组合机床相关毕业设计的中英文翻译--对组合机床滑台动态性能的调查报告(编辑修改稿)

组合机床相关毕业设计的中英文翻译--对组合机床滑台动态性能的调查报告(编辑修改稿)内容摘要：

motion unstability due to periodical change of load in operation will affect the surface quality of the workpiece machined, and the tool would be broken off under serious conditions, By using the method of power bond graph and state space analysis, the dynamic mathematical model of the system used to drive slide unit is estab lished, that is called as selfadjusting back pressure speed control system and abbreviated to SABP system. In order to improve slide unit39。 s dynamics, it is necessary to find out the main reasons and affecting factors, that must be based on puter digital simulation and study on the results. DYNAMIC MATHEMATICAL MODEL The schematic diagram of SABP system is shown in , the system is used to perform the cycle of feeding, stopping and returning. Four way control valve works in the right position during slide unit39。 s feeding. The supply pressure of the pump is approximately constant under the action of pressure relief valve, the oil through the control valve and pressure pensated flow control valve enters the nonrod chamber to put slide unit forward. At the same time, the oil from the rod chamber is discharged through SABP valve and directional control valve to tank. In this process, the state of two check valves and pressure relie f valve is not changed, To establish the mathematical model as reasonably and simply as possible, consideration must be focused on main affecting factors for a plex nonlinear system such as the SABP system. It is illustrated by theoretical analysis and test result 39。 , that the transient time of the system is much longer than that of the flow control valve, and the flowrate overshoot of the valve in transients affects very small to slide unit speed because of the。 large effective sectional area of nonrod chamber in cylinder. For investigating the system39。 s dynamics widely and deeply, the initial modeltn is further simplified in this paper, and so the study can be efficiently made with microputer. It is assumed that the flowrate through the flow contr ol valve is constant in the whole transient process, and is denoted to a flow shows the structure diagram of the dynamic model of the system, it is posed of cylinder, slide unit, SABP valve and pipe line。 etc. By using the method of power bond graph and state space analysis in this paper, the dynamic mathematical model of the system is to be established The power bond graph is a power flow diagram, which expresses abstractly the actions among subsystems as three effects, . resistance effect, capacitive effect and inertia effect, according to the way of energy transform, on the basis of practical structure and by means of method of lumped parameters. The model is characterized by a clear conception in physics, and nonlinear system can be accurately analysed in bination with method of state space analysis, thus it is a effective method used in the dyna mic investigation of plex nonlinear system in the39。 timedomain. From。