Injection nozzle, blast processing device and blast processing method with the injection nozzle, method of forming lubricating layer by the blast processing method, and sliding product with the lubricating layer formed by the method

摘要

A method enabling to form a lubricating layer on a work piece and a device to form the same in a simple blast processing are provided, in which injection materials can be injected at higher speed than the conventional way, thereby even a small specific gravity injection materials such as graphite and the like can be used for blast operation. In an injection nozzle of a direct pressure type blast processing device which injects a mixture of injection materials and compressed gas, an aperture which is formed in an axial direction of the injection nozzle has such shape that meets the following conditional equations (1) and (2) in a cross section orthogonal to the axial direction at an arbitrary distance x away from the entrance of the injection nozzle. $$ \begin{array}{cc}a={\frac{G}{p_1}\left[\frac{2g\kappa }{\kappa -1}\frac{1}{{\mathrm{RT}}_1}\left\{{\left(\frac{p}{p_1}\right)}^{\frac{2}{\kappa }}-{\left(\frac{p}{p_1}\right)}^{\frac{\kappa +1}{\kappa }}\right\}\right]}^{-\frac{1}{2}}& \left(1\right)\\ \frac{p}{p_1}=1-\left(1-\frac{p_2}{p_1}\right)\left(\frac{x}{L}\right)& \left(2\right)\end{array}$$