補強砥石の設計

補強の限界と最適補強径

抄録

A design principle is proposed on the reinforced vitrified grinding wheels with harder grade material or resin-penetration around the arbor hole. And, through this design procedure, an adequate combination of two wheel materials to be used and an appropriate dimensions (inner-outer diameter ratio a and reinforced material diameter ratio f) are discussed for getting larger increasing ratio R in centrifugal bursting speed by reinforcement. Main results are as follows:
1) The maximum value R_max of R grows larger with decreased a and this enables to manufacture the wheel having larger bursting speed than that of the inner material. The optimum value f_max of. f resulting in R_max comes near the inner diameter when a<0.5, but near the outer diameter when a>0.5. f_max and R_max vary by the Young's modulus ratio A and the density ratio B of the outer material to the inner material.
2) For the reinforcement A<1 and B<1 are necessary, and for getting the maximum profits by reinforcement A_??_0.8 and B_??_0.9 are recommended from considerations of qualities and dimensions of wheels used generally. Hereupon, it goes without saying that a considerable increase in bursting strength of each wheel material is required.
3) Resin-penetrated reinforced wheels are expected theoretically an increment of about twenty percent in the bursting speed from without penetration, but its attainment depends upon completeness of resin penetration in manufacturing.
4) The experimental results are almost in good agreements with the calculated ones.