1, Basic concepts of drilling
When drilling, due to the structural defects of the drill bit, it will leave marks on the processed areas of the product, affecting the machining quality of the workpiece. The machining accuracy is generally below IT10 level, and the surface roughness is Ra12.5 μ Around m, it belongs to the rough machining category.
2, The operation process of drilling
1 Dashing
2 inspection squares or inspection circles
3. Sample punching
4 clamps
5 Trial drilling
6 Boreholes
3, Methods with higher drilling accuracy
When accurately marking with a height ruler, it is important to maintain accuracy and accuracy. When marking, the angle between the marking needle and the marking plane of the workpiece should form an angle of 40-60 degrees (along the marking direction), so that the drawn lines are clear and uniform.
3. Correct clamping is crucial
Normally, for holes with a diameter less than 6mm, if the accuracy is not high, the workpiece can be clamped with pliers for drilling; For holes with a diameter of 6-10mm, if the workpiece is regular and flat, it can be clamped with flat pliers, but the surface of the workpiece should be perpendicular to the spindle of the drilling machine. When drilling holes with larger diameters, the flat pliers must be fixed with bolt pressure plates; When drilling larger workpieces with a diameter of 10mm or more, use the method of clamping with a pressure plate for drilling.
There are two types of alignment: static alignment and dynamic alignment. The so-called static alignment refers to aligning the center line of the drilling machine spindle with the intersection point of the workpiece cross line before the drilling machine is initiated. This method is safe and convenient for beginners, and is relatively easy to grasp. However, due to the lack of consideration of uncertain factors such as the swing of the drilling machine spindle, the drilling accuracy is relatively low. Dynamic alignment is carried out after the drilling machine is initiated, taking into account some uncertain factors during the alignment process, resulting in relatively high accuracy.
5 Careful inspections cannot be omitted
For holes with high drilling accuracy, we generally use drilling, reaming, and reaming processing techniques. After drilling the small hole in the first step, use a caliper to detect the offset from the center of the bottom hole to the reference plane. After actual measurement, the orientation between the bottom hole and the center of the aspiration can be calculated. If the offset is not greater than {{0}}.10mm, the top angle of the drill bit can be appropriately increased and the automatic centering effect can be weakened when expanding the hole. The workpiece can be appropriately pushed in the positive direction, and the drill tip diameter can be gradually increased for compensation. If the amount of error is greater than 0.10mm, a mixed round file can be used to repair the walls on both sides of the bottom hole. The repaired part should be connected to the smooth transition of the bottom hole arc.
