When machining ultra-long parts in a CNC gantry machining center, the general through-hole machining method is not applicable. Considering that the pre-machining is wire-cut through-hole machining, you can choose EDM. A 700mm long white steel is processed with a wire-cut through hole, and then a square through hole is processed with wire cutting in the center.
1. The part parameters of the gantry machining center are Baigang with an outer diameter of 20 mm and a length of 700 mm. The hardness value is 60-70hrc. Due to the long length and internal requirements of processing 4 mm square holes, the commonly used drilling processing methods cannot be applied here, and can only be used for wire cutting. First, a 1 to 2 mm wire-cut hole is pre-processed in the center, and then a 4 mm square hole is cut by wire cutting inside the part. When dealing with perforated holes, the positions of the holes at both ends of the part and the outer ring should be less than 1.2 mm coaxial.
When processing this part in a CNC gantry machining center, a hollow copper electrode with a diameter of 2 mm and a length of about 1 m is used for perforation processing. Due to its small electrode diameter and poor self-stiffness, it is easy to shake or bend during processing, and the electrode length is too large to accurately position and linear feed processing. Therefore, it is necessary to use the electrode guide to locate the electrode feed direction and enhance its strength. To deal with the deep hole does not deviate from the center position. The common electrode guide device has only one guide device, which is installed at the separation of the body and the workpiece of the CNC gantry machining center, and the center position of the workpiece cannot be accurately positioned. The electrode extension time is too long to fix the feed direction of the electrode, which may result in CNC gantry machining The center electrode deviated from the center position prematurely.
2. The tooling design of the gantry machining center The countermeasures for the above problem are to design a CNC machining center suitable for deep hole machining. The guiding device can accurately position the electrode, and furthermore, it can be used to enlarge the deep hole machining of the gantry machining center. .
The electrode guide device includes a base fixing device and a double-headed guide sleeve. The double-headed guide sleeve of the CNC gantry machining center is shown in Figure 2, which includes a guide sleeve body and diamond-shaped guide sleeves installed at both ends. Figure 3 shows the base fixing device, including the mounting base, the V-shaped support block, the pressure plate and the locking support bolt. The mounting base is provided with a mounting hole, a positioning hole for fixing the V-shaped block, and a mounting hole for mounting the workpiece to be processed. The V-shaped block is fixed on the base through bolts and positioning holes. The guide sleeve is placed on the two V-shaped blocks on the upper end of the bottom plate. After the center position is aligned, fix it with the pressure plate. A V-shaped block and other fixing devices for fixing the workpiece can be installed at the lower end of the substrate.
The utility model has the advantages of simple structure, convenient operation, low cost and durability. The guide rail device uses the "two-point alignment" in the mathematical theorem. The double-headed guide rail device can accurately locate and execute the linear feed of the electrode of the gantry machining center, improve the rigidity of the electrode, and the V-shaped blocks of the guide rail and the workpiece are evenly arranged in On the chassis, corresponding to the center, it is convenient to find the center position and accurately locate when installing the workpiece.
3. The gantry machining center uses the CNC vertical machining center guide of the machining process to fix the V-shaped block on the base through the bolt and the base installation positioning hole; place the guide sleeve on the V-shaped block on the upper end of the base, and fix the bolt through the pressure plate And support bolts are fixed on the V-shaped block; the workpiece is aligned with the center of the guide plate and the guide sleeve and then fixed on the lower end of the guide sleeve. The V-shaped block finds the correct position .. Since the guide sleeve and the pressure plate are detachable, the guide sleeve and The distance between the workpieces, the lower end of the base can be replaced with other workpieces for drilling ..
As shown in Figure 4, when the CNC gantry machining center is processing, the electrode first passes through the guide sleeve, and the V-shaped block is adjusted to ensure accurate positioning between the electrode and the workpiece, and then the machining operation can be started. Since the guide sleeve adopts double positioning devices at both ends, the machining direction of the electrode can be accurately positioned when processing the workpiece, and the rigidity of the electrode and the stability of linear feed can be enhanced. In summary, the electrode will not shake or bend during the processing, thereby effectively improving the processing efficiency and solving the problem of processing deep and small holes. Because the V-shaped block is fixedly installed on the bottom plate and corresponds to the center, it is easy to align the center position when installing the guide sleeve and the workpiece, so as to achieve the goal of always maintaining accurate positioning and linear feed during the processing of the electrode.
After machining parts with tools, the deviation between the entrance and exit ends from the center position is only 0.8mm, which fully meets the process requirement of a maximum deviation of 1.2mm.
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