In-depth explanation of CNC lathe chucks

In-depth explanation of CNC lathe chucks

Everyone must have a certain understanding of CNC lathes, so do you know the chucks on it? Let’s briefly talk about CNC machine tool chucks.
The chuck fixture of the lathe mainly refers to the fixture installed on the lathe spindle. This type of fixture is connected to the machine spindle and drives the workpiece to rotate with the spindle.
Lathe chuck fixtures are mainly divided into two categories: Various chucks, which are suitable for the processing of disc parts and short shaft parts; Center hole, center centering and positioning fixtures for workpieces, suitable for shaft parts with larger length or more processing steps. CNC turning processing requires that the fixture should have high positioning accuracy and rigidity, simple structure, strong versatility, easy installation of fixtures on the machine tool, rapid loading and unloading of workpieces, automation and other characteristics.
1. Various chuck fixtures In CNC lathe processing, most of the time, the outer circle of the workpiece or blank is used for positioning. The following types of fixtures are fixtures that are positioned by the circumference.
Three-jaw chuck ⑴ Features of three-jaw chuck Three-jaw chuck is the most commonly used universal fixture for lathes. The biggest advantage of three-jaw chuck is that it can be automatically centered, has a large clamping range, and has a fast clamping speed. However, there are errors in the centering accuracy, and it is not suitable for secondary clamping of workpieces with high coaxiality requirements. In order to prevent the deformation and vibration of the workpiece during turning from affecting the processing quality, the overhang length of the workpiece should not be too long when it is clamped in the three-jaw self-centering chuck. For example: if the workpiece diameter is ≤30mm, its overhang length should not be greater than 3 times the diameter; if the workpiece diameter is >30mm, its overhang length should not be greater than 4 times the diameter. At the same time, it can also prevent the workpiece from being bent or dropped by the turning tool, causing tool-breaking accidents. ⑵ Jaws There are two commonly used standard chuck jaws for CNC lathes, hard jaws and soft jaws. 2. When the jaws are clamped on an unprocessed surface, such as a casting or a rough bar surface, and a large clamping force is required, use hard jaws; usually to ensure rigidity and wear resistance, hard jaws must be heat treated and have a higher hardness. Soft jaws should be used when it is necessary to reduce the diameter runout deviation of two or more parts, and when clamping marks are not desired on the processed surface. Soft jaws are usually made of low-carbon steel. Before using soft jaws, they must be bored to match the workpiece being processed. The biggest feature of soft jaw clamping is that the workpiece can still maintain a certain position accuracy after multiple clamping.