Technical requirements for the guide post:

 

1, the main surface and its processing plan

 

The main surface is the inner cylindrical surface? 32H7Ra0.2um, the outer cylindrical surface? 45r6Ra0.4um, its processing scheme: inner cylindrical surface: drilling - rough boring (expansion) - semi-rough boring - rough grinding - fine grinding; for outer cylindrical surface: Rough car - semi-finished car - rough grinding - fine grinding.

 

2, positioning benchmark

 

According to the principle of benchmark selection, the inner and outer cylindrical surfaces are selected as the reference.

 

3. Heat treatment

 

If the guide bush material is 20 steel carburized, the heat treatment is carburizing, quenching and low temperature tempering; if the guide bush material is T10A steel, the heat treatment is quenching low temperature tempering.

 

4. Technical key and measures taken

 

(1) The main surface is an inner cylindrical surface, the dimensional tolerance level is high, and the surface roughness value Ra is small. Measures taken: division of the processing stage, the process route uses: drilling - rough boring (expansion) - semi-fine boring (hinge) - rough grinding - fine grinding - grinding; selection of precision machine tools; control of cutting amount; adequate cooling.

 

(2) Since the dimensional tolerance of the outer cylindrical surface is high and the surface roughness value Ra is small, the measures taken are as follows: the requirements for the division of the machining stage, the selection of the machine tool, and the control of the cutting amount are the same as those of the inner cylindrical surface. In addition, the process route is: rough car - semi-finished car - rough grinding - fine grinding.