The chuck fixture of the lathe mainly refers to the fixture installed on the spindle of the lathe. This type of fixture is connected with the spindle of the machine tool and drives the workpiece to rotate with the spindle. Today, Wanguo Intelligent CNC will take you to understand how to choose the CNC lathe chuck. Let's take a look.
Lathe chuck fixtures are mainly divided into two categories: various chucks, which are suitable for the processing of disc parts and short shaft parts; fixtures for the central hole, centering and positioning of the workpiece, suitable for large lengths or processing procedures More shaft parts. CNC turning processing requires fixtures with high positioning accuracy and rigidity, simple structure, strong versatility, easy to install fixtures on machine tools, rapid loading and unloading of workpieces, automation and other characteristics.
1. Various chuck fixtures are processed by CNC lathes, in most cases, the outer circle of the workpiece or blank is used for positioning. The following fixtures are fixtures that are positioned by the circumference.
Three-jaw chuck Three-jaw chuck features Three-jaw chuck is a common lathe universal clamp, the advantage of the three-jaw chuck is that it can be automatically centered, the clamping range is large, and the clamping speed is fast, but there is an error in the centering accuracy , not suitable for secondary clamping of workpieces with high coaxiality requirements. In order to prevent the machining quality from being affected by the deformation and vibration of the workpiece during turning, the overhang length of the workpiece should not be too long when the workpiece is clamped in the three-jaw self-centering chuck.
How to choose CNC lathe chuck?
For example, if the diameter of the workpiece is less than or equal to 30mm, the overhang length should not be greater than 3 times the diameter; if the diameter of the workpiece is >30mm, the overhang length should not be greater than 4 times the diameter. At the same time, it can also prevent the workpiece from being bent and dropped by the turning tool, which may cause a knife-hitting accident. Jaw CNC lathes have two commonly used standard chuck jaws, hard jaws and soft jaws.
2. When the jaws are clamped on unprocessed surfaces, such as castings or rough bar surfaces, when a large clamping force is required, use hard jaws; usually to ensure rigidity and wear resistance, hard jaws are heat treated , the hardness is higher. Soft jaws should be used when there is a need to reduce the runout deviation of the diameter of two or more parts, and when pinch marks are not desired in the machined table. Soft jaws are usually made of low carbon steel. Before the soft jaws are used, they need to be bored to match the workpiece to be processed. The major feature of soft jaw clamping is that the workpiece can still maintain a certain positional accuracy even after multiple clampings.