Make full use of CAD two-dimensional software, CATIA three-dimensional software and DEFORM-3D finite element numerical simulation software to carry out die two-dimensional design, three-dimensional modeling and Simulation of forming process respectively. Through numerical calculation and finite element simulation, the following relevant conclusions are obtained:
(1) The blank size, die design and forming force of closed die forging, one-piece ring rolling and two-piece ring rolling are calculated. It is concluded that the blank weight of closed die forging is 3.3kg, the forging weight is 2.7kg, and the material utilization rate is 81.8%. The calculated forging force is f = 17567kn. 2000t hot die forging press is selected as the forming equipment. The blank weight of single ring rolling is 2.85kg, the forging weight is 2.62kg, and the blank utilization rate is 91.9%. The calculated rolling pressure f = 48.819kn. The equipment is air hammer blank making, and the ring is formed by d51-250c ring rolling machine. The blank weight of two-piece ring rolling is 5.5kg, the forging weight is 5.2kg, and the material utilization rate is 94.5%. The calculated rolling pressure f = 116.921kn. The equipment selected is air hammer blank making, and the ring is rolled by d51-250k ring rolling machine. The different processes of forming single piece gear blank are compared and analyzed. Compared with the closed die forging process, the material utilization rate is increased by 12.3%. The closed die forging equipment has the advantages of large tonnage, high cost and high cost. According to the above comparative analysis, the ring rolling process is finally selected as the optimal process scheme for machining spiral bevel gear blank.
(2) The blank size of ring rolling is based on the theoretical calculation value. According to the principle of constant volume, three groups of ring blanks with different sizes are selected for numerical simulation of ring rolling forming. According to the analysis of the distribution of stress and strain respectively according to the simulation results, it is concluded that the ring blank contacts with the step and fillet first, and the stress and strain are generated first. With the downward feeding of the driving roller, the stress area increases, and the deformation area increases, On the whole, the stress and strain outside the ring is greater than that inside the ring. The above conclusions are in line with the law of ring rolling. The forming dimensions and forming conditions of the three groups of schemes are compared respectively. The size of the formed forging in scheme 1 is slightly smaller and the fillet is not filled with defects. The size of the formed forging in scheme 3 meets the requirements, but there is a “fishtail” phenomenon on the side. Finally, the size of scheme 2 is selected as the best ring blank size for forming the spiral bevel gear blank of this subject, which achieves the purpose of process optimization.
(3) Based on the single ring rolling process, the forming of two-piece ring rolling is numerically simulated, and the double ring is successfully rolled. It is concluded that the stress and strain distribution of two-piece ring rolling meet the deformation law, and the forming size meets the requirements of forgings. It can be seen from conclusion 1 that the material utilization rate of spiral bevel gear blank formed by single ring rolling process is 91.9%. The material utilization rate of single spiral bevel gear blank formed by two-piece ring rolling process is 94.5%. Compared with the one-piece ring rolling process, the material utilization rate of the two-piece ring rolling process is increased by 2.8%, and the production efficiency is improved and the cost is reduced. The proposal of this process provides a certain theoretical basis for its application in production practice in the future.
Because the formed two-piece small spiral bevel gear blank has not been operated and processed in the actual production, the numerical simulation is only simulated and formed in a relatively ideal environment. Some objective factors affecting the forming quality in the actual processing are not taken into account, and the simulation results are only used as a theoretical basis. Therefore, the problems and defects of the two-piece ring rolling formed gear blank in the actual production need to be improved and optimized.