Research On Dynamic Balancing System Of The Grinding Wheel Based On PLC

The problem of mechanical vibration is widely concerned in the engineering. In the process of grinding, the unbalance of the grinding wheel is the main reason for the vibration and low grinding quality. Therefore, in order to decrease the vibration, ensure the quality of grinding and enhance the life of grinding wheel axis, the dynamic balancing for grinding wheel is necessary.The grinding wheel dynamic balance mainly includes three ways:artificial balance, semi-automatic balance and online automatic balance. However, complex operation and low accuracy of artificial balance always lead to great error; semi-automatic balance depends on the dynamic balancing instrument and has a low timeliness due to the inspection of one dynamic balancing instrument for the grinding machines; online automatic dynamic balancing system is highly expensive and in a state of foreign technology monopoly, so only the CNC machine tools required for high machining accuracy will be equipped with the on-line dynamic balancing system. Therefore, it has highly important practical value to develop a new type of grinding wheel dynamic balance test system with low cost to equip per grinding machine.This paper develops a new grinding wheel dynamic balancing system and detailly discusses the design from the hardware and software. The dynamic balancing sysyem has the future of low-cost and great accuracy, thus to make each grinding machine can be equipped with a set of dynamic balance test system. The concrete research content is as follows:1. This paper proposes a new type of test system with the structure of mater-slave for grinding wheel dynamic balance. The master machine adopts PLC and touch screen to make human-computer interaction and dynamic process monitoring possible. While the slave machine mainly consisted of MCU shoulders the responsibility to collect data and recognize unbalance. The communications between master and slave machine is achieved through the design and implementation of the communication interface based on RS-485.2. The identification of unbalance vibration based on cross-correlation analysis and DFT method under different condition and the principle of the grinding wheel dynamic balance based on influence coefficient method are further studied in this paper. Finally, the suitable dynamic balancing method for grinding wheel is determined.3. The design for slave machine is also put forward. The paper emphasis on describing the design of signal preprocessing circuit including the amplification, filtering and dc bias of vibration signal and the shaping preprocessing of speed signal. In the meantime, this paper fulfills related software programming.4. The dynamic balancing tests on the simulated grinding experiment platform indicate that the amplitude of unbalance vibration range within 0.03 mm/s and the phase range within 6°; the effect of equilibrium is ideal:the decrease rate of vibration is 91.5～95.0%. Through a large amount of data, the grinding wheel dynamic balancing system turns out to have certain application value.