| Five-axis gantry quenching machine tool is a kind of NC machine tool that is used to the heat treatment on the surface of the large covering of the automobile die.At present,most of this kind of machine tools using a closed computer numerical control(CNC)system with high cost cannot meet the requirements of the openness and low cost on modern processing at home and abroad.With the rapid development of automobile industry,in order to satisfy the needs of the automotive industry,it is necessary to study open CNC system to perform heat treatment on the surface of the large covering for automobile die,and develop CNC quenching machine tools which have the high efficiency,high precision and low cost.Combining the characteristics of the large covering of automobile die and the requirements of quenching process,five-axis gantry quenching machine tool was developed.Based on PMAC motion control card,the CNC system for the heat treatment on the surface of the large covering was developed which has high-adaptable and openness functions.In the dissertation the main researched contents are as follows:Through the study of the properties of the large covering for automobile die and the analysis of the quenching functions of quenching machine tools,a design scheme of the machine tool was proposed,and five-axis gantry quenching machine tool was developed,mainly including the design of structure of five-axis gantry quenching machine tool,the modeling of kinematics and part selection.In order to reduce effect on the accuracy of machine tool movement by rack and pinion drive,caused by the design of the rack and pinion seamless transmission mechanism to eliminate gaps between teeth,improving the accuracy of machine movement,designed a rack and pinion seamless transmission mechanism to eliminate teeth gap,improve the accuracy of machine tool movement.T he architectures of various open CNC system were analyzed,based on which PC+PMAC control mode was developed.According to the control requirements of the machine tool,the components used in the control system were selected.Based on the principles for circuit design and the requirements for the installation of electrical control cabinet,the electrical control cabinet was designed and installed.At the same time,the control platform was set up for the machine tool.To ensure that the movement functions of the machine tool,the parameters of driven motor has been set.In order to ensure the smooth movement and precision by machine tools,research of PID algorithm,the PID parameters of PMAC motion control card were adjusted.PMAC motion control card I/O signal processing by PLC programming technique,the development of the operation and control functions of CNC panel and manual pulse generator.According to the structural characteristics of the machine tool and research the hardening requirements of the large covering die,using the modularization programming idea,developed a five-axis gantry quenching machine dedicated CNC software was developed by VC++6.0.On the host computer can be programmed to call PMAC dynamic link library functions to achieve the communication between PC and PMAC motion control card.The interface of real-time management module was fulfilled utilizing multi-thread technology,information processing mechanism.The data acquisition interface was developed by real-time data collecting technology.The preview interface of quenching trajectory was accomplished by means of VC+MATLAB hybrid programming.In order to solve problem of the workpiece coordinate system is converted to machine coordinate system,a workpiece coordinate system calibration method was proposed.Research for locus of space circular,space circular interpolation method for PMAC was proposed.The rationality by the five-axis gantry structure quenching machine structure design scheme and the perfection by CNC system was validated through motion experiment,and the job requirements for the five-axis gantry quenching machine tool can be fulfilled. |
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