Auto Matic On-line Detection Technology And Device Research And Development On The Diameter Of PCB Drill Bit Made By Centerless Grinding

PCB drill’s centerless grinding process is a changing, complex random process,The changing process parameters determine the accuracy of the product. Automatic measurement system is the closed-loop control system through the direct detection of the workpiece to track the processing status of each process parameter changes and achieve a fully automatic feeding. To further improve the quality of the workpiece grinding, online detection system is used for Grinding, making the centerless grinding process to form a closed loop control system. The topics make PCB drill rod’s diameter measuring for example, in the current displacement sensor technology, based on integrated single chip technologies and PC to complete the on-line measurement system’s research.The automatic measurement system established with adaptive control theory that based on PC and SCM system. And this is the workflow: Measuring device measured the error signal during processing, the make it amplification and A/D converter and sent to the PC, PC receive the information and compared it to the standard parameters and calculate the possible future processing error, Then change it into control signal to control the stepper motor to compensate feed in order to eliminate processing errors and improve accuracy. In the text separately from the hardware and software described in detail as follows:1. Mechanical design. It mainly describes the structural design of the Centerless Grinder size measurement devices. There is an overview of its overall function and an important part of the selection and analysis; Finally, the three-dimensional body shape measuring devices work were outlined.2. Control part of hardware and software design. According to the on- line measurement requirements of grinder, designed a microcontroller as the core of the circuit to the sensor and conditioning circuit, the output signal acquisition, processing, display and feedback to the grinder, to achieve closed-loop control of grinding process.The subject’s major task is researching the problems in the centerless grinding to be able to detect the mismachining tolerance automaticly and better accuracy of the parts processing.The paper uses measuring method appropriately to design and exploit a measurement and control system used computer of the abrasive machining by changing the centreless grinder appropriately under guaranteeing the internal structure of grinding.The system make the computer detect and control the mismachining tolerance automatically.For achieving the purposes of high degree of accuracy,high efficiency and low cost,the system contains a grating sensor to detect the workpieces through contacting them and use singlechip to measure and feedback PCB bar workpieces in centreless grinder. So the system can control the mismachining tolerance much better and form production model which has characters of high efficiency, unmanned and high degree of accuracy.The topics verify the feasibility and correctness of the automatic measurement system solutions by measuring the simulation system software debug, which is not only for the realization of the real line automatic measurement of the foundation, but also provides means and programs for the transformation of other kinds of machine tools.