Xiao Jing Li

Reconstructing of Prototype Surface with Reverse Engineering and Data Process Technology

Design and manufacture of pioneer products with lower cost and shorter cycle is a major mission for an enterprise, and reverse engineering (RE) plays an important role in accelerating product research and borrowing ideals from other business. However, due to special structure and complex topology relation, obtaining full surface data of a prototype is not an easy thing and should carry out complex data process procedure to get global model. This paper describes the origin point cloud acquisition method and the data processing steps for better point quality. Based on reverse engineering system of a toy prototype, a fine surface reconstruction module is developed. Measurement data are acquired by scanning the physical object using three-dimensional coordinate measuring machine (CMM) and an optical scanning device. The model establishment and data process of the prototype, such as noise elimination, data interpolation, data smoothing, data filtering, data splicing and surface reconstructing are conducted subsequently. Through processing of measurement data, the authors succeed in creating a CAD model of the prototype and gaining a good result.

Numerical Analysis for Braking System of Virtual Automobile Model

The excellent braking characteristics is a key security measure for automobile operation. The study focuses on modeling and parameter settings of brake system, tire system and body system. During automobile design stage, a full model of automobile is established in ADAMS software circumstance in according to structural feature and main parameters. Virtual model technology can simulate the working condition, analyze whole performance of related products, solve some drawbacks in the traditional design and manufacturing process. Based on the requirement of country standard and national standard, the braking performance analysis and appraise is carried out in this study, at the same time, the braking performance is optimized.

Study on System Design Scheme for Electrical Control Scheme of Boiler

The breeding plumbing boiler is a full automatic temperature adjustment system with double efficacy of winter heating and summer cooling, constituted by host, auxiliary engine, control system and plumbing pipes, etc. Intermediate between PLC output port and AC contactor is to achieve the isolation between weak current and strong current, enhance the reliability of the system. Two frequency changers are designed for the hardware of system. Frequency converter input power linked up front access air switch. Frequency converter input terminals main circuit switch and the three phase power through air connection, frequency converter main circuit output terminals connected to the contactor three-phase motor. It is proved by field experimental operation that the control system proposed not only can realize automatic control of boiler burning process efficiently, but also reduced energy consumption greatly and effectively improved the level of boiler control management.

Crystallization Characteristic Study for Amorphous of Nd60Al10Cu20Ni10

Since the first synthesis of an amorphous phase in Au-Si system from liquid, a great number of amorphous alloys have been prepared by rapid solidification. Almost all amorphous alloys require high cooling rates and a lot of studies have been carried out for these metallic glasses. In this study, metallic glass of Nd60Al10Cu20Ni10 have been fabricated, and experimental research was carried out to reflect thermal features. It indicates that the Nd-based amorphous has shown a distinct glass transition and stable super-cooled liquid region. The research results show that the paramagnetic performance of Nd60Al10Cu20Ni10 metallic glass is different from other hard magnetic alloys at ordinary temperature. From the DSC experiment, it is found that the glass transition temperature is increasing with the heating temperature.

Mechanical Performance Study for Rapid Prototyping of Selective Laser Sintering

Selective laser sintering (SLS) is an additive manufacturing technique used for the low volume production of prototype models and functional components.The lower strength of prototype parts might leads to bad finished quality. In this study, author used the coated sand casting as the material of selective laser sintering experiment, studied the processing temperature and time on the mechanical properties of post-processing, and the influence on gas-forming property and collapsibility of the pieces. And combined with casting experimental we can analyze the accuracy influence factors of precoated sand sintering parts and other performance assessment. Through analysis, it indicates that the post-processing of temperature influences on tensile strength of coated sand specimens under three different insulation temperature conditions.

Key Technology and Architecture of Reconfigurable Manufacturing System

Reconfigurable manufacturing system is essential for sustainable change, rapid response ability important characteristics, research, development and application of manufacturing system. The main architecture and major characteristics of reconfigurable manufacturing systems is explored. Normally, the quality of RMS can be evaluated by several factors. Firstly, the gross cost of production and reconstruction should be less. Secondly, The time of design and manufacture (ascent time) should be shorter. Thirdly, the utilization ratio of existed resource should reach to the utmost. Finally, the cargo stream planning in common space should keep in optimal condition. At last, The author give an example to shown the RMS, the hydraulic integrated package for a gearshift device in automobile, are mentioned to compare and analyze.

Study on Technology Parameters for Coated Carbide Cutting Tools

Metal cutting processing is the most fundamental, most widely and the most important processing in industrial production. Because the development of mechanical manufacturing level plays a very important role in the coating technology material machining process. A coated carbide cutting tool with its high hardness and high wear resistance, good chemical stability and extensive compatibility characteristics, is widely applied in the metal cutting processing field. The author mainly studies the cutting force contrast between coated carbide cutting tools and not coated ones. Cutting tests have testified that if PVD technology applied on cutting, the cutting force of hard alloy cutter will alter with the change of feeds (f), depth of cutting (ap) and cutting velocity (v). The experiment suggests that the size of three-way cutting force of either the brand ZP25 hard alloy cutter or the carbide cutter by employing matrix ZP25 hard alloy cutter to respectively using PVD technology coat TiN or TiCN coating is successively FZP25>FTiCN>FTiN. The main reason for this is that the difference of frictional factor of the three kinds of cutter material and the workpiece material.

Thermal Analysis Based on Finite Element Analysis for Motorized Spindle

High-speed motorized spindle is a key device of modern industry and has been widely used in numerical control machine. Temperature distribution, speed control loading characteristics, precision maintenance, liberation intensity and circumgyration error are not only the key demand of motorized spindles capability but also an important index to evaluate its performance. Therefore, this study has detailed described the main structure of motorized spindle. The basic structure and working principal was introduced, and then demonstrated a series of models and specifications of motorized spindle. The finite element model of high-speed motorized spindle was built up and carried out thermal analysis to study the heat generation and heat transfer. With the help of ANSYS finite element software, the temperature field distribution and the temperature rise condition for motorized spindle were analyzed. The result shows that the front bearing has a higher temperature than that of back bearing. The maximum temperature of inner ring is bigger than that of outer ring. The results contribute to selection of appropriate bearing for motorized spindle system.

Structural Design and Finite Element Analysis for Planet Wheel Gear System

Calculation the gear bottom bending strength and the gear surface contacting stress are traditional wheel gear design method. It takes a long time to design and works out parameters for gears system. Nowadays, the optimization design and reliability theory are introduced into modern engineering, we can make full use of the calculator tool to look for the best design parameter. Modern powerful finite element analysis software packages such as ANSYS are now not only an analysis tool but a design tool as well. This kind of technology makes planet wheel gear system design quantified precisely combining with physics principles in one. In the study, we designed a planet carrier with traditional method and built three dimensional full-scale model in Pro/E software. Based on finite element analysis, the finally result of stress distribution and deformation distribution is obtained. The results indicate that the design can meet the requirement.

The Effect of the Scanning Mode on the Finished Precision for SLA Technology

Stereo lithography apparatus is an advanced technology that uses photopolymers as the raw materials from which the prototypes are built. The RP manufacture system uses lasers or ultraviolet light to expose selectively the surface of the liquid resin and builds a three-dimensional part according its CAD model in a layer-by-layer manner. The absorption of energy causes photo-polymerization that changes the liquid resin into a solid, expanding the cured volume but shrinking simultaneously. The primary reason for the volume distortion and deformation of the stereo lithography apparatus part are the interlaminar stress generated by resin contraction. The volume shrinkage and curl distortion of the resin will lead to poor accuracy of the built prototype because the bending stress cannot be compensated for. Selecting a non-standard gear as experimental object and manufactured in the SCPS350B rapid prototyping machine. Four kinds of scanning mode, includes X-X mode, X-Y mode, XY mode and XY ST mode, are respectively carried out. From the results, it is found that SLA parameters, i.e. scanning mode and scanning speed significantly affect the forming precision of the prototype. The accuracy of the prototype with XYST mode is prior to the XY mode, and the X-Y mode is prior to the X-X mode. With the lower scanning speed and surface recoating process can further improve the finished precision.