Papers by Author: Rong Guo Hou

Abstract: The interaction between abrasive waterjet and target is studied by computational fluid dynamics (CFD) and finite element method (FEM). The flow field inside and outside abrasive waterjet (AWJ) nozzle is obtained by CFD software. Then the pressure distribution of the fluid on the target is plotted, which is in well agreement with the force distribution of the AWJ impacting on the target and leads to the material deformation. The interaction between the AWJ and target and the fluid-solid coupling is happened. The cloud figure of the target’s deformation and stress are obtained by FEM software. The AWJ parameters such as the flow velocity, off-set and abrasive volume factor have a great effect on the material deformation and the stress distribution. The study results provide a new method to study abrasive water jet machine mechanism and help to optimize process parameters.

Abstract: This paper presents an experimental investigation of the machining characteristics of IN718 nickel-based super alloy in wire electrical discharge machining (WEDM) process. During experiments, parameters of discharge current and pulse on time were changed to explore the effect on various aspects of the surface characteristic. Scanning electron microscopy (SEM), surface roughness and micro hardness tests were performed. Experimental results reveal that the surface roughness will increase with the increasing of current and pulse duration. Micro hardness tests show there is no hard phenomenon.

Abstract: the robot working space is the volume which a reference point on its wrist to be reached. It is an important evaluation index of the robot geometry characters. Firstly, the size of the movable cotton robot palletizer structure is calculated by analyzing its movement, then, its working space is calculated base on graphing method. This method is working as these: a referent point P on the wrist is selected, the space of it reaching will be the volume which is the movable cotton robot palletizer working space, by fixing a limiting position at a robot wrist, the reference point P on the total working space XOY is analyzed by drawing, the geometrical analysis and calculation method are used to acquire the motion curve equation, within XOY plane, the movement of the wrist and two slides is decoupling to calculate the limiting position of the robot wrist movement, at the end, the final movement space of the robot is determined.

Abstract: An abrasive water jet micro-turning experiment device is designed to solve the problem for micromachining the revolving parts. This device is composed of the machine body, hydraulic system, collection devices and control equipment etc. This paper emphasizes on the structure design of the moving parts of the abrasive water jet turning process, clamp, lathe bed, abrasive water jet injecting system and collection system. The turning spindle system and feed drive mechanism are designed, and the strength, stiffness and precision of the ball screw transmission mechanism are calculated and checked to meet the needs of the abrasive water jet micro-turning experiments.

Abstract: For purpose of maximum using land utilization and minimum the cost of the parking equipment, a intelligent automatic annular three-dimensional garage system is designed, the major characters of it are multifunction, intelligence and highly automatic, which are obtained by using annular form as the frame structure and micro control unit as the cybernetics core. By using this equipment, the parking labor intensity is relieved; the environment pollution is also controlled

Abstract: A floor typed spatial robot of abrasive water jet machining is designed, which can be applied to machine three-dimensional complicated work-pieces. Its merits are simple structure and flexible moving. The structure and transmission programmer are discussed in detail. The working range of the abrasive water jet robot is analyzed to meet the need of the various sized work-pieces. The motion of the each joint is realized by means of various transmission programmers. The precise movement of the robot is realized by the stepping motor, and the required power of the robot is calculated.

Abstract: The energy transfer method is used to measure the flow velocity of the outside the high pressure water jet (WJ) and Abrasive water jet (AWJ) nozzle. The impact forces of the flow measured by the piezoelectricity ergometer will be transformed to the velocity value, the average velocity of the flow outside the nozzle will be obtained. The result indicates the velocity will reduce along the direction of the flow, and the velocity of the AWJ flow will reduced greatly than the WJ flow, which indicates that the length of the core part of the AWJ flow is shorter than the WJ Flow, the stand-off should be within the 0mm-15mm ranges to gain the most effective machining.

Abstract: Motion profile smooth control is significant to reduce the obvious impact on machine tool in high speed and high accuracy CNC machining. However, the jerk is discontinuous and brings about flexible impact on machine tool in the linear Acceleration/Deceleration (ab. Acc/Dec), exponent Acc/Dec and S curve Acc/Dec approach. In the paper, the CNC machine tool dynamic model is built up to analyze the cause of machine impact, to describe the mathematics and physics meanings of jerk. Then a new Acc/Dec approach in which the jerk is continuous is put forward. And the motion profile smooth control algorithm based on continuous jerk is developed in details according to the permissible maximum acceleration, the permissible maximum jerk, the machining program segment displacement and the instruction feedrate. The motion profile smooth control algorithm can achieve continuous jerk, reduce impact on machine tool effectively, and be important to high speed and high accuracy CNC machining.

Abstract: Simulation of the gas-liquid-solid three-phase flow field of outside the abrasive water jet(AWJ) nozzle is studied by the computed fluid dynamic software- FLUENT, and the velocity field of the three-phase flow is obtained, the velocity value of the flow between the nozzle and work-pieces is also obtained. Serial experiments have been done to verify the simulation method. In the experiments, the impact force signal of the AWJ outside the nozzle is collected by the piezoelectricity ergometer, then it is filtered by the vibration signal and dynamic signal software. The testing values are transformed to the velocity values, which will be compared with the simulation values. The comparison result indicates that the value of the simulation is changing similarly with the experiment value, and both value is almost the same, which proves that the simulation method is successful, the simulation model and the boundary conditions are right.

Abstract: Sintered NdFeB permanent magnet is widely used in many areas because of its excellent magnet property. In this study, the machining parameters of electrical discharge machining (EDM) are varied to study the effects of electrical discharge energy on material removal rate and surface roughness of NdFeB magnet. Moreover, the micro-cracks on the machined surface induced by EDM are also examined. The experimental results reveal that the MRR increases with the electrical discharge energy. The number of surface cracks on the machined surface increases with the enhancement of discharge energy Thus, using EDM process to machine sintered NdFeB magnet depends on setting the machining parameters to prevent surface crack.