Advanced Materials Research Vols. 591-593

Abstract: The design process of involute spur modified gear is very complicated, especially the accurate mapping of the tooth profile curve, in which it must demands specialized knowledge to designers by procedural programming method. According to the tooth profile curve calculation method as well as its relationship with cutter, get the curve equation of involute and tooth root transition curve. Compiled each the program of the calculating curve of tooth profile by Visual Basic, and built the precision model of involute spur modification gear based on the SolidWorks through the secondary development. This paper realizes the parametric precise modeling of modified gear and improves the accuracy and automation level of the design of gear. It has important significance to the dynamic simulation of gear and interference inspection as well as finite element analysis.

Abstract: This paper puts forward a kind of method which can calculate tool accessible domain for tool axis optimization in the complex curved surface multi-axis machining. At first , the point model has been construced on the base of constrained surface.The second, based on any possible direction of tool axis vector of a given cutting contact point, the distance between a point and a line is used to decide whether occurs collision and interfence. The third, two angles related with cutter-axes vector is definied. The regulation of tool accessible domain can be implemented by getting the boundary of the discrete points in the coordinate planes. Finally, a tool has been developed to calculate tool accessible domain, and an example is given to verify the effectiveness of the method.

Abstract: In response to the awareness of environmental conservation-oriented society and low carbon economy , this paper puts forwarding the load sensing control that is applied to the copper anode shaping machine hydraulic system energy transformation in the light of copper electrolytic anode shaping machine hydraulic system energy conservation issues, through the shaping machine hydraulic system energy loss analysis, and then uses AMESim software for plastic machine load sensing control system performance simulation and analysis, in order to achieve the purpose of energy saving.

Abstract: The support vehicles of coal mine belt horizontal extension application of new materials, is to change the traditional coal mine machinery "rough" and stupid" feature to make it more light, green and environmental protection. First introduced the horizontal extension of the overall structure of the supporting of coal mine belt which leads to support the working environment of the vehicles, then comparison of traditional materials and new materials to support the vehicle body, trying to replace traditional materials with new materials, and new materials for static mechanics and fatigue analysis, we found the support body after the application of new materials fatigue life less than ideal requirements, and thus try to use new materials to support the car body laser coating technology to improve, after ANSYS fatigue test, and validation support guide the application of coating on the car body can effectively improve the fatigue strength, has good application prospects.

Abstract: Mckibben pneumatic muscle actuators (PMA) have many advantages such as high power-mass ratio and low price, but their strong nonlinear characteristics makes modeling and controlling very hard, which limits their applications. This paper presents the modeling of PMA and methods to enhance their dynamic performances. Considering the incorporated models of fast-switching valves and PMAs, the entire system model is modified in some aspects and the dominant model parameters are determined through experimental results to estimate the dynamic characteristics precisely. Simulation and proper experiments reveal that the dynamic performance of PMA can be improved through filling the PMA with materials of high thermal conductivity. The slow time-varying disturbance caused by the temperature variation of inner gas can be reduced much, which lowers the difficulty of controlling.

Abstract: The chain transmission’s feature, the main failure form of roller chain and the research for the simulation of the chain transmission mechanism are introduced. Taking the simulation of the chain transmission mechanism in feeding system of a mechanical equipment as the research object, the kinematical properties and the affecting factors are analysed in this paper. It adopts the advanced connection pair to establish relationship between the sprocket-wheel and rollers, and realistically simulates the kinematical characteristics of the chain transmission mechanism. It provides a reference for the optimization design of the structure of the chain and sprocket wheel, through the analysis on the moving velocity and acceleration curve of the chain. It also provides a basis for verifying whether the chain and sprocket-wheel meet the design requirements or not.

Abstract: Pressure distribution inside a fluid-conveying pipe is significant information for reasonable pipe design or mitigation of pipe vibration caused by fluid impact. Generally, a steady solution of pressure information can be obtained based on traditional CFD simulation if the inlet velocity of pipe is time independent. Unfortunately, strong oscillation of inlet velocity often happens in real engineering operations such as fuel injection or pumping process. This paper focuses on the simulation of the transient phenomenon of fluid flow inside a pipe based on the time-dependant inlet velocity. A 2D numerical pipe with an elbow is built based on Eulerian scheme and structured mesh. It is found that numerical instability occurs and convergence becomes difficult if inlet velocity presents obvious cyclic oscillation with big amplitude. Numerical oscillation increases especially when inlet velocity decreases from a big value to zero. Traditional finite volume method and cavitation model are tried and numerical results show that the convergence can be improved evidently based on cavitation model although numerical instability can not be overcome completely.

Abstract: In this paper, the Lattice Boltzmann Method is applied to set up the numerical model of cavitations. The surface of the part is introduced into the symmetric bubble model to form the more realistic model called asymmetric bubble. With the help of simulation, no pulsation is detected but it is noticed that the pressure is no longer present uniform distribution for the four virtual surfaces symmetrically set around the bubble. The pressure close to the part’s surface is slightly higher and the velocity gradient is larger than those further away from the solid surface. And the distortion along the flow line is discovered at the end of the solid surface. The asymmetric bubble collapses in a complicated way thanks to the various velocities in different point of the bubble wall. What is more, a micro jet with radius of 10μm is generated which leads to the sharp reduction of momentum of the wall and the increase of the pressure near the bubble wall. According to the simulation, the impact on the work piece peaks at 1.6GPa.

Abstract: Many parts such as craftworks and hand draw pictures were manufactured based on the image. Their shape was irregular and couldn't measure accurately. And the dimension was not labeled definitely. So the CNC machining code couldn't directly generate. The paper studied the methods and the machining performance of this kind of part. The digital image could be obtained through the scanner or the digital camera, and pretreated by computer. The digital images were transferred into the vector document and the boundary dimension parameters could be gotten. The NC instruction was generated through the automatic module. Finally the procedure of programming and process was verified by an image

Abstract: In the metal building and garment industries, product model is required to be or closed to be developable surface (can be flattened onto planar patterns without any distortion, tear or stretch).Current work mainly focuses on interpolating only two curves with a narrow developable strip, and lose the generality of applications in industries, which often require N (N>2) curves to determine the final shape feature, and seek one interpolated developable surface. In this paper, a new developability degree criterion is introduced first and a novel lofting algorithm is proposed to model a quasi-developable mesh surface for the given characteristic curves. The curves are first adaptively sampled and then planar triangles are tiled to interpolate all sampling points. The optimal triangulation in terms of given criterion is mapped as one shortest-path finding graph problem, which can be solved by using well-known Dijkstra’s algorithm.