How to choose a machine tools

With the rapid development of the manufacturing industry, new materials and new technologies that continue to emerge will make multi-functional composite tools and high-speed and efficient tools become the mainstream of tool development. Faced with the increasing number of difficult-to-machine materials, the tool industry must improve tool materials, develop new tool materials and more rational tool structures. CNC tools are one of the prerequisites for improving machining efficiency. The choice of the tool depends on the geometry of the part being machined, the material state, and the rigidity of the tool used in the fixture and machine tool. Therefore, when choosing a tool that is more suitable for you, you should consider the following aspects:

1. Cutting performance of the material to be processed

Tool material is a fundamental factor in determining the cutting performance of a tool, and has a great influence on machining efficiency, machining quality, machining cost, and tool durability. The harder the tool material is, the better its wear resistance is. The higher the hardness, the lower the impact toughness and the more brittle the material. Hardness and toughness are a pair of contradictions and a key to the tool material. Therefore, the user needs to select the tool according to the cutting performance of the part material. For cars or milled high-strength steels, titanium alloys, and stainless steel parts, it is recommended to select indexable carbide tools with good wear resistance.

2, choose the tool according to the specific use

According to the type of machine tool, it is not necessary to say that the tool is small. The small series should mention that in the machining process, the roughing stage is mainly to remove the margin, and the rigidity should be selected and the precision should be low. In the tool, semi-finishing and finishing stages, to ensure the machining accuracy and product quality of the parts, the tools with high durability and high precision should be selected. The precision of the tools used in the roughing stage is the lowest, and the precision of the tools used in the finishing stage. highest. If the same tool is selected for roughing and finishing, it is recommended to use the finishing tool to eliminate the roughing tool, because the tool wear condition of the finishing process is mostly the slight wear of the blade, the coating wear and light, and the use will affect the finishing. Processing quality, but less impact on roughing.

3. Select the tool according to the characteristics of the processing area

Tools with large diameter and long diameter ratio should be used when the structure of the part is allowed; the end mill edge of the thin-walled and ultra-thin wall parts should have sufficient centripetal angle to reduce the cutting of the tool and the cutting part. force. When processing parts of soft materials such as aluminum and copper, you should select an end mill with a slightly larger front corner, and the number of teeth should not exceed 4 teeth.

4. When selecting a tool, the size of the tool should be adapted to the surface size of the workpiece being machined.

As the saying goes, "Good horses are equipped with good saddles." For different "horses", of course, they should be equipped with different "saddles". Different workpieces also need to be processed by the corresponding tools. For example, in the production, the peripheral contour of the planar parts is processed by the end mill. When milling the plane, the cemented carbide insert milling cutter should be selected; the bosses and concaves should be machined. When selecting the groove, select the high-speed steel end mill; when machining the surface of the blank or roughing the hole, the corn milling cutter with the carbide insert can be selected; for the machining of some three-dimensional and variable bevel contours, ball-end milling is often used. Knives, ring milling cutters, conical milling cutters and disc milling cutters. In the free-form surface machining, since the cutting speed of the end of the ball-end tool is zero, in order to ensure the machining accuracy, the cutting pitch is generally small, so the ball-end milling cutter is suitable for the finishing of the curved surface. The end mill is far superior to the ball end mill in both surface quality and machining efficiency. Therefore, when roughing and semi-finishing the surface, try to select the end while ensuring that the part is not cut. Milling cutter.

The principle of "a penny and a share of goods" is reflected in the knives. The durability and accuracy of the tool are highly dependent on the price of the tool. In most cases, the tool selected by the company increases the cost of the tool, but the resulting increase in processing quality and processing efficiency greatly reduces the overall processing cost. . Of course, in the process of processing, in order to maximize the value of the tool, it is also necessary to "soft and hard combination", that is, to select high-quality processing programming software to cooperate.

In the machining center, all the tools are pre-installed in the tool magazine, and the corresponding tool change is performed by the tool selection and tool change commands of the NC program. Therefore, the corresponding standard shank suitable for the machine tool system specification must be selected so that the CNC machining tool can be quickly and accurately mounted on the machine tool spindle or returned to the tool magazine.