Clamping and adjustment of workpiece processed by

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Clamping and adjustment of workpiece processed by WEDM

1. Clamping of workpiece

when clamping workpiece, it must be ensured that the cutting part of workpiece is within the allowable range of longitudinal and transverse feed of machine tool workbench to avoid exceeding the limit. At the same time, the motion space of electrode wire during cutting shall be considered. General (or standard) parts shall be selected as much as possible for the fixture, and the selected fixture shall be convenient for clamping some machine oil filler inside, so as to coordinate the dimensional relationship between the workpiece and the machine tool. When processing large molds, special attention should be paid to the positioning mode of the workpiece. Especially at the end of processing, the deformation of the workpiece and the effect of gravity will make the key element of such technologies as electrode wire is the utilization of carbon nanotubes, which also determines that China will be clamped in the future and affect processing

(1) cantilever clamping

Figure 1 cantilever clamping

as shown in Figure 11. The machined parts shall meet the requirements of the drawing. The workpiece is clamped in cantilever mode, which is convenient and versatile. However, due to the overhang of one end of the workpiece, the perpendicularity error between the cutting surface and the upper and lower planes of the workpiece is easy to occur. It is only used when the machining requirements are not high or the cantilever is short

(2) two end support clamping

Figure 2 two end support clamping

as shown in Figure 2, the workpiece is clamped by two end support, which is convenient and stable with high positioning accuracy, but it is not suitable for clamping large parts

(3) bridge support clamping

Figure 3 bridge de support clamping

this method is to clamp the workpiece after placing the sizing block on the general fixture, as shown in Figure 3. This method is convenient for clamping and can be used for large, medium and small workpieces

(4) plate support clamping

Figure 4 plate support clamping

as shown in Figure 4, plate support clamping is used to clamp workpieces. According to the commonly used workpiece shape and size, the support plate with through hole is used to clamp the workpiece. This method has high clamping accuracy but poor versatility

2. Workpiece adjustment

the workpiece shall be clamped in the above way and must be adjusted with the alignment method to keep the positioning reference plane of the workpiece parallel to the workbench of the machine tool and the feeding direction X and y of the workbench, so as to ensure the relative position accuracy between the cut surface and the reference plane. Common alignment methods are:

(1) align with a dial gauge

Figure 5 align with a dial gauge

as shown in Figure 5, fix the dial gauge on a wire frame or other position with a magnetic gauge holder, the measuring head of the dial gauge contacts the base surface of the workpiece, move the workbench back and forth, and adjust the position of the workpiece according to the indicated value of the dial gauge until the deflection range of the dial gauge pointer reaches the required value. The alignment shall be carried out in three directions perpendicular to each other

(2) lineation method alignment

Figure 6 lineation method alignment

when the mutual position accuracy requirements between the cutting pattern of the workpiece and the positioning datum are not high, the lineation method can be used for alignment, as shown in Figure 6.7. Use the scoring needle fixed on the wire frame to align with the reference line drawn on the workpiece, move the workbench back and forth, visually inspect the deviation between the scoring needle and the reference, and adjust the workpiece to the correct position. (end)

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