Vitrified grinding stone and method of manufacturing the same

Abstract

A vitrified grinding stone includes an abrasive grain and a vitrified binder. The vitrified grinding stone has a porosity, a degree of concentration of abrasive grains and an abrasive grain diameter according to a preset processing efficiency and a processing precision of grinding.

1 . A vitrified grinding stone comprising: 
 an abrasive grain; and    a vitrified binder,    wherein the vitrified grinding stone has a porosity, a degree of concentration of abrasive grains and an abrasive grain diameter according to a preset processing efficiency and a processing precision of grinding.    
   
   
       2 . The vitrified grinding stone according to  claim 1 , wherein when said processing precision of grinding ranges from 0.1 to 1.6 Rz (μm), the processing efficiency of grinding ranges from 0.1 to 2.0 mm 3 /(mm·sec).  
   
   
       3 . The vitrified grinding stone according to  claim 1 , wherein said porosity ranges from 30 to 70 volume percent with respect to a volume of the whole grinding stone.  
   
   
       4 . The vitrified grinding stone according to  claim 1 , wherein said porosity comprises a forced porosity based on burnout pores formed by burning out a pore-forming material.  
   
   
       5 . The vitrified grinding stone according to  claim 4 , wherein said forced porosity ranges from 5 to 35 volume percent with respect to a volume of the whole grinding stone.  
   
   
       6 . The vitrified grinding stone according to  claim 4 , wherein said pore-forming material has a size 0.1 to 3 times the average grain diameter of the abrasive grain.  
   
   
       7 . The vitrified grinding stone according to any of claims  1 , wherein a ratio of pores having a size 1 to 3 times an average grain diameter of the abrasive grain in a volume of whole pores ranges from 20 to 70 volume percent.  
   
   
       8 . The vitrified grinding stone according to  claim 1 , wherein a ratio of pores having a size 0.1 to 1 time an average grain diameter of the abrasive grain in a volume of whole pores ranges from 30 to 70 volume percent.  
   
   
       9 . The vitrified grinding stone according to  claim 4 , wherein said pore-forming material is a polymer compound.  
   
   
       10 . The vitrified grinding stone according to of  claim 1 , wherein said abrasive grain has an average grain diameter ranging from 10 to 90 μm.  
   
   
       11 . The vitrified grinding stone according to  claim 1 , wherein said degree of concentration of abrasive grains ranges from 50 to 160.  
   
   
       12 . The vitrified grinding stone according to  claim 1 , wherein said abrasive grain is a cubic boron nitride abrasive grain.  
   
   
       13 . A vitrified grinding stone comprising: 
 an abrasive grain; and    a vitrified binder,    wherein a ratio of pores having a size 1 to 3 times an average grain diameter of the abrasive grain in a volume of whole pores ranges from 20 to 70 volume percent.    
   
   
       14 . A vitrified grinding stone comprising: 
 an abrasive grain; and    a vitrified binder,    wherein a ratio of pores having a size 0.1 to 1 time an average grain diameter of the abrasive grain in a volume of whole pores ranges from 30 to 70 volume percent.    
   
   
       15 . The vitrified grinding stone according to  claim 13 , wherein said abrasive grain has an average grain diameter ranging from 10 to 90 μm.  
   
   
       16 . The vitrified grinding stone according to  claim 13 , wherein the degree of concentration of said abrasive grains ranges from 50 to 160.  
   
   
       17 . A method of manufacturing a vitrified grinding stone comprising an abrasive grain and a vitrified binder, the method comprising: 
 setting a processing efficiency and a processing precision of grinding; and    setting a porosity, a degree of concentration of abrasive grains and an abrasive grain diameter according to the processing efficiency and the processing precision.    
   
   
       18 . The method of manufacturing according to  claim 17 , wherein said processing precision of grinding is set within a range of 0.1 to 1.6 Rz (μm) and said processing efficiency of grinding is set within a range of 0.1 to 2.0 mm 3 /(mm·sec).  
   
   
       19 . The method of manufacturing according to  claim 17 , wherein said porosity is set within a range of 30 to 70 volume percent with respect to a whole volume of the grinding stone.  
   
   
       20 . The method of manufacturing according to  claim 17 , wherein said porosity comprises a forced porosity based on burnout pores formed by burning out a pore-forming material.  
   
   
       21 . The method of manufacturing according to  claim 20 , wherein said forced porosity is set within a range of 5 to 35 volume percent with respect to a whole volume of the grinding stone.  
   
   
       22 . The method of manufacturing according to  claim 20 , wherein a pore-forming material having a size 0.1 to 3 times an average grain diameter of the abrasive grain is employed as said pore-forming material.  
   
   
       23 . The method of manufacturing according to  claim 17 , wherein a polymer compound is employed as said pore-forming material.  
   
   
       24 . The method of manufacturing according to  claim 17 , wherein an abrasive grain having an average grain diameter ranging from 10 to 90 μm is employed as said abrasive grain.  
   
   
       25 . The method of manufacturing according to  claim 17 , wherein said degree of concentration of abrasive grains is set within a range of 50 to 160.  
   
   
       26 . The method of manufacturing according to  claim 17 , wherein a cubic boron nitride abrasive grain is employed as said abrasive grain.  
   
   
       27 . The vitrified grinding stone according to  claim 14 , wherein said abrasive grain has an average grain diameter ranging from 10 to 90 μm.  
   
   
       28 . The vitrified grinding stone according to  claim 2 , wherein said porosity ranges from 30 to 70 volume percent with respect to a volume of the whole grinding stone.