scholarly journals Technical solution for evaluation of contact stiffness and strength of the joint surfaces of injector

Author(s):  
N. Koteneva ◽  
A. Borisova ◽  
N. Perfileva

От работоспособности форсунки зависит качество работы двигателя, его долговечность, соответствие экологическим нормам и требованиям, а от контактной прочности, жесткости и работоспособности ее сопрягаемых поверхностей (различных соединений, которые можно отнести к условно-неподвижным) – нормальная эксплуатация рассматриваемой конструкции в целом. На базе существующей технологии производства форсунок и с использованием физико-математической модели упругопластического контактирования, созданной авторами, предложено техническое решение для оценки контактной жесткости и прочности стыковых поверхностей форсунки для распыления топлива. Авторами установлено, что работа двигателя в целом зависит от характеристик контактирующих поверхностей форсунки, а именно параметров микрогеометрии шероховатого слоя, фактической площади соприкосновения, податливости, физико-механических свойств материалов контактной пары, условий нагружения. На основе проведенных авторами исследований и комплексного анализа при заданных геометрических размерах конструкции форсунки двигателя внутреннего сгорания и условий работы ДВС разработано техническое решение, позволяющее повысить контактную жесткость стыковых сопряжений форсунки для распыления топлива и равномерного его распределения в камере сгорания дизеля в 1,2–1,5 раза. Таким образом, предлагаемое авторами решение показало свою эффективность, и его можно рекомендовать для применения в ДВС, в том числе в судовых двигателях.

Author(s):  
Yongquan Zhang ◽  
Hong Lu ◽  
Xinbao Zhang ◽  
He Ling ◽  
Wei Fan ◽  
...  

Considering the rough surface as a fractal model makes the research of contact parameters more practical. In the fractal model of the machined surface, the parameters describing the surface topography are independent of the measurement resolution. Based on the elastic, elasto-plastic and plastic deformations of a single pair of contact asperities, a normal contact stiffness model using the fractal model for surface topography description is proposed in this paper. The specimens machined by milling and grinding methods are used to verify the proposed contact stiffness model based on the fractal theory. The experimental and theoretical results indicate that the proposed contact stiffness model is appropriate for the machined joint surfaces.


2020 ◽  
Author(s):  
Chao-Chao Yin ◽  
Hai-Hong Huang ◽  
Dan Zhou ◽  
Zhi-Feng Liu

Abstract Effects of surface texturing on the normal contact stiffness of joint surfaces had been investigated by experiments in many previous researches; however, there are relatively few theoretical models in this regard. The rough surface with surface texturing can be divided into two parts: the textured zone and the remaining zone, and their theoretical models are established respectively in this research. For the textured zone, the texture is modeled theoretically based on the three-dimensional topographic data obtained via a 3D-CCMP1 type laser profilometer from TRIMOS. For the remaining zone, the model of normal contact stiffness is established based on the fractal theory for the surface topography description and elastic-plastic deformation of surface asperities, and the structure function method is used to calculate the fractal dimension of rough surface profiles. In the experiment, the normal contact stiffness of specimens is obtained under different normal loads, and the test results are compared with the theoretical predictions. The result shows that the predictions of proposed theoretical model are in good agreement with the experimental data. For the joint surfaces with Sa>2.69 μm, the normal contact stiffness can be effectively increased through proper surface texturing.


2017 ◽  
Vol 88 (4) ◽  
pp. 525-541 ◽  
Author(s):  
Wujiu Pan ◽  
Xiaopeng Li ◽  
Linlin Wang ◽  
Na Guo ◽  
Zemin Yang

2013 ◽  
Vol 437 ◽  
pp. 8-12
Author(s):  
Yao Yang ◽  
Jun Tang Yuan ◽  
Zhen Hua Wang ◽  
Biao Yang

The method for dynamic modeling of joint surfaces is proposed to predict dynamic performance of machine tool accurately by virtual material layer elements in this paper. For this process, the numerical relations of contact stiffness and virtual material layer parameters are obtained by finite element theory, and the finite element model is founded by virtual material layer elements and multiple point constrain technique (MPC). Modal analysis of a simple model under different contact stiffness is carried out. It has shown the relative errors between theoretical natural frequencies and simulated ones of this model are less than 2%.


2015 ◽  
Vol 85 (12) ◽  
pp. 1997-2008 ◽  
Author(s):  
Junping Shi ◽  
Xiaoshan Cao ◽  
Yifeng Hu ◽  
Hong Zhu

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