What are the different types of CNC machine tools?
Select the rigid frame, materials, casting, and connection mode to compare, in addition to the parts of each section or grade standards, if the manufacturer is able to provide you with: screw guide rail, motor driver, and other major parts of the model. But today, instead of classification, I'd like to share with you the classification of machine tools.
First, according to the classification of processing mode and process use.
1. conventional CNC machine tools Ordinary CNC machine tools refer to a process in which automatic machine tools, such as CNC milling machines, CNC lathes, CNC drilling machines, CNC grinding machines, and CNC gear machining machine tools, are controlled digitally. Ordinary CNC machine tools do not have a high enough level of automation.
2, machining center A machining center is a CNC machine tool that includes a tool library and an automated tool change unit. It can perform milling, boring, drilling, expanding, reaming, tapping, and other processes on most of its machining surface.
Second, according to the classification of movement
1, power of a single point The exponential control scheme for CNC machine tool point control only controls the precise location of the tool or worktable from one point to another point, then performs fixed point processing, with no need to control the path between points. CNC drilling machines, CNC boring machines, and CNC jig boring machines all use this type of power.
2, linear control of a single point Point-positioning on a CNC machine tool In addition to controlling the precise positioning of the starting point and end point of the linear trajectory, linear control also controls the linear cutting between these two points at the required feed rate. CNC milling machines, CNC lathes, and CNC grinders all use this type of control.
3, power of the contour The CNC machine tool, also known as continuous trajectory control, can control two or more coordinate directions of joint movement at the same time. The numerical control device has the function of interpolation operation, which makes the tool's trajectory approach the specified contour curve with the least amount of error, and coordinates the velocity of each coordinate direction, so that the specified feed velocity can be maintained throughout.
Three, according to the classification of control modes
1. Control system with an open loop The term "open loop control system" refers to a control system that does not have a feedback mechanism and is made up of a stepper motor driving line and a stepper motor. Through the control operation, the numerical control unit sends out pulse signals, each of which causes the stepper motor to rotate at a specific angle and forces the working table to travel a specific distance through the ball screw.
The closed loop control system is in the open loop control system of servo mechanism with angular displacement detection device, by detecting servo mechanism of ball screw, and the closed loop control system is in the open loop control system of servo mechanism with angular displacement detection device. After comparing the difference of control, make the displacement of moving parts added, Control system until the difference is removed. Angle of indirect measuring the displacement of the moving parts and then feedback to the CNC device comparator, comparing with input displacement of the original instruction value, after comparing the difference of control, make the displacement of moving parts added, Control system until the difference is eliminated. This servo mechanism has better precision, speed, and dynamic characteristics than an open loop servo mechanism, and it is used in most small and medium-sized CNC machine tools.
3. closed loop control system is closed loop control system in machine tool moving parts position directly with linear position detection device, can detect the actual displacement feedback to the CNC device comparator, comparing with displacement value input of the original instructions, use as a supplement after comparing the difference between the control displacement of moving parts
The numerical control system, known as coordinate linkage, controls multiple coordinate axes according to the functional relationship needed to coordinate the movement at the same time. The number of linkage axes can be divided into:
1, linkage of two axes CNC machine tools can monitor two coordinate axes linkages at the same time, making them ideal for CNC lathe machining rotating surfaces or CNC milling machine milling plane contours.
2. On the basis of two axes, two-axis semi-linkage increases the rotation of the Z-axis. When the computer coordinate system's X and Y axes are set, the Z-axis can be fed on a regular basis. Layered machining is possible with two-axis and semi-linkage machining.
Linkage of three axes The CNC machine tool can monitor the connection of three axes at the same time, and can be used for general curved surface processing as well as general cavity mold processing.
4, linkage of several coordinates At the same time, a CNC machine tool can monitor the linkage of more than four coordinate axes. The multi-coordinate CNC machine tool has a complex structure, a high precision requirement, a complex program, and is ideal for processing complex form parts such as impeller blade parts. Two axis, two axis half, and three axis processing are usually possible with three axis machine tools.
from Everyone's Blog Posts - Fashion Industry Network https://ift.tt/2OS6fJO
No comments: