Key Engineering Materials Vols. 392-394

Abstract: The vacuum hot bulge forming has been used in aerospace industry to manufacture cylindrical workpiece with improved mechanical properties and reduced fabrication cost. Vacuum hot bulge forming is based on the material soften and the stress relaxation theory. Different from other metal forming techniques, deformation of the workpiece takes place well below yield point and the amount of plastic deformation is directly relaxed to heating temperature and holding time. In this paper, a two-dimension thermo-mechanical coupled finite element model was developed. In this model, nonlinear radiation heat transfer and thermal physical properties of material depending on temperature were considered. This paper carried out numerical simulation of vacuum hot bulge forming of BT20 Ti-alloy cylindrical workpiece by using finite element software MSC.Marc. The temperature field, deformation field and stress field of hot bulge forming of BT20 Ti-alloy cylindrical workpiece were calculated. Numerical simulation results were accorded with experimental ones, which provided for the practice production as theory bases.

Abstract: A position-finding method for machining huge workpiece is presented in this paper, and the principle of intelligent position-finding machining system is proposed. Based on automatic determining the position and orientation of the fixed workpiece frame relative to the movable machine-tool frame, the position-finding model is erected and solved by modified Euler angle and Hong-Tan algorithm. The theoretical analysis and simulation examples demonstrate the validity of the proposed method, and the results indicate that the method is suitable for machining huge workpiece in significant scientific projects.

Abstract: The technique core of the 3-D outline tracking intelligence control, which adopted in measure automobile outline parameters, lies in the adoption of several photoelectric sensors, laser measuring sensors and super sonic wave measuring sensors to carry on probing, the intelligence control unit makes the photoelectric signal examined as the control basis, and controls the step motor to drive measurement machines and probing sensors to make outline tracking and scans movement along high and breadth direction of the vehicle, and record its outline track, and the data measured is delivered to the computer, finally, acquires the size of the vehicle checked through the place of computer data processing. Then, by comparing with the original vehicle data in the vehicle management database, it makes the adjudicate whether the size of vehicle is within the prescribed limit. System composite: mechanical structure, 3-D intelligence tracking and control unit, data handle computer and intelligence communication between them. The measuring accuracy index is ±0.1% of checked object.

Abstract: The fluid-driven clamping devices extensively used in the manufacturing industry nowadays are unable to adapt to the development requirements for green manufacturing technology owing to their low energy utilization, severe problems of noise and environment pollution. This article describes a clamping technology sparing the need of hydraulic pump and air compressor. It causes the thermal sensitive material to quickly expand or shrink linearly with the help of semiconductor heating/refrigeration conversion technology; then with the area effect stroke amplifier, the linear extension generated by the material is amplified around 100 times, and is output and passed to the clamping element in a linear motion manner to clamp the workpiece. This clamping device is an intelligent controlled electromechanical-hydraulic integrated system, featuring high energy utilization, extra low noise and fluid leakage etc.

Abstract: Mine-used tri-ring chains have been bent by hand in some machine-mining enterprises. However, this type of process is old-fashioned. The labor intensity of operating workers is high and production efficiency is low. At the same time, the production quality is also unstable. This type of process has not adapted itself to the manufacture of the product. So, for the mine-used tri-ring chains, a novel and simple auto-bending ring machine has been designed. The machine has the advantage of a simple frame, convenient mould-removal, production efficiency, steady production quality, and so on. The machine can be used for medium and small manufacturing. The machine can also be adapted for auto-bending of tri-ring chains if it is equipped with a delivery device, heating device and the appropriate controlling circuit.

Abstract: The parameters of impellers and the pump housing as key assembly to differential velocity vane pump of eccentric-noncircular gears has been designed in this paper. By researching vane spacing angles, vane numbers, vane angle and maximal opening angle on impellers, the results are gained that vane spacing angles are the periodic function of noncircular gear angular velocity, vane numbers is identical with centrodes vane numbers of noncircular gear. Assuring right and reliable working to the impellers, numbers, positions and opening angles of the matching holes of the pump housing are analyzed; defining that actual impeller vane angle must be less-than theoretical value, numbers of the matching holes must be vane numbers and opening angles of the matching holes must be less-than theoretical value, which provide the condition for concrete structure design for differential velocity vane pump of eccentric-noncircular gears.

Abstract: This paper studied the way to work out distributed collaborative design involving product life-cycle management. It constructed the three-dimensional model of distributed collaborative design for supporting PLM, which was composed of component model, structure model and process model. Component model provided information management platform for PLM, and structure model offered information transmission method, and process model combined component model with structure model and afforded integrated frame of enterprise’s whole processes. The system model has been successfully applied in manufacture enterprises, and demonstrated its feasibility in theory and method.

Abstract: In the paper, polishing free-form surfaces of die are studied with magnetic abrasive finishing. The principle of magnetic abrasive finishing free-form surface, the design of magnetic pole, the composition and categories of magnetic abrasive are introduced. Through digitizing of free-form surface by using trimmed NURBS, based on residual roughness, machining accuracy and other parameters, the offset variable of free-form surface, which is the path of magnetic pole, is derived with the computer aided geometric design theory. These will provide theoretic foundation for the realization of finishing free-form surfaces of die automatically.

Abstract: A FEM-numerical simulation system is developed to simulate the process of rotary draw bending of tube. The emphasis is to discuss some factors such as tube materials, bending moment of fan-shaped die, pushing force of sliding slot and tube relative bending radius which have an effect on tube bending quality. The quality parameters of ovality, thinning ratio and thickening ratio are the same as the measurement values in the practical production. Some improved methods are put forward to according to the simulation results. The experiment shows that the simulation system can forecast accurately the deformation in the process of tube bending, so the production manufacturing cost decreases greatly.

Abstract: The paper analyses the problem of beer bottles detection techniques on the beer bottles production line, uses digital image processing technique on the beer bottles online defect detection. The paper puts forward the designing ideas of the hardware, developing flow of the software and the algorithm of beer bottles detection. TMSDM642 is used to set up the real-time video processing system of the hardware .The hardware system is mainly composed of three parts: the part of memory, the part of the input and the part of the output. When beer bottles are put into the work area, the video images of the bottle-mouth and bottle-bottom will be gained by the CCD camera, firstly, preprocessing is used to eliminate video image noise. Secondly, the image segmentation algorithm is used to detect defects in video images. Lastly the goal of extracting defects will be accomplished. The experimental result indicated that this system may effectively exam the flaw or the unqualified beer bottles.