Key Engineering Materials Vols. 392-394

Abstract: Thin-walled parts with complex configurations are extensively used in aerospace and precise instrument industry. However, because of low stiffness, cutting forces, clamping forces and residual stresses in cutting have been the main factors influenced on machining accuracy of thin-walled parts. Furthermore, biggish deviation exists between practical finished surface and theoretical value as a result of machining deformation caused by cutting force namely “cutter relieving” phenomenon; besides, direct relation exists between determination of clamping force and generation of machining residual stress and cutting force, so it is necessary to build up accurate cutting force prediction model to improve the machining accuracy of thin-walled parts. Therefore, cutting force prediction model based on Johnson-Cook’s flow stress model and Oxley’s shear angle model has been developed, which takes the property of high strain, high strain ratio in area of cut and high cutting temperature into account fully and determines shear angle more accurately on the basis of force balance principle; with different cutting and tool geometric parameters existing, perform simulation and experiment studies on cutting force prediction model, verify the validity of prediction model and obtain the response rules resulted from cutting force prediction model acting on cutting and tool geometric parameters.

Abstract: The spatial contour error which exists in multi-axis machine tools is believed relative with the track-lag error existing in the single axis, the set value of feed-rate and the curvature of the contour. A spatial error model is taken for presenting a vector method to calculate the contour error in three-axis machine tool and an adaptive cross coupled controller which is based on neural network is presented. The simulation results of cross coupled control in three-axis, indicate that the contour precision can be improved effectively which exists in the machine tool, and the errors influenced by the change of curvature and the set value of feed-rate can be obviously reduced.

Abstract: To help electronic manufacturers implement their green manufacturing (GM) strategies more friendly to environment and more effectively in saving resources, an operational GM model is proposed based on systematical analyses of each stage of the electronic product life cycle including material selection, design, production, use, end-of-life product disassembly and recycling, etc. This model consists of three levels-supply chain, enterprise and workshop and each level deals with different issues. Supply chain level focuses on manufacturing plants and remanufacturing plants based on the analysis of the whole supply chain-raw materials supply, production and marketing, etc. Enterprise level consists of GM implementation motivation, enterprise strategies, system implementation, supporting elements such as information systems. Based on analysis of the main resources and environment problems, workshop level mainly includes green manufacturing process such as lead-free soldering, process improvement, process monitoring and data acquisition, etc.

Abstract: Equations of confirming the parameters of device were established through the study of the characteristics of high-speed dot-matrix pulse jet generator which is important unit of the printing machine. Dynamical equations which could be rule for calculating parameters of valve and pipeline were established. Consequently, theory foundation for design and manufacture of high-speed dotmatrix pulse jet generator is provided. The driver mode of jet generator was analyzed and optimized. The design and analyses are proved feasible by experiments.

Abstract: As the research object, the mobile robot chassis is designed. Firstly, the mobile robot chassis intensity design is processed in accordance with the chassis external load. According to the design results, the structure model is constructed in ANSYS, the strength and stiffness is checked and its structural dynamics characteristic is computed. Then, based on the numerical value analysis, the non-sensitive variable of the bodywork is analyzed and the optimization model of the body structure is established. The result of the Numerical Optimization proved that, the inherent structure frequency characteristics did not change significantly in the case of the body weight components reduced. The mobile robot platform is set up in the laboratory, the experimental results showed that the robot chassis design is reasonable, in line with the requirements of mobile robots.

Abstract: This paper presents a partial least squares neural network modeling method for CNC machine tool thermal errors. This method uses the neural network learning rule to obtain the PLS parameters instead of the traditional linear method in partial least squares regression so as to overcome the multicollinearity and nonlinearity problem in thermal error modeling. The basic principle and architecture of PLSNN is described and the new method is applied on the thermal error modeling for a CNC turning center. After model validation with two groups of new testing data and performance comparison with other five different modeling methods, PLSNN performs better than the others with better robustness.

Abstract: As an importantly functional and safe part of automobile, gasoline tank is gradually made by plastic instead of metal. To shorten the production cycle time and increase the output of plastic automobile gasoline tank, its cooling and solidification can be put on special fixture by wind or water after being taken from mold. An automatic plastic gasoline tank water-cooling equipment was designed with Solidworks software. The operation procedure was automatically controlled by program instead of manual work. By using PLC as control center and touch-screen as man-machine interface, the control system can be carried out to solve the difficulty of setting the technical parameters, such as water temperature and cooling timeless. The results show that the production output was increased and production quality was improved effectively.

Abstract: The existing problems of temperature measurement for CNC machine tool are pointed out through analyzing research results of temperature measurement methods, temperature measurement points optimum and temperature variables selection technology. The devices and properties of contact and non-contact temperature measurement are compared and evaluated. The error measurement devices and their technology development of CNC machine tool are described. The measurement methods and results of temperature and error are analyzed by testing on a concrete CNC machine tool. It is concluded that some objective rules exist in various machine tools. The locations of sensitive points for temperature and errors as well as its number can be defined.

Abstract: The fluid magnetic abrasives (FMA) are a new type of precision finishing abrasives, which can be used to finish the work-pieces with intricate or complex shape to a quite low surface roughness value. As a key parameter, the material removal rate has a great impact on the finishing capabilities and the final surface roughness. In order to get a better understand of FMA removal mechanism, the numerical analyses was used to simulate the shearing stress field and velocity distribution. The experimental results are discussed as well in this paper.