Two Turning Methods for Inner Holes of Sleeve-like Workpieces in Metal Machining.
The vertical turning machining method is to boring the inner hole of a workpiece on a vertical lathe. At this time, the workpiece is rotated together with the random bed table, and the clamping force of the jaws is quite large, but the clamping force exceeds the assembly and causes the workpiece to deform, which is too small. There is a risk that the workpiece will oscillate during machining. In order to make the machining process reliable, special clamping devices are designed.
The fixture base is cast, so that the overall stability of the fixture is good. The positioning ring is designed to support the positioning and can also expand the application scope of the fixture through the replacement of the positioning ring. The material of the positioning ring is selected from 20 steels, combined with carburizing and hardened treatment to improve its service life, and is used at the large end of the workpiece with a pressure plate. Compaction. Because the workpiece is vertically placed on the work table of the machine tool and the center of gravity is relatively high, the floating top tight mechanism is designed at the upper and lower parts of the fixture, which can reduce the vibration phenomenon of the workpiece during processing and ensure the roundness of the hole in the workpiece. And cylindricity, as well as the surface roughness requirements eliminate the knife pattern.
The horizontal turning machining method is to boring the inner hole of a workpiece in a horizontal lathe. This method uses a horizontal lathe after transformation, and the workpiece is fixed on the machine tool guide rail (guide rail of the original carriage) by a clamping device. The small end of the clamping device is fixed on the workpiece by means of the principle of clamping and positioning of the spring ring, so that the wall thickness of the workpiece can be increased; and then the part where the spring ring is installed at the thick end of the workpiece and the small end of the large end hole wall, Design adjustable tightening mechanism (in use, the straightness check of the clamped workpiece hole is required). The special mast is designed to pass through the workpiece (the mast must have sufficient rigidity and length) so that one end of the mast is clamped and centered on the machine tool disk by a three-jaw self-centering chuck, and the other end is tightened with the tailstock tip. This prevents the mast from being too long and sinks. During the machining, the boring bar drives the boring knife to rotate. At the same time, the workpiece moves along the tool guide rail, and the roundness, cylindricity and surface roughness quality of the internal hole are guaranteed once.