How to choose a machining center that can meet the manufacturability, precision requirements, chip efficiency, and price. We brought a professional introduction.
First, to meet the manufacturability
The geometry and processing area of the workpiece determine the type and size of the model. Generally speaking, the CNC lathe is used for the processing of the rotary body.
The machining accuracy requirements of the rotary body with some planes or grooves can generally be completed by multiple times. The CNC lathe and the vertical machining center are selected separately, and the products with high accuracy, especially the position requirements, should be completed by the turning center.
Drilling and tapping in a working surface (small hole diameter less than 12mm) should use the clamp arm drilling and tapping machine, and the large hole diameter is suitable for vertical machining centers to complete.
There are small and medium-sized workpieces that are required for plane milling and free-form milling, drilling, boring, etc. in a plane or in several different positions where the degree of position is not required. Select a vertical machining center, and different planes have Non-ferrous metals, soft metals, and ferrous metals (iron, steel, stainless steel, etc.) with relatively small machining allowances that require a relatively high degree of position. Parts with relatively small workpiece sizes are suitable for use in the form of a vertical machining center with a fourth axis.
Larger (more than 500mm square) multi-faced machining parts with high accuracy requirements, it is more reasonable to use horizontal machining centers.
Large parts complex curved surface processing, plane processing, drilling and tapping are generally selected to complete the gantry machining center. If there is a need for side processing, gantry side milling heads can be selected.
The number of processes and processing time determine the choice and type of tool magazine.
The process is simple and does not require frequent tool changes (the processing time of one tool is greater than 10 minutes). The labor intensity of the workers is moderate. You can choose a machining center without a tool magazine (CNC vertical milling machine, CNC horizontal milling machine).
If the process is complicated and the tool demand is large, a machining center with an automatic tool changer is generally selected. When the tool processing time is relatively long (more than 10 minutes), the tool change time (7 to 30 seconds of the bucket-type) can be ignored. The bucket-type machining center can be used; in order to improve the machining efficiency and the time of the tool change time is relatively obvious. Manipulator type tool magazine (also called disc type and tool arm type), which is characterized by a manipulator simultaneously grabs the target knife and the tool on the spindle, and has the function of pre-selecting the tool. In parallel, there is no need to interrupt and wait, the tool change time is between 2.5 and 5 seconds).
Second, meet the accuracy requirements
According to our experience, 0.05mm is the watershed between the roughing machine and the finishing machine. We must also consider that the accuracy of the new machine tool will decrease after the running-in period. Therefore, the drawings require accuracy (mainly position tolerance, shape tolerance such as ellipticity can be passed through the process and The selection of cutting tools such as the original arc milling, the ellipticity is out of tolerance, and then changed to boring cutter boring.) Reduce 0.005-0.015mm to consider the accuracy of the machine tool.
At present, the popular method is: products with general accuracy requirements (> = 0.1mm) can basically meet CNC equipment (you can choose Ningbo Hengda Machinery Products); products with accuracy requirements (0.05-0.1mm) choose domestic equipment, The quality of key parts in Taiwan and above is sufficient. For products with precision requirements (0.01-0.05mm), choose a domestic machine with design capabilities or a Taiwan machine or an original Taiwan machine with a factory in the mainland. For products with precision requirements (<= 0.01mm), select CNC equipment.
There is a case where the product requires high precision and large quantity. Our recommended method is to buy a domestic machine with good system stability for roughing and semi-finishing, and then allocate a small amount of equipment for finishing, which is both efficient and costly. A big drop is a good choice.
III. Chip efficiency and process optimization determine processing efficiency
One is the heavy cutting type of mechanical structure. The bottom of the vertical machining center is widened and the inverted Y-shaped design and the widening of the front and back of the column and the reasonable reinforcement layout are the keys to improve the rigidity and stability of the machine. Ningbo Hengda Machinery products are based on This concept organizes production and sales; second, the size of the electrical system motor determines the processing capacity of the machine tool. For the mold processing industry, it is suitable to consider heavy cutting machine tools; and product processing, especially large batches of small processing products, must optimize the process, tighten or concentrate the process, reduce auxiliary working time such as clamping and handling, and improve the efficiency of the machine tool, including selection Quick tool changer, etc.
Fourth, the purchase cost plus the use cost determines the value of the machine tool
Purchasing cost is determined by the final purchase contract price of the supplier in the case of inquiry comparison. Generally speaking, it is easier than the price. People are also a thing that must be done during procurement. One thing worth mentioning is the configuration decision. "Preservation of accuracy and stability", but can not guarantee a good configuration, there must be good accuracy, this is two different things, just like people often say "full set of German parts get domestic assembly, and the things that come out are original German The reason is very different. The supplier's technical level, production process and inspection methods can only produce good machine tools with good raw materials. A concept of cost of use is mentioned here, which includes the failure rate of the machine tool, the timeliness and accuracy of maintenance, the labor intensity of the workers and the consumption of energy, such as tools, electricity, the size of the occupied space, the level requirements of the operator, etc. Wait……
In summary, choosing a machine tool not only needs to select a machine tool body that can meet the processing requirements, but also considers the technical strength of the supplier that affects the use cost, and makes every effort to reduce the relatively invisible use cost.
