Five key points for spring collet machining
October 31, 2019
In addition to the application effect at the end of indirect impact of spring collet quality, it is also the focus of customers' selection. What points should manufacturers pay attention to when grinding? As a professional manufacturer, we get the following key points:
1. For the conical surface of the finish turning collet, the thread tire is used to ensure the machining accuracy of the collet body on each surface of the finish turning. After the holes are equally drilled, the element conical surface is turned again. When turning the conical surface, the thread surface is used as the guide datum. We design a thread tire, which can ensure the machining accuracy when turning the circular conical surface. As shown in the following figure of processing principle, first screw the chuck onto the thread tire, then install the thread tire onto the main shaft of the machine tool, and use the small tool holder on the support plate to expand the cutting spring chuck.
Spring chuck
2. Milling equal slot: when milling the slot above the chuck, first use the end milling cutter to mill the 20 mm × 40 mm six slot, and then use the piece milling cutter to mill the 3 mm wide six slot. However, this slot must not be milled through, and the end face has 3-4 mm connecting bars, so that the chuck body is still whole, so as to ensure that the chuck will not deform after heat treatment and the machining of all guiding surfaces of the chuck is fine. degree
After over lapping, cold treatment shall be carried out for the fixture, but the parts to be treated shall be proper, the head and tail of the chuck shall be quenched, and the hardness shall not be quenched as the lower part of the 40-45hrc chuck, so as to ensure the elasticity of the chuck.
3. Grinding the conical surface of the collet: use the thread tire to ensure the grinding accuracy when grinding the conical surface of the collet. The conical surface is a key positioning surface in the clamping process of the chuck. The poor and good accuracy of the conical surface indirectly impacts the accuracy of the whole chuck. The designer has designed a set of threaded tyre clamp for grinding, and the guide datum still uses the threaded surface. After grinding, the conical surface is equivalent to the same axis degree of the threaded surface, which can reach 0.1mm.
4. Inner diameter of spring collet: use the inner diameter of the grinding wheel to ensure the grinding accuracy. The inner diameter of the collet is also a positioning surface. Use the inner diameter of the collet to clamp the card block, and then use the card block to clamp the workpiece again. Therefore, the accuracy of the inner diameter also indirectly impacts the accuracy of the workpiece being ground, which suggests that the inner diameter and the conical surface must be fixed. We have designed a special clamping chuck for grinding inner diameter jig. The jig is located on this conical surface. Its grinding principle is shown in the following figure. After grinding, the inner diameter of the collet is equal to the same axiality of the conical surface, usually up to 0.02mm.
5. Guiding surface of spring collet: the same way is to use thread tire to ensure the grinding accuracy. The guiding surface plays a guiding role in the collet. It is suggested that the guiding surface and the conical surface must be fixed. The clamp head is still clamped by the thread tyre used for grinding the conical surface. The grinding principle is as shown in the following figure. After grinding, the same axis degree of the guide surface relative to the conical surface can reach 0.04mm. The accuracy of the chuck is achieved through the processing technology of more than five parts and guarantee measures. However, the poor and good accuracy of the clamp block installed in the chuck also indirectly impacts the accuracy of the whole chuck.
