载重汽车用直齿圆柱齿轮连续冷挤压冷整形复合成形关键技术研究

发布时间：2018-04-20 23:02

本文选题：直齿圆柱齿轮 + 冷挤压　；参考：《重庆大学》2016年博士论文

【摘要】：直齿圆柱齿轮作为载重汽车轮边减速器中最常见的传动零件,市场需求量巨大,一般采用切削加工方法制造。随着精密塑性成形工艺的发展,直齿圆柱齿轮的生产也越来越多的采用这种净近成形的方法制造,其成形后的齿面光洁,金属流线连续,轮齿承载能力高,因此采用精密塑性成形工艺制造直齿圆柱齿轮具有广阔的应用前景。随着模具制造技术的提高和新型模具材料的研发及应用,大模数、大齿宽直齿圆柱齿轮精密塑性成形技术正逐渐应用于工业生产,但仍存在成形质量不稳定、成形精度差的问题。因此,如何提高直齿圆柱齿轮的成形质量和成形精度是精密塑性工艺的关键。本文以载重汽车轮边减速器用直齿圆柱齿轮为研究对象,提出一种全新的直齿圆柱齿轮通过式连续“冷挤压+冷整形”复合成形工艺方案,并从直齿圆柱齿轮冷挤压工艺参数多目标优化、大模数冷挤压直齿轮冷整形方式和整形量的选择、直齿圆柱齿轮冷挤压组合凹模的优化设计等方面对直齿圆柱齿轮通过式连续“冷挤压+冷整形”复合成形关键技术进行了系统全面的研究。论文的主要研究工作有以下几点:(1)对原成形工艺通过式冷挤压生产的直齿圆柱齿轮成形质量差、成形精度低的问题进行了分析,得出导致成形齿轮质量差、精度低的主要原因为:冷挤压时背压力不足和冷挤压齿轮的弹性回复。基于分析结果提出一种全新的直齿圆柱齿轮通过式连续“冷挤压+冷整形”复合成形工艺。(2)研究分析了冷挤压主要工艺参数对直齿轮成形质量的影响规律,提出采用数值模拟和实验设计相结合的方式,以响应面法作为优化方法,成形质量和成形载荷作为优化目标,对各工艺参数进行多目标优化设计,得出最佳工艺参数组合。误差分析和生产实践证明,采用优化工艺参数组合,能有效提高齿轮成形质量和降低齿轮成形载荷。(3)基于冷挤压齿轮实际测量的数据建立误差模型,分析了不同冷整形方式及整形量对齿轮冷整形过程中金属流动及齿轮精度的影响规律,并确定了合理的冷整形方式及整形量。采用只整形齿面的冷整形方式和双侧整形量为0.15mm进行工艺实验,检测结果显示,齿轮齿形精度由8级提高至7级,齿向精度由10级提高至8级,冷整形工艺可以显著地提高冷挤压齿轮的精度。(4)采用实验设计与数值模拟相结合的方法,构建直齿圆柱齿轮冷挤压组合凹模结构参数与模芯最大等效应力之间的Kriging模型,运用粒子群算法对其进行全局寻优,得出冷挤压组合凹模最佳直径比和过盈系数。优化后的组合凹模整体尺寸仅为经验法设计尺寸的68.75%,有效减小了组合模具的整体尺寸,节约了模具材料,采用优化后的组合凹模进行实际生产,模具使用寿命约15万件,与原经验法设计的组合凹模相比较,使用寿命保持不变。(5)采用直齿圆柱齿轮通过式连续“冷挤压+冷整形”复合成形工艺进行生产试制,尺寸检测结果显示,上、下端齿顶最小直径分别为74.40mm和73.86mm,均达到后续车外圆要求,下端端面外凸约2mm,上端端面凹陷约2mm,优于原工艺加工的齿轮。齿轮精度检测结果显示,齿廓总偏差最大为12.2μm,达到了GB/T10095齿形精度等级6级;螺旋线总偏差最大为26.6μm,达到了GB/T10095齿向精度等级8级。因此采用复合成形工艺可以加工生产出精度为8级的大模数直齿圆柱齿轮。
[Abstract]:As the most common transmission part in the wheel side reducer of the truck, the straight tooth cylindrical gear has a huge market demand, which is usually made by cutting method. With the development of the precision plastic forming technology, the production of the straight tooth cylindrical gear is also more and more manufactured by this net forming method. The tooth surface after forming is smooth and metal. With the continuous flow line and the high bearing capacity of the tooth, the precision plastic forming technology has a broad application prospect. With the improvement of the mould manufacturing technology and the development and application of the new mold material, the large modulus and the large tooth wide straight cylindrical gear precision plastic forming technology is gradually applied in the industrial production, but still remains. Therefore, how to improve the forming quality and forming precision of the spur gear is the key to improve the forming quality and forming precision of the spur gear. In this paper, a new type of straight spur gear continuous "cold extrusion + cold shaping" is put forward by using the spur gear of the wheel side reducer of heavy truck as the research object. "Compound forming process plan", and from the cold extrusion process parameters optimization of straight tooth cylindrical gear, the selection of cold extrusion method and plastic volume of large modulus cold extruding spur gear and the optimization design of cold extrusion die for straight tooth cylindrical gear, the key technology of the continuous continuous "cold extrusion + cold shaping" of straight tooth cylindrical gear is made. The main research work of the paper is as follows: (1) the problems of poor forming quality and low forming precision of the straight tooth cylindrical gear produced by the cold extrusion of the original forming process are analyzed, and the main reasons for the poor quality of the forming gear and the low precision are the insufficient back pressure and cold extrusion in the cold extrusion. Based on the analysis results, a new process of continuous "cold extrusion + cold shaping" composite forming for straight spur gear is proposed. (2) the influence of the main process parameters on the forming quality of the spur gear is studied and analyzed, and a combination of numerical simulation and experimental design is proposed, and the response surface method is adopted. As optimization method, forming quality and forming load are the optimization targets, the optimum design of various process parameters is carried out, and the optimum combination of process parameters is obtained. Error analysis and production practice prove that the optimization of process parameters can effectively improve the quality of gear forming and reduce gear forming load. (3) based on the practice of cold extruded gear. The error model of the measured data is set up. The influence of different cold shaping methods and plastic volume on the metal flow and gear precision in the cold shaping process of the gear is analyzed. The reasonable cold shaping method and the plastic volume are determined. The cold shaping method and the bilateral plastic volume of the tooth surface are used for the process experiment of 0.15mm, and the test results are shown, The precision of gear tooth shape is raised from 8 to 7, and the precision of tooth direction is raised from 10 to 8. Cold shaping technology can improve the precision of cold extruded gear. (4) the Kriging model of the structure of the cold extrusion die of the straight spur gear and the maximum equivalent stress of the core is constructed by combining the experimental design with the numerical simulation. The optimum diameter ratio and interference coefficient of the combined die for cold extrusion are obtained by the particle swarm optimization. The overall size of the combined die after the optimization is only 68.75% of the design size of the experience method, which effectively reduces the overall size of the combined die, saves the mold material, and uses the optimized combined die to make the actual production, the die makes the die. Compared with the combined die designed by the original experience method, the service life remains unchanged. (5) the production test is made by the continuous "cold extrusion + cold shaping" composite forming process of straight tooth cylindrical gears, and the size detection results show that the minimum diameter of the upper and lower teeth is 74.40mm and 73.86mm respectively, which all reach the outside of the vehicle. The end face is convex about 2mm, and the end face is convex about 2mm, the end face of the upper end is about 2mm, which is better than the original process gear. The gear precision test results show that the maximum tooth profile deviation is 12.2 u m, reaching the 6 grade of GB/T10095 tooth shape precision grade; the maximum spiral line deviation is 26.6 mu m, and the GB /T10095 tooth direction precision grade is 8. It can produce a large modulus spur gear with a precision of 8.

【学位授予单位】：重庆大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TH132.41;TG376.3

【引证文献】