The common automatic tool selection mode in Dongguan CNC processing plant: automatic control of tool magazine refers to the automatic control process of tool magazine by CNC system after executing user instructions, including program tool finding and automatic tool changing. The tool selection instruction issued by CNC of machining center turns the tool magazine to the position where the tool number is needed, which is called automatic tool selection. There are two methods for automatic tool selection: sequential tool selection and random tool selection.
Sequential tool selection: the method of sequential tool selection is that the tools are inserted into the tool magazine according to the sequence of the predetermined process. When they are used, they are transferred to the tool taking position in sequence. The used tools can be put back into the original tool holder, or they can be put into the next tool holder in sequence. In this way, Dongguan CNC processing plant does not need the tool recognition device, and the drive device control is relatively simple and reliable, which can be directly realized by the dividing machine of the tool magazine. However, each tool in the magazine can not be reused in different processes. If the tools are not installed in the magazine in sequence, serious consequences will occur. The number of tools and the capacity of tool magazine must be increased to reduce the utilization rate of tools and tool magazine.
Random tool selection: the method of random tool selection is to select the required tool according to the instruction requirements. At this time, there must be a tool identification device. The cutting tools in the tool magazine do not have to be arranged according to the processing order of the workpiece, and can be stored arbitrarily. Each tool (or tool holder) is coded. During automatic tool change, the tool magazine rotates and each tool is recognized by the "tool identifier". When the tool code is consistent with the CNC instruction code, the tool is selected and the tool magazine rotates to send the tool to the tool change position, waiting for the manipulator to grasp. The advantage of random tool selection is that the arrangement order of the tools in the tool magazine is independent of the machining order, and the same tools can be used repeatedly. Therefore, the number of tools is relatively small, and the tool magazine is relatively small. For random tool selection, the tool must be coded for identification. There are three kinds of coding.
1. Tool coding mode: Dongguan CNC processing plant adopts special toolholder structure for coding. The tie rod at the back end of toolholder is equipped with equal spacing coding ring, which is fixed by locking nut. There are two kinds of coding ring diameter, one is big and the other is small, which represent binary "1" and "0" respectively. Through the different arrangement of the two rings, a series of codes can be obtained. For example, a code that can distinguish 63 (26-1 = 63) kinds of cutting tools can be formed by six rings with large and small diameters. Generally, all 0 codes are not allowed to be used to avoid confusion with the condition that there is no tool in the cutterbed.
2. Coding mode of tool holder: code the tool holder and the tool, and put the tool into the tool holder with the corresponding number. When changing the tool, the magazine rotates so that each tool seat passes through the tool detector in turn, finds the tool seat, and the magazine stops rotating. At this time, there is no coding ring on the handle, which simplifies the handle.
3. Coding accessory mode: this mode includes coding key, coding card, coding rod and coding disk, among which coding key is the most widely used. First, attach a coding key with the tool number to each tool. When each tool is stored in the tool holder of the tool magazine, the number of the key is transferred to the tool holder, and the coding key is inserted into the key hole next to the tool holder to number the tool holder. Dongguan CNC processing plant is really good, worthy of attention!!