| Synchronizer block ring is a key part of synchronous speed in vehicle gearbox,and its performance is related to fuel economy and dynamic driving performance of the vehicle.This kind of parts with large quantities and stable demand in the market have high precision requirements and bad working conditions.At present,complex wear-resistant brass is mainly used in the industry to obtain them.Forging is mainly processing.Due to the use of complex wear-resistant brass materials,the stability of the forming quality,the mechanical properties of the parts and the life of the die during the precision forming restrict the further development of this parts.Therefore,starting from the high temperature thermal deformation behavior of the block ring material HMn64-8-5-1.5 manganese brass,combined with finite element simulation analysis,the precision forming process and microstructure properties of copper ring were studied in this paper.The main research work of this paper is as follows:1.The high temperature rheological properties of gear ring materials are obtained by hot compression experiment.For the wear-resistant brass HMN64-8-5-1.5 used in the gear ring of the synchronizer,the thermal compression experiment was carried out on the material with the thermal simulation machine,and the true stress-strain curve was obtained.By combining the stress strain and the microstructure of the material in different states,the hot deformation and flow rule of the material at high temperature was analyzed,and the mathematical model was established based on the experimental data obtained.2.According to the actual production needs,determine a reasonable process.The acquisition mode,microstructure and mechanical properties of various gear ring blank were analyzed,and the process route of extruded pipe-fine forging-machining-inspection-packaging was determined.At the same time,considering the influence of thermal expansion and elastic deformation,the cavity size design of the precision forging tooth shape die was completed.3.With the help of DEFORM-3D simulation analysis software,the forming process feasibility and quality robustness of the gear ring are simulated and analyzed.In this part,the analysis is focus on of the forming flow law of the gear ring.4.Multi-factor experiment method was adopted to simulate and analyze the process parameters of ring precision forging by DEFORM-3D.The effects of friction coefficient and the initial forging temperature of blank on the equivalent stress and material damage of the ring were analyzed under the working conditions.The most appropriate forming parameters were determined to obtain uniform stress distribution,low material damage and low forming force.5.Engineering production verification.The actual production of the process route was verified.On the premise of testing the hardness,composition and size of the forming die,the metallographic structure,Brinell hardness,spectral composition and mechanical properties of the tooth ring blank were confirmed to be qualified.The rationality of the process was verified by testing the shape,size,microstructure and hardness of the forming tooth ring.The research work in this paper mainly focuses on the case study of a certain type of small modulus gear ring,but the research ideas can provide direction guidance for the processing of the same series of thin-walled small modulus gear ring parts.The inspection techniques and methods used are in line with the practical engineering significance. |
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