Grinding tool

Abstract

A grinding tool for grinding at least one hard-coated brake disc. The grinding tool includes a base body and a grinding layer, and the grinding layer includes diamond grains and CBN grains. The diamond grains and CBN grains are bonded multi-layered in a sintered metal bond and/or resinoid bond in the grinding layer. A grain mixing ratio between the diamond grains and the CBN grains is substantially 1:1, and the grain sizes of the diamond grains and/or the CBN grains are more than 50 μm.

1 . A grinding tool for grinding at least one hard-coated brake disc, wherein the grinding tool comprises:
 a base body and a grinding layer,   wherein the grinding layer comprises diamond grains and CBN grains,   wherein the diamond grains and CBN grains are bonded multi-layered in a sintered metal bond and/or resinoid bond in the grinding layer,   wherein a grain mixing ratio between the diamond grains and the CBN grains is substantially 1:1, and   wherein the grain sizes of the diamond grains and/or the CBN grains are more than 50 μm.   
     
     
         2 . The grinding tool according to  claim 1 , wherein the grain sizes of the diamond grains and/or the CBN grains are 51 μm to 300 μm, preferably 91 μm to 252 μm. 
     
     
         3 . The grinding tool according to  claim 1 , wherein the grain size ratio between the CBN grains and the diamond grains is from 0.3 to 2.8, preferably from 0.5 to 1.0. 
     
     
         4 . The grinding tool according to  claim 1 , wherein the grinding layer is formed annular, in particular wherein:
 an outside diameter is 200 to 900 mm, preferably 260 to 800 mm, and/or   a layer width is 5 to 40 mm, preferably 15 to 25 mm, and/or   a layer height is 5 to 20 mm, preferably 6 to 10 mm,   and/or wherein the grinding layer has a grinding surface which is formed substantially flat and/or is arranged orthogonal to an axis of rotation of the grinding tool.   
     
     
         5 . The grinding tool according to  claim 1 , wherein the grinding layer is formed of segments, which are preferably spaced apart from each other by slits, in particular wherein the slits run substantially radially with respect to an axis of rotation of the grinding tool. 
     
     
         6 . The grinding tool according to  claim 1 , wherein the grinding layer is applied to the base body by sintering, soldering, welding and/or by a binder, preferably adhesive. 
     
     
         7 . The grinding tool according to  claim 1 , wherein the base body is formed cup-shaped with a base and a side wall adjoining the base, preferably wherein the base has a centrally arranged drilled hole. 
     
     
         8 . The grinding tool according to  claim 1 , wherein the base body consists of metal, in particular steel and/or aluminum. 
     
     
         9 . An arrangement comprising:
 at least two grinding tools, each of the grinding tools corresponding to the grinding tool according to  claim 1 , and   at least one workpiece to be machined by the at least two grinding tools, in particular a hard-coated brake disc,   preferably wherein the workpiece to be machined is arranged between the at least two grinding tools, particularly preferably wherein the at least two grinding tools are aligned symmetrically with respect to the workpiece and the grinding layers of the at least two grinding tools are facing the workpiece.   
     
     
         10 . A method for machining a workpiece, preferably a hard-coated brake disc, in an arrangement according to  claim 9 , wherein the, preferably rotating, workpiece is ground, preferably on both sides, by the at least one grinding tool, preferably the at least two grinding tools, by means of rotation of the grinding tool or the grinding tools about their respective axes of rotation. 
     
     
         11 . The method for producing the grinding tool according to  claim 1 :
 providing a base body;   providing a grinding layer, preferably formed of segments, comprising diamond grains and CBN grains;   wherein a grain mixing ratio between the diamond grains and the CBN grains is substantially 1:1, and   wherein the grain sizes of the diamond grains and/or the CBN grains are more than 50 μm; and   applying, preferably by sintering and/or gluing, the grinding layer to the base body or to a carrier body fastened to the base body.   
     
     
         12 . The method according to  claim 11 , wherein the provision of the grinding layer comprises:
 providing a mixture of the diamond grains, CBN grains, the metal bond and/or resinoid bond and preferably the fillers; and   compressing the mixture, in particular under controlled pressure and/or temperature conditions.   
     
     
         13 . A use of the grinding tool according to  claim 1  for grinding at least one hard-coated brake disc.