排列3二码分布图

数控机床的种类很多，可以从不同的角度进行分类，不同的分类标准对应不同的分类，小编为大家介绍其中的两种分类方法，那就是按运动方式和控制方式进行分类，具体的内容如下： 数控机床按运动方式分，可分为： (1)点位控制系统 只控制刀具从一点移到另一点的位置，而在移动过程中不进行切削加工，如坐标镗床、钻床和冲床等。要求坐标位置有较高的定位精度，为提高生产效率，采用机床设定的最高进给速度进行定位运动，在接近定位点前要进行分级或连续降速，以便低速趋近终点，从而减少运动部件的惯性过冲和因此引起的定位误差。在定位移动过程中不进行切削加工，因此对运动轨迹没有任何要求。 (2)直线控制系统 直线控制系统是控制刀具或基础工作台以一定速度，沿平行于某一坐标轴方向，由一个位置到另一位置的精确移动。也称点位直线移动控制系统。 (3)轮廓控制系统 是对两个或两个以上的坐标轴同时进行控制(二轴、二轴半、三轴、四轴、五轴联动)，它不仅要控制机床移动部件的起点和终点坐标，而且要控制整个加工过程的每一点的速度、方向和位移量，即要控制加工的轨迹，加工出要求的轮廓。运动轨迹是任意斜率的直线、圆弧、螺旋线等。这类机床的数控装置的功能是最齐全的，能够进行两坐标甚至多坐标联动的控制，也能够进行点位和直线控制。 数控机床按运动方式分，可分为： (1)开环数控机床 指不带反馈的控制系统，系统内没有位置反馈元件，通常采用步进电机作为执行机构。输入的数据经过数控系统的运算，发出指令脉冲，通过环形分配器和驱动电路，使步进电机转过一个步距角，再经过传动机构带动工作台移动一个脉冲当量的距离。移动部件的移动速度和位移由输入脉冲的频率和脉冲个数决定的。 (2)半闭环数控机床 在驱动电机端部或在传动丝杠端部安装角位移检测装置(光电编码器或感应同步器)，通过检测电机或丝杠的转角间接测量执行部件的实际位置或位移，然后反馈到数控系统中。获得比开环系统更高的精度，但它的位移精度比闭环系统的要低，与闭环系统相比，易于实现系统的稳定性。现在大多数数控机床都广泛采用这种半闭环进给伺服系统，惯性较大的机床移动部件不包括在检测范围内 There are many kinds of CNC machine tools, can be classified from different angles, different classification standards corresponding to different classification, small make up for you to introduce two kinds of classification methods, that is, according to the motion mode and control mode classification, the specific content is as follows: According to the motion mode, CNC machine tools can be divided into: (1) point position control system To control the movement of the tool from one point to another without cutting, such as jig boring, drilling, and punching machines. High positioning accuracy is required for the coordinate position. In order to improve production efficiency, the highest feed speed set by the machine tool is adopted for positioning movement. Before approaching the positioning point, classification or continuous speed reduction should be carried out to make the low speed approach the end point, so as to reduce the inertia overshoot of moving parts and the positioning errors caused by it. In the process of positioning and moving, there is no cutting, so there is no requirement on the trajectory. (2) linear control system The linear control system is the precise movement of the tool or base table from one position to another in a direction parallel to a certain coordinate axis at a certain speed. Also known as point position linear movement control system. (3) contour control system Of two or more than two axes simultaneous control (two and a half shaft, two axis, three axis, four axis, five-axis linkage), it is not only to control the beginning and end of the machine moving parts coordinates, and to control the whole process of every bit of speed, direction and displacement, namely to trajectory control processing, work out the outline of requirements. The trajectories are straight lines, arcs, spirals, etc. This kind of machine tool's numerical control device function is the most complete, can carry on two coordinates even many coordinates linkage control, also can carry on the point position and the straight line control. According to the motion mode, CNC machine tools can be divided into: (1) open-loop CNC machine tool A control system without feedback, in which there is no position feedback element, usually a stepper motor is used as the actuator. The input data is processed by the numerical control system, and the command pulse is sent out. Through the annular distributor and drive circuit, the stepper motor turns a step Angle, and the drive mechanism drives the workbench to move a pulse equivalent distance. The velocity and displacement of moving parts are determined by the frequency and number of pulses. (2) semi-closed-loop CNC machine tools An angular displacement detection device (photoelectric encoder or inductosynchro) is installed at the end of the driving motor or the end of the driving screw to measure the actual position or displacement of the executing part indirectly by detecting the Angle of the motor or the screw, and then feed back to the numerical control system. The accuracy is higher than that of the open-loop system, but its displacement accuracy is lower than that of the closed-loop system. Now most of the CNC machine tools are widely used in this semi-closed loop feed servo system, inertia of the machine moving parts are not included in the detection range.