Advanced Materials Research Vols. 655-657

Abstract: According to the characteristics of constant flow and closed hydrostatic rotary table used in heavy duty CNC machine, in order to consider the interaction between structural deformation of worktable and the supporting force of oil pads, an iteration method between hydrostatic theory calculation and finite element method (FEM) is used to get the real supporting force of each oil pad at different carrying state. The result is compared with the situation which is not considering the deformation of worktable and the difference between them can be used to guide the design of hydrostatic oil pads. The optimal radius of supporting point of work piece is also achieved using this method, which can provide theory basis for supporting point distribution of heavy work piece.

Abstract: The paper introduces the structure and functional modules of the cutting tools information integrated system technology. We can manage the information on cutting tools efficiently by using the system. According to process feature we may select the appropriate cutting tools and the optimized cutting parameters .The system has the advantage of good generality, flexible application and fine opening. By using it, the efficiency of selecting tools and cutting parameters can be greatly improved.

Abstract: The precision of its processes is affected by static error and dynamic error. This paper focuses on modeling about dynamic errors and proposed an algorithm of the dynamic error for Table-tilting 5-axis machine tool, which is using Homogeneous Transformation Matrix to establish the dynamic errors formula, so as to structure a model of its dynamic error. Dynamic errors about rotary and linear axis of a 5-axis machining center with tilting rotary table type are defined. At last, we performed the operation and measurement of Table-tilting 5-axis machine, in order to compare and verify the dynamic errors, and to use as adjusting the Table-tilting 5-axis machine tool, and improve the precision of its machining. The result of a synthesis example verifies the effectiveness of the proposed modeling.

Abstract: In order to reduce non-cutting time and improve machining efficiency, the macro program of automatic tool changer (ATC) has been designed firstly, which was based on the macro theory and parameter settings. Then, the machining simulation environment of the automatic tool changing was established, based on which, the digital simulation of automatic tool changing process is realized by mapping of the practical changing tool process in the virtual machining environment. The simulation results effectively verify and improve the macro program performance.

Abstract: Through the research and analysis on the metamorphic cutting mechanism of cutting equipment for complex-surface, the configuration transformation of metamorphic cutting mechanism based on genetic evolution principles is analyzed, and the solution of the first structure is completed. the structures and configuration transformation of the metamorphic cutting mechanism is researched based on graph theory and adjacent matrix.

Abstract: In order to estimate and optimize the static and dynamic characteristics of machine tool, the full parameterized FEM model of it is established and studied in the paper. After the FEM analysis of bed, this paper takes a machine bed as example, presents a method of combination of BP Neural-Network(NN) and Genetic-Algorithm(GA) to optimize dynamic characteristics and realizes the structural optimization of the bed. It proved that this method takes less time, and more precision compared to traditional method.

Abstract: Gear machine tool main drive shaft to avoid resonance problem is studied.The force of the drive shaft is analyzed, and the vibration form of the drive shaft is confirmed. Using the lumped parameter method to simplify the main drive shaft, the lumped mass model and the force model were been obtained. When bending vibrating, the natural frequency of the main drive shaft is calculated using the transfer matrix method. The calculated critical speed is 43755r/min, which far outweighs the motor rated speed .It means that the drive shaft under normal work won't be resonance, which accords with the request of production.

Abstract: Determining regularity and convexity of NURBS curves is necessary in computer aided geometric design. In this paper, the problems above are converted to the questions related to polynomials. Then based on properties of algebraic equations and isolation theorem of roots, a simple and practical method for determining those geometric properties of NURBS curves is put forward. Compared with traditional method it will save us much computation

Abstract: A five-axis machine can be developed with various mechanisms as it simply adds two axes to three coordinate axes. Therefore, five-axis machining utilizes post-processor for conversion to NC code, which the five-axis machine can read, with tool path CL data created by CAM depending on the mechanism of each device. This study introduces a post-processor program that tilts from axis B, of which the head is inclined at about 45 degrees, moves straight toward the X and Z axes, rotates the table from C, and then moves along axis Y. The post-processor mechanism was applied to the program after calculating the rotation angles and tilting angles using inverse kinematics and mapping the part coordinate system by machine coordinate system. Then, to evaluate the established post processor formula, it was verified twice. First, a tool path that was identical to that created by a commercial post-processor program, Post Works, was post-processed and comparably reviewed to, verify the performance of the proposed method. Secondly, a test specimen was manufactured by creating NC data from the developed post processor program. After manufacturing the test specimen, the compatibility was verified, suggesting the possibility to commercialize the five-axis machine and the post -processor program.

Abstract: Currently, the number of cars in city is dramatically rising; meanwhile, car parking is becoming the serious problem in city. A way to solve this problem is to use the parking space efficiently; therefore, a control system of stable stereo circulating parking garage is introduced in this paper which contained multi-layers and various parking lots. The system adopted PLC as the primary controller. It discussed the structure of the hardware and software of its electrical system, and its control method in detail, in order to provide a new storing solution for stereo parking garage.