Papers by Keyword: Precision Forging

Abstract: Due to its advantages including high quality of the forging parts and low production costs,hot closed-die forging (HCDF) play an essential role in the machine building industry. However, in recent decades, the pace of its development is gradually slowing down. In the hope of drawing up some new ideas about future development of the HCDF, this paper presents a brief overview of it. This study roughly prospects several potential research issues of the HCDF. Some new research fields such as precision forging, combined forging and numerical simulation have been shown. Challenges and possible response to them have been discussed.

Abstract: A CAE analysis on the precision forging of big semimonocoque of vehicle axle was conducted based on DEFORM-3D software. It discussed effects of forging billet size and shape on the forging property and effect of forging shape on the flow law of metal materials, and analyzed equivalent stress, strain distribution and load-stroke curve during the forging process. Research results are used to optimize mold structure and technological parameters. Precision forging of big semimonocoque was verified valid by practical production.

Abstract: Rapid development of automotive industry brings increasing demand for die forgings made from non-ferrous metals. Market economy stimulates drop forges to produce forged pieces of highest quality and dimension precision with the accent on reduction in production costs. Precision die forging without flash belongs to progressive and economical technologies of die forgings production. This paper describes an experiment of precision forging in closed die of magnesium alloy type AZ 31. Given alloy type Mg-Al-Zn is suitable for bulk forming and is characterized by good hot formability. Achieved results may be applied in practice at production of longitudinal shaped forgings e.g. levers and connecting rods. In order to verify a design of closed die forging technology regarding the lever-shaped forged piece, simulation program MSC.SuperForge was used. Numeric simulation was significantly helpful at optimization of semi-product shape and dimensions and confirmed correct plastic flow of material in closed die cavity. The objective of this contribution was to point out current trends in searching for economical measures at production of die forgings from alloys of non-ferrous metals.

Abstract: Automotive industry is nowadays constantly strengthening its dominant position. Its primary objective is to reduce weight of automobiles in order to decrease fuel consumption and amount of harmful pollutant emissions. From the viewpoint of further development in the field of automotive industry, very interesting are the issues of die forgings production from light non-ferrous metals. This article describes research of precision die forging technology in closed die with regard to magnesium alloy type AZ 31. Given alloy type Mg-Al-Zn is suitable for bulk forming and is characterized by good formability at hot conditions. Results of this research may be applied to production of forgings with longitudinal shape, e.g. levers and connecting rods. In order to verify the design of forging technology in closed die for lever-shaped forged piece the simulation program MSC.SuperForge was used. Numeric simulation of die forging process confirmed suitable designed shape and dimensions of semi product and also correct material plastic flow in cavity of closed die.

Abstract: The Tooth Impact Factor was defined and introduced into the formula of forming load of closed-upsetting. Thus the formula for calculating the forming load of hot precision forging of cylindrical gears was put forward. The equation for the Tooth Impact Factor was fitted using the data from FE simulation of forging process in which gears with different modules were forged. Some forging tests for gears were conducted and the forming load was measured to ensure the validity of the formula. The tests also revealed that the formula is suitable for forming load calculation of hot precision forging of both spur and helical gears in a wide size range.

Abstract: The whole precision forging process of spur-gear with large module (module: 4) including warm forging, cold extrusion and cold sizing is analyzed. By using finite element method, cold sizing step of spur-gear basing on hollow-divided-flow method is simulated, the influenc of hollow diameter on the forging force and material flow is discussed in detail. Futher research shows that appropriate different tooth reduction is benefit to forming tooth profile without mechaning after forging. According to the research, to form such spur gear with module 4 and breadth 59mm studied in this paper, the hollow diameter should be 18mm and the tooth reduction should be 1.2mm. The necessary reference and basis to realize practical precision forging process of spur gear with large module is provided eventually.

Abstract: The system of collaboration between design and manufacturing is proposed in order to meet the precision forging manufacturing. The configuration of the system and functions are studied and analyzed in detail. The system integration mode based on PDM (Product Data Management) is put forward. Application systems around the process of collaboration between design and manufacturing can be integrated seamlessly by integration mode. And two key enable technologies are analyzed in detail. Model association method based on WAVE technology is used to implement design of precision forged die. The work model and data structure based on the collaboration system is studied. Finally, an application engineering system is developed and a case study is given to demonstrate the above ideas in the environment of aero-engine manufacturing enterprise.

Abstract: By analyzing the characteristics and forming technology of hypoid driving gear, it was suitable for adopting fully enclosed die forging principle to form the gear. Based on different forging methods, three kinds of blank shape and corresponding forming schemes were designed. The three dimensional models of blank and die were created by the UG software. The three forming schemes were simulated by the Deform-3D software. The simulation results of distribution of equivalent stress, distribution of equivalent strain and load-stroke curve were comparatively analyzed. Then the most reasonable scheme was chosen. At last, the rationality of numerical simulation can be further verified by the optimized scheme was proved by experiment.

Abstract: In this study, the precision forging process of spur gears has been investigated by means of numerical analysis. The effect of some parameters such as teeth number and module on the forming force and specific pressure were presented. The simulation works were performed rigid-plastic finite element method using DEFORM 3D software. In order to validate the estimated numerical results, they were compared with those obtained experimentally during precision forging of spur gear using lead as a model material. Results showed that the optimum number of gear teeth is between 10 to 20, that is because of being the specific pressure in its minimum value. Also the results obtained from analyzing the effective strain distribution showed that the maximum strain is located on the root area of the teeth. The work presented in this paper might be used for basic data in the design of the precision forging process.

Abstract: The precision forging processes for gears have advantages in saving material and energy consumption, reducing the cost and improving the quality of products. Gears have complicated geometries and are difficult in precision deformation. Two kinds of forging process of gears were put forward according to the structure characteristic of gears. 3D FEM model of the precision forging process of gears was established. The forming laws, material plastic behavior, changed geometries and the qualities of the workpieces are explored by finite element simulation. According to the simulation results, completely filled gear teeth were obtained using a lower forging load by the designed process which is the effective forging process for manufacturing of gears. From this study, it was expected that designed process could be efficiently used in the gear forging for practical use in the industry.