【作者】 王俸生；

【导师】 陈新；

【作者基本信息】 广东工业大学 ， 机械电子工程， 2012， 硕士

【摘要】 螺旋伞齿轮是一类齿形复杂的齿轮,具有传动效率高、传动比稳定、承载能力高等特点,被广泛应用于汽车、航空航天、工程机械等行业领域。作为机械装备业的核心零部件,螺旋伞齿轮的制造水平一定程度上代表了一个国家机械装备业的发展水平。目前,我国螺旋伞齿轮的生产大部分还是依靠传统的“热锻造+机加工”的方式。如何在现有生产设备的基础上提高生产效率和齿轮的制造质量是企业非常关心的问题。本文的研究内容正是基于了企业的这种需求。本文提出了齿轮毛坯锻造过程数值模拟的多步分析方法,运用有限元软件DEFORM-3D分别对主动螺旋伞齿轮毛坯的拔长过程、模锻过程和对从动螺旋伞齿轮毛坯的镦粗过程、模锻过程进行了多步分析。得到了主、从动螺旋伞齿轮毛坯锻造成形过程中的金属流动规律,得到了锻造过程中应力、应变和温度随时间的变化曲线,得到了毛坯终锻时的应力、应变和温度分布,得到了锻造过程的行程-载荷曲线和迭代步-能耗曲线等数据。结果表明,锻造成形过程中金属材料在阶梯处流动较困难,导致毛坯锻造过程中和终锻时阶梯处出现大的应力、应变和高的温度。本文研究了模具结构、始锻温度和摩擦系数对锻造成形效果的影响。对模具结构进行了改进,数值模拟了模具结构改进后的锻造过程,对比了模具结构改进前后毛坯终锻时的应力、应变和温度分布。结果表明,对模具结构进行合理地改进能有效改善材料的成形效果,数值模拟结果可为模具结构设计与改进提供指导。数值模拟了始锻温度分别为1000℃、1050℃和1100℃,摩擦系数分别为0.3和0.7时的锻造过程,对比了不同始锻温度和摩擦系数下毛坯终锻时的应力应变、行程-载荷曲线和迭代步-能耗曲线。结果表明,在1000℃-1100℃范围内,当始锻温度越高,摩擦系数越小时,毛坯终锻时的应力应变也越小,温度越低,成形载荷越小,锻造能耗越少,成形效果越好。针对主动螺旋伞齿轮毛坯拔长工步中由于自由锻拔长工艺而引起的锻件弯曲的问题,提出了采用挤压成形方法来拔长棒料。运用DEFORM-3D对挤压成形过程进行了数值模拟,得到了挤压成形后坯料的形状、应力应变和温度分布等数据,并结合模锻过程进行了多步分析。挤压成形方法解决了锻件弯曲问题,但挤压成形方法存在生产效率低和能耗大的问题,本文又提出了旋压成形方法。设计了一个旋压装置以用于旋压成形,运用SOLIDWORKS软件对旋压装置进行了几何建模,并运用有限元软件ABAQUS对旋压成形过程进行了数值模拟,得到了旋压成形后坯料的形状、应力云图和应变云图等数据,验证了使用旋压成形方法代替自由锻拔长的可行性。将旋压成形的能耗与挤压成形的进行了对比,旋压成形比挤压成形节省能量。更多还原

【Abstract】 Spiral bevel gear is a kind of gear with complex tooth shape,high transmission efficiency.stable transmission ratio and high bearing capacity.lt is widely used in automotive,aerospace.engineering machinery and other industries.As the core of the mechanical equipment industry parts,the manufacturing level of spiral bevel gears, to a certain extent, represents a national mechanical equipment industry development level.At present, the production of spiral bevel gears still rely on the traditional way-"hot forging+machining" in our country.How to improve production efficiency and manufacturing quality on the basis of the existing equipment is the question that the enterprise concern about.The research content of this paper is based on that demand of the enterprise.Many-steps analysis method is put forward to simulate the forging process of spiral bevel gear blank.The finite element software DEFORM-3D is used to simulate the pull long process and die forging process of driving spiral bevel gear blank and the upsetting process and die forging process of driven spiral bevel gear blank. The metal flow law of forging process, the curves of stress,strain and temperature changing with time throughout the forging process, the stress,strain and temperature distributions when the forging process is completed, and the stroke-load curves and the step-energy curves of forging process are got. The results show that the stress and strain are great and the temperature is high in the ladder place,because the metal flow difficultly in the ladder places.The effect that die structure, initial forging temperature and friction coefficient on forging are researched.The die structures are improved.The forging processes when the die structures have been improved are simulated.And the stress,strain and temperature distributions are compared before and after the die structures are improved. The results show that the forming quality of forgings are improved due to the die structures are improved. The results of numerical simulation can provide guidance for the die structure design and improvement. The forging processes are simulated when the initial forging temperature is1000℃,1050℃,1100℃and the friction coefficient is0.3,0.7.The numerical simulation results are compared. The results show that when the initial forging temperature is higher and the friction coefficient is less.the stress.strain.temperature.load and energy are lower.Squeezing forming method is proposed to solve the problem of forgings bent because of the problem happening in free forging of driving spiral bevel gear blank. DEFORM-3D software is used to simulate the squeezing forming process. The blank shape, stress,strain and temperature distributions after squeezing forming are got.and the squeezing forming process is simulated together with the die forging process. The problem of forgings bent is solved.But the production efficiency of squeezing forming method is low and the energy consumption is high,so spinning forming method is proposed.A spinning device is designed for spinning forming.3d modeling software SOLIDWORKS is used to establish the geometric model of spinning device.and the finite element software ABAQUS is used to simulate the spinning forming process.The blank shape, stress rainbow and strain rainbow after spinning forming are got.The free forging can be replaced by spinning forming.The energy consumption of squeezing forming and spinning forming are compared.the spinning forming is less.更多还原