窄深槽磨削用风冷式砂轮设计及气流场特性

Design of the air-cooled grinding wheel for narrow-deep-groove grinding and experimental study on its airflow field characteristics

针对窄深槽磨削过程中冷却困难而突发烧伤问题,设计制造了一种风冷式砂轮。采用热球风速仪测量风冷式砂轮在不同导风轮开口度、砂轮转速和径向测点距离的出风口和入风口处气流场的流速和压力,研究风冷式砂轮的气流场分布特性和强化冷却性能,获得了风冷式砂轮磨削区冷却气流流速预测模型。试验结果表明,风冷式砂轮入风口气流以扰动运动为主且流速较缓;砂轮出风口的气流受到扰动气流和径向出射气流的共同作用,风冷式砂轮出风口最大气流流速增大约35.2%;砂轮气流场的流速和压力随着导风轮开口度和砂轮转速的增大而增大,随径向测点距离增大而减小。风冷式砂轮的气流场特性证明环境空气被较高效地压入空气流道,风冷式砂轮的设计合理。

In this article, aimed at the burning problem caused by the difficulty in cooling in the process of narrow-deep-groove grinding, an air-cooled grinding wheel is designed and manufactured. The thermal anemometer is used to measure the airflow field at the outlet and inlet of the air-cooled grinding wheel. The flow velocity and pressure are worked out at different opening degrees of the air-guiding wheel, the wheel’s rotation speed and the radial measuring-point distance. The distribution characteristics of the airflow field and the cooling-enhancement performance of the air-cooled grinding wheel are explored. The prediction model of the cooling airflow velocity in the grinding zone of the air-cooled grinding wheel is set up. The experimental results show that the airflow at the inlet of the air-cooled grinding wheel is mainly embodied by disturbed movement and the flow velocity is slow. The airflow at the outlet of the wheel is affected by the combined action of the disturbed airflow and the radial outflow airflow, and the maximum flow velocity increases by 35.2%. The flow velocity and pressure of the airflow field of the air-cooled grinding wheel go up with the increased opening degrees of the air-guiding wheel and the rotational speed of the grinding wheel, and go down with the increasing radial measuring-point distance. The airflow field characteristics of the air-cooled grinding wheel have revealed that the ambient air is pressed into the airflow channel more efficiently, and the design of this air-cooled grinding wheel is reasonable.