This post we will introduce the milling characteristics of right-angel grooves and spiral grooves in precision parts machining, hope will help you know them better.
Features of Right Angle Groove Milling
In the machining of precision parts, a right-angle groove is composed of three planes, and its cross-sectional shape is three straight lines, and the adjacent straight lines are perpendicular to each other. Right-angle grooves are usually divided into three forms: closed, semi-closed and open right-angle grooves. Right-angle grooves can be distributed on flat and cylindrical surfaces. The more classic right-angle grooves are keyways, which can be divided into ordinary flat keyways and semicircular keyways. The characteristics of the milling process of the right-angle groove are as follows:
- Use fixed-diameter or fixed-width milling cutters (such as keyway milling cutters, semicircular keyway milling cutters, disc-shaped groove milling cutters, etc.) to control the groove width with high precision, such as shafts that are matched with flat keys and semicircular keys Upper keyway, open right-angle groove with matching accuracy requirements, etc.
- In the machining of precision parts, the symmetrical position of the keyway on the shaft usually adopts different tool setting methods according to the different accuracy grades. The keyway with high symmetry requirement can be adjusted by the indicator ring table method to align the relative position of the workpiece axis and the tool axis or the middle section of the disk milling cutter. The keyway with low symmetry requirement can be processed by the notch tool method.
- The keyway processing on the shaft usually adopts V-shaped block positioning, or adopts indexing head self-centering chuck for clamping to ensure the main machiningaccuracy requirements such as the symmetry of the workpiece.
Spiral Groove Milling Features
Spiral grooves processed by milling machines in precision parts processing are usually spiral grooves formed by Archimedes lines, which can be divided into plane spiral grooves and cylindrical spiral grooves. The machining of the plane spiral groove is similar to the machining of the linear forming surface of a disc cam. The processing of cylindrical spiral groove has the following technological characteristics:
- The universal indexing head is usually configured with exchange gears for processing. There are two methods for the configuration of exchange gears: the side shaft configuration of the indexing head and the main shaft configuration to meet the needs of different leads.
- Cylindrical surface spiral groove milling can use disk milling cutters or finger milling cutters. During milling, if a disk milling cutter is used, the milling cutter and the axis of the workpiece should be at an included angle, and the rotated angle is calculated as the helix angle , The rotation of the angle is generally realized by the worktable or the end milling head.
- There is interference in the milling of cylindrical spiral grooves. Milling interference is caused by the helix angle changes of different diameters and the radius of curvature of the disk milling cutter. Interference will affect the groove shape of the spiral groove.
- In the processing of precision parts, special milling cutters are used to mill spiral grooves, such as the spiral tooth grooves of twist drills, which must be adjusted in accordance with the designed tool setting parameters and have reached the processing requirements that meet the design parameters.