1. Precision turning of the conical surface of the chuck requires the use of a threaded tire to ensure the machining accuracy. After finishing turning each surface of the chuck and drilling the equally divided holes, the conical surface is then turned. When turning the conical surface, the threaded surface is used as the positioning reference. We have designed a threaded tire that can ensure the machining accuracy when turning the conical surface. The processing principle is shown in the following figure. First, screw the chuck onto the threaded tire, then install the threaded tire onto the machine tool spindle, and finally use the small knife holder on the support plate to cut the spring chuck.
2. Milling equal grooves: When milling the grooves on the chuck, first use an end mill to mill 20mm × 40mm hexagonally divided slot, and then use a chip milling cutter to mill the 3mm wide hexagonally divided narrow slot for dividing, but this slot cannot be milled through. There are 3 to 4mm connecting ribs left on the end surface, so that the chuck body remains integral, ensuring that the chuck does not deform after heat treatment and grinding the processing accuracy of each positioning surface of the chuck
After the above processing, the fixture shall be subjected to heat treatment, but the parts to be treated shall be reasonable. The head and tail of the chuck shall be quenched, and its hardness shall be about 40 to 45 HRC. The middle part of the chuck shall not be quenched to ensure the flexibility of the chuck.
3. Grinding the conical surface of the chuck: When grinding the conical surface of the chuck, use a threaded tire to ensure the grinding accuracy. The conical surface is an important positioning surface in the clamping process of the chuck, and the accuracy of the conical surface directly affects the accuracy of the entire chuck. A set of grinding screw thread clamping chucks is designed, and the positioning reference is still the threaded surface. After grinding, the coaxiality of the conical surface relative to the threaded surface can reach 0.1mm.
4. Spring collet inner diameter: Use a grinding inner diameter tire to ensure the accuracy of grinding processing. The inner diameter of the collet is also a positioning surface. Use the inner diameter of the collet to hold the clamp block, and then use the clamp block to clamp the workpiece. Therefore, the accuracy of the inner diameter also directly affects the accuracy of the workpiece being processed, which requires that the inner diameter and the conical surface must be coaxial. We design a special clamping chuck for grinding the inner diameter of the tire. This tire is positioned with a conical surface, and its grinding principle is shown in the following figure. After grinding, the coaxiality of the inner diameter of the chuck relative to the conical surface can generally reach 0.02 mm. (For specific related content, please refer to the relevant content of Zhengxin machine tool accessory "What are the general precautions for chuck maintenance?")
5. Spring collet guide surface: Also use threaded tires to ensure grinding accuracy. The guide surface plays a guiding role in the collet, and it is required that the guide surface and the conical surface must be coaxial. Or use the threaded tire to clamp the chuck when grinding the conical surface. The grinding principle is shown in the figure below. The coaxiality of the grinding guide surface to the conical surface can reach 0.04 mm. The accuracy of the chuck is achieved through the above five parts of the processing technology and assurance measures, but the accuracy of the clamp block installed inside the chuck also directly affects the accuracy of the entire chuck.