Method for processing precision parts of trapezoidal thread

In the processing of various precision parts, the application of threads is very wide, such as screws, nuts, screws, screws, etc. It is mainly used to connect various machine parts, and can also be used to transfer motion and load. There are many kinds of thread classification methods.According to the tooth shape of the thread, it can be divided into triangle, trapezoid zigzag, circle, trapezoid, etc.; according to the outer shape of the thread, it can be divided into cylindrical thread and conical thread; according to the nature of the fit, the size unit, etc. sort.

    The following is the processing method of trapezoidal thread:

    1. General technical requirements of trapezoidal thread

    The axial cross-sectional shape of the trapezoidal thread is an isosceles trapezoid. Used as a transmission, high precision requirements, small surface roughness, turning trapezoidal threads are more difficult than turning triangular threads. The general technical requirements for trapezoidal threads are as follows:

1. The middle diameter of the thread must be coaxial with the reference journal, and its large diameter should be smaller than the basic size.

2. The coordination of the trapezoidal thread is centered by the middle diameter, therefore, the tolerance of the middle diameter must be guaranteed when processing the trapezoidal thread

3. The tooth angle of the trapezoidal thread must be correct.

4. The surface roughness of both sides of the trapezoidal thread profile should be small.

    2. Clamping requirements for trapezoidal threaded shaft parts when machining precision parts

When turning trapezoidal threads, the cutting force is large. Workpieces are generally clamped by one clamp and one top. In the axial direction, a limit step or limit support is used to fix the axial position of the workpiece, so as to prevent the workpiece from moving or displacing in the axial direction during the turning process, which may cause tooth disorder or damage to the turning tool.

    3. Clamping of trapezoidal thread turning tools

The tip of the thread turning tool should be the same height as the axis of the workpiece. The bisector of the angle between the two cutting edges should be perpendicular to the axis of the workpiece. When clamping, use a trapezoidal thread to correct the knife template to avoid thread half-angle errors.

    4. Matters needing attention in trapezoidal thread turning

1. When processing trapezoidal thread, the left and right borrowing method should be used to process, which will avoid the simultaneous cutting of the three cutting edges of the tool, resulting in a knives.

2. The profile angle of the thread should be correct, and the surface roughness of the two sides of the profile should be small.

3. During the processing of threaded precision parts, care should be taken not to change the speed, otherwise it will mess the teeth.