The Study On Optimization Of Forming Process For A Kind Of Rotary Cultivator Curved Knife Blade

Rotary cultivator is a widely used land machinery. Rotary blades on rotary cultivators are wore down and consumed a lot, so have a high demand. Rotary blades need of camber mainly relies on in-plane bending by uneven rolling to form. In practical production, factories get the camber by first rolling blade and then in-plane bending, the main problem is that for uneven thickness of plate, the plane bending process is more difficult to control, it is hard to bring out because it is easy to bent offset and workpiece can be stuck in the mold. What`s more, to use the thinner part of blade as a fulcrum will lack strength, and easily be bit and out of shape by the edge of die, then increase the condition of workpiece sticking. Start from the aim of simplify production process, reduce production costs, the study directly use the mill to roll camber-right workpiece and optimize the existing forming process. The main contents are as follows:(1) Introduce in-plane bending(rolling bend) process in connection with this study, which emphasizes the bite stages on plate rolling and in-plane bending(rolling bend) mechanism.(2) Use Solidworks software to set up numerical model of plate and rollers, use Deform-3D software to simulate rotary blade forming processes, and track the feature points, according to the simulation results, it analyzes rolling forming load, stress and strain changes, damage degree and bite angle and so on.(3) By analyzing the relation of the deflection angle and the rolling bend degree, the best bite angle can be found, and obtain the most ideal camber workpiece in production. In “beng after rolling”project, 10°~15° deflection angle is the best bite angle, in “bend before rolling” project, 30°~40°deflection angle is the best.(4) Comparing the simulation results of “beng after rolling” and “bend before rolling”, including the difficulty of technology and the quality of workpiece forming, the results showed that the advantage is not obvious in“bend before rolling”, and no superiority in the quality of workpiece forming.(5) Aimed at the condition that rolling camber in “beng after rolling” process is not big enough, the study tried to use original rollers rolling with unequal thickness plates, adjusted the rollers wedge rolling with equal thickness plates, adjusted the rollers wedge rolling with unequal thickness plates, and the simulation results all showed that tests can get rolled pieces with some camber, but can not get the same camber with rotary blade, and also has the similar shortcomings to “bend before rolling”.In this article, it combine theoretical analysis and numerical simulation methods to determine the “bend before rolling” technique is not feasible, and not suitable for production inputs. It saves the expenses for the physical experiments and practical production test, and has some reference value for the research of similar parts forming process.