When machining manufacturers produce workpieces, in order to obtain relatively high accuracy of machined workpieces, they should select the correct tool to cut the workpieces. There are many main factors to be considered in the selection of tools. First, the material and performance of the workpiece to be processed, such as whether the material is metal or non-metal, and how hard, rigid, plastic, ductile and wear-resistant the machined material is.
The next thing to consider is the processing technology category formulated by the machining plant. When machining parts, select CNC turning, drilling, CNC milling, boring or rough machining, semi finishing, finishing and super finishing, and determine the appropriate tool according to the processing technology.
There is also information about machined workpieces, cutting parameters that the tool can withstand and various auxiliary factors. What is the geometric shape of the workpiece, the size of machining allowance, the technical requirements and economic indicators of the parts. There are three main elements of tool cutting parameters, including spindle speed, cutting speed and cutting depth; Auxiliary factors, including operation interruption time, vibration frequency, power fluctuation or sudden interruption, also need to be considered.
In machining, the position accuracy of the machined surface to other surfaces depends mainly on the clamping of the workpiece. Direct alignment clamping is a clamping method that directly aligns the position of the machined workpiece on the machine tool with a dial indicator, a marking plate or a visual inspection.
Marking and aligning clamping is to draw the center line, symmetry line and processing line of each surface to be machined on the blank according to the part drawing, then install the workpiece on the machine tool, and align the clamping position of the workpiece on the machine tool according to the marked line. This clamping method has low productivity, low accuracy, and high requirements for workers' technical level. It is generally used for processing complex and heavy parts in single piece small batch production, or where the blank size tolerance is large and can not be directly clamped with a fixture.
Fixture clamping is specially designed according to the requirements of the process to be processed. The positioning elements on the fixture can enable the workpiece to quickly occupy the correct position relative to the machine tool and cutter. It does not need to find the clamping and positioning accuracy of the positive energy workpiece. Fixture clamping has high production rate and positioning accuracy, but it needs to design and manufacture special fixtures, which are widely used by machining manufacturers for batch and mass production.
