Wang J.,Tsinghua University |
Zhang J.,Tsinghua University |
Feng P.,Tsinghua University |
Xu W.,Zhejiang Wanliyang Transmission Co.
Zhongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Central South University (Science and Technology) | Year: 2014
In order to study the static clamping characteristics of power-operated compensating chuck, a mathematic model for the clamping efficiency and compensating dosage of the chuck was developed. The investigation performed shows that the clamping efficiency of chuck not only directly affects the coefficient of force transfer but also the stability of static clamping force against the deterioration of the lubrication. The chuck structure which has a higher clamping efficiency will have a fewer static clamping force loss caused by the enlargement of friction. While the compensating chuck is working, the smaller the diameter of workpiece chucked is, the lower the clamping efficiency will be. The compensating dosage is proportional to the product of lever ratio and the clearance space between the floating sleeve and the guide bushing, and its proportion depends on the wedge angle of floating sleeve and the angle between the two arms of lever. Based on the establishment of mathematical relationship between the coefficient of force transfer and compensating dosage, the optimized design method for floating chuck is put forward considering fully the realization of clamping and compensating function.
Hong L.,Zhejiang University |
Wang D.,Zhejiang Wanliyang Transmission Co. |
Bian G.-D.,Zhejiang Normal University |
Wang L.-L.,Zhejiang Normal University |
Hu S.-G.,Zhejiang University
Acta Metallurgica Sinica (English Letters) | Year: 2015
The objective of this research was to develop a novel self-lubricating coating on an AA6061 aluminum alloy. Three coatings were prepared by the plasma electrolytic oxidation (PEO) process using 50-, 500-, and 1000-Hz pulsed direct current, respectively. The as-deposited coatings were then post-treated using two different methods, viz., ultrasonic vibration-aided vacuum oil impregnation (UVOI) and oil impregnation under ambient pressure (OIAP). After posttreatment, an oil-containing, self-lubricating top layer was formed on the coatings. The effects of the coatings' surface morphologies and structures on their oil-holding capabilities were discussed. The results revealed that coatings prepared with higher frequency had a greater oil-holding capacity using OIAP post-treatment, while those prepared with lower frequency had a greater oil-containing capability using UVOI post-treatment. These phenomena are related to the morphologies of the coatings produced with various current modes. The tribological properties of the coatings before and after post-treatments were investigated by pin-on-disc sliding wear tests. Due to the formation of a lubricant-containing top layer, the post-treatment coatings had a lower friction coefficient and improved wear resistance compared with the asdeposited coatings. In addition, the coatings after UVOI treatment had better wear performance than those post-treated using the OIAP process. Among all coatings, the coating produced with a 50-Hz pulsed current followed by UVOI posttreatment achieved the lowest friction coefficient (0.03) and best wear resistance when sliding against a Si3N4 ceramic counterface. This study indicates that a novel self-lubricating coating can be prepared by a PEO process combined with vacuum oil impregnation post-treatment. © The Chinese Society for Metals and Springer-Verlag Berlin Heidelberg 2015.
Jin L.,Zhejiang Wanliyang Transmission Co. |
Deng S.,Zhejiang Normal University |
Xie C.,Zhejiang Normal University |
Wang Z.,Zhejiang Normal University |
Gao C.,Zhejiang Normal University
MATEC Web of Conferences | Year: 2015
Stainless steel thin-walled tube are widely used in automobile industry at present, but as a result of thin wall pipe is poor strength and poor rigidity,which lead to deformation, shaped differencer and other problems in the process, it is hard to ensure the processing quality of parts. This paper proposes a method of thin stainless steel thin wall pipe cutting process in vehicle, greatly improved the problems and technical difficulties in the traditional process, the main research is about the cutting system and the hydraulic fixture design, obtained under low cost circumstances, it can realize high precision stainless steel pipes, high degree of automation to automatic cutting,simplified operation steps at the same time, increased the applicability of the system, provided a kind of advanced stainless steel thin wall pipe cutting device for the small and medium-sized enterprises. © Owned by the authors, published by EDP Sciences, 2015.
Zhang J.F.,Tsinghua University |
Chen Z.M.,Tsinghua University |
Feng P.F.,Tsinghua University |
Xu W.H.,Zhejiang Wanliyang Transmission Co.
Applied Mechanics and Materials | Year: 2013
A comparative experimental study on the orthogonal cutting of titanium alloys by a polished tool, a tool containing a chip breaker groove, and a surface-textured tool was performed. The effects of different cutting tools on chip morphology, chip thickness, length and width of crack defects inside the chip, saw-teeth of the chip, and chip curl radius were analyzed during the cutting of a titanium alloy. Compared to chips formed by other tools, curled chip fragments formed by the surface-textured tool exhibited greater thickness and longer crack defect depths but smaller chip tooth pitches and curvature radii. The microstructural mechanisms involved in the interaction between the micro-texture surface cutting tool and the chips were analyzed by evaluating the cutting and texture parameters. The chip-breaking mechanism is that the micro-texture on the tool surface creates a sticky texture, leading to the micro-cutting and wrenching of chips, thereby increasing the magnitude of the tool's work-hardening and chip-breaking effects. © (2013)Trans Tech Publications,Switzerland.
Zhou Q.-Z.,Shenyang Ligong University |
Ning G.-L.,Shenyang Ligong University |
Xu W.-H.,Zhejiang Wanliyang Transmission Co.
Information Technology Journal | Year: 2013
In order to thoroughly promote the enterprise digital construction and meet the demand of production management, the space based multi-level process data organization model has been put forward. Firstly, according to the practical division situation of enterprise production space, the multi-level organization method of production space has been proposed. Then through analyzing the manufacturing process of the products in different space layers, the space based multi-level process flow idea has been presented. At the same time, the mathematical model and formalized expression of multi-level technological process have been established. Finally, the in-output material flow relationship between different levels process flow units has been analyzed and the source of input object as well as the disposition of the output object of various level process flow units has been put into detailed analysis. At the meantime, particular statistical sum and trace arithmetic are provided so as to profoundly illustrate the essence of manufacturing process in theory. As a result, the models proposed in this study are not only express the manufacturing process flow of the product in an intuitive and clear way, but also satisfy all types of demands of production management. © 2013 Asian Network for Scientific Information.