Technical knowledge points for milling of right-angle grooves and special grooves for precision parts

The common right-angle grooves in the processing of precision parts are open, closed and semi-closed. Among them, the tail of the semi-closed groove has a vertical milling cutter arc (vertical arc) and a disc milling cutter arc (horizontal) Circular arc) Two forms, the keyway on the shaft is a typical right-angle groove that connects the shaft and the sleeve with a flat key. The special grooves milled on the milling machine include V-groove, T-groove, semicircular keyway and dovetail Slot etc.

V-groove is often used for the positioning of machine tool guide rails and shaft parts: T-groove is mainly used to wear T-shaped bolts, such as T-shaped grooves on the working table of machine tools. For machine tool guides, such as longitudinal and vertical guides for milling machines.

1. Milling technical requirements for right-angle grooves and special grooves

(1) Dimensional accuracy: The width, length and depth of the groove have certain dimensional accuracy requirements, especially for the parts that cooperate with other parts, the dimensional accuracy requirements are relatively high. For example, the two sides of the key slot, due to the cooperation with the flat key, the width dimension tolerance is less than or equal to 0.052mm.

(2) Shape accuracy: After the grooves of various shapes are processed by milling precision parts, they should meet the shape accuracy requirements of the drawings. Both right-angle grooves and special-shaped grooves are composed of flat surfaces. Therefore, there are usually basic requirements for flatness and straightness. The shape of the plane used for mating is relatively high, such as the two sides of the key groove, the two sides of the T-slot reference straight groove, the V-shaped surface of the V-shaped groove, the mating slope of the dovetail groove and the horizontal surface.

(3) Position accuracy: There is generally a position accuracy requirement between the machining groove of the precision part and the reference. For example, the key groove on the shaft generally has the symmetry requirements of the width of the groove on the workpiece axis, and the parallelism between the middle plane of the T-shaped groove and the reference side. Requirements, the parallelism requirements between several T-shaped grooves, in addition, the grooves distributed on the shaft parts, there is a requirement for equal precision or included angle.

(4) Surface roughness: There are surface roughness requirements for each surface that constitutes the groove, and the surface used for cooperation requires a small surface roughness value, such as the two sides of the reference straight groove of the T-slot of the worktop is often used for fixture positioning Therefore, it is required to have a small surface roughness value.