electrode 18 is shaped in accordance with the base body 2. The base body 2 is held by means of the handling device 16 in such a way that the second electrode 18 lies essentially over the entire surface against a rear side of the base body 2. The Griffungseinrich device 16 holds the base body 2, for example mechanically and / or pneumatically. Between the first electrode 17 and the second electrode 18 there is an electrical voltage U _E which is generated by means of a voltage source 27 and is adjustable.

The adhesive 11 is first applied to a surface facing away from the second electrode 18, so that the adhesive 11 arranged on the base body 2 forms a three-dimensionally shaped adhesive surface. The adhesive 11 is applied manually, for example or by means of the handling device 16. For example, the base body 2 is immersed with the surface in the adhesive 11 by means of the handling device 16.

The base body 2 is then positioned by means of the handling device 16 in the z direction above the first electrode 17, so that the adhesive surface is partially arranged in the electrostatic field E between the electrodes 17, 18. The field lines emerge perpendicularly from the surface of the first electrode 17 and enter the surface of the second electrode 18 perpendicularly, so that the field lines run essentially perpendicularly through the adhesive surface.

By means of the conveyor 20, the grinding grains 10 are transported into the electrostatic field E to form the three-dimensionally shaped grinding grain layer 12. For this purpose, the metering device 19 provides the grinding grains 10. The grinding grains 10 are metered by means of the dosing device 19 to the conveyor belt 21 and distributed thereon. By means of the electric drive motor's 24, the conveyor belt 21 with the grinding grains 10 arranged thereon is moved in the conveying direction 26, so that the grinding grains 10 are brought into the electrostatic field E. The transport speed in the conveying direction 26 can be adjusted by means of the electric drive motor 24.

By means of the electrostatic field E, the abrasive grains 10 are moved counter to the gravity FG TO the adhesive 11 or the adhesive surface and aligned along the field lines. If the abrasive grains 10 hit the adhesive surface, they remain there. The abrasive grain layer 12 is formed on the base body 2 by the adhering abrasive grains 10. In order to apply the abrasive grains 10 uniformly and homogeneously, the base body 2 is rotated about a central longitudinal axis 28 by means of the handling device 16.

After the grinding grain layer 12 has been applied to the basic body 2, the basic body 2 forms a semifinished product with the adhesive 11 and the grinding grain layer 12. The half tool is released from the handling device 16 and arranged in a heating device, where the adhesive 11 is cured. The cover bond 13 and the cover layer 14 are then applied to the Schleifkom layer 12 in a usual manner. With regard to further details and features of the grinding tool 1 and the electrostatic application of the grinding kömer 10 is expressly referred to WO 2018/149 483 A1, the content of which is incorporated here by reference.

A second exemplary embodiment of the invention is described below with reference to FIGS. 8 and 9. In contrast to the previous exemplary embodiment, the base body 2 comprises damping particles D. The damping particles D are, for example, rubber particles and / or foam particles. The damping particles D are incorporated into the base body 2 in the manufacture thereof. The damping particles D form additional connection-free areas V and themselves have noise and vibration damping properties.

The grinding tool 2 further comprises a support layer 29 which is connected to the base body 2 and which provides a surface for arranging the grinding layer 2. The support layer 29 is made of a metallic material. The support layer 29 is connected monolithically to the base body 2. For this purpose, the base layer 29 is produced together with the base body 2. This is illustrated in Figure 9. The support layer 29 is electrostatically coated with abrasive grains 10 before and / or after the connection to the base body 2 in the manner described. Regarding the further construction, the further production and the further functioning of the grinding tool 1, reference is made to the previous embodiment.

In general:

The grinding tool 1 according to the invention does not have a continuous or full-area binder compound within the base body 2, so that there are connection-free spaces or areas within the base body 2, such as, for example, inclusions of grease. The base body 2 has such an amount of binder B that on the one hand a relative movement is made possible within the base body 2, but on the other hand the base body 2 is sufficiently firm and does not delaminate during grinding. This is achieved by island-like or fine wetting of the fiber layers Fi. The free relative movement within the fiber layers Fi or the respective fiber layer Fi enables a high level of vibration and noise damping. Due to the fiber layers Fi connected to each other by means of the binder B and the possible relative movement within the respective fiber layer Fi, the structure of the base body 2 is such that it alternates between hard and soft layers. An additional rubber layer for It is not necessary to achieve a high level of vibration and noise damping. The shifting fiber layers Fi enable a high level of vibration and noise damping, but do not guarantee wrinkling. The base body 2 can be produced with any three-dimensional shape, in particular by draping the fiber layers Fi and connecting the fiber layers Fi with the binder B. The respective fiber layer Fi has a bilateral connection with the binder B, so that no delamination of the fiber layers Fi occurs. The B demittel B connects the individual fiber layers Fi, which are still flexible in itself. The binder B is, for example, an elastomer, which supports the vibration and noise damping of the basic body 2. The at least one fiber layer Fi is padded, for example. The at least one fiber layer Fi is coated, laminated, coated or silanized, for example, with the binder B. The respective fiber layer Fi is designed as a fabric or scrim. The fiber layers Fi within the base body 2 are designed as fabrics and / or scrims. For example, the fabric has a twill weave. A twill weave ensures movement or displacement within the weave as well as easy drapability. The fiber layers Fi are arranged in the base body 2 as inner fiber layers and / or outer fiber layers. The abrasive layer 3 can comprise an abrasive grain layer 12 or an abrasive fleece. The Schleifkom 10 is, for example, a coated ceramic grain. The base layer 29 serves as an intermediate layer between the base body 2 and the grinding layer 3. The base layer 29 can be designed as paper, foil and / or fabric. The support layer 29 is, for example, made of a metallic material. The base body 2 or the base layer 29 are preferably directly coated with Schleifkom 10.

Claims

1. Comprehensive grinding tool

- A base body (2) with

a binder (B),

- At least one in the binder (B) embedded fiber layer (Fi to F ₄ ) and

- an abrasive layer (3),

characterized,

that the at least one fiber layer (Fi to F ₄ ) in the binder (B) is partially movable.

2. Grinding tool according to claim 1, characterized in

that each fiber layer (Fi to F ₄ ) comprises a plurality of threads, which are embedded in the binding agent (B) in a partially movable manner.

3. Grinding tool according to claim 1 or 2, characterized in

that the base body (2) comprises a plurality of fiber layers (Fi to F ₄ ) embedded in the binder (B), which can be moved relative to one another in regions.

4. Grinding tool according to at least one of claims 1 to 3, characterized in that the base body (2) comprises a plurality of fiber layers (Fi to F ₄ ) with a plurality of threads, and the threads are embedded in the binding agent (B) in such a way that they can move relative to one another.

5. Grinding tool according to at least one of claims 1 to 4, characterized in that the at least one fiber layer (Fi to F ₄ ) comprises at least one fabric and / or at least one scrim.

6. Grinding tool according to at least one of claims 1 to 5, characterized in that the base body (2) comprises a number N of fiber layers (Fi to F ₄ ), where: 1 <N <12, in particular 2 <N <10, and in particular 4 <N <8.

7. Grinding tool according to at least one of claims 1 to 6, characterized in that that for a ratio M of a mass IU _{B of} the binder (B) to a mass IU _F of at least one fiber layer (Fi to F ₄ ) applies: 1/25 <M <1/2, in particular 1/20 <M <1 / 3, in particular 1/15 <M <1/4, and in particular 1/12 <M <1/6.

8. Grinding tool according to at least one of claims 1 to 7, characterized in that the base body (2) comprises damping particles (D), in particular rubber particles and / or foam particles.

9. Grinding tool according to at least one of claims 1 to 8, characterized in that the binder (B) is an organic adhesive, in particular phenolic resin, epoxy resin and / or rubber.

10. Grinding tool according to at least one of claims 1 to 9, characterized in that the base body (2) is curved.

11. Grinding tool according to at least one of claims 1 to 10, characterized in

by means of a base layer (29) connected to the base body (2), on which the grinding layer (3) is arranged.

12. Grinding tool according to at least one of claims 1 to 11, characterized in that the grinding layer (3) is three-dimensionally shaped.

13. A method of manufacturing a grinding tool comprising the steps:

- Providing at least one fiber layer (Fi to F ₄ ) and a binder (B),

- Generating a base body (2) by heating and then cooling the Bin demittels (B), wherein the at least one fiber layer (Fi to F ₄ ) after cooling in the binder (B) is partially movable, and

- Forming an abrasive layer (3).

14. The method according to claim 13, characterized in

that several fiber layers (Fi to F ₄ ) are used to produce the base body (2).

15. The method according to claim 13 or 14, characterized in

that the binder (B) is heated under pressure.

16. The method according to at least one of claims 13 to 15, characterized in that the provision is made such that the at least one fiber layer (Fi to F ₄ ) on one

Side and / or in some areas on two sides with the binder (B).

17. The method according to any one of claims 13 to 16, characterized in that the provision is made such that a first fiber layer (Fi, F ₄₎ adjacent without a binder (B) to a second binder (B) fiber layer (F ₂ provided , F ₃ ) is arranged.

18. The method according to at least one of claims 13 to 17, characterized in that the provision is made in such a way that the at least one fiber layer (Fi to F ₄ ) is arranged adjacent to a layer of binder (B).

19. The method according to at least one of claims 13 to 18, characterized in that a base layer (29) is arranged on the base body (2).

20. The method according to at least one of claims 13 to 19, characterized in that the formation of the abrasive layer (3) is carried out by electrostatic application of abrasive grains (10).