In the previous article, we introduced the technical requirements for processing keyway in milling machine and the preparation before machining. Today, let's introduce the specific method of milling keyway.
1. Milling method for keyway on shaft
1) Milling the keyway on shaft. Shaft groove for the groove or one end of the arc-shaped half-slot, generally use disc-shaped slot cutter to milling. If the part is longer and the outer circle has been ground accurately, you can use the flat clamp clamp for milling. In order to avoid the workpiece out of the jaw is too long and produce vibration and bending, can be extended in the jack with the jack support, as shown. If the workpiece diameter only after rough processing, the use of three-jaw self-centering chuck and tailstock to the top of the folder, and the middle need to use jack support. Workpiece clamping is completed and adjusted to the center, adjust the side cutting depth ae.
When adjustment, first turn the milling cutter cutting edge and the workpiece cylindrical contact, and then exit the workpiece, then the table up ae to the depth of the shaft, you can start milling. When the cutter starts cutting into the workpiece, move the work table slowly and carefully. In the width of the milling layer ap close to the width of the cutter, if the side of the axis of the phenomenon, indicating that the cutter is not aligned with the workpiece center, the workpiece should be a side of the side of the cutter side move to the center. When the workpiece is clamped with a V-shaped block or a central T-shaped platen of the table, the press plate can be pressed against the end of the workpiece. The length of the workpiece is drilled from the end of the workpiece and then stopped to move the platen to the end of the workpiece. Mat on the copper to re-press the workpiece, as shown in the figure, observe the milling cutter will not touch the plate, and then start the spindle, milling full length.
2) Milling the close keyway on the shaft. With keyway cutter cut slot, commonly used methods are as follows:
①Layered milling method. Milling with a milling cutter with a keyway width size. Layered milling method in the cutter with blunt, just sharpen the end face, cutter diameter is not affected, it will not produce a clear "knife" phenomenon. But in the ordinary milling machine processing, the production efficiency is low. The stratified milling method is mainly suitable for milling with short length, single or small batch slot.
②Expansion milling method. First with a diameter less than 1mm slot width of the keyway cutter for stratified rough milling to the groove depth, groove at both ends of the remaining margin of 0.2 ~ 0.5mm, and then use the exact size of the key milling cutter fine milling.
2. Shaft groove detection method
1) The width of the shaft groove detection. Common plug or plug block detection, as shown.
2) The length and depth of the shaft groove detection, as shown.
3) The measurement of the symmetry error of the axis of the center plane of the shaft groove. As shown in the figure, the workpiece is placed in the V frame, choose a gauge block and the shaft groove width of the same size in the axial groove, and the block plane in a horizontal position, with dialgage detection gauge A surface and plane and reading, and then the workpiece is rotated 180 degrees, with a dial indicator measuring gauge B the flat surface and the reference surface and reading, reading two times the difference is half shaft keyway symmetry error.
