Study on Development of Low Noise Plastic Gear and Injection Control

注塑齿轮广泛用于旋转和动力传动。一般情况下，齿轮齿面容易出现变形层。从齿轮强度的角度出发，要求有较薄的变形层。因此，使用变形层的建议对注塑齿轮的静音是有用的。为了无声地帮助开发出性能优良的塑料齿轮，结晶树脂注塑成型塑料齿轮齿面产生的变形层表明，成型条件对齿轮的厚度和力学性能有影响。本课题选用了两种聚缩醛树脂，并在不同的成型条件下制作了注塑成型的塑料齿轮。对塑料齿轮在不同成型条件下的偏光显微镜观察和硬度检测进行了分析。此外，还对齿轮的噪声进行了EX…检查通过齿轮功率运行检测机对变形层厚度的影响进行了较为深入的研究。研究结果如下：(1)树脂熔体与模具的温差影响牙齿的硬度和表层厚度。(2)噪声水平过低，齿轮齿面产生的变形层较厚。(3)在气缸温差和模型温差较低的情况下生产的齿轮的噪声水平比在大温差条件下生产的齿轮的噪声水平有升高的趋势。(4)齿轮的磨粒磨损受齿轮变形层厚度的影响，齿轮的寿命可视为噪声水平异常升高的时刻。(5)变形层较薄的聚缩醛共聚物齿轮磨损量较小，而聚缩醛均聚物齿轮的磨损量则没有相同的趋势。通过选择合适的注塑工艺条件，可以展示低噪声塑料齿轮的成型方法。较少

The injection molded plastic gears are widely used for rotation and power transmission. Generally, the deformed layer appears easily in the tooth surface of the gear. The thin deformed layer is demanded from the viewpoint of gear strength. Therefore, the proposal to use the deformed layer is useful for the silence of the injection molding plastic gear. To assume a help of the development of an excellent plastic gear in silence, the deformed layer generated to teeth of the injection molding plastic gear manufactured by crystalline resin showed that the thickness and mechanical properties were influenced on the molding conditions. Two kinds of polyacetal resins were chosen in this problem, and the injection molding plastic gears were manufactured under various molding conditions. In this study, the polarization microscope observation and hardness examination of the plastic gear manufactured under various molding conditions were analyzed. Furthermore, the noise of the gear was examined ex … More perimentally on the influence of the deformed layer thickness by a gear power operation examining machine. The results obtained in this study were as following : (1) The temperature difference of melted resin and the mold influences the hardness and the skin layer thickness of tooth. (2) The noise level becomes so low that the deformed layer produced for the gear's tooth is thick. (3) The noise level of gear that was produced on conditions of the low temperature difference of cylinder and model is in a higher tendency than the gears produced on the conditions of the large temperature difference. (4) The abrasive wear of gear is affected by the thickness of the deformed layer of the tooth, and the life of gear can be considered the moment when a noise level rose abnormally. (5) The amounts of wear in the polyacetal copolymer gears with the thin deformed layer were little, but that of polyacetal homopolymer gears didn't become the same tendency. The molding method of a low noise plastic gear was able to be shown by selecting a proper injection molding conditions. Less