1、 Fabrication of soft claw
Generally, the material of the jaw is carbon tool steel T7, and its hardness after quenching is not less than 62Hrc. The soft claw is reprocessed by brazing a piece of low carbon steel on the old three claw head. The copper hardness of the claw head welding is 36-130hb, and the hardness of low carbon steel is less than 47hrc, so the claw head can be turned.
2、 Usage of soft claw
Install the soft claws on the three claw chuck in sequence, and clamp the soft claws according to the clamping force that the workpiece should bear. Then drill a hole of the same size in the center of the soft claw according to the size of the axis of the workpiece turning and clamping, and then loosen the soft claw, clamp the workpiece after turning and process it, so as to ensure the same circumference of the workpiece. For mass production, this is an important way to ensure quality and improve labor productivity.
3、 Adjustment of soft claw
The positioning accuracy of the workpiece can be improved after the claw processing of the soft claw chuck. For the new three claw chuck, the positioning accuracy of the workpiece after installation is less than 0.01mm. For example, the plane thread of the three jaw chuck is seriously worn and has poor accuracy. After changing the soft jaw and light processing, the positioning accuracy of the workpiece after installation can still be maintained within 0.05mm. The soft claw chuck clamps the machined surface or soft metal, which is not easy to damage the surface. For thin-walled workpiece, sector claws can be used to increase the contact area with the workpiece and reduce the deformation of the workpiece. The soft jaw chuck is suitable for the semi precision turning and precision turning of workpieces when the machined surface is used as the positioning precision benchmark in mass production.
The correct adjustment and turning of soft jaw chuck is the primary condition to ensure the accuracy of soft jaw chuck. The bottom surface of the soft claw and the positioning platform should slide with the claw base and be correctly positioned. The part of the soft claw used to clamp the workpiece is 10 ~ 15mm longer than the hard claw for multiple turning, and it should be assembled according to the number; The diameter of the turning soft claw should be the same as the diameter of the clamped workpiece, either large or small, which cannot guarantee the clamping accuracy. Generally, the turning diameter of the claw is about 0.2mm larger than the workpiece diameter, that is, the diameter of the clamped workpiece, which should be controlled within a certain tolerance range; When turning the soft claw, in order to eliminate the gap, a painting column or ring with appropriate diameter must be installed in or outside the claw. Their installation position in the soft claw should be consistent with the direction of workpiece clamping, otherwise the positioning accuracy of workpiece cannot be guaranteed.