1. The selection of the processed object before confirming the selected object
First of all, it is necessary to clarify the object to be processed. Generally speaking, parts with the following characteristics are suitable for processing in machining centers: Multi-process intensive workpieces refer to the need to use many tools for processing on one workpiece. For workpieces with complicated positioning, such as multi-hole machining that requires accuracy of positioning hole distance, it is very convenient to implement by taking advantage of the high positioning accuracy of machine tools. Repetitive production-type workpieces are suitable for processing single-piece and small-batch production. Small batch refers to 1-100 pieces, the quantity of each batch is not large, but repeated production is required.
In addition, even if the shape and size of the workpieces are different, but they are similar workpieces, it is easy to realize the parts of the group processing (GT) process. Complicated shape parts molds, aviation parts and other complex shape workpieces can process various special-shaped parts on the machining center with the help of automatic programming technology. Box and plate parts use the rotary table on the horizontal machining center to process multi-faceted box parts, such as spindle box, pump body, valve body, internal combustion engine cylinder block, etc. If even the top surface needs to be processed in one clamping, a pentahedron machining center can be selected. The vertical machining center is suitable for machining box heads, cylinder heads, flat cams, etc. The gantry machining center is used to process large box and plate parts, such as diesel locomotive cylinder, machining center column, bed, printing wall panel machine, etc.
2. The selection of machine tool specifications is based on the determined size of the workpiece to be processed, and the table size of the required machine tool and the travel of the three linear coordinate systems are determined accordingly. The size of the worktable should ensure that the workpiece can be clamped smoothly on it, and the processing size must be within the stroke of each coordinate. In addition, the limitations of the tool change space and the interference area of each coordinate should also be considered.
3. The accuracy of the selected machining center of machine tool accuracy is classified into ordinary type and precision type, and its main accuracy items are shown in the following table: The main accuracy items of machining center accuracy items Ordinary type (mm) Precision type (mm) Linear positioning accuracy ±0.01/full range ± 0.005/Full repeat positioning accuracy ±0.006±0.002.