半轴齿轮温（热）精锻成形技术研究
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摘要
闭塞式精锻工艺属于金属塑性加工的先进工艺，齿轮精锻就是通过精密锻造直接获得完整齿形，且齿面不需或仅需少许精加工即可使用的齿轮制造技术。它有效地改善了齿轮的组织和性能。精锻使金属三向受压，晶粒及组织变细，致密度提高，微观缺陷减少；精锻还使金属流线沿齿形连续均匀分布，提高了齿轮的机械性能。且精锻齿轮的齿形精度能达到精密级公差、余量标准，工件只需少量精加工就可进行热处理，提高了生产效率及材料利用率，降低了生产成本，大大提高了齿轮制造的市场竞争能力。
近年来，随着计算机技术的飞速发展，闭塞式精锻技术也取得了巨大的进步。本课题以半轴齿轮为例，先利用模具CAD技术对半轴齿轮进行三维实体建模，然后应用FEM模拟技术等对半轴齿轮的成形过程进行数值模拟仿真。分析了金属在成形过程中各种场变量的变化，预测金属流动趋势，并就不同的凸、凹模结构及形状尺寸、连皮厚度、连皮相对于齿轮端面距离等对半轴齿轮的成形载荷、金属流动情况（或充填性）以及模具寿命等的影响规律进行了研究，确定了最优的凸、凹模结构、连皮厚度以及连皮相对于齿轮端面的距离等工艺参数。并根据优化出来的结果设计出了一套合理的温精锻工艺和基于800吨双动液压机的模具。最后利用优化结果进行了实验，并将数值模拟结果与实验结果进行比较，得出了以下主要结论：改进凹模结构，在齿模大端尖顶处设置尖角，成形时该尖角可以起到容纳多余金属的作用，并确保齿廓面的完全成形；改进凸模结构，在凸模下端与顶杆上端加一大小、形状适当的凸台，可对毛坯产生一定的径向力，便于金属分流，更有效的改善了齿形的充填条件；合理的连皮厚度和连皮位置对齿形的充填也起着重要的作用，当连皮厚度t=0.3d，h=0.5H时，齿形的充满情况最好；锻件上小于φ25的孔，只要模具结构合理，锻出来更有利于齿形的充满。
通过本课题的研究，将精密锻造理论，数值模拟仿真技术以及模具CAD/CAM技术结合起来，达到了提高生产效率、缩短产品开发周期、提高模具寿命、降低能耗和生产成本等目的。本课题的研究成果可以为其他锥齿轮的生产以及相关的模具设计提供理论和实践依据。
Enclosed-die forging process is one of the advanced processes in the field of metal forming. Full tooth of gear can be obtained through precision forging process, and the tooth need no or little precision machining only. The structure and performance of gear can be improved effectively through this process. The process can make material depressed stress in three directions. So it can attenuate crystal grains, improve the density and decrease microcosmic defects. It can also make metallic fibre streamline of teeth more continuous and symmetrical, and lead to the improvement of mechanical performance of gear. The precision of gear shape can come to a very high level。The workpiece needs only a little of machining before heat treatment. The process increases productivity rate and use ratio of materials, decreases the cost of production. Therefore the competing ability of gears is improved greatly.
During recent years, with the rapid development of computer technology, the technology of enclosed-die forging has achieved great progresses. In this research a kind of half axle gear was introduced, whose model was made by the CAD technology. The forming process of the half axle gear was simulated by FEM software. The transformations of the fields during the process of metal forming were investigated, the tendency of metallic flow was forecasted，and the rules how various items affect the forming load, metallic flow, the life of dies were discovered. The factors include the different structures of male and female die, web thickness, the distance between web and big-end face of gear, etc. And the most suitable die structure，web thickness and distance were made certain. A proper warm forging process and a die-set based on 800-ton double action hydraulic press were designed according to the result of FEM simulation. Finally some experiments were made. Contrasting the simulation result with the experiment result some conclusions were made: modifying die structure (setting a tip at the big-end of gear to hold unwanted material) can ensure the complete forming of the tooth; modifying male die structure (adding a dummy on the bottom of male die to produce a radial force helping to divide material flow) can improve the filling ability in the area of teeth; proper web thickness and wed position play an important role in the forming of gear (the proper values are t=0.3d and h=0.5H); If a hole with diameter less than 25mm on the gear should be forged by proper die structure, it even helps to metallic flow in the area of teeth.
The theory of precision forging, technology of FEM simulation and mould CAD/CAM are integrated through this research, which helps to shorten developing period, prolong life-span of die, and cut down the cost, etc. The progeny of the research can provide accordance for other bevel gears' producing.
近年来，随着计算机技术的飞速发展，闭塞式精锻技术也取得了巨大的进步。本课题以半轴齿轮为例，先利用模具CAD技术对半轴齿轮进行三维实体建模，然后应用FEM模拟技术等对半轴齿轮的成形过程进行数值模拟仿真。分析了金属在成形过程中各种场变量的变化，预测金属流动趋势，并就不同的凸、凹模结构及形状尺寸、连皮厚度、连皮相对于齿轮端面距离等对半轴齿轮的成形载荷、金属流动情况（或充填性）以及模具寿命等的影响规律进行了研究，确定了最优的凸、凹模结构、连皮厚度以及连皮相对于齿轮端面的距离等工艺参数。并根据优化出来的结果设计出了一套合理的温精锻工艺和基于800吨双动液压机的模具。最后利用优化结果进行了实验，并将数值模拟结果与实验结果进行比较，得出了以下主要结论：改进凹模结构，在齿模大端尖顶处设置尖角，成形时该尖角可以起到容纳多余金属的作用，并确保齿廓面的完全成形；改进凸模结构，在凸模下端与顶杆上端加一大小、形状适当的凸台，可对毛坯产生一定的径向力，便于金属分流，更有效的改善了齿形的充填条件；合理的连皮厚度和连皮位置对齿形的充填也起着重要的作用，当连皮厚度t=0.3d，h=0.5H时，齿形的充满情况最好；锻件上小于φ25的孔，只要模具结构合理，锻出来更有利于齿形的充满。
通过本课题的研究，将精密锻造理论，数值模拟仿真技术以及模具CAD/CAM技术结合起来，达到了提高生产效率、缩短产品开发周期、提高模具寿命、降低能耗和生产成本等目的。本课题的研究成果可以为其他锥齿轮的生产以及相关的模具设计提供理论和实践依据。
Enclosed-die forging process is one of the advanced processes in the field of metal forming. Full tooth of gear can be obtained through precision forging process, and the tooth need no or little precision machining only. The structure and performance of gear can be improved effectively through this process. The process can make material depressed stress in three directions. So it can attenuate crystal grains, improve the density and decrease microcosmic defects. It can also make metallic fibre streamline of teeth more continuous and symmetrical, and lead to the improvement of mechanical performance of gear. The precision of gear shape can come to a very high level。The workpiece needs only a little of machining before heat treatment. The process increases productivity rate and use ratio of materials, decreases the cost of production. Therefore the competing ability of gears is improved greatly.
During recent years, with the rapid development of computer technology, the technology of enclosed-die forging has achieved great progresses. In this research a kind of half axle gear was introduced, whose model was made by the CAD technology. The forming process of the half axle gear was simulated by FEM software. The transformations of the fields during the process of metal forming were investigated, the tendency of metallic flow was forecasted，and the rules how various items affect the forming load, metallic flow, the life of dies were discovered. The factors include the different structures of male and female die, web thickness, the distance between web and big-end face of gear, etc. And the most suitable die structure，web thickness and distance were made certain. A proper warm forging process and a die-set based on 800-ton double action hydraulic press were designed according to the result of FEM simulation. Finally some experiments were made. Contrasting the simulation result with the experiment result some conclusions were made: modifying die structure (setting a tip at the big-end of gear to hold unwanted material) can ensure the complete forming of the tooth; modifying male die structure (adding a dummy on the bottom of male die to produce a radial force helping to divide material flow) can improve the filling ability in the area of teeth; proper web thickness and wed position play an important role in the forming of gear (the proper values are t=0.3d and h=0.5H); If a hole with diameter less than 25mm on the gear should be forged by proper die structure, it even helps to metallic flow in the area of teeth.
The theory of precision forging, technology of FEM simulation and mould CAD/CAM are integrated through this research, which helps to shorten developing period, prolong life-span of die, and cut down the cost, etc. The progeny of the research can provide accordance for other bevel gears' producing.
引文
[1] 藤川真一郎.3次元锻造シミュレ-ション课题与展望.塑性と加工.1999,
[2] S.Kobayashi, S.I.Oh and T.Altan, Metal Forming and the Finite Element Method, New York, Oxford University Press, 1989 No.5
[3] 彭颖红.金属塑性成形仿真技术.上海交通大学出版社.1999.P3-4,71
[4] 夏巨谌，丁永祥，胡国安.闭式模锻.机械工业出版社.1993.P1
[5] 金 炫琪,山中 雅仁.ァメリカにぉける锻造分野でのシミュ レ-ション技术とその利用状况. 塑性と加工.1999,No.5
[6] Choi J C. A Study on the forging of spur gears. Int.J. Mech. Sci.,1996,38(12):1333-1347
[7] Chitkara N R. Near-Net shape forging of spur gear forms: An analysis and some experiments. Int.J.Mech.Sci.,1996,38(8-9): 891-916
[8] 林治平.带轮毂直齿圆柱齿轮精锻的计算机模拟.金属成形工艺, 1997, 15（2）：12-15
[9] 刘庆斌.直齿圆成形数值模拟及实验研究.金属成形工艺, 1995, 13(1)：34-38
[10] 李洪波.圆柱直齿轮精锻成形的UBET数值模拟.金属成形工艺，1996, 14(3)：21-23
[11] 程军.塑性加工工步的光塑性分析与图象处理.[博士学位论文],南昌大学,1998
[12] 陈泽中.直齿圆柱齿轮精锻工步分析与实验研究.[硕士学位论文],南昌大学,1998
[13] Vazquez,V., Walterss, J., Altan T. Forging Process Simulation - State of the Art in USA,Neuere Entwicklungen in der Massivumformung(体积成形最新研究进展)，in Fellbach bei Stuttgart,am 19 und 20. Mai 1999.
[14] 林治平.在摩擦压力机上精锻直齿圆.塑性加工理论与技术新进展.南昌：江西高教出版社,1997
[15] 田福祥.直齿圆柱齿轮热精锻-冷推挤精密成形研究.锻压机械, 1997(6)
[16] 田福祥.直齿圆柱齿轮精锻模具齿形设计.锻压技术, 1998, 23(2): 57-59
[17] 李洪波.圆柱直齿轮浮动式精锻模设计.模具工业，1995（9）：43-45
[18] Yohimura H., Tanaka K. & Wang C.C Precision Forging of Aluminum and Steel, Especially in Enclsed-Die Forging, Neuere Entwicklungen in der Massivumformung，in Fellbach bei Stuttgart,am 19 und 20. Mai 1999.
[19] Walters, J., Wu, W. T., Arvind,A., Guoji,L., Lambert,D., and Tang,J. Recent Developments of Process Simulation for Industrial Applications,Proceedings of the 4th International Conference on Precision Forging-Cold,Warm and Hot Forging. October 12-14,1998,Columbus,Ohio.1998
[20] Modern Cold Forging Applications for the Manfacture of Complex Automotive Parts, Journal of Material Processing Technology.Vol.46.(1994)
[21] Neher R. Cold Forging of Gears and Profiles of Couplings，Neuere Entwicklungen in der Massivumformung,in Fellbach bei Stuttgart,am 19 und 20. Mai 1999.
[22] 吴诗惇. 冷温挤压技术.国防工业出版社.1995.P3-5
[23] 田福祥. 新型行星齿轮锻模设计. 模具工业，2003（2）：35
[24] 汪大年.金属塑性成形原理,第二版.北京:机械工业出版社.1982
[25] 陈军等.体积成形过程的三维塑性有限元模拟技术研究.上海交通大学学报.1996，No.9
[26] 李尚健.金属塑性成形过程模拟.北京.机械工业出版社.1999
[27] 赵新海等.金属体积成形预成形设计的现状及发展.塑性工程学报.2000,No.3
[28] 王纪武.体积成形的三维有限元变形弹塑性有限元法的研究.塑性工程学报.2000，No.1
[29] Beom-soo kang, Naksoo Kim and S. Kobayashi·Computer-aided perform design in forging of an airfoil section blade.·Int.J.March.Tools manufact.·vol.30.no.1.p.43-52·1990
[30] S.Kobayashi,S.I.Oh and T.Altan,Metal Forming and the Finite Element Method, New York,Oxford University Press,1989
[31] 杨济民等.金属塑性成形研究方法综述.金属成形工艺.1990,No.2
[32] S.Kobayashi,Metal Forming and the Finite Element Methodpast and Future,Proc.25th Int.J.MTDR Conf.,Birmingham,,1985. P17
[33] 周杰等.摩擦对收口的影响研究.锻压技术.2001, No.1
[34] Kobayashi, S., Thermoviscoplastic analysis of metal forming problems by the finite element method, Numericl Methods in Industrial Forming Processes, Pineridge Press,1982, p17
[35] Hwang, S. M. and Kobayashi,S., Preform design in disk forging,Int.J.Mach.Tool Des. Res., 1986,Vol.26, p231
[36] 赵国群等.塑性有限元模拟中材料体积损失的控制方法.金属成形工艺.1999,No.6
[37] 小板田宏造.塑性变形の有限要素解析.机械の研究.第35卷，No.1~12
[38] 王仲仁.塑性加工力学基础.北京:国防工业出版社.1989
[39] N.K.Lee, J.H.Yoon and D.Y.Yang,Finite Element Analysis of Large Deformation by Automatic Renoding as A Weak Remeshing Technique, Int.J.Mech.Sci., 1992, Vol.34, No.4, P155-273
[40] Juipeng Tang,W.T.Wu, John Walters,Recent Development and Application of Finite Element Method in Metal Forming, J.Mater.Proc.Tech.,1994,Vol.46, P117-126
[41] 夏巨谌. 精密塑性成形工艺. 北京：机械工业出版社,1999.P48
[42] 田福祥. 直伞齿轮精锻模齿模的设计与制造. 模具制造，2002（12）：28~33.
[2] S.Kobayashi, S.I.Oh and T.Altan, Metal Forming and the Finite Element Method, New York, Oxford University Press, 1989 No.5
[3] 彭颖红.金属塑性成形仿真技术.上海交通大学出版社.1999.P3-4,71
[4] 夏巨谌，丁永祥，胡国安.闭式模锻.机械工业出版社.1993.P1
[5] 金 炫琪,山中 雅仁.ァメリカにぉける锻造分野でのシミュ レ-ション技术とその利用状况. 塑性と加工.1999,No.5
[6] Choi J C. A Study on the forging of spur gears. Int.J. Mech. Sci.,1996,38(12):1333-1347
[7] Chitkara N R. Near-Net shape forging of spur gear forms: An analysis and some experiments. Int.J.Mech.Sci.,1996,38(8-9): 891-916
[8] 林治平.带轮毂直齿圆柱齿轮精锻的计算机模拟.金属成形工艺, 1997, 15（2）：12-15
[9] 刘庆斌.直齿圆成形数值模拟及实验研究.金属成形工艺, 1995, 13(1)：34-38
[10] 李洪波.圆柱直齿轮精锻成形的UBET数值模拟.金属成形工艺，1996, 14(3)：21-23
[11] 程军.塑性加工工步的光塑性分析与图象处理.[博士学位论文],南昌大学,1998
[12] 陈泽中.直齿圆柱齿轮精锻工步分析与实验研究.[硕士学位论文],南昌大学,1998
[13] Vazquez,V., Walterss, J., Altan T. Forging Process Simulation - State of the Art in USA,Neuere Entwicklungen in der Massivumformung(体积成形最新研究进展)，in Fellbach bei Stuttgart,am 19 und 20. Mai 1999.
[14] 林治平.在摩擦压力机上精锻直齿圆.塑性加工理论与技术新进展.南昌：江西高教出版社,1997
[15] 田福祥.直齿圆柱齿轮热精锻-冷推挤精密成形研究.锻压机械, 1997(6)
[16] 田福祥.直齿圆柱齿轮精锻模具齿形设计.锻压技术, 1998, 23(2): 57-59
[17] 李洪波.圆柱直齿轮浮动式精锻模设计.模具工业，1995（9）：43-45
[18] Yohimura H., Tanaka K. & Wang C.C Precision Forging of Aluminum and Steel, Especially in Enclsed-Die Forging, Neuere Entwicklungen in der Massivumformung，in Fellbach bei Stuttgart,am 19 und 20. Mai 1999.
[19] Walters, J., Wu, W. T., Arvind,A., Guoji,L., Lambert,D., and Tang,J. Recent Developments of Process Simulation for Industrial Applications,Proceedings of the 4th International Conference on Precision Forging-Cold,Warm and Hot Forging. October 12-14,1998,Columbus,Ohio.1998
[20] Modern Cold Forging Applications for the Manfacture of Complex Automotive Parts, Journal of Material Processing Technology.Vol.46.(1994)
[21] Neher R. Cold Forging of Gears and Profiles of Couplings，Neuere Entwicklungen in der Massivumformung,in Fellbach bei Stuttgart,am 19 und 20. Mai 1999.
[22] 吴诗惇. 冷温挤压技术.国防工业出版社.1995.P3-5
[23] 田福祥. 新型行星齿轮锻模设计. 模具工业，2003（2）：35
[24] 汪大年.金属塑性成形原理,第二版.北京:机械工业出版社.1982
[25] 陈军等.体积成形过程的三维塑性有限元模拟技术研究.上海交通大学学报.1996，No.9
[26] 李尚健.金属塑性成形过程模拟.北京.机械工业出版社.1999
[27] 赵新海等.金属体积成形预成形设计的现状及发展.塑性工程学报.2000,No.3
[28] 王纪武.体积成形的三维有限元变形弹塑性有限元法的研究.塑性工程学报.2000，No.1
[29] Beom-soo kang, Naksoo Kim and S. Kobayashi·Computer-aided perform design in forging of an airfoil section blade.·Int.J.March.Tools manufact.·vol.30.no.1.p.43-52·1990
[30] S.Kobayashi,S.I.Oh and T.Altan,Metal Forming and the Finite Element Method, New York,Oxford University Press,1989
[31] 杨济民等.金属塑性成形研究方法综述.金属成形工艺.1990,No.2
[32] S.Kobayashi,Metal Forming and the Finite Element Methodpast and Future,Proc.25th Int.J.MTDR Conf.,Birmingham,,1985. P17
[33] 周杰等.摩擦对收口的影响研究.锻压技术.2001, No.1
[34] Kobayashi, S., Thermoviscoplastic analysis of metal forming problems by the finite element method, Numericl Methods in Industrial Forming Processes, Pineridge Press,1982, p17
[35] Hwang, S. M. and Kobayashi,S., Preform design in disk forging,Int.J.Mach.Tool Des. Res., 1986,Vol.26, p231
[36] 赵国群等.塑性有限元模拟中材料体积损失的控制方法.金属成形工艺.1999,No.6
[37] 小板田宏造.塑性变形の有限要素解析.机械の研究.第35卷，No.1~12
[38] 王仲仁.塑性加工力学基础.北京:国防工业出版社.1989
[39] N.K.Lee, J.H.Yoon and D.Y.Yang,Finite Element Analysis of Large Deformation by Automatic Renoding as A Weak Remeshing Technique, Int.J.Mech.Sci., 1992, Vol.34, No.4, P155-273
[40] Juipeng Tang,W.T.Wu, John Walters,Recent Development and Application of Finite Element Method in Metal Forming, J.Mater.Proc.Tech.,1994,Vol.46, P117-126
[41] 夏巨谌. 精密塑性成形工艺. 北京：机械工业出版社,1999.P48
[42] 田福祥. 直伞齿轮精锻模齿模的设计与制造. 模具制造，2002（12）：28~33.