Several selection steps of CNC machine tools

With the development of modern manufacturing technology, it is a general trend for enterprises to choose CNC equipment. At present, the numerical control equipment on the market can be described as dazzling. How can we choose economically and reasonably suitable CNC equipment for the company? It has always been a topic of concern. This article completely discusses the problems that should be paid attention to in the selection process from the technical point of view.

1.Determine the typical processing workpieces
Determining which parts to process is the first step in choosing a device. According to the needs of technological transformation and production development, the enterprise determines which parts, those processes are ready to be completed with new processing equipment, and can be divided into ordinary grades and precision grades according to the processing precision requirements. The classification of typical parts is clear, and the basic processing equipment is relatively clear.

2.The design of the process specification of the typical part
After the machining of the parts, the process planning must be carried out with a new perspective on the process flow, including the transformation of the original process production process, the feasibility of exploring new process methods, and the exploration of modern production management and logistics management. Feasibility, explore the feasibility of using advanced tooling tools to greatly improve production efficiency, explore the rational preparation process of CNC equipment and other equipment (general, special aircraft) on the production line, in order to obtain the best after using CNC machine tools. Process manufacturing process. Below are the reasonable processing techniques for several typical types of parts. Shaft parts: milling end face center hole → CNC lathe (roughing) → CNC grinding machine (finishing); flange and disc parts: CNC lathe (roughing) → turning center (finishing); ☆ cavity mold parts : Ordinary machine tool processing shape and base surface → CNC milling machine processing surface → high-speed CNC milling and finishing → polishing or electro-corrosion molding; plate parts: double-axis milling machine or gantry milling machine processing large plane → vertical machining center processing various types Hole; box parts: processing the bottom surface on the vertical machining center → processing the peripheral surface of each processing surface on the horizontal machining center.

3.The selection of the main features of CNC machine tools
Machine specifications should include model, machine specifications and machine main motor power. Under the premise of determining the content of the process, the choice of the model is clearer. For example, the processing of rotary parts is mainly for the selection of equipment such as lathes, turning centers, CNC grinding machines, etc.; the processing of the box should be mainly vertical or horizontal machining centers. For example, turning centers and CNC lathes can machine shaft parts, but the price of a turning center that meets the same processing specifications is several times higher than that of a CNC lathe. If there is no further process requirement, the CNC lathe should be reasonable. In the processing of cavity mold parts, CNC milling machines and machining centers of the same specifications can meet the basic processing requirements, but the price difference between the two machine tools is 20% - 50%, so the process of changing tools in the mold processing can be arranged. An optional CNC milling machine with a machining center and a fixed tool for long-term milling. The main specifications of CNC machine tools are the stroke range of several CNC axes and the power of the spindle motor.

4.CNC system selection
As market demands diversify, machine tool builders often offer the choice of multiple CNC options for the same machine tool or multiple selection options for the CNC system. The CNC system of the machine tool configuration provided by the machine tool manufacturer is divided into the mainstream system and the adaptable system. The mainstream system is relatively mature in technology, and the performance varies greatly in the available systems, which directly affects the price structure of the equipment. Therefore, it is not possible to pursue high-level, new systems one-sidedly, but should mainly meet the performance of the host, make a comprehensive analysis of system performance and price, and select the appropriate system.

5.Automatic tool changer (ATC), automatic exchange workbench (APC) and tool holder selection configuration. ATC's choice
On some CNC machine tools with comprehensive processing capabilities, such as machining centers, turning centers and CNC punching machines with exchange punches, automatic switching devices are the basic features of these devices. The quality of their work is directly related to the quality of the machine. It is also an important part of the investment in equipment (10% of the cost of the whole machine - 30%). Therefore, it is necessary to pay attention to the working quality and tool storage of the ATC automatic tool changer when selecting the host device. At present, the automatic tool changer of the machining center is more standardized. The following is an example of the ATC device of the machining center. Field experience shows that about 50% of the faults in the machining center are related to the ATC device, but ATC is the basic component to improve the processing efficiency of the equipment. Therefore, it is recommended that the user should choose the structure as simple and reliable as possible. The high ATC can also lower the price of the whole machine accordingly.

6.Machine selection function and selection of accessories
When purchasing CNC machine tools, in addition to the functions and basic components that meet the basic requirements, you should also fully consider the selection function and accessories. The selection principle is: comprehensive configuration, give full play to the maximum potential of the host, and consider the benefits in the near future. For some price increases, but for the convenience of use, it should be fully equipped. The accessory package should ensure that the machine tool can be put into use immediately after it arrives at the scene. It is forbidden to spend hundreds of thousands of dollars or even millions of machines purchased. After the arrival of the goods, the lack of a tens or hundreds of yuan attachments can not be used for a long time. happened.

7.Technical Services
When purchasing equipment, you should also consider purchasing pre-sales and after-sales technical services around the equipment. The purpose is to make the equipment work as soon as possible. For some new CNC machine users, the most difficult thing is not the lack of funds to buy equipment, but the lack of a high-quality technical team, so new users from the beginning of the selection of equipment, including the subsequent equipment arrival and acceptance, equipment Manpower and technical support are required for operations, programming, mechanical and electrical maintenance.