Matters need attention
1. The fit clearance between screw compression zone and rod barrel compression zone:
The screw compression zone refers to the taper of 5-7cm at the front of the screw, and the compression zone of the outlet barrel refers to the taper of 6-8cm at the back of the barrel (our factory adopts "tapered" compression, the compression zone is 6-8cm, and the "tapered" diameter difference is 2cm. Generally, the taper of the barrel compression zone is 5-7 degrees, and the taper of the screw compression zone is also 5-7 degrees (keeping the same taper as that of the barrel compression zone), and their lateral clearance should be between 2-4mm (diameter). Longitudinal clearance fit: The leading edge of the screw should be 4-5cm behind the compression zone of the rod barrel (new barrel). So that their fit clearance is in the best fit state. In this condition, the tapping speed and tapping density are very good, and the wear of screw compression zone and tapping barrel compression zone is also reduced to the lowest degree.
If a certain raw material is used alone, the angle, height and length of the spiral front edge (i.e. the fit clearance between the spiral front edge and the compression area of the sleeve) suitable for this raw material should be adjusted.
When the rod barrel is used for a period of time, the compression area will be gradually dented. At this time, the spiral front should be gradually moved forward, that is, the spiral should be gradually lengthened, or the rod barrel should be repaired (the wear sleeve cannot be repaired by electric welding) to ensure that their fitting clearance is in the best state.
2. The fit clearance between the screw and the feeding sleeve of the machine head:
Their clearance should be between 2-4mm (diameter distance). That is, the diameter of the feeding sleeve should be 2-4mm larger than that of the screw stem. If the raw material is light and thick, it should be larger, otherwise it should be smaller. Six "ribs" should be planed longitudinally on the feeding sleeve to prevent the raw materials from slipping in the feeding sleeve and affecting the feeding. When the feeding sleeve is worn, six "ribs" should be welded on the sleeve, and the height should not be lower than the diameter of the screw stem.
3. Angle of screw front in screw compression zone:
Its vertical angle, that is, one week from the front of the spiral, gradually increases from 90 degrees to 60-45 degrees. It should be further explained that, at 90 degrees, it is necessary to keep the same distance with the following screw, and it can only be greater than or less than the following screw pitch. At the beginning of the spiral front, it can only be lower than the normal size but not higher than the normal size.