Intensified processing of shot blasting machines is one of the methods to improve the fatigue strength of parts. It has been widely used in coal mining machinery, aviation industry, automobile manufacturing, agricultural machinery and other industries in the 1970s. Belden Machinery has also developed a CNC shot peening machine. When the CNC shot peening machine is used for the shot peening of the surface of the engine blade and the root of the blade body, the workers only carry out the operation of loading and unloading the parts, and the rest is completely automatically completed by the machine. In the automatic working state, the work turntable, spray gun, shot peening flow rate, elevator, vibrating screen, spiral separator, and shot peening time are all automatically controlled.
Its working principle is that the mechanical arm can direct the nozzle to align the hidden and complicated corners of the workpiece to clean the blind areas and dead corners. The constantly swinging nozzle further accelerates the cleaning process. The robot can either manually control and strengthen a single workpiece, or it can strengthen a series of workpieces fully automatically. The robot can use pellets of any size and shape according to different workpiece surface requirements. Robot programming is carried out by the operator controlling the joystick, and the sandblasting and cleaning of similar workpieces can be automatically completed through the programmed program in the future.
Shot peening is driven by compressed air, and fine spherical cast steel shots are selected from the nozzle of the spray gun to form a high-speed pill stream of tens of meters per second, which strikes the gear tooth surface to complete the strengthening treatment, resulting in a thin high residue Stress layer. When an external load is applied to the shot-peened gear, the surface compressive stress after shot-peening is reduced because the tensile stress caused by the load is offset. If the load applied to the part does not exceed 40%-50% of the ultimate tensile strength of the material, or is below the elastic limit or yield point, the compressive stress after shot peening will still remain in the part. According to the crack propagation theory, the crack Will not expand into the compressive stress layer. Therefore, through shot peening, the fatigue life of parts can be increased, the internal stress generated by machining tool marks can be eliminated, and the lubrication performance can be improved.
The effect of shot peening depends on two basic factors: (1) the condition of energy transmission of the processed material and the amount of energy absorbed by the material; (2) shot peening must be based on the law of elastoplastic deformation of different materials. According to the shot peening mechanism, an algorithm is drawn up based on this mechanism. By controlling the curvature of the variable stiffness plate, the residual stress is distributed along the section of the part, and the optimization solution is carried out according to the law of surface deformation.
In shot peening, a reasonable and reasonable shot peening process or sand blasting process can also be determined through a reliable algorithm, which can make the processing effect more perfect.