Currently, CNC machine tools Varieties has been basically complete, standard range, according to incomplete statistics, there are more than 400 varieties and specifications. Can be classified according to various principles. But sum up, based on the following four kinds of common methods to classification. 1, according to technology use classification (1) General CNC machine tools. Such machine tools and machine tools of traditional common types, have a numerically controlled lathe, milling, boring, drilling, grinding, etc., but there are many varieties of each, such as NC Milling In there milling, horizontal milling, milling tools, such as gantry milling. The possibility of such machine tools and common tool similar process, the difference is that it can process parts with complex shapes. (2) NC Machining Center Machine. Such tools are generally based on the CNC machine tool developed. It is a general installation of CNC Machine Tool (the tool can accommodate more than 10-100) and the automatic tool changer consisting of a kind of automatic tool changer CNC machine tools (also known as multi-process or boring and milling CNC machine tools type machining centers, machining centers customarily referred to as?? MachiningCenter), which enable CNC machine tool automation and efficiency to further develop in the direction. CNC machining centers and CNC machine tools is the difference between the general: the workpiece by a clamping, the Control Unit can control the machine to automatically change tools, continuous surface of the workpiece automatically complete the processing of milling (car), boring, drilling, hinge and the tapping process and many other processes. Most of these are boring and milling machine tools based mainly used to process box parts. How is it compared to the NC machine tool has the following advantages: to reduce the number of machine units, easy to manage multiple processes parts for as long as one machine will be able to complete all processing, and can reduce the amount of semi-finished goods inventory; As long as a workpiece clamping, thus reducing the installation as many times caused by positioning error, you can rely on precision machine tools to ensure processing quality; process focused on reducing the auxiliary time and increase productivity; As the parts in one machine in a single setup can be done processing multi-channel process, so greatly reducing the number of dedicated fixtures, further reducing the production lead time. As the CNC machining centers has many advantages, popular with users, and therefore the production of CNC machine tool plays an important role.
There is also a class of machining center is developed on the basis in the lathe, and to processed objects as the main shaft. In addition to turning, boring, but also can face and the surface of any part of weeks of drilling, milling and tapping process. Such processing center also has Tool, the tool can be installed 4-12, habits, said such tools as Turning Center (TC: Turning Center).
Figure 1 five-axis NC machining (3) multi-axis CNC machine tools. Some of complex shape parts, with three coordinates of the CNC machine tool or can not be processed, such as propeller, aircraft and other surface parts of the process, need to coordinate synthesis of three or more sports can be processed into the required shape. Incidentally, multi-axis CNC machine tools, characterized by the number of NC axis control device more complicated machine structure, the number usually depends on its axis machining parts of the process requirements. Now commonly used is the 4,5,6 coordinates CNC machine tools. Figure 1 Schematic diagram of five-axis NC machining. At this time, x, y, z 3 coordinate with the turntable rotating, swing the tool can also linked to processing of wing and other parts.
2, according to classification of numerical control machine tool trajectory
According to the control of the relative motion between tool and workpiece trajectory can be divided into the point position control of CNC machine tools CNC machine tools, point and linear control of CNC machine tools, contour control of CNC machine tools and so on. Are summarized as follows:
(1) point and control of CNC machine tools. Such tools can only control the machine tool numerical control device moving parts from one location (point) precisely to another position (point), which controls only the end of the coordinates of stroke in the move without any cutting, as the two correlation between point and line speed depends on productivity. In order to pinpoint the basis of a productivity as high as possible, so the movement between the two related points in the first to move quickly to close to a new location, and then slow down and 1-3, so slow closer to positioning points to ensure positioning accuracy.
Such machine tool jig Boring , CNC drilling, CNC punch press and CNC measuring machine, with its corresponding numerical control device called the point position control device.
(2) point and linear control of CNC machine tools. These machines work, not only to control the position between the two related points (ie, distance), but also control the movement between the two related points, speed and route (ie path). The route generally parallel to the axis by and composed of straight line. It and position control CNC difference: when the machine moving parts move, you can along the a axis direction (in general can also be carried out along the 45 ° oblique cut, but not the slope of the straight line along any cutting) for cutting processing, and its accessibility than the position control of CNC machine tools and more, for example, to increase the spindle speed control loop feed processing, tool selection and other functions. There are simple tools such
CNC lathe , CNC milling machine and CNC machining centers. Numerical control device called the point of the corresponding bit line control device.
(3) contour control CNC machine tools. Control device such machines can simultaneously two or more continuous control axes. Processing time not only to control the start and end, but also control of the processing speed and position of each point, so that machining the line drawings of complex shape parts. Its accessibility is relatively complete.
Main type of CNC lathe machine, CNC milling, CNC Grinder And EDM machine tools. The corresponding contour control device called the Control Unit (or continuous control device).
3, by way of servo control of the system classification
CNC controlled variables according to whether the detection of the feedback device can be divided into open and closed loop two. In the closed-loop system, according to measurement devices and locations can also be divided into closed loop and two semi-closed loop. In the open-loop system based on open loop also developed a type of compensation CNC System .
(1) open-loop control of CNC machine tools. In the open-loop control, the machine did not detect feedback device (see Figure 2).
Figure 2 Block diagram of the open-loop control system
NC device signal is a one-way process, so there is no system stability problems. It is due to one-way signal flow, its moving parts of the actual machine position is not inspected, so machines plus I am an expert from wifiusbadapters.com, while we provides the quality product, such as rp-sma antenna Manufacturer , usb adapters for laptops, wireless 54mbps adapter,and more.
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