Papers by Author: Li Zhi Gu

Abstract: In order to supply premium blades of Gang Saw for cutting stone, segments with diamond abrasive are supposed to weld onto the blade base in proper position. Analyze the requirements of the blades and put forward high precision location of the segment with respect to the blade base symmetry based on the double stochastic numbers for the longitudinal allocation and on the over-lapping principle of location for the symmetry. Accordingly the design of feeding and locating of both the blade bases and the segments are accomplished. Theoretically, the locating errors are zero, and the real locating accuracy reaches the level of micrometer, satisfying the need of applications in engineering. The feeding and locating system, together with the clamping devices, so designed for the blade welding operation works well.

Abstract: By analyzing factors affecting the accuracy of boring process on the precision boring machine, the article aims at putting forward a method of improving the accuracy of boring process by means of installing polymer elastic shock absorbers on unilateral boring tools. In addition, the situation of non-linear radial forced vibration is formulated by a dynamic model of second-order differential equation. Based on the model, vibration prevention principles of unilateral boring tools have been discussed and systematic parameters have been optimized for enhancement of the boring process accuracy.

Abstract: With the wide use of NC, higher accuracy in machining is increasingly required for premium mechanical components. However, machining accuracy is affected by many factors, especially by the way of the tool positioning and the geometry of the tool nose. This paper, based on the actual NC lathe tool and turning, generalized and abstracted the machining process by establishing the imaginary tool nose and the tool tip’s arc centre as the cutter-contact point, and analyzed systematically the influence of the factors, including the way of the tool positioning, the nose, and the tool tip’s arc radius, on the machining accuracy when machining transverse, cylindrical-surface, circular cone, quarter-circular and some surfaces can be expressed by formula etc.. Derived the error calculating formulas for turning in different surfaces. Put forward two error compensation methods, direct calculating method and enveloping method of error compensation. Experiments were carried out and results have shown that the two error compensation methods can considerably reduce the machining error in NC turning operations.

Abstract: Green manufacturing is the embodiment of the strategy for sustainable development of human society in the field of manufacturing sector. The manufacturing of parts and components can not carry out without mechanical processing. The environmental pollution caused by the traditional mechanical processing technics is very serious, especially the emissions of waste water and waste liquid during the process of machining. This paper discussed several mechanical processing technics geared to green manufacturing which are beneficial to the environmental protection, such as the dry cutting, quasi-dry cutting, low temperature air-cooling cutting, high-speed cutting as well as the near net shape forming, and finally drew the conclusion that the new mechanical processing technics combined with green technology with full consideration of the carrying capacity of resource and environment is an important part of green manufacturing in the future.

Abstract: This paper focused on the sustainable development of advanced manufacturing technology, discussed the information technology, new materials technology and biotechnology on the enormous supporting of advanced manufacturing technology, and their important roles were pointed out. The information technology was the soul of advanced manufacturing technology, and many advanced manufacturing modes were based on information technology. New material technology was the key to the further development of advanced manufacturing technology, and it was the basis of the actual application of advanced manufacturing technology. Biotechnology provided new manufacturing models and methods for advanced manufacturing technology, so that advanced manufacturing technology had made encouraging progress, and as a result, the bio-manufacturing engineering was a kind of advanced manufacturing mode and the bionic design was a kind of advanced design method based on biotechnology.

Abstract: This paper took the application of nanotechnology for green manufacturing as a point of departure, discussed the important roles of nanotechnology in green design, green material, green process, green package and green treatment as follows: nanotechnology reflected the use of natural resources embodying the harmonious coexistence between human being and nature which happened to coincide with the basic idea of green design; with the further integration of nanotechnology and environmental protection, nanotechnology led the development of green material into a new level; the introduction of nanotechnology gave new ideas to the development of green process; green package based on nanotechnology could meet the special functional requirements of package with outstanding green efficacy; the development of nanotechnology enhanced the existing level of green treatment technology, many existing problems could be resolved. And finally it was pointed out that the green manufacturing technology would make further development under the push of nanotechnology.

Abstract: Nanoscience and nanotechnology is one of the most important researches in the 21st century. This paper took the application of nanotechnology for mechanical manufacturing as a point of departure, discussed the nano-material technology, nano-processing technology, nano-assembly technology and nano-measurement technology in mechanical manufacturing, and described the resulting theory nano-mechanics which was different from the traditional mechanics. Moreover the important role of nano-technology for the development of mechanical manufacturing was pointed out at the end of the paper.

Abstract: Low-frequency vibration cutting is a new kind of advanced manufacturing process with several features of advantages, compared with conventional cutting operation. Based on the review of the history of low-frequency vibration cutting, its special technological effects and applications were discussed, and presented in detail the research progress in mechanism and experiment study on low-frequency vibration cutting. Three primary problems, lack of unified awareness of mechanism, establishment of a unified standard for the choice of certain parameters, application level, still in expertise for low-frequency vibration cutting were explored and the development tendency as well as the prospect of low-frequency vibration cutting in future was foreseen.

Abstract: The evaluation of technological process in CAPP based on fuzzy mathematics was explored and researched. Aiming at fuzzy auto-evaluation，factors set, weight set and assessment set were built with the applying membership function and weight of fuzzy mathematics .Then the evaluation matrix of technological process was received through fuzzy matrix calculation. According to the principle of maximum membership degree, the grade of technological process was determined. The optimum technological process was obtained on the comparison among the grades of processes, giving an example of the automatic fuzzy comprehensive evaluation for the disc-like component.

Abstract: Based on the analysis of origination of the machining errors, and selection of major influencing factors - those errors rising from the machine tool, the fixture, and the cutting tool, the error signal source library was created at the sampling points on coordinates X, Y, and Z. By making use of the written knowledge and workshop experience, the library was extendable and built with technique of ADO database access. And virtual real-time presentation of machining errors on the machined surfaces was also constructed with a mathematical model of weighed random method, considering the error of the sampling points and the drifting of the sampling points themselves from the perfect position. And a virtual measurement system was formed for the test of errors of the machined surfaces of mechanical components programmed with Visual C++ 6.0and OpenGL 3Dgraphical library. An example of the step-shaft with five kinds of tolerances was given and has been shown that the virtual system with the extendable library of errors and model for weighed random method was practical. Such weighed random method presented well the real errors of processing operations on the field with the proper model showing the principle of the error origination in metal machining.