Lapping plate-conditioning grindstone segment, lapping plate-conditioning lapping machine, and method for conditioning lapping plate

Abstract

In a lapping machine comprising a lapping plate and a conditioning carrier disposed thereon, the carrier being provided with bores for receiving conditioning grindstone segments, the lapping plate is polished and conditioned by cooperatively rotating the lapping plate and the carrier and feeding loose abrasive grains to the lapping plate. The conditioning grindstone segment of a shape of arcuated trapezoid having an included angle of 180°-90° is fitted in the carrier bore.

1 . In connection with a lapping machine comprising a lapping plate and a conditioning carrier disposed on the lapping plate, the carrier being provided with at least one bore for receiving a conditioning grindstone segment, wherein the lapping plate is polished and conditioned by cooperatively rotating the lapping plate and the carrier and feeding loose abrasive grains to the lapping plate,
 the conditioning grindstone segment which is fitted in the bore in the carrier has a shape of arcuated trapezoid defining an included angle of 180° to 90° with respect to the center of the corresponding circle.   
   
   
       2 . The conditioning grindstone segment of  claim 1  wherein the shape of the conditioning grindstone segment has a radial width of 10 to 20% of the diameter of the circle. 
   
   
       3 . The conditioning grindstone segment of  claim 1 , which has a Rockwell hardness (HRS) of 80 to 150. 
   
   
       4 . The conditioning grindstone segment of  claim 1 , which is microporous. 
   
   
       5 . The conditioning grindstone segment of  claim 1 , which is a synthetic resin bond grindstone segment. 
   
   
       6 . The conditioning grindstone segment of  claim 5 , which has a microporosity of 50 to 90%. 
   
   
       7 . The conditioning grindstone segment of  claim 5 , which is a microporous polyurethane bond grindstone segment having a pore size of 20 to 150 μm. 
   
   
       8 . The conditioning grindstone segment of  claim 5 , which has abrasive grains distributed and bonded therein, said abrasive grains being the same as loose abrasive grains used in lapping of workpieces. 
   
   
       9 . The conditioning grindstone segment of  claim 8  wherein the abrasive grains are present in an amount of 20 to 50% by weight of the grindstone. 
   
   
       10 . The conditioning grindstone segment of  claim 1 , which is a cast iron grindstone segment. 
   
   
       11 . The conditioning grindstone segment of  claim 10 , which has a microporosity of 10 to 50%. 
   
   
       12 . A lapping plate-conditioning lapping machine comprising a lapping plate and a conditioning carrier disposed on the lapping plate, the carrier being provided with at least one bore for receiving a conditioning grindstone segment, wherein the lapping plate is polished and conditioned by cooperatively rotating the lapping plate and the carrier and feeding loose abrasive grains to the lapping plate,
 the conditioning grindstone segment of  claim 1  being fitted in the bore in the carrier.   
   
   
       13 . The lapping plate-conditioning lapping machine of  claim 12  wherein the carrier is provided with 2 to 20 circumferentially spaced apart bores each for receiving a conditioning grindstone segment so that the conditioning grindstone segments fitted in the bores figure a petal shape as a whole. 
   
   
       14 . In connection with a lapping machine comprising a lapping plate and a conditioning carrier disposed on the lapping plate, the carrier being provided with at least one bore for receiving a conditioning grindstone segment, wherein the lapping plate is polished and conditioned by cooperatively rotating the lapping plate and the carrier and feeding loose abrasive grains to the lapping plate,
 a method for conditioning the lapping plate using the conditioning lapping machine of  claim 12 .   
   
   
       15 . A method for conditioning the lapping plate according to  claim 14 , further comprising feeding loose abrasive grains to the lapping plate during the conditioning operation.