【作者】 田希杰；

【导师】 高军；

【作者基本信息】 山东大学 ， 材料加工工程， 2009， 硕士

【摘要】 精锻齿轮,是指齿轮的轮齿直接模锻成形且无需切削加工的齿轮。直齿锥齿轮,以其结构上的可锻性,成为国内外研制最早、发展最快、应用最多的精锻零件之一。同利用切齿加工相比,精锻齿轮在提高寿命、节能、节材等方面具有显著的效果。然而,受技术和装备等水平的影响,7级以上精度的齿轮难以实现批量精锻,限制了精锻齿轮在现代汽车特别是轿车、重型车中的应用。采用齿轮齿形修形技术可有效地改善齿轮传动装置的工作平稳性,降低齿轮的噪声和振动,提高齿轮的承载能力,延长齿轮的使用寿命。圆柱齿轮的齿形修形易于实现,已取得了明显的效果,而圆锥齿轮齿形修形技术,受到齿轮结构的影响,加工出的鼓形量较小且鼓形位置难以调整,达不到齿形修形的根本目的。精锻锥齿轮靠模具成形,研究通过模具型腔修形实现齿轮产品的修形是经济的。论文综合分析了齿轮齿形修形技术的国内外究现状,以目前难以实现齿形修形的精锻直齿锥齿轮为研究对象,提出并研究实现了精锻直齿锥齿轮的等距化铣修形工艺。该工艺研究应用化学铣切方法,通过对齿轮精锻模电极齿轮的等距修形,实现精锻模具型腔的修形,从而实现精锻锥齿轮的齿形修形。通过在某汽车差速器齿轮的精锻生产证明,应用本研究技术,可以提高精锻齿轮产品运动精度和工作平稳性精度一级,齿轮产品的接触区分布较好,齿面粗糙度得以降低,精锻模具寿命得到提高20%。通过研究分析证明,提出的等距化铣修形技术,不仅可以方便地实现精锻直齿锥齿轮的齿顶修缘和鼓形齿加工,而且,修形后的表面仍然保持齿轮的渐开线特征。提出以齿形修形后,精锻齿轮能否顺利脱模作为修形设计的主要依据,并根据修形齿轮的结构特点,建立了计算精锻直齿锥齿轮齿面上任意修形部位点脱模校核的数学模型,编制了通用的修形精锻直齿锥齿轮脱模计算程序。通过对常用电极齿轮材料—紫铜的化铣实验,认为:化铣液主要成份Fe³⁺的含量在8-12g/l、化铣温度宜在40-60℃、化铣时间在10分钟以上时,对紫铜材料的化铣速度达到较大值且波动较小,化铣面的表面粗糙程度保持在较低程度;对于一般齿轮的齿形修形量在0.02-0.05mm的情况下,采用本化铣工艺能够保证对紫铜材料化铣的均匀性。根据直齿锥齿轮的齿形修形技术需要,提出了精锻直齿锥齿轮齿形修形设计综合技术研究路线,认为修形直齿锥齿轮的三维实体建模是本技术研究的基础,论文基于SolidWorks系统,采用尺寸驱动法进行了等距修形直齿锥齿轮的三维实体建模模块开发。更多还原

【Abstract】 The teeth of gear named fine forging gear can be formed directly by the forging die without chip-removal machining. Especially for the bevel gear, it was the one of fine forging parts which were developed and applied earlier. Compared with the machining gears, some merits can be obtained to the gears made by fine forging technology as high mechanical performance, long life, energy saving and less materials. But due to the limitation of forming technology and equipments, fine-forging bevel gears with high precision better than 7-grade are hardly manufactured in batch and then their application are out of modern automobile industry. It is proved that the transmission stability, precision and service life of gear box can be improved as well as the vibration and noisy can be lightened with the usage of teeth profile modification technology in manufacturing of gears. It is easy to modify the profile of spur gears, and only minimal modification of profile can be obtained in bevel gears even with some certain location. The modification technology of bevel gears then used seldom. In fact it is efficient and effective to modified the teeth profile of fine forging gears if the modification was printed on the forging die previously.Based on the synthetical analysis of the research and application of the gear modification technology, this thesis put forward and developed the Equidistance Chemical Machining Modification Technology(ECMMT) which is available to the bevel gears modification. The electrode gear, used to form the cavity of fine forging die by the Electrode Discharge Machining(EDM), are modified by the ECMMT. The modification the is "copied" on the die. Large batch of fine forging gears with the special modification therefore are "duplicated" by the unique die. The ECMMT was used in the production of a certain type bevel gear used in the car, as the result, the transmission precision and stability of the bevel gears improved to the 7-grade, the touch area is quite better, the roughness of the teeth face is increased greatly, and the life of forging die is lengthened.By use of ECMMT, both edge modification and the drum area on the gear tooth surface can be implemented easily, as well, the involute characteristic of the modified teeth of bevel gear keeps the normal gear profile.One of the principles of gear teeth modification is researched in this thesis, that is whether the forging gear with teeth modification can be lift out of the die cavity or not. And the calculating model is constructed based on the study of the modified bevel gear structure. Further the universal program is developed and tested effective as the tool to design the figure and the location of modification area.The useful results are obtained by the experiments of chemical milling parameters on copper samples. It’s tested that the best chemical milling parameters to reach the excellent machining result are those, the Fe3+ content of electrolyte is 8-12 g/l, the work temperature keeps between 40℃to 60℃, the milling time is not less than 10 minutes. By use of the chemical machining technology with the parameters above, such ideal and operable results as the well-proportioned milling velocity, lower surface roughness and the material equidistance removal of varied surfaces when the milling depth in 0.02-0.05mm.It is necessary to build the comprehensive research way to design the modification area and size precisely for the straight-teeth bevel gear. In this thesis, the 3-D modeling system of equidistance modification bevel gear is developed based the universal CAD software SolidWorks with main help of the tool integrated in SolidWorks-Size Drive Method.更多还原