Advanced Materials Research Vols. 139-141

Abstract: Polishing the titanium plate is commonly necessary step before being used in many fields. Experiments of the titanium plate polished in the condition of including abrasive and existing abrasive are carried out to study the roughness of polished surface in given state. Surface roughness and morphology were investigated in experiments and experimental results were analyzed. In both experiments, the polished surface roughness value reduces with increase in processing time, and the detects on titanium plate before polishing decreases, which attributes to the mechanical and chemical tooth rising from lap between workpiece and polishing machine with the help of energy required. Material removal block in abrasive polishing is higher than that in case of existing abrasive. This helps to deepen the understanding of change in roughness of surface polished and indicates the promising operation technology for processing titanium in factory and workroom.

Abstract: Precision ultrasonic vibration cutting (UVC) is a promising technology in field of precision and ultra-precision machining. It is a kind of the pulsing cutting process with a constant vibration frequency and sine-wave amplitude of vibration. Its practicability has been a research focus since it came into being. In this article, an precision UVC system is built by designing this system, including the selection of precision machine and ultrasonic generator, the design of ultrasonic transducer, and then many cutting experiment are been done. Different of chips under the conditions of ultrasonic and no ultrasonic are made, and deformation coefficient of chip obtained by vibration cutting is smaller. The effect of cutting parameters on roughness is discussed in precision vibration cutting, the surface roughness decreased with the increase of the amplitude and the decrease of the cutting depth or feed rate, at the same time, there is an optimum cutting speed to receive the best surface.

Abstract: The ultrasonic vibration drilling presents superior technology effect than common methods in small-diameter deep hole machining areas, and can improve the machining quality and efficiency remarkably. The amplitude transformer usually is designed by users according to the requirement of production. Thus the design and manufacturing of amplitude transformer and the realization of the resonance of device are key problems in ultrasonic vibration drilling system. In this paper, we firstly analyzed the structure of amplitude transformer in the axial ultrasonic vibration drilling, and then designed and manufactured the composite amplitude transformer for small-diameter deep holes in the ultrasonic vibration drilling. After we carried out the test in the sound vibration system, the result indicated that the resonance of the sound system could be satisfied and the demand of small-diameter deep hole drilling could be met.

Abstract: This article is a research about the transmission theory of ultrasonic honing device for "Bending Vibration Disc - Flexible Rod - Whetstone Base" subsystem ultrasonic vibration, and gives out an optimization program of the subsystem. It launches a modal analysis of the ultrasonic vibration honing subsystem by using kinetic analysis and element analysis, and gets the resonant frequency, mode vibration shape and node displacement for both optimized and traditional vibration sub-system. The modal vibration shape of the optimized subsystem is well consistent with the requirements of ultrasonic honing, which will greatly improve the processing capability and reliability of the ultrasonic honing device. The modal analysis results agree well with the theoretical analysis and the optimization program, which provided new ideas and methods for the further development of ultrasonic honing technology.

Abstract: Combining the refrigeration and machining technology, the dry cold air at -35°C was gained. With the injecting feeding manner of the cold air for cutting, all application of the green technology is realized in turning manufacturing trials. In order to clarify the cooling and lubrication mechanism of cryogenic cold air, the cutting temperature, cutting forces, wear of cutting tool and cutting chip have been systematically researched with the help of numerical calculation and experiments. The cooling and lubrication effects, as well as the performance of machining quality improvement, enhanced by the low temperature air injecting, have also been analyzed in detail. The results arc as follows. Temperature measurements at several locations on the cutting tool insert agree with the simulation results. The performance of cooling-air spray jet with 25(Nm3/h ) on reducing the cutting tool temperature achieved a maximum effect

Abstract: This paper investigates the constant position suspension altitude control problem for a novel magnetic levitation linear guide. The magnetic levitation linear guide is comprised of a magnetic suspension processing platform and a linear motor direct-drive system. The magnetic suspension system has several characteristics of complicated nonlinearity, parameter perturbation and strong disturbance. In view of these characteristics, an adaptive integral-type sliding mode control (AISMC) technique is used to design magnetic suspension system constant position suspension altitude controller. The AISMC can alleviate chattering and reduce steady error by estimating the boundary of uncertain perturbation. The adaptive tuning algorithm is derived in the sense of the Lyapunov stability theorem, thus the stability of the system can be guaranteed. Simulation results indicate that the proposed AISMC has a better stability, transient and robustness compared with PID control.

Abstract: The surface of ants was observed, analyzed and tested by using of scanning electron microscopy and X-ray energy spectrometer technology. On different surface of the ants, the waveform characteristics which were formed by different sizes of grooves were found. These cross sections of waveform surface were waveform curves which had continuous periods and amplitudes. Their sizes varied with different part of the ant. In addition, there was distribution of setae of various sizes on surface of the body. Under higher multiple of electron microscope, the bigger setae had the waveform surface of smaller periods and amplitudes. The results of composition analyzing indicated that the surface of ants contained multi-elements. Among these elements, the most abundant was O which content was over 57%. The following abundant element was C which content was more than 23%. The other elements such as Na, Mg, Zn, Si, P, S, Cl, K, Ca remained less than 3% respectively. The distribution of morphological characteristics and surface composition may contribute to the property of reducing soil adherence.

Abstract: . A new bionic biped walking mechanism (BWM) was put forward in this paper. Simple in construction, easy in control and droved by usual motor are all advantages of this mechanism. But disadvantage should not be ignored. Especially up and down bumpy of the centroid will influence the smoothness of the motion during walk. Through theoretical analysis of kinematics, motion characteristics and the movement of the spindle were obtained in a circle. To aim to bring down the uneven of the BWM, the relationship of all parameters was found and the scope of the fluctuation was established. In the end, all of the results were verified by simulation program of Matlab. The result provided theoretical guidance for optimal design of the mechanism in the further research.

Abstract: . In order to study the influence of contractive and dilative motion of blood vessel to robot, the moving surface is to simulate contractive and dilative motion of blood vessel, the model is used for the turbulent of blood flow. The results show that the blood flow field is impacted by the inlet velocity waveform and motion of blood vessel, the variation amplitude of flow parameter is greater than that of rigid blood vessel, the flow physical quantities change with inlet velocity waveform, and different positon has different variation tendency.

Abstract: . The slippage often occurs between conveyor belt and driving drum, reduces the transmission efficiency and even causes accidents due to lack of enough friction. By the analysis of friction drive principle in belt conveyor, three ways were presented to increase the frictional traction. Learning from the bionic tribology theory, we proposed a new structure design of the drum coating layer surface. The micro contact area of fly's seta that can adhere to any surface was taken as a prototype, and its microscopic structure was analyzed, then the surface structure of coating layer with recess long blocks was designed, finally, the solid modeling was created with CAD software. The new surface has sub atmospheric pressure absorption. The purpose is to increase the friction between conveyor belt and driving drum, and to avoid the slippage.