Views: 0 Author: Leapion Publish Time: 2022-05-27 Origin: https://www.leapioncnc.com/
Today, Leapion will tell you how to change tool in CNC Machining.
Rotary Tool Holder
Rotary tool post is one of the simplest automatic tool changers, commonly used in CNC lathes. It can be designed into various forms such as square tool rest, hexagonal tool rest or disc type axial tool rest. Four, six or more tools are respectively installed on the rotary tool holder, and the tools are changed according to the instructions of the numerical control device.
The rotary tool holder must have good strength and rigidity in structure to withstand the cutting resistance during rough machining. Since the turning machining accuracy largely depends on the position of the tool tip, for CNC lathes, the tool position is not adjusted manually during the machining process, so it is more necessary to choose a reliable positioning scheme and a reasonable positioning structure to ensure the rotary tool After each indexing, the rack has the highest possible repeat positioning accuracy (usually 0.001-0.005mm).
Under normal circumstances, the tool change action of the rotary tool holder includes the tool holder lifting, the tool holder indexing and the tool holder pressing.
Spindle Head Changing
Spindle head changing is a relatively simple tool change method for CNC machines with rotating tools. This spindle head is actually a turret tool magazine.
There are two types of spindle heads: horizontal and vertical. Usually, the spindle head is replaced by the index of the turret to realize automatic tool change. On each spindle of the turret, the rotating tools required for each process are pre-installed. When a tool change command is issued, each spindle head turns to the processing position in turn, and the main motion is turned on, so that the corresponding spindle drives the tool to rotate. The other spindles in the non-processing position are disconnected from the main motion.
This spindle tool changing device saves a series of complicated operations such as automatic loosening, clamping, unloading, loading and tool handling, thereby shortening tool changing time and improving tool changing reliability. However, due to the limitation of the space position, the structure size of the main shaft components cannot be too large, thus affecting the rigidity of the main shaft system. In order to ensure the rigidity of the main shaft, the number of main shafts must be limited, otherwise the structure size will increase. Therefore, the turret spindle head is usually only suitable for machines with few processes and low precision requirements, such as CNC drilling and milling machines.
Automatic Tool Changing System
Since the rotary tool rest and turret head type tool changer can not accommodate too many tools, they cannot meet the processing needs of complex parts. Therefore, automatic tool change CNC machines mostly use automatic tool changers with tool magazines. The automatic tool changing device with a tool magazine consists of a tool magazine and a tool changing mechanism, and the changing process is more complicated. First of all, all the tools used in the machining process should be installed on the standard tool holder, and after pre-adjusting the size outside the machine, put them into the magazine in a certain way. When changing, first select the tool in the magazine, and then the tool changer will take out the tool from the magazine or the spindle for exchange, put the new tool into the spindle, and put the old tool back into the magazine. The tool magazine has a large capacity and can be mounted on the side or above the headstock. Since there is only one spindle in the headstock of the CNC machine with the automatic tool changer with the magazine, the rigidity of the spindle components should be high to meet the requirements of precision machining.
In addition, the number of tools in the magazine is large, so multi-process processing of complex parts can be carried out, which greatly improves the adaptability and processing efficiency of the machine. The automatic tool changer system with tool magazine is suitable for CNC drilling centers and machining centers.