RU2012144480A - METHOD FOR CENTERLESS GRINDING OF A HIGH-SOLID POWDER MATERIAL - Google Patents

Abstract

A method of centerless grinding of a high-hardness powder material, in which the product is informed of axial rotation and movement and is processed with a rotating abrasive tool at selected grinding mode parameters, characterized in that the force per one abrasive grain is determined first for the abrasive tool, and the cutting grain holding force is set a bunch of abrasive tools, based on the condition that the cutting force per one abrasive grain does not exceed the holding force Ia bonded cutting grain instrument, determine the maximum grinding depth and naprohod treatment is performed to a depth not exceeding the values: where r - radius statistical average grain high hard material powder; B = [Н · R-А / [Р]) / (2 · (Н-Н)), Н, Н - microhardness of the components of a two-component powder material, R - average statistical distance between the centers of grains of high-hardness powder material, K - coefficient the shape of the top of the abrasive grain, K is a parameter depending on the volume structure of a standard abrasive tool and the conditions for editing its working surface, d is the characteristic size of the abrasive grain of the tool, V is the speed of abrasive cutting, V is the speed of the product, V is the longitudinal speed of the product, d, D - diameters respectively processed articles and abrasive tools, ζ - the chip shrink, η - the angle of sliding friction, γ - rake angle cutter unit, [P] - holding force cutting grain bonded abrasive tool.

Claims (1)

A method of centerless grinding of a high-hardness powder material, in which the product is informed of axial rotation and movement and is processed with a rotating abrasive tool at selected grinding mode parameters, characterized in that the force per one abrasive grain is determined first for the abrasive tool, and the cutting grain holding force is set a bunch of abrasive tools, based on the condition that the cutting force per one abrasive grain does not exceed the holding force Ia bonded cutting grain instrument, determine the maximum depth of grinding and naprohod treatment is performed to a depth not exceeding the values: $$t=r-\sqrt{r^2-B^2}$$

, where r is the average statistical radius of the grains of high hardness powder material; B = [H _V1 · R-A / [P _Z1 ]) / (2 · (H _V1 -H _V2 )), Н _V1 , Н _V2 - microhardness of the components of a two-component powder material, R - average statistical distance between the centers of grains of high-hardness powder material, $$A=\frac{0.185\cdot H_{V\mathrm{one}}\cdot H_{V2}\cdot R\cdot K_{\mathrm{at}}\cdot K_{\delta }\cdot d_a^{2.5}\cdot V_D\cdot V_K}{{\left(V_K+V_D\right)}^2+V_{np}^2}\sqrt{\frac{d+D}{d\cdot D}}\cdot \frac{{\zeta }^2+2\cdot \zeta \cdot \sin \gamma +\mathrm{one}}{\zeta \cdot \cos \gamma }\times$$

$$\times \frac{\zeta \cdot \cos \left(\eta +\gamma \right)}{\zeta \cdot \cos \left(\eta +\gamma \right)-\sin \eta }$$

, K _в is the coefficient of the shape of the tip of the abrasive grain, K _δ is a parameter depending on the volumetric structure of a standard abrasive tool and the conditions for editing its working surface, d _a is the characteristic size of the abrasive grain of the tool, V _K is the speed of abrasive cutting, V _D is the speed of the product , V _np is the longitudinal velocity of the product, d, D are the diameters of the workpiece and abrasive tool, respectively, ζ is the chip shrinkage, η is the sliding friction angle, γ is the rake angle of a single cutter, [P _Z1 ] is the holding force of the cutting grains by the bond of the abrasive tool enta.