Ceramic insulators for spark plugs are important components responsible for the dielectric barrier to generate high-voltage pulses required to ignite the air–fuel mixture and for providing mechanical support to the center electrode. To ensure a high degree of reliability, many manufacturers apply corrugation patterns to the glazed upper part of an insulator to prevent flashover and parasitic discharges as well as to reduce the leakage current. The corrugation pattern design based mostly on simple cylindrical and conical shapes has changed very little over the years. This gives rise to the question whether an application of more sophisticated curves such as spherical, polynomial, or exponential can improve the surface resistance of a ribbed spark plug insulator. Quantitative analysis based on form factor and leakage distance calculations was used as a design method to optimize the shape of the spark plug insulator and its pollution performance. Furthermore, a novel concept of concave insulator corrugation patterns formed by quadratic and exponential functions was proposed and discussed as an alternative solution suitable for practical application. It was found that insulator ribs completed with supplementary concave corrugation ensure a longer leakage distance than conventional patterns. According to the results of calculations and measurements performed on three-dimensional printed samples, it was stated that the novel concave corrugation patterns can significantly increase the surface resistance of spark plug insulators.

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关于陶瓷绝缘体形状因素的火花塞可靠性改进

火花塞的陶瓷绝缘体是重要的部件，它负责产生点燃空气燃料混合物所需的高压脉冲的介电屏障，并为中心电极提供机械支撑。为了确保高度的可靠性，许多制造商在绝缘体的玻璃上部应用波纹图案，以防止闪络和寄生放电以及减少泄漏电流。多年来，主要基于简单圆柱和圆锥形状的波纹图案设计变化很小。这就产生了一个问题，如球面、多项式或指数曲线等更复杂曲线的应用是否可以提高带肋火花塞绝缘体的表面电阻。基于形状因子和泄漏距离计算的定量分析被用作优化火花塞绝缘体形状及其污染性能的设计方法。此外，提出并讨论了由二次函数和指数函数形成的凹绝缘体波纹图案的新概念，作为适合实际应用的替代解决方案。结果发现，与传统图案相比，带有补充凹形波纹的绝缘肋确保了更长的泄漏距离。根据对三维印刷样品进行的计算和测量结果表明，新型凹形波纹图案可以显着增加火花塞绝缘体的表面电阻。