Materials Science Forum Vols. 800-801

Abstract: The impeller is an important typical part of machinery and equipment industry, and is widely used in energy and power, aerospace, petrochemical, metallurgy and other fields. However, due to the complex shape of the impeller blades, forming more difficult. Flank milling have many advantages, such as forming good accuracy, high efficiency. Therefore, in the paper will choose flank milling for impeller milling. Based on the properties of titanium alloy material and the external characteristics of the impeller blades, proposed control method for machining distortion of impeller blades. Using three offset method to calculate the initial tool position of cylindrical cutter flank milling undevelopable ruled surface, then calculate the initial tool position of cone ball cutter to plan tool path of milling. Through the VERICUT software to simulate the whole process of the impeller flank milling, in order to verify the tool path planning and determine the interference between the tool and the workpiece, the tool and the workpiece does not occur. Finally, through experiments to verify the feasibility of planning algorithm. The trajectory planning and simulation of flank milling titanium impeller blades are foundation of improvement the processing efficiency of the impeller blades and better surface quality.

Abstract: Heavy machinery processing industry has its own disadvantages, that is, the large size and heavy weight of workpieces. Some of them may even weigh hundreds of tons. When processing horizontal lathe, the turning diameter of it can be as long as six meters and the vertical lathe can reach ten meters. Heavy duty cutting mainly concerns about how to improve the processing efficiency, enhance the equipment utilization and to reduce energy consumption. Therefore, this proposes a higher requirement to heavy cutting tool, especially the design of the blade is of great importance. Based on the analysis of heavy cutting blade’s structure, this dissertation uses the method of parametric design which is suitable for Solidworks, with the combination of OLE and COM technology. It also utilizes Visual Basic on the Solidworks platform for secondary development and design, and develops the fast digital modeling software design. The software can not only realize the rapid modeling of heavy cutting blade, but also shorten the design cycle and improve the efficiency of the cutting tool which benefited from the convenient design of the heavy blade, which has a significantly practical application value.

Abstract: The existing processes of controlling machining error just controlled the maximum error. However, it did not effectively control the distribution of the error.The reliability of the assembly precision of the key joint surface did not meet the requirements, thereby affecting the service performance of machine tool. To solve this problem, the error matrix and transformation matrix was used to ascertain the location of joint surface positioning error occurred. The influence of processing error on the the positioning accuracy of machine tool was analyzed. The control objective of milling process was proposed. At the same time, the effects of cutting parameters on the processing error were also studied according to the milling experiments. The process error and its distribution characteristics of joint surface were obtained by analyzing the relationship between deformation of joint surface and cutting parameters. The milling process control methods were proposed.

Abstract: The meshing impact noise caused by the gradually engagement between double helical synchronous belt and the pulley was reduced due to its spiral angle effect. Therefore, double helical synchronous belt transmission receives much concern with its excellent characteristics of de-noising, low transmission error and high carrying capacity. The profiles of synchronous belt and belt pulley were studied based on conjugate-curvature high degree contact meshing theory under the circumstance that the pitch of belt and belt pulley are identical. The higher contact strength of the belt teeth and a smaller clearance in the contact point adjacent area were ensured with Hertz contact theory as the synchronous belt is in contact with pulley. And then a conjugated arc tooth profile with two-step contact and three-step adjacent gap infinitesimal was proposed based on the simple easy to processing method, which was adopted as main parameters for double synchronous belt and pulley’s normal teeth profile. The three-dimensional transmission model was built and the static nonlinear contact analysis was done with finite element software ANSYS. Finally, the noise experiment was conducted on the high speed test bench to compare the noise reduction effect between double helical synchronous belt and straight tooth timing belt with the identical end face profile. The simulation and experiment result show that the double helical synchronous belt transmission can reduce noise level by 11dB approximately compared with straight tooth timing belt transmission.

Abstract: To improve the efficiency and precision of five-axis numerical control machining for undevelopable ruled surfaces,a cutter-location optimization algorithm was proposed for flank milling of blades with a toroidal-end cutter. Firstly, it is established initial cutter-location of toroidal-end cutter by optimizing algorithm of three-point offset based on geometry features of toroidal-end cutter, and optimized cutter vector by introducing scaling factors. A new method which was based on dynamic sliding index calculating optimal cutter orientation vector was proposed. The method which applied deviation measurement algorithm computed overcut or undercut values of programming error in different scaling factors state. Finally, through the instance of machining verified the rationality of the method, and effectively reduces programming error.

Abstract: Use the international universal theory of evaluation of special cognitive ability with Mental Cutting Test (MCT) to test the students of Science and Technology University. Compare the MCT average scores of fore-and-aft drawing education, it shows that the effect of descriptive geometry teaching is positive correlative with the scores of MCT, the students improved their special cognitive ability from planar drawing to three-dimensional drawing significantly. The students who got lower MCT scores before taking drawing courses improved their MCT scores obviously. The effect of mechanical drawing teaching is feeble correlative with the scores of MCT; it shows feeble improvement in students’ special cognitive ability.

Abstract: With the rapid development of machinery industry, the processing parameters which affect on the quality of the products in machining and measuring index also appeared diversified, which makes the study of multi-objective optimization problem is very important. Among the many factors, cutting consumption plays a key role in many indicators, in effect, cutting force and cutting temperature on the quality and performance of products is the most prominent, so this paper takes PCBN tool cutting Cr12MoV steel as the experimental basis, the cutting parameters to optimize the parameters;the cutting force and cutting temperature as the index;with the aid of the BP neural network modeling of cutting force and cutting temperature, at the same time, this paper improved particle swarm optimization algorithm to achieve multiple objectives, provides multi objective optimization parameters more reliable for die steel production process.

Abstract: High-speed machining puts forward higher requirements not only for tools and fixtures, but also for the tool path patterns with the development of manufacturing. The focus is on analyzing different characteristics of tool path patterns, and influencing factors of choice in milling curvature-mutated surface. Then a reasonable choice is presented on the principle of tool path patterns. According to surface features, milling characteristics and programming requirements, the surface with the curvature changing seriously is subdivided into two patches, thus the subdivision surfaces are roughing machining. Finally, Powermill is used to verify further its feasibility.

Abstract: Targeting the current status of cutting tool design long cycle and inefficient, this research presents an integrating system of cutting tool design (CAD) and simulation (CAE). First, the paper proposes the system architecture and analyzes the process. And then based on the architecture, the system prototype integrating SIEMENS NX and ANSYS is developed on the Visual Studio 2008 platform. The prototype can generate cutting tool 3D model on SIEMENS NX and continue to simulate on ANSYS based on the information from users. Finally, a kind of ball end mill is presented to certificate this system.

Abstract: Take the T-shaped tube as the research object, studied the principles and theory. The paper researched the influence of single liner internal pressure loading path and bilinear internal pressure loading path and the gradient of internal pressure loading path on the forming quality of T-shaped tube with the help of FEA and DYNAFORAM simulation software. The paper researched the each method of forming process, and the relation between wall thickness thinning/thickening and the loading path of internal pressure, compared the similarities and differences. The results show that the gradient of internal pressure loading path is the best way, and the internal pressure should be increased growth rate in the pre-formed, so that get a small thickness reduction part.