【正文】 tical and horizontal, relatively simple structure, applicable to economic CNC lathe. Rotary Tool in the structure must have good strength and stiffness, resistance to bear rough Cutting Tool in the cutting force and reduce the role of deformation and improve processing accuracy. Rotating Tool to choose reliable positioning programme structure and reasonable position, in order to ensure that each rotary turret to a higher position after repeated positioning accuracy (typically to ). Figure shows the spiral movements of the Quartet Turret. Auto Rotary Tool in the simplest of ATC, is 180 186。, ATC pleted. ATC most of their time and processing time coincidence, the only real tool change time turret transposition of the first time, this approach mainly used for ATC and NC NC drilling file bed. 2. system for the automatic tool change Figure shows the knife and the whole machine tool CNC machine tools for the appearance of Fig. Figure shows the knife and splittype machine to the appearance of CNC machine tool plans. At this point, knife storage capacity, a heavier tool can, and often additional transport unit to plete the knife between the spindle and cutting tool transport. Daidao the knife from the ATC, the election knives, automatic loading and unloading machine tool and tool exchange institutions (manipulator), posed of four parts, used widely. Tool Automatic Tool Change the manipulator system, the whole process more plicated ATC. We must first used in the processing of all installed in the standard tool on the knife handle in the machine outside the presize, according to a certain way Add to the knife. ATC, selected first in the knife knife, and then from ATC, from the knife from the knife or spindle, exchange, the new knife into the spindle, the old knife back into the knife. ATC, as the former two knives to acmodate a limited number can not be too many, can not meet the needs of plex parts machining, CNC machine tool Automatic Tool Change Daidao the use of the automatic tool change devices. The knife has more capacity, both installed in the spindle box side or above. As for the automatic tool change Daidao device CNC machine tool spindle box only a spindle, spindle ponents to high stiffness to meet the machining requirements. The number of establishments in larger knife, which can meet the more plex parts of the machining processes, significantly improving productivity. Daidao system for the automatic tool change applied to drilling centres and CNC machining centers. The parison drawn Daidao automatic tool change system is the most promising. control of the knife random mode of election 3. 1Common methods of automatic election knife Automatic control of the knife CNC refers to the system after the implementation of user instructions on the knife library automation process, including the process to find knives and automatic tool change [(63,71]. CNC Machining Center device (CNC) directive issued by the election knife , a knife, the tool required to take the knife position, said the election automatic knife. automatically elected knife There are two ways: random sequence election knives and knife election method. order election knife Tool Selection order is the process tool according to the sequence of the insert knife, the use of knives in order to take place, used knives back at the original knife, can also order Add Block, a knife. In this way, no need Tool identification devices, and drive control is a relatively simple, reliable and can be used directly from the points of the knife machinery to achieve. But the knives in each of the tool in different processes can not be reused, if the tool is installed in accordance with the order of the knife, there will be serious consequences. The need to increase the number of knives and knife the capacity of the tool and reduce the utilization of the knife. election knife Random election under the knife is arbitrary instructions to select the required tools, then there must be tool identification devices. Tool knife in the library do not have the processing in accordance with the order of the workpiece can be arbitrary storage. Each of the tool (or knife blocks) are for a code, automatic tool change, the rotary cutter, every tool have been the tool identification device acceptable identification. When CNC tool code and the code in line with directives of the tool selected, the rotary cutter knives will be sent to the ATC position, waiting to grab manipulator. Random knife election is the advantage of the cutter knife in the order has nothing to do with the processing sequence, the same tool can be used repeatedly. Therefore, the relatively small number of knives, knife the corresponding smaller. Random elections knife on the tool must be coded to identify. There are three main coding. 1. Tool coding. Adopt special knife handle structure coding, the drawbars on the knife handle backend packages such as spacing of the coding part of the locknut fixed. Coding diameter ring diameter of a size two, respectively, said that binary 1 and 0 to the two rings are different, can be a series of code. For example, there are six small diameter of the ring can be made to distinguish between 63 (261 = 63) of the coding tool. All of 0 normally not allowed to use the code, to avo