1999 Vol.12(2)

Display Mode:          |     

STUDY ON THE CUTTING TEMPERATURE IN GEAR HOBBING
1999, 13(2).
[Abstract](2299) [PDF 231KB](108)
Abstract:
According to work-tool thermocouple principle, the equipment for measuring hobbing temperature is developed. The changing character of cutting temperature in gear hobbing, the relation between cutting conditions and hobbing temperature, and the influence of cutting conditions on hobbing temperature are discussed by means of experiments. All these have provided the reference standards for the equitably selecting cutting conditions and geometrical parameter of hob, prolonging the life of gear hobs, and predicting processes of gear hobbing.
A NEW MODELING METHOD FOR MACHINE-FOUNDATION COUPLING SYSTEM AND ITS APPLICATION TO THE CONTROL OF POWER FLOW
1999, 13(2).
[Abstract](2133) [PDF 251KB](208)
Abstract:
A new concept, namely, the equivalent mobility matrix of coupling subsystem is proposed, and the corresponding three-subsystem coupling progressive approach is explored. With the new efficient approach presented, the complexity in dealing with a more complicated dynamic clupling system is greatly reduced. The new modeling method is then combined with the theory of power flow to investigate the dynamics of the overall non-rigid isolation system from the viewpoint of energy. The interaction between the resilient machine of its main modes and the resonant behavior of the flexiblefoundation on power flow transmission is studied. Taking a machine tool mounted on a multi-story working plant as an example, the dynamic characteristics of the machine-foundation coupling system are analyzde, and their effects on power flow transmission are revealed under various service frequency bands. Some advisable control strategies and the design principle for machinery mounted on flexible structure are proposed.
ENVELOPING THEORY BASED METHOD FOR THE DETERMINATION OF PATH INTERVAL AND TOOL PATH OPTIMIZATION FOR SURFACE MACHINING
1999, 13(2).
[Abstract](2107) [PDF 193KB](91)
Abstract:
An enveloping theory based method for the determination of path interval in three-axis NC machining of free form surface is presented, and a practical algorithm and the measures for improving the calculating efficiency of the algorithm are given. Not only the given algorithm can be used for ball end cutter, flat end cutter, torus cutter and drum cutter, but also the proposed method can be extended to arbitrary milling cutters. Thus, the problem how to strictly calculate path interval in the occasion of three-axis NC machining of free form surfaces with non-ball end cutters has been resolved effectively. On this basis, the factors that affect path interval are analyzed, and the methods for optimizing tool path are explored.
A NEW ALGORITHM FOR ELIMINATING PHASE-SHIFT EFFOR IN PHASE SHIFTING INTERFEROMETRY
1999, 13(2).
[Abstract](2130) [PDF 177KB](74)
Abstract:
The effect of phase-shift error in phase shifting interferometry is investigated. A new algorithm with two sets of 4 samples for eliminating phase-shift error is presented. The computer simulation and experiment result show that the phase-shift offset should be π when the algorithm is used, and this algorithm has gotten better result than the original 4-sample algorithm.
CONTROLLED HOT FORMING OF RETAINING RING OF GENERATOR
1999, 13(2).
[Abstract](2134) [PDF 153KB](113)
Abstract:
The relevant results of thermodynamics simulation test, recrystallization study and FEM numercal simulation are described. A method is also introduced that the controlled hot forming is carried out by adopting the program of expansion-extrusion compound forming.
COLLISION-FREE MOTION PLANNING OF DUAL-ARM ROBOT
1999, 13(2).
[Abstract](2143) [PDF 338KB](82)
Abstract:
A profound approach about dual-rem robot collision-free motion planning is made. The method of configuration space is first and successfully applied to the collision-free motion planning of dual-arm robot, and a new concept, slave-arm collision state graph, is presented. In this algorithm, the problem of dual-arm robot collision-free motion planning is reduced to a search in the collision state graph. With this algorithm, a time optimum trajectory would be found, or the condition that there is no feasible solution for the slave-arm is proved. A verification of this algorithm is made in the dual-arm horizontal articulated robot SCARATES, and the results ascertain that the algorithm is feasible and effective.
DYNAMIC MODELLING OF BAR-GEAR MIXED MULTIBODY SYSTEMS USING A SPECIFIC FINITE ELEMENT METHOD
1999, 13(2).
[Abstract](2142) [PDF 209KB](96)
Abstract:
A new dynamic model for mixed, flexible bar and gear multibody systems is developed based on a specific finite element method, and a new gear-element is proposed. The gear-element can take into account the time variant stiffness, the gear errors and mass unbalance. The model for geared multibody systems can couple the gear meshing and the flexibility of all contained components. The kinematic and dynamic analyses of the geared multibody systems are expounded and illustrated on an example composed of three gears, two bars and one slider.
DRIVE AND CONTROL OF VIRTUAL-AXIS NC MACHINE TOOLS
1999, 13(2).
[Abstract](2190) [PDF 218KB](125)
Abstract:
The structure features and driving models of virtual-axis NC machine tools are studied. According to different application requirements, the three-axis control method, the five-axis control method and the six-freedom control method are put forward. These results lay a foundation for the product develpoment of the virtual-axis NC machine tools.
HEAT-SPINNING TECHNOLOGY OF HARMONC GEAR-CLOSED FLEXSPLINE
1999, 13(2).
[Abstract](2209) [PDF 197KB](92)
Abstract:
Based on the experiments,hear-spinning forming technology of the closed flexspline is studied and forming area and the laws of variations under the different technological parameters are gained. The semifinished flexspline products which can meet the quality demands have been successfully applied by matching the optimum technological parmenters in the forming area. The research results create the conditions for spreading and applying the harmonic drive.
AN EXPLOITATION OF THE EXPERT SYSTEM OF MECHANICAL DESIGN BASED ON VIRTUAL REALITY
1999, 13(2).
[Abstract](2173) [PDF 192KB](98)
Abstract:
Object-oriented methodology is introduced to build the model on expert system of mechanical design. The combination of knowledge representation with object-oriented method and neural network make the expression of the complex knowledge in mechanical design world reasonably and properly, and the complicated system is built successfully. Also, the merging of virtual reality art and conventional mechanical design theory puts visual three-dimensional mechanical movement into realities.
APPLICATION OF FUZZY MATHEMATICS IN MULTI-OBJECTIVE OPTIMAL DESIGN
1999, 13(2).
[Abstract](2164) [PDF 233KB](80)
Abstract:
In order to overcome the problem that theoretical research lags behind practical application in the multi-objective optimal design, a practical method is suggested. In this method the fuzzy nearness is used to seek an overall solution of the multi-objective optimal design and analyse the features of the curved surface. The method is tested using three practical examples.
EXPERIMENTAL STUDY ON REDUCING ADHESION IN COAL HOPPER BY SURFACE ELECTRO-OSMOSIS
1999, 13(2).
[Abstract](2185) [PDF 404KB](126)
Abstract:
The adhesion mechanics of coal and the behavior of the coal adhesion to the hopper are analyzed. A model coal hopper is developed, and the model experiments are made by using the surface electro-osmosis technology according to the processing conditions. The parameters of the surface electro-osmosis technology are optimized by the method of orthogonal polynomial regression designing. The result shows that the surface electro-osmosis technique is one of the good methods to solve the adhering problem of coal to the coal hopper in transfer piping.
STUDY ON THE MECHANISM OF CHATTER VIBRATION OF INITIAL PENETRATION IN DRILLING
1999, 13(2).
[Abstract](2176) [PDF 282KB](93)
Abstract:
Using time domain data, orbital plots, and spectrum analysis of drill point displacement, cutting force and torque signals, the initial penetration in drilling is experimentally investigated. The mechanisms of drill wandering motion are analyzed by means of three principles of self-excited vibration, I.e. the regenerative principle, velocity component principle and mode coupling principle.