Nc milling machine is a kind of automatic processing equipment which is developed on the basis of general milling machine. The machining process of the two is basically the same and the structure is similar. Nc milling machine is divided into two categories: no knife and knife. The CNC milling machine with the tool bank is also called machining center.
In addition to the characteristics of normal milling machine, numerical control milling machining has the following characteristics:
1. Good adaptability and flexibility in the processing of parts, which can be used to process parts that are particularly complex or difficult to control dimensions, such as mold parts, shell parts, etc.
2. Parts that can be processed by ordinary machine tools that cannot be processed or difficult to process, such as complex curved parts described in mathematical models and three-dimensional space curved parts;
3. After being able to process the positioning of the clamping, the parts that need to be processed by multiple processes are required;
4, high machining precision and machining quality is stable and reliable, pulse equivalent of CNC equipment usually is 0.001 mm, high precision can be up to 0.1 mu m CNC system, in addition, also to avoid the numerical control processing operator error;
5. High degree of production automation can reduce the labor intensity of operators. Facilitate the automation of production management;
6, high efficiency, CNC milling machine generally do not need to use special process equipment, such as special fixture in replacing artifacts need to call a stored in the process of numerical control device, clamping tools and adjusting tool data, thus greatly shorten the production cycle. Secondly, nc milling machine has the function of milling machine, boring machine and drilling machine, which makes the process highly concentrated, which greatly improves the production efficiency. In addition, the spindle speed and speed of the CNC milling machine are infinitely variable speed, so it is advantageous to choose the best cutting amount.
The basic structure
Numerical control milling machines have various forms, different types of CNC milling machines are different in composition, but there are many similarities. This paper introduces the composition of XK5040A CNC vertical milling machine. Ⅺ saw 040 a type nc vertical milling machine is equipped with four 3 Ⅳ ma CNC system, using digital ac servo driver. The machine tool consists of 6 main parts. It is the bed part, the milling head part, the worktable part, the horizontal part, the lifting platform part, the cooling, lubricating part. The internal layout of the bed is reasonable, with good rigidity, with 4 adjusting bolts on the base, easy to adjust the machine tool, and the cutting fluid reservoir is located inside the machine tool base.
Numerical control machine tools are used to process complex parts, but the structure of the fixture is often not complicated. The selection of the CNC milling fixture can be determined according to the batch of the production parts.
For single piece and small batch, larger workload, mould processing, generally can be directly on the machine table by adjusting the realization of positioning and clamping, and then through the processing coordinate system is set to determine the location of the parts.
The table and the bed saddle are supported on the horizontal guide rails of the platform. The vertical feed of the workbench is driven by the servo motor mounted on the right end of the workbench. The precision ball screw is cut through the inner gear wheel, so that the workbench can get the vertical feed. The left hand side of the table is equipped with handwheel and dial for manual operation. TuRcllE B is applied to the vertical guide surface of the bed saddle, which improves the wear resistance of the guide rail, the stability of the movement and the retention of precision, and eliminates the low-speed crawling phenomenon.