Grinding wheel and grinding method

Abstract

A grinding wheel includes an annular base, a plurality of pipe grindstones annularly arranged on the annular base, and a grinding water supply unit that supplies grinding water to the pipe grindstones. The grinding water supply unit includes a ring-shaped grinding water retaining part formed between a mount surface and an opposite surface of the annular base, a plurality of water supply holes opening in the mount surface, and a plurality of water feeding holes formed to allow communication between the grinding water retaining part and an inside of each of the pipe grindstones.

What is claimed is: 
     
         1 . A grinding wheel comprising:
 an annular base having a mount surface mounted to a spindle mount of a grinding apparatus;   a plurality of pipe grindstones annularly arranged on an opposite surface of the annular base opposite to the mount surface; and   a grinding water supply unit that supplies grinding water to the pipe grindstones,   wherein the grinding water supply unit includes
 a ring-shaped grinding water retaining part formed between the mount surface and the opposite surface of the annular base, 
 a plurality of water supply holes opening in 
 a plurality of water feeding holes formed to allow communication between the grinding water retaining part and an inside of each of the pipe grindstones. 
   
     
     
         2 . The grinding wheel according to  claim 1 , wherein the grinding water retaining part has at an inner circumferential surface thereof a ring-shaped annular opening that opens to atmosphere. 
     
     
         3 . A grinding method for grinding a workpiece by use of a grinding wheel including an annular base having a mount surface mounted to a spindle mount of a grinding apparatus, a plurality of pipe grindstones annularly arranged on an opposite surface of the annular base opposite to the mount surface, and a grinding water supply unit that supplies grinding water to the pipe grindstones, the grinding water supply unit including a ring-shaped grinding water retaining part formed between the mount surface and the opposite surface of the annular base, a plurality of water supply holes opening in the mount surface, and a plurality of water feeding holes formed to allow communication between the grinding water retaining part and an inside of each of the pipe grindstones, the grinding method comprising:
 supplying grinding water into each of the plurality of pipe grindstones;   temporarily retaining the grinding water in the grinding water retaining part by centrifugal force generated by rotation of the grinding wheel; and   grinding the workpiece by lower ends of the pipe grindstones while supplying the grinding water retained in the grinding water retaining part into each of the pipe grindstones from upper ends of the pipe grindstones.   
     
     
         4 . The grinding method according to  claim 3 , wherein the grinding water is supplied from the grinding water retaining part into each of the pipe grindstones, and grinding water overflowing from the grinding water retaining part is supplied to an outer circumferential surface of each of the pipe grindstones.