Large cone surface machining adjustment method and spindle

The processing of the small cone surface workpiece, the process basically the use of the diameter of the spindle using a dial gauge (dilometer) calibration grinding machine rotary table or lathe tool holder angle, to achieve processing. However, if the above method is adopted for a workpiece with a large-angled conical surface, the depth of the table is limited, resulting in that the moving distance of the tool rest or the rotary table is too small, and the angle accuracy of the calibration is difficult to guarantee. The stepped mandrel and face mandrel introduced in this article can overcome the above defects. Both mandrels use their own difference, use the accuracy of the dial gauge to calibrate the table or tool holder angle, high precision, and mandrel manufacturing is simple. low cost. 1 Stepped mandrel The mandrel is generally used for workpieces with a unilateral angle of less than 45°. The mandrel uses its own height difference to replace the lack of a depth indicator for dial gauges. And using the accuracy of the dial gauge, the correct angle of the large-angle tool holder or rotary table can be corrected to ensure the correctness of the workpiece.

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figure 1

Mandrel accuracy requirements Stepped mandrel structure shown in Figure 1. Accuracy requirements: cylindricity ≤ 0.005mm/500mm, roundness <0.003mm, parallelism ≤ 0.005mm/500mm. Mandrel basic size requirements d ≥ 30mm, L'> 3L (L is the length of the workpiece cone surface). The calibration step pre-adjusts the lathe angle of the lathe or grinder table by the angle of the workpiece. Lathe horizontal handle (middle carriage) feed, with large diameter D touch table 0.1mm, table zero, read horizontal handle scale value M, return. The feed length L' of the small carriage longitudinal handle is L' = Dd 2sina where a is the unilateral angle of the workpiece. The lathe's transverse handle (middle carriage) feeds, and d touches the table 0.1mm to zero: reads the lateral handle scale value N. Constantly adjust the angle of the small carriage or table so that M = N, get sina = sina' = Dd 2L' 2 face end mandrel face mandrel suitable for workpieces with unilateral angle greater than 50 °, used to calibrate the table or knife holder angle.

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figure 2

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Mandrel size and accuracy requirements Mandrel structure shown in Figure 2. The dimensions and accuracy requirements are as described above. School table steps. With the edge of the footpath at the table touch 0.1mm, table adjustment zero (later large drag the table can not return after touching the table, so as to avoid errors). Under the state of 0.1mm, touch the small carriage directly (Figure 3) to distance L' to the large diameter end face. Adjust the angle of the knife holder or table a' so that the length of the touching table on the both ends of the walking L' distance is 0.1 mm, and sina = sina' = SL'. Of course, the walking distance L' can also be arbitrarily set. The depth of the touching table S + ∆ S', ​​find other unilateral angle values. 3 Cautions After finishing the spindle, roughening and tempering require hardness ≥315HB. After the heat treatment, grinding at both ends of the center hole is required. The dial gauge (the dial indicator) must be perpendicular to the mandrel touch surface to avoid detection errors. The clearance of the nut of the device should be eliminated in all measurement processes to ensure the correctness of the measurement. When calibrating, both tops should not be too tight or loose for the top spindle. The first workpiece must be painted and matched with the fitting or taper ring plug gauge to verify the accuracy. Using the above mandrel calibration angle not only has high accuracy, but also can effectively improve the accuracy of the taper surface.