Advanced Materials Research Vols. 562-564

Abstract: With rapid economic development and global manufacturing competition, developing a low heat input and high reliability full digital welding power became an important research field of welding. This paper designed a soft switching inverter AC welding power supply, in which two DSP controlling chips dsPIC30F6011A and dsPIC30F2020 were used as the core of the fully digital control system. Thanks to the control circuit and the corresponding software, the closed loop output power control was completed. A large number of soft-switching parameters were optimized, which effectively improved the reliability of power supply

Abstract: This paper describes the process optimization of compressor cylinder block machining and supporting technology, which ensures the implementation of this optimization. This paper also provides detailed instructions about the design of quick change type semi automatic hydraulic jig and combination cutting tool of fine boring crankshaft hole. The practical experience evidenced that the process optimization is a good way to improve the product quality.

Abstract: In order to realize the rapid nondestructive testing for Hami Big Jujubes’ quality detection, a detecting system based on computer vision was established to detect Hami Big Jujubes’ size and defect. The image grabbing card and CCD camera were consisted of the hardware system, which was used to collect image data. Visual Basic6.0 and image processing toolbox of Mil9.0 constituted the software system. The function of MIL9.0 was called in the Visual Basic6.0 to realize the detection. During image processing, the threshold was all chose (0.1,0.7).Many methods were used to identify the features rapidly and get the H value’s mean and variance, such as colour space transformation, mathematical morphology processing and mask etc. Experimental results showed that the correlation coefficient between the projective areas and weights was 0.945.The correlation between projective areas, transverse diameter and vertical diameter was 0.951.The defects grading models were built by BP neural network .The discriminating rate was as high as 99.16％ in training set，and 91.43％ in prediction set. The average testing time was 80 milliseconds, which can satisfy the detection system’s requirements of time．

Abstract: Power dissipation problems for Insulated Gate Bipolar Transistor (IGBT) are requiring increasingly complex design solutions. While designs that are more efficient make thermal management possible, current systems still require CFD methods for dissipating heat. Parameter optimization of the air-cooled heat sink is carried out to cool a three-chip, 2400w IGBT plate. The parameters are compared using maximum junction temperature and fan efficiency.

Abstract: Aircraft basic performance is the foundation of the research on aircraft, which is characterized by many parameters. According to the example of the shortest rising time spent on flying from an altitude to another arbitrary one, and the example of matching control of joystick and throttle lever, it is demonstrated that the visualization in scientific computing method is useful for promoting engineering research.

Abstract: Based on research and analysis of current condition of CNC transformation, the essay proposes a scheme to reconstruct X6132 universal horizontal miller. Analyze the technical parameters of old X6132 universal horizontal miller according to the techniques request of machining objects, then project the general transformation blue print of old machine. Design and calculation of mechanical part in machine, according to the general transformation blue print, the longitudinal feed system and the transverse feed systems are reconstructed. Hardware circuit design of CNC system, utilize single chip 8031(MCS-51 series) to compose control system which can control feed movement of the longitudinal feed system and the transverse feed system with Micro-computer.

Abstract: After the railway speeding-up, a large number of railway level-crossing has changed to the underpass or overpass type of structure. In the underpass type of structure, the most of structure take the underpass bridges or frame bridge structure. This paper put forward the level-crossing rebuild into the frame structure bridge method of design, through using the object-oriented program design method realizes the frame structure bridge automatic design analysis，calculation and drawing process, greatly enhancing the frame structure bridge design work efficiency, accelerating the changing level crossing to grade rate, and eliminating the safety trouble of crossings.

Abstract: K-WRS technology has a better edge drop control effect in cold tandem rolling mill, but it still exists some problems such as contact pressure peak beyond the limit, transition peak and the uneven distribution of contact pressure between the rolls in practical application. In this paper, tapered work roll shape is designed and optimized. The simulation analysis shows that the optimized roll shape not only can effectively control the edge drop of strip，but also can improve the contact pressure between the rolls. At the same time, it also can reduce the influence on the flatness control from the edge drop control.

Abstract: Shape processing of frame is one of the important and trouble working procedures for shipyards, and its robotized research has been carried on until it is gradually put into use in recent years. This paper introduces a CNC frame cold-bending machine, including the components of its machine, the principle of its NC control, the hardware and software of its NC control system.

Abstract: This paper introduced the design process of shell-breaking machine for hand-stripping hickory-nut. Hand-stripping hickory-nut is an instant snack food. Like peanut, it’s easy to separate kernel from shell. The paper compared methods of shell-breaking nuts which is in common use, got inspiration from manual process and absorbs useful experience of traditional processing techniques combining with impact method. Then the mechanism of striking shelling in the way of mechanical knocking is designed. The design of robot percussion arm mechanism, feed mechanism, force regulating mechanism and principle prototype were proposed. The hemispherical grooves are approximately half spherical, which match the shape of hickory-nut. And then the component strike force can be reasonably reduced. The experiment results showed that the machine have good effect in shell-breaking for the Hickory-nut of different specification. Hickory-nut is not convenient to eat because the nuts are deeply embedded in the spaces formed from the hard shell. Hence, special tools are usually needed such as Hickory-nut clamp. Recently years, the hand-stripping hickory-nut is popular in the market. It is an instant snack food. As peanuts, it needs to separate kernel from shell while eating. The traditional processing method is to put it in the special mold and then strike it with the special hammer. But the productivity is low and it will produce secondary pollution easily. Besides, shortage of labor will lead to short supply. Thus mechanized production has become our urgent demand.