The Development Of The Robotic Grinding System Facing Plasma Spray Tooling And Its Experimental Research

As a kind of rapid metal tooling method, Rapid Plasma Spray Hard Tooling(RSHT)has been used to manufacture the panel molds of the fields such as automobile, motorcycle, electrical appliance and architecture decoration. It has great application foreground because of its advantages of low cost, rapid speed, high surface reproduced accuracy and no limitation in the spray material or mould size. In order to solve the problem of long grinding time and hard labor intensity of manual grinding during grinding the big or medium-sized autobody panel moulds, this paper summarizes the latest research in the field of robotic grinding system home and abroad and then developed a robot-assisted automatic grinding system using the Motoman-UP20 6-axis robot. Firstly, this paper designed a NC swivel table for the robot and realized the strict controlling of its turning speed and angel. In this paper, the principle of the control motor's selection, the drive organ and the mechanical design have been detailed. Among the control cell, the PLC has been selected as the center to control the rotate speed and rotate angle of the NC swivel table. Based on the NC swivel table, the robotic grinding experiment platform has been completely constructed by developing a robotic end executor with the center of an air hand-grinder and a robotic test system with the DA-5 displacement sensor. For ensuring the grinding quality and efficiency, the selecting of different grinding tool to different surface is analyzed and the mold-assisted grinding system was successfully developed. Furthermore, two path-planning methods have been designed to acquire the grinding path. One is planning the tool path and generating the G-code file based on the UG-CAM software considering the actual grinding technics, then the G-code file was transferred to the required format file that can be run in the robot by the developing software in the paper. The other is developing the software that can directly program grinding path on the platform of Visual C++ and it just can be applied in the plat surface. In order to ensure the planning grinding paths feasible, the robot simulation software has been introduced. Through the simulating of the grinding process in ROTSY provided by MOTOMAN Company, it can be decided whether the tool intervenes with the workpiece surface and the robot can be correctly controlled. Finally, a serial of processing experiments were carried out and the effects of grinding angle, robot moving speed and grinding path on the surface quality were studied and the suitable grinding parameters were obtained. Then choosing suitable grinding parameters, a grinding experiment on a simple freeform surface has been done and verified the established system can be used in general moulds'grinding. According to the above experiments, two different experiments on the film without grinding liquid have been executed. Through analyzing the grinded film construction, it can be concluded that the wet grinding is more suitable to grind the mould manufactured by plasma spay tooling.