According to the lathe machine cutter selection command of the CNC device, the required tool is transferred from the tool magazine to the tool-taking position, which is called automatic tool selection. In the tool magazine of the machine tool, there are usually two ways to select tools: sequential tool selection and optional tool selection.
The tool selection method of the machine tool sequence is to insert the used tools into the JJ seat of the tool magazine according to the sequence of the predetermined process, and turn to the tool picking position in order when using. Put the used lathe machine cutter back in the original tool holder. This method does not need a tool identification device, so its drive control is relatively simple and its work is reliable. But each tool in the tool magazine cannot be reused in different processes.
In order to meet the processing needs, only the number of tools and the capacity of the tool magazine are increased, which reduces the utilization rate of the tools and the tool magazine. In addition, you must be very careful when installing the tool. If the tools are not installed in the tool magazine in sequence, there will be serious consequences.
The optional lathe machine cutter mode is to arbitrarily select the required tools according to the requirements of the program instructions. The tools in the tool magazine do not have to be arranged in the order of adding T of the small pieces, and can be stored arbitrarily. Each tool (or tool holder) is coded. The tool magazine rotates during automatic tool change and each tool (or tool holder) is recognized by the "tool recognition device".
When the code of a tool matches the code of the numerical control command, the tool is selected and the tool magazine sends the tool to the tool change position, waiting for the manipulator to grab it.
In this way, each tool is coded. Since each tool has its own code, it can be stored in any tool seat of the tool magazine. In this way, the knives can be reused many times in different sequences, and the used knives may not necessarily be put back in their original positions. In the J block, the accident caused by the wrong order of the murder knives stored in the tool magazine is avoided. However, each lathe machine cutter has a special coding system. The length of the tool increases, thus making it difficult to manufacture and reducing the rigidity. The structure of the tool magazine and the manipulator is complicated.
The specific structure of the tool code of the machine tool is set on the tie rod 4 at the rear end of the tool handle 1 with the code rings 2 at equal intervals, which are fixed by the lock nut 3. The coding ring can be either a whole or assembled from a circular ring. The diameter of the coding ring has two sizes, the large diameter is binary "1", and the small diameter is "0".
Through the different arrangements of these two kinds of rings, a series of codes can be obtained. For example, it is possible to distinguish 63 (261=63) kinds of tools from six rings of different diameters. In this way, it can avoid confusion with no tool in the holder. In order to facilitate the operator's memory and identification, the machine tool can also be represented by binary code.