Automatic turret
Automatic rotary turret for machining precision mechanical parts is a simple automatic tool changing device used in CNC machine tools. It has many forms, such as square turret and hexagonal turret. Four, six or more tools are installed on the rotary turret, and the tool is changed according to CNC instructions. There are two kinds of rotary turrets, vertical and horizontal, with simple structure, which is suitable for economical CNC lathe.
When machining precision mechanical parts, the rotary turret must have good strength and rigidity in structure, so as to bear the cutting resistance in rough machining, reduce the deformation of the turret under the action of cutting force, and improve the machining accuracy. Reliable positioning scheme and reasonable positioning structure should be selected for the rotary turret to ensure that the rotary turret has high repeated positioning accuracy (generally 0.001 ~ 0.005mm) after each rotation. Figure 2.1 shows the spiral lifting type square tool rest.

The simplest tool changing device in the automatic rotary turret of Dongguan CNC processing plant is 180o rotary tool changing device, as shown in Figure 2.2. After receiving the tool change command, the machine tool control system will control the spindle to the specified tool change position; At the same time, the tool magazine moves to an appropriate position, and the tool changing device rotates and cooperates with the tools of the spindle and tool magazine at the same time; The pull rod is removed from the spindle tool, and the tool change device takes the tool down from their respective positions; The tool changer rotates 180o and takes the spindle tool and tool magazine tool away; When the tool changer rotates, the tool magazine adjusts its position to accept the tool removed from the spindle; Next, the tool changer loads the tool to be replaced and the tool to be removed into the spindle and tool magazine respectively. Finally, the tool changer returns to the original "standby" position. At this point, the tool change is completed and the program continues to run. The main advantages of this tool changing device are simple structure, less movement involved and fast tool changing. The main disadvantage of machining precision mechanical parts is that the tool must be stored in the plane parallel to the spindle. Compared with the side post tool magazine, the chip and cutting fluid are easy to enter the tool holder, so the tool must be protected. Chip on the taper surface of the tool holder may cause tool change error, and even damage the tool holder and spindle. Some machining centers use the transfer bar and set the tool magazine on the side. When the tool change command is called, the transfer bar takes down the tool from the tool magazine, turns it to the front of the machine tool, and locates it in the position matching with the tool change device. The 180o "rotary tool changer can be used in both horizontal and vertical machine tools.