Research On Speed-depended Dynamics Of CNC Machine Tool Structure Under No-machining Operational Conditions

Dynamic property of machine tool is an important factor which affects machining quality and machining efficiency. With the development of researches in dynamic property of machine tool, people found that the influence on machining capability by structural dynamics of machine tool should not be ignored. According to the previous researches on the dynamics of machine tool structure, we can find that the dynamic properties can be influenced by the speed factor of machine tool. But these researches are only about the differences of machine tool structural dynamic properties when the machine tool is under static states and under operating conditions. There is no related research on how the dynamic properties of machine tool structure are influenced by the speed factor of machine tool. So, with the help of related project, we had a deep and systemic research on the speed-depended dynamic properties of machine tool structure. In this paper, the main research contents are as follows:A method to analysis the main mode of machine tool structure under operating conditions is put forward in this paper, and this method is also verified by the following experiments in the paper. This method offers an effective tool to analysis the main mode which has the greatest influence on the vibration of machine tool structure and to the do following researches on speed-depended dynamic properties of machine tool structure.Has a research on the speed-depended dynamic properties of machine tool structure when the machine tool is under one-axis operating condition. With the experimental method, studies on natural frequencies, damping ratio, main modes and the corresponding distribute states of machine tool structure when the machine tool is under one-axis operating condition of X direction, Y direction and Z direction respectively. And analyzes the characteristics of speed factor influence on dynamic properties of machine tool structure when the machine tool is under one-axis operating condition.Researches the speed-depended dynamic properties of machine tool structure when the machine tool is under two-axis operating condition. With the similar experimental method, studies on natural frequencies, damping ratio, main modes and the corresponding distribute states of machine tool structure when the machine tool is under two-axis operating condition of XY direction and XZ direction respectively. And obtains the characteristics of speed factor influence on dynamic properties of machine tool structure when the machine tool is under two-axis operating condition.Establishes the dynamic speed-spectrum of machine tool structure when the machine tool is under no machining conditions. Puts forward a speed-spectrum which is used to describe the characteristics of speed factor influence on main modes and the corresponding distribute states of machine tool structure. This research is a preliminary research to find out an appropriate way to describe the characteristics of speed factor influence on dynamic properties of machine tool structure.