Research On Multi-directional Controllable Precision Forming Technology Of Excavator Bucket Teeth

With the rapid development of engineering machinery,excavator function has gotten great improvement.The demand of high-precision,high-performance and shape-complicated forgings is becoming greater and greater during the engineering machinery industry.The development of new forging process,energy saving and material reduction technology is especially important for the production of new construction machinery parts.As the key wearing parts of excavator,the bucket teeth directly contact with the ore material,subjected to the action of peening wear and bending moment.The bucket teeth have strict requirements on its structure,material composition and mechanical properties.So exploring the reasonable forging method of this kind of parts has great significance for the development of mining machinery industry in china.In this dissertation,the multi-direction precision forming technology of excavator bucket tooth was investigated systematically by combination of theoretical analysis,numerical simulation technique and field test.The main results are as follows:?1?The hot deformation process of new low-alloy wear-resistant steel used for forging bucket teeth was simulated experimentally with the aid of the Gleeble-1500D experiment machine.The true stress-true strain curves under different temperatures and different strain rates were obtain.?2?Based on the experimental data,the constitutive model of forged bucket tooth steel was established.This model was derived from the integration of the Z parameter model and the Arrhenius hyperbolic sine function.In this model,the effect of the strain on the constitutive equation parameters was considered specifically.The mathematical relationship among temperature,strain rate,strain and flow stress of forged bucket tooth steel can be well characterized by the model,which also can provide material model data for simulating the multi-direction precision forming process of excavator bucket tooth.?3?The hot processing maps of the new low-alloy wear-resistant steel was established.Based on hot processing maps,the analysis results show that the appropriate hot working parameters ranges of testing steel are 912¹167?,0.01²s^-1,and the optimal ranges are 1057¹167?,0.2⁰.5s^-1??4?Velocity field,stress field,temperature field,load size and die stress state in the multi-direction precision forming process of bucket tooth were analyzed by using Deform-3D.Based on these analysis results,the processes were optimized and the multi-direction controllable flow molding of excavator bucket tooth was put forward.?5?Based on the existing equipment conditions,the core step of the forming process was tested.The defects and problems in the test results were analyzed.Combined with the analysis results,the improvement plan of process test was put forward.Finally,it were obtained that the bucket teeth were full filled with no flying edge,the size was uniform and the metal streamline was complete.The test results show that the process is feasible and effective.The above conclusions and results will breakthrough the traditional production process of excavator bucket teeth,which are helpful to promote the development of precision forming technology of the engineering machinery parts and improve our national engineering machinery status that the parts have low-added value and shortage of high precision parts is severe.The study content has important theoretical value and practical significance.