Improvement Of Compression Device And Analysis Of Compression Process Of Straw Briquetting Machine With Ring Mode

The design of compression device for agricultural fiber materials and the analysis of compression process are of practical significance for optimizing processing technology,improving production efficiency and product quality.In order to effectively solve the problem that the hole of the ring mold is easy to be blocked due to the accumulation of materials,this thesis takes the ring mold straw briquetting machine as the research object,redesigns the surface structure of the roller,and makes the corresponding improvement on the wedge block which constitutes the ring mold hole,so as to optimize the compression mode of straw materials.At the same time,Solid Works is used to build the three-dimensional model,ANSYS is used to build the flexible body model of corn straw,and the virtual prototype model of the new compression device and the flexible body model of corn straw is established in Adams environment through rigid flexible coupling.The displacement,velocity and acceleration of corn straw under different spindle input speeds are analyzed through systematic analysis of the situation,the change of the force on corn straw in the feeding area,pre compression process and main compression process of the new compression device was obtained.At the same time,the workbench module of ANSYS is used to establish the geometric model of the briquette,and the finite element simulation analysis of the briquette forming and extrusion process of corn straw in the new compression device is carried out,and the total deformation law and equivalent stress distribution law of corn straw in the briquette forming and extrusion process are obtained.The main results are as follows:(1)For the redesign of the compression device,"involute teeth" are set on both sides of the outer surface of the circumference of the pressure roller.The number of teeth on the pressure roller is 84,the full height of the teeth is 5mm,and the axial thickness is 1.5mm;In order to make the pressing roller and the ring die fit smoothly,the geometric relationship between the pressing roller and the improved pressing roller is obtained by improving the upper part of the ring die hole.The groove depth of the wedge block is 5mm,and the groove width of the wedge block is 1.7mm.(2)In the feeding area of the new compression device,the involute teeth on the roller mainly promote the corn straw;In the process of precompression,with the increase of straw materials and the friction between them,the driving force of roller applied to corn straw becomes rolling friction;In the main compression process,the friction force of corn straw in the conical area of the ring die hole is less than the extrusion force of the "involute tooth" on the pressure roller,and the straw material is gradually pressed into the die hole.At this time,the pressure value fluctuates in a small range and gradually tends to be stable.(3)When the "involute tooth" on the corn straw pressure roller passes through the upper part of the conical area,the root and the forming cavity in turn,the total deformation and the equivalent stress value of the corn straw increase with time,and the deformation amplitude and the maximum stress distribution near the inner wall of the ring die hole are significantly higher than those at the core of the corn straw,both of them reach the maximum value and keep in a certain level after the corn straw passes through the conical area of the annular die orifice and enters the molding cavity.