EP3504028B1 - Roughing grinding tool - Google Patents

Description

The invention relates to a roughing-grinding tool according to the preamble of claim 1, in particular for operating hand-held angle grinders.

In machining processes, roughing refers to the lifting of material with a large chip volume. Rough grinding tools should enable a high removal rate to achieve a short machining time and at the same time have a long service life.

From the EP 3 015 222 A1 a grinding wheel with a carrier plate and a plurality of grinding discs is known. The carrier plate is stepped in such a way that several ring sections are formed, to each of which a grinding disc is attached. In this way, the grinding discs form a multi-layer grinding disc package. The grinding wheel package forms an essentially frustoconically stepped recess. This enables the grinding wheel to be placed on a workpiece surface at different angles and to work through the grinding wheel package as completely as possible until the carrier plate hits the workpiece surface and the grinding wheel is worn.

From the EP 2 433 748 A2 , which forms the basis for the preamble of the independent claim, a flap disc is known which comprises a support disc with attached abrasive flaps. The carrier disk is made of a fiber-reinforced matrix material with abrasive grains embedded in it.

From the WO 2007/101 957 A2 a grinding wheel for deburring and cutting is known. The grinding wheel includes layers with abrasive grains and layers without abrasive grains.

From the DE 10 2013 212 666 A1 a method of making an abrasive is known.

The invention is based on the object of creating a robust roughing-grinding tool that is easy to manufacture and that has a high stock removal rate in conjunction with a long service life.

This object is achieved by a roughing-grinding tool with the features of claim 1. According to the invention, the support body is designed for rough grinding and comprises an abrasive grain. The support body thus serves on the one hand to support the at least one grinding disc during rough grinding and on the other hand itself for rough grinding, whereby a high level of robustness and a long service life of the roughing-grinding tool are achieved. The support body is designed in particular in such a way that it withstands the safety requirement "single-point side load" according to the German standard DIN EN 12413 "Safety requirements for abrasives made from bonded abrasives (May 2011 version). The support body is also simple in design and easy to manufacture. By the choice of abrasive grain a high stock removal rate is achieved for the material to be processed.

The roughing-grinding tool is designed, for example, as a grinding wheel or a cup wheel. The support body is preferably designed in the form of a disk and in particular has an offset. The roughing and grinding tool is easy to manufacture and robust. One as a rough grinding wheel The trained roughing-grinding tool can also be used universally. The support body and / or the at least one grinding disc and / or at least one of the grinding discs preferably have an offset.

The roughing-grinding tool has one or more grinding discs which is or are arranged on the support body. The grinding disc adjacent to the support body is attached to the support body by gluing and / or rivets and / or screws and / or stapling. If the roughing-grinding tool has several grinding discs, each additional grinding disc is attached to the grinding disc below by gluing and / or riveting and / or screws and / or stapling. The bonding takes place by means of an adhesive layer, which preferably comprises a resin.

The at least one grinding disc is fastened in the connection area and is not fastened in the working area surrounding the connection area. The roughing-grinding tool thus guarantees a high stock removal rate. If, for example, the roughing-grinding tool has several grinding discs, the grinding discs of a grinding disc pack are unconnected and unlaminated close to one another in the work area. Because the at least one grinding disc is not connected in the work area, it is removed in a simple manner from the grinding process after it has been worn out. The at least one grinding disc is made from coated abrasives. An abrasive grain is thus arranged on a carrier layer or a base by means of a binding agent. After the abrasive grain has worn out, targeted wear of the carrier layer or the base in the work area is achieved in the grinding process, so that an underlying grinding disc or the carrier body is in comes into engagement with the workpiece to be machined in a simple and quick manner. This results in a high stock removal rate and a high level of aggressiveness in the roughing and grinding tool. The working area of the at least one grinding wheel is designed to be essentially ring-shaped or disk-shaped.

The at least one grinding disc each has at least one grinding layer with oriented abrasive grain and / or non-oriented abrasive grain. The abrasive grain is selected in particular from diamond, cubic boron nitride (CBN), silicon carbide (SiC), natural corundum and / or synthetic corundum. The corundum is, for example, zirconium corundum and / or aluminum oxide (Al ₂ O ₃ ).

A roughing-grinding tool according to claim 2 ensures a long service life. The abrasive grain is bound by means of a binding agent and forms a grinding layer or a grinding area. The binder is in particular a synthetic resin such as phenolic resin. The grinding layer preferably has a thickness in the direction of an axis of the roughing-grinding tool which corresponds to a thickness of the support body. This means that the support body forms the grinding layer over its entire thickness. The abrasive grain is selected in particular from diamond, cubic boron nitride (CBN), silicon carbide (SiC), natural corundum and / or synthetic corundum. The corundum is, for example, zirconium corundum and / or aluminum oxide (Al ₂ O ₃ ). The grinding layer or the grinding area is formed at least on an upper side and / or on an underside of the support body. The abrasive grain of the support body is identical and / or different from an abrasive grain of the at least one grinding disc. The grinding layers or the grinding areas of the Carrier bodies have an identical abrasive grain or different abrasive grain.

A roughing-grinding tool according to claim 3 ensures a long service life. The support body preferably has two support body reinforcements adjacent to the outer sides of the support body, that is to say adjacent to the upper side and the underside of the support body. The at least one support body reinforcement is connected to the support body by means of a binding agent or a resin. The outer support body reinforcements are impregnated with the binder or resin, for example. The outer support body reinforcements are preferably designed as a fabric, in particular as a glass fabric or glass fiber fabric.

A roughing-grinding tool according to claim 4 ensures a long service life. The support body preferably has an inner support body reinforcement which is embedded in the grinding layer or the grinding area. The inner support body reinforcement is penetrated by the bonded abrasive grain.

A roughing-grinding tool according to claim 5 ensures a high level of robustness and a long service life. The outer diameter of the carrier body preferably corresponds to the outer diameter of the grinding wheel.

A roughing-grinding tool according to claim 6 has an extremely long service life. The at least one grinding wheel, in particular a grinding wheel package formed from a plurality of grinding wheels, is arranged between two support bodies which each include an abrasive grain for rough grinding. The support bodies are constructed identically or differently. The first support body is arranged on an upper side with the adjacent one connected to the first grinding wheel of a grinding wheel package, whereas the second support body is connected on an underside to the adjacent last grinding wheel of the grinding wheel package.

A roughing-grinding tool according to claim 7 ensures a high level of robustness and a long service life. The grinding discs of the grinding disc pack are arranged in layers on top of one another.

A roughing-grinding tool according to claim 8 ensures simple manufacture. The grinding discs are arranged one above the other in a simple manner and adjacent grinding discs are connected to one another. The connection takes place in particular by gluing. Adjacent grinding discs are preferably connected to one another in an internal connecting area and are not connected to one another in a working area surrounding the connecting area. The support body and the grinding wheel package are therefore easy to manufacture.

A roughing-grinding tool according to claim 9 ensures simple manufacture. The first grinding disc is attached directly to the support body, whereas the second grinding disc is attached exclusively to the first grinding disc. The second grinding wheel is therefore not directly but only indirectly connected to the support body. The connection is made in particular by gluing. The grinding blanks preferably have an inner connecting area in which the first grinding blanks are connected to the support body and the second grinding blanks are connected to the first grinding blanks, and a working area surrounding the connecting area in which the grinding blanks are not connected.

A roughing-grinding tool according to claim 10 ensures a high stock removal rate. The directed abrasive grain results in a high level of aggressiveness and a high removal rate. In particular, this enables the roughing-grinding tool to be used flat. The abrasive grain is preferably made of diamond, cubic boron nitride (CBN), silicon carbide (SiC), natural corundum and / or synthetic corundum. The corundum is, for example, zirconium corundum and / or aluminum oxide (Al ₂ O ₃ ).

A roughing-grinding tool according to claim 11 ensures a high level of robustness. The grinding wheel reinforcement achieves a high level of strength against tearing of the respective grinding wheel. The grinding wheel reinforcement is attached to the at least one grinding wheel in at least one work area. The grinding wheel reinforcement is preferably attached to the at least one grinding wheel over the entire surface, that is to say in a work area and a connection area. The grinding wheel reinforcement is in particular attached to a rear side of the at least one grinding wheel. The grinding wheel reinforcement is preferably attached to the back of the grinding wheel by means of a binding agent, for example phenolic resin. In particular, a grinding wheel reinforcement is attached to each of the grinding discs. The grinding wheel reinforcement is connected, for example, to the rear or underside of the grinding wheel by means of a resin. Preferably, all grinding discs are connected to an associated grinding disc reinforcement. If necessary, only individual grinding discs can be connected to a grinding disc reinforcement. A grinding wheel reinforcement is preferably attached to a rear side or underside of the at least one grinding wheel and / or embedded in a grinding layer of the at least one grinding wheel. The binding agent, in particular the resin, for fastening the grinding wheel reinforcement also serves, in particular, to attach the grinding disc to the support body or to the grinding disc lying underneath.

A roughing-grinding tool according to claim 12 ensures simple manufacture. The at least one grinding disc is made from coated abrasives. The backing forms a carrier layer for the abrasive grain placed on it. The carrier layer is designed in particular as paper, volcanic fiber, fleece and / or as a carrier textile, such as, for example, as a woven fabric and / or scrim. The abrasive grain is arranged in a directional and / or non-directional manner on the carrier layer. The abrasive grain is bonded to the backing layer by means of a binder. In addition, a cover layer or cover bond can be arranged on the abrasive grain. The carrier textile preferably comprises polyester fibers, cotton fibers and / or glass fibers and is in particular a polyester-cotton mixture. The roughing and grinding tool thus guarantees easy production and a long service life. The carrier textile is in particular a carrier fabric with at least one thread in a warp and a weft direction. The carrier textile is preferably designed as a polyester and cotton blend.

A roughing-grinding tool according to claim 13 ensures a long service life. The at least one grinding wheel is stiffened with a filling resin, so that a cyclical deflection of the at least one grinding wheel is reduced when a workpiece is being machined. Due to a pronounced cyclical deflection, the abrasive grain is torn from the base before the abrasive grain is worn out and has reached its material removal potential. In addition, the abrasive layer is weakened by torn abrasive grains, since neighboring abrasive grains can no longer support each other. The stiffening creates a pronounced cyclic deflection prevented. The stiffening takes place by subsequently adding a filling resin to the grinding discs, which are formed from abrasive on a backing, and then curing the filling resin. The filling resin is selected, for example, from the group consisting of thermosets, elastomers, synthetic resins and / or thermoplastics and combinations thereof. The filling resin is preferably a thermoset, such as phenolic resin. The grinding discs are provided or soaked with the filling resin in a simple manner after they have been connected to the support body or to a grinding disc lying underneath. The at least one grinding wheel is preferably immersed in a bath with filling resin.

A roughing-grinding tool according to claim 14 ensures a high level of robustness and a long service life. The at least one support body reinforcement and / or the respective grinding wheel reinforcement is preferably a fabric, in particular a glass fiber fabric.

A roughing-grinding tool according to claim 15 ensures a long service life. The at least one grinding layer of the respective grinding wheel comprises an abrasive grain. Each grinding disc can have a grinding layer on an underside facing the carrier body and / or an upper side facing away from the carrier body. All grinding discs preferably have a grinding layer on the respective top side and / or the respective bottom side. The grinding layers of the respective grinding wheel are formed from an identical abrasive grain or different abrasive grain. Furthermore, the grinding layers of different grinding discs are formed from identical abrasive grain and / or from different abrasive grain.

Fig. 1

eine schematische Schnittansicht eines Schrupp-Schleifwerkzeugs gemäß einem ersten Ausführungsbeispiel,

Fig. 2

eine Explosionsdarstellung des Schrupp-Schleifwerkzeugs in Fig. 1 zur Veranschaulichung des Aufbaus,

Fig. 3

eine vergrößerte Schnittansicht eines Tragkörpers sowie einer ersten Schleifronde und einer zugehörigen ersten SchleifrondenArmierung des Schrupp-Schleifwerkzeugs in Fig. 1,

Fig. 4

eine schematische Schnittansicht eines Schrupp-Schleifwerkzeugs gemäß einem zweiten Ausführungsbeispiel, und

Fig. 5

eine vergrößerte Schnittansicht eines Tragkörpers sowie einer ersten Schleifronde und einer zugehörigen ersten SchleifrondenArmierung des Schrupp-Schleifwerkzeugs in Fig. 1 bzw. 4.

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

Fig. 1

a schematic sectional view of a roughing-grinding tool according to a first embodiment,

Fig. 2

an exploded view of the roughing and grinding tool in Fig. 1 to illustrate the structure,

Fig. 3

an enlarged sectional view of a support body and a first grinding disc and an associated first grinding disc armor of the roughing-grinding tool in FIG Fig. 1 ,

Fig. 4

a schematic sectional view of a roughing-grinding tool according to a second embodiment, and

Fig. 5

an enlarged sectional view of a support body and a first grinding disc and an associated first grinding disc armor of the roughing-grinding tool in FIG Fig. 1 or 4.

The following is based on the Figs. 1 to 3 a first embodiment described. A roughing-grinding tool 1 is a roughing-grinding wheel and has a disk-shaped or plate-shaped support body 2 and a grinding wheel package 3. The support body 2 and the grinding wheel package 3 form a through opening 5 for fastening a tool drive concentrically to a common axis M. The support body 2 forms an annular crank 6. A flat working area 7 is arranged radially outside the crank 6, whereas a connection area 8 and a clamping area 9 are arranged radially inside the crank 6. Alternatively, the roughing grinding wheel can be made flat.

The grinding wheel package 3 has a number N of grinding wheels S and associated grinding wheel reinforcements A, where the following applies to the number N: 1 N 9, in particular 2 N 8, and in particular 3 N 7. In Fig. 2 a grinding wheel package 3 with four grinding wheels and four associated grinding wheel armatures is shown by way of example, the grinding wheel being designated in detail with S ₁ to S ₄ and the associated grinding wheel armoring with A ₁ to A ₄ . The respective grinding wheel reinforcement A ₁ to A ₄ is attached to a rear side 10 of the respective associated grinding wheel S ₁ to S ₄ . Fastening takes place, for example, over the entire surface by means of a binding agent such as a phenolic resin. The respective grinding wheel reinforcement A ₁ to A ₄ is provided at least in the working area 7 of the respective grinding wheel S ₁ to S ₄ and is attached to the rear 10 over the entire surface. The respective grinding wheel reinforcement A ₁ to A ₄ is, for example, a fabric made of glass fibers and / or a fabric made of jute fibers.

The first grinding wheel S ₁ with the associated first grinding wheel reinforcement A ₁ is fastened in the connecting area 8 to the support body 2. Fastening takes place in particular by gluing. For example a circumferential adhesive layer 4 is applied in the connection area 8 near the crank 6, by means of which the first grinding blank S ₁ including the associated grinding blank reinforcement A ₁ is glued. The adhesive layer 4 is formed in particular by the binding agent or resin with which the grinding wheel reinforcement A _{1 is} attached to the grinding wheel S ₁ . The second grinding wheel S ₂ including the associated second grinding wheel armoring A ₂ is attached to the first grinding wheel S ₁ in the connecting area 8. Fastening takes place in particular by gluing. For example, a circumferential adhesive layer 4 is applied in a corresponding manner in the connection area 8 near the crank 6, by means of which the gluing takes place. The bonding of the grinding wheel S ₂ to the grinding wheel S ₁ underneath is carried out in particular with the binding agent or resin, which is also used to attach the grinding wheel reinforcement A ₂ to the grinding wheel S ₂ . In a corresponding manner, the third grinding wheel S ₃ with the associated third grinding wheel armoring A _{3 is} attached to the second grinding wheel S ₂ and the fourth grinding wheel S ₄ with the associated fourth grinding wheel armoring A _{4 is} attached to the third grinding wheel S ₃ . The first grinding wheel S ₁ with the associated grinding wheel armoring A ₁ is thus attached to the support body 2, whereas the other grinding wheels S ₂ to S ₄ with the associated grinding wheel armoring A ₂ to A _{4 are} attached to the grinding wheel S ₁ to S below _{3 are} attached. The grinding discs S ₂ to S ₄ with the associated grinding disc reinforcements A ₂ to A ₄ are therefore not attached directly to the support body 2. In the work area 7, the grinding discs S ₁ to S ₄ with the associated grinding _{disc reinforcements A 1} to A _{4 are} unsecured or unconnected and lie close to one another without a lamination.

The support body 2 has a support body outer diameter D _T and the grinding discs S ₁ to S ₄ with the associated grinding disc armatures A ₁ to A _{4 have} a grinding disc outer diameter Ds, where preferably: 0.1 · D _S D _T 1.2 · D _S , in particular 0.5 · D _S D _T 1.1 · D _S , and in particular 0.8 · D _S D _T D _S. In the embodiment according to Fig. 2 The following applies as an example: D _T ≈ D _S.

The grinding discs S ₁ to S ₄ are made of abrasive on a backing. The grinding discs S ₁ to S ₄ comprise a backing layer 11 to which a directional abrasive grain 13 is bound by means of a binding agent 12. A cover layer 14 is formed on the directed abrasive grain 13. The carrier layer 11 forms the rear side 10 for fastening the respective grinding wheel reinforcement A ₁ to A ₄ . The binding agent 12 with the abrasive grain 13 and the cover layer 14 forms a respective grinding layer 17 of the grinding discs S ₁ to S ₄ . The grinding layer 17 is arranged on an upper side of the respective grinding disc S ₁ to S ₄ facing away from the support body 2. Alternatively or additionally, the grinding layer 17 can be arranged on an underside facing the support body 2. A grinding layer 17 is preferably arranged on an upper side and on a lower side, so that working on both sides is made possible.

The carrier layer 11 is designed, for example, as paper, vulcanized fiber, fleece and / or as a carrier textile. A carrier textile preferably comprises polyester fibers, cotton fibers and / or glass fibers. The carrier layer 11 is designed in particular as a polyester-cotton blend fabric. The binder 12 is, for example, a synthetic resin, in particular phenolic resin. The directed abrasive grain 13 is, for example, a diamond abrasive grain. The abrasive grain 13 is selected in particular from diamond, cubic boron nitride (CBN), silicon carbide (SiC), and natural corundum and / or synthetic corundum. The corundum is, for example, zirconium corundum and / or aluminum oxide (Al ₂ O ₃ ).

The support body 2 is designed for rough grinding. It comprises an abrasive grain 16 bound by means of a binding agent 15 and support body reinforcements 18 and 19. The abrasive grain 16 is selected, for example, from diamond, cubic boron nitride (CBN), silicon carbide (SiC), natural corundum and / or synthetic corundum. The corundum is, for example, zirconium corundum and / or aluminum oxide (Al ₂ O ₃ ). The outer support body reinforcements 18 are arranged adjacent to an upper side 20 facing _{the first grinding disc S 1 and an underside 21 facing away from the grinding disc S 1} , whereas the inner support body reinforcement 19 is embedded in the support body 2 and from the binding agent 15 and the abrasive grain 16 is interspersed. The support body 2 has a support body thickness d _T in the direction of the axis M, with which the support body 2 forms a rough grinding layer or grinding layer 22. The support body reinforcements 18, 19 are preferably designed as a fabric. The fabric includes in particular glass fibers and / or jute fibers.

The following is based on the Fig. 4 a second embodiment of the invention described. In contrast to the first exemplary embodiment, the roughing-grinding tool 1 embodied as a roughing-grinding wheel has a second support body 23, so that the grinding wheel package 3 is arranged between the first support body 2 and the second support body 23. The second support body 23 is designed identically to the first support body 2. The second support body 23 is oriented in the same way as the first support body 2 and is fastened _{in the connection area 8 to the last grinding blank S 4.} Fastening takes place in particular by gluing. In addition, the grinding _{discs S 1} to S _{4 have} a filling resin 24 impregnated, which stiffens the grinding discs S ₁ to S _{4 after hardening.} The filling resin 24 is thus additionally introduced into the grinding discs S ₁ to S _4, which are formed from grinding media on a support. For this purpose, the roughing-grinding tool 1 is _{impregnated with the filler resin 24, for example after the grinding discs S 1} to S _{4 have been} attached, preferably by immersion in a bath of filler resin 24. The filler resin 24 is, for example, a synthetic resin, preferably phenolic resin. The filling resin 24 soaks in particular the carrier layer 11 and stiffens the threads contained therein. With regard to the further structure, reference is made to the description of the first exemplary embodiment.

In Figure 5 a third embodiment is described, which can also be combined with the first two embodiments. The grinding _{discs S 1} to S ₄ each form two grinding layers 17 so that the respective grinding disc reinforcement A ₁ to A ₄ is embedded in the associated grinding disc S ₁ to S _4. One of the grinding layers 17 faces the support body 2 or 23, whereas the other grinding layer 17 faces away from the support body 2 or 23. This means that the grinding layers 17 are formed on an upper side and on a lower side of the respective grinding disc S ₁ to S ₄ . This enables both sides to work with the roughing-grinding tool 1. With regard to the further structure, reference is made to the first exemplary embodiment.

The support body 2 or the support bodies 2, 23 serve according to the invention to support the grinding wheel pack 3 and at the same time themselves for rough grinding. The fact that the grinding discs S ₁ to S ₄ with the associated grinding _{disc reinforcements A 1} to A _{4 are not connected} in the work area 7 and lie close to one another without a lamination, a targeted wear is made possible, so that in the grinding process continuously unworn Abrasive grain 13 comes into grinding engagement. The directed abrasive grain 13 achieves a high removal rate and a high level of aggressiveness, so that the roughing-grinding tool 1 can be used with the advantages according to the invention in particular even at flat angles of attack. The supporting body 2 or the supporting bodies 2, 23 themselves have the properties of a roughing-grinding tool, in particular a roughing-grinding wheel. The roughing-grinding tool 1 is designed, for example, as a roughing-grinding wheel or as a roughing-grinding cup. If necessary, an additional paper separating layer can be provided between a grinding wheel reinforcement and one of the neighboring grinding wheels.

Claims (15)

1. A roughing grinding tool having

   - a supporting body (2, 23), whereas the supporting body (2, 23) comprises an abrasive grain (16) for roughing grinding, and

   - a trough-opening (5) for fastening a tool drive,

   characterized by at least one abrasive circle (S₁ to S₄), whereas the at least one abrasive circle (S₁ to S₄) forms a joining region (8) and a working region (7) surrounding the joining region (8), and the at least one abrasive circle (S₁ to S₄) is fastened in the joining region (8) and is unfastened in the working region (7).
2. The roughing grinding tool as claimed in claim 1, characterized in that the supporting body (2, 23) forms an abrasive region (22) that comprises the abrasive grain (16) bonded by means of a bonding agent (15).
3. The roughing grinding tool as claimed in claim 1 or 2, characterized in that the supporting body (2, 23) comprises at least one supporting-body reinforcement (18), which is arranged in particular next to a top side (20) and/or underside (21) of the supporting body (2, 23).
4. The roughing grinding tool as claimed in claim 3, characterized in that at least one supporting-body reinforcement (19) is embedded in the abrasive region (22).
5. The roughing grinding tool as claimed in one of claims 1 to 4, characterized
   in that the supporting body (2, 23) has a supporting-body outside diameter D_T and the at least one abrasive circle (S₁ to S₄) has an abrasive circle outside diameter D_S, wherein: 0.1·D_S ≤ D_T ≤ 1.2·D_S, in particular 0.5·D_S ≤ D_T ≤ 1.1·D_S, and in particular 0.8·D_S ≤ D_T ≤ D_S.
6. The roughing grinding tool as claimed in one of claims 1 to 5, characterized
   in that the at least one abrasive circle (S₁ to S₄) is arranged between a first supporting body (2) and a second supporting body (23).
7. The roughing grinding tool as claimed in one of claims 1 to 6, characterized
   in that, for a number N of the at least one abrasive circle (S₁ to S₄): 1 ≤ N ≤ 9, in particular 2 ≤ N ≤ 8, and in particular 3 ≤ N ≤ 7.
8. The roughing grinding tool as claimed in one of claims 1 to 7, characterized
   in that a plurality of abrasive circles (S₁ to S₄) are arranged one on top of another, wherein a first abrasive circle (S₁) is fastened to the supporting body (2) and each further abrasive circle (S₂ to S₄) is fastened to an underlying abrasive circle (S₁ to S₃).
9. The roughing grinding tool as claimed in one of claims 1 to 8, characterized
   in that a first abrasive circle (S₁) is fastened to the supporting body (2) and a second abrasive circle (S₂) is fastened to the first abrasive circle (S₁).
10. The roughing grinding tool as claimed in one of claims 1 to 9, characterized
    in that the at least one abrasive circle (S₁ to S₄) has an oriented abrasive grain (13).
11. The roughing grinding tool as claimed in one of claims 1 to 10, characterized
    in that an abrasive circle reinforcement (A₁ to A₄) is fastened to at least part of the surface of the at least one abrasive circle (S₁ to S₄).
12. The roughing grinding tool as claimed in one of claims 1 to 11, characterized
    in that the at least one abrasive circle (S₁ to S₄) comprises a backing layer (11) with abrasive grain (13) arranged thereon, wherein the backing layer (11) is configured in particular as paper, vulcanized fiber, nonwoven and/or backing textile.
13. The roughing grinding tool as claimed in one of claims 1 to 12, characterized
    in that the at least one abrasive circle (S₁ to S₄) is stiffened with a filling resin (24).
14. The roughing grinding tool as claimed in one of claims 3 to 13, characterized
    in that the at least one supporting-body reinforcement (18, 19) and/or the abrasive circle reinforcement (A₁ to A₄) comprises glass fibers and/or jute fibers.
15. The roughing grinding tool as claimed in one of claims 1 to 14, characterized
    in that the at least one abrasive circle (S₁ to S₄) forms in each case at least one abrasive layer (17), which is arranged in particular on a top side and/or on an underside of the at least one abrasive circle (S₁ to S₄).

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