Abrasive Block Design For Rust Removal Wall Of 90° Elbow Based On Constant Pressur Design And Simulation Research

The subject designed a mechanical rust removal device and a grinding block structure for rust removal for the rust removal of the inner wall of the small diameter elbow pipe.According to summary of the geometric laws of the elbow and the"eccentricity"of the device during the rust removal process to design the structure of the grinding block and its installation structure.Througuout the rust removal,due to the constant pressure on the abrasive block,the depth of rust removal is different.This paper uses the finite element simulation software ABAQUS to establish a simulation model for the rust removal of the abrasive block with the pressure as the boundary condition to verify the designed opposite bending of the abrasive block.This dissertation includes the following contributions:1.The structure design of the elbow derusting device.Aiming at the problem of poor derusting effect of the elbow at this stage,the shape of the grinding block 1 2 and the installation structure are designed by analyzing the geometry of the elbow.According to the geometric relationship of the contact arc length between the grinding block and the wall in the bend,the parameter formulas of the two grinding blocks are deduced.Considering the passability requirements of the elbow and the arc length relationship at the symmetrical position in the bend,the range of the parameter value of the grinding block is determined.2.Research on simulation method and micro-mechanism of constant pressure grinding.Throught the rust removal,the pressure of the two abrasive blocks is approximately constant and the grinding depth is different due to the spring connection.Therefore,from a microscopic point of view,the article establishes a simulation model of abrasive grain grinding with pressure as the boundary condition and simulates.The results are compared with the theoretical analysis results,verifying that the method of applying constant pressure is feasible.The simulation obtained the change law of the grinding depth curve of the abrasive particles under the constant pressure state.Under pressure,the cutting depth of the abrasive particles gradually increased and then stabilized.After the stability,the curve still fluctuates;the chip formation process of the workpiece material is analyzed;The signal curves of the components of the ablational force along the three coordinate axes are shown.3.Simulation experiment of grinding block rust removal.A simulation experiment of derusting the elbow pipe by the grinding block under constant pressure is established.First,the topography model of the grindingstong 1 is established.According to the rust removal result of the grinding block 1 on the bottom of the elbow pipe,to obtain the regression equation of pressur F_Nand the depth of cut a_p.Substitute the ideal grinding depth value a_p1of grinding block 1into the regression equation to get F_N1.Keeping the value unchanged,the influence of the motor speed n on the rust removal depth a_pis obtained by changing the angular velocity of the grinding block 1.The simulation indicated that the value of a_pdecreases with the increase of n.Use abrasive blocks 2 with three abrasive concentrations to remove rust on the top in the bend and at the junction,and judge the rust removal quality of the elbow based on the stability of the abrasive block d and the depth of rust removal a_p2-真.After comparison,the concentration of abrasive C（28）50%can be guaranteed.The rust removal depth is reasonable and smooth.