Abstract

The influence of pulsating dynamic loads at nonstationary self- and parametric oscillations in surface layers of the parts under plastic deformation regarding the quality of finished products after cold rolling, knurling, breaking-in, drawing and punching has been provided. In order to describe the parametric interaction effects between the tool and the workpiece, a schematization of the technological process is adopted, in which the workpiece bulk or a part manufactured from it serves as an anisotropic medium. This is elastically bound to the contact’s surface of the outer hardened layers with the inner bulk of the part. Based on the proposed physical model, the conditions have been determined that lead to failure of integrity, manifestation of cracking and corrugation of external fibers during the hardening process. The second dynamic problem for the surface layers is formulated and solved at the interface between the machined hardened outer layers and bulk of the workpiece. The frequency and amplitude characteristics of unstable parametric oscillations have been found, which lead to deterioration of the quality of finished products. Measures to reduce vibration activity in the interaction zone between the tool and the workpiece, and in the power elements of machines for cold metal working have been suggested.

中文翻译：

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变形工具与钢坯相互作用期间的摩擦自激振动的参数分析

摘要

提供了在塑性变形下零件表面层的非稳态自动和参数振荡下的动动脉动对冷轧，滚花，磨合，拉拔和冲压后成品质量的影响。为了描述工具与工件之间的参数交互作用，采用了工艺过程的示意图，其中工件的整体或由其制造的零件用作各向异性介质。这弹性地绑定到外部硬化层与零件内部的接触面。基于所提出的物理模型，确定了导致硬化过程中整体纤维失效，外部纤维开裂和起皱的表现的条件。表面层的第二个动态问题是在机加工的硬化外层与工件主体之间的界面处制定和解决的。已经发现不稳定的参数振荡的频率和幅度特性，这导致成品质量的下降。已经提出了减少工具和工件之间的相互作用区域以及冷金属加工机器的动力元件中的振动活动的措施。