Analysis of tool and tool holder requirements for CNC lathe

1. Requirements for the tool

CNC lathes can double as coarse and fine turning. In order to make the rough car can eat big knife and big knife, the rough car tool is required to have high strength and good durability; the fine car first guarantees the machining precision, so the tool requires high precision and good durability. In order to reduce the tool change time and facilitate the tool setting, the machine clamp should be used as much as possible. Use the machine clamp to prepare conditions for automatic tool setting. If it is only an initiative to use a machine clamp on a conventional lathe, then a machine clamp on a CNC lathe is a requirement. The cutter body of the machine clamp requires high manufacturing precision, and the method of clamping the blade should be selected reasonably. Since the machine clamp is mounted on a CNC lathe, generally no spacer adjustment is made, so the accuracy of the tip height should be guaranteed during manufacture. For the inner diameter arbor with a large ratio of long diameter, it is preferable to have an anti-vibration structure. The coolant of the inner diameter knife is preferably introduced into the cutter body first and then ejected from the vicinity of the cutter head. For inserts, coated carbide inserts should be used in most cases. The coating exhibits its superiority at higher cutting speeds (>100 m/min). The cutting speed of a general lathe is generally not good, so the cemented carbide insert used may not be coated. Blade coatings cost less than double the cost, while durability can be more than doubled when used on CNC lathes. The use of coated inserts on CNC lathes increases the cutting speed and thus increases machining efficiency. The coating material generally has titanium carbide, titanium nitride and aluminum oxide, and the same blade can also be coated with several layers of different materials to form a composite coating. CNC lathes have higher requirements on the chipbreaker of the blade. The reason is simple: CNC lathes are highly automated, and cutting is often done in a closed environment, so it is difficult to manually dispose of large amounts of chips during turning. If the chip is not broken well, it will wrap around the bit, which can both crush the blade and strain the cutting surface. Carbide inserts for general lathes are typically two-dimensional chipbreakers, while CNC turning inserts often use three-dimensional chipbreakers. Three-dimensional chipbreakers come in many forms and are typically shaped into several standards in blade manufacturing plants. Its common feature is good chip breaking performance and wide chip breaking range. For the specific material parts, after the cutting parameters are set, pay attention to the slot shape of the blade. Some theoretical discussions can be made during the selection process, but more importantly, the actual cutting test is carried out. In some cases, the cutting parameters can also be modified based on the groove pattern of the existing blade. There is no doubt that the blade is required to have high durability.

CNC lathes also require consistent blade durability for easy tool life management. When using tool life management, blade durability is set based on the lowest durability blade in the batch. In this case, the consistency of blade durability is even more important than its average life. As for the accuracy, the precision consistency between the blades is also required.

2. Requirements for the holder (clip)

Knives (blades) are rarely mounted directly on the tool holder of a CNC lathe. They are usually transitioned between the holders (also called tool holders). The structure of the tool holder mainly depends on the shape of the tool body, the shape of the tool holder and the arrangement of the tool holder to the main shaft. Nowadays, there are many kinds of tool holders, and the production plants are doing their own thing, and the degree of standardization is very low. The standardization degree of the machine clamp body is relatively high, so there are not many types and specifications; there are only a few ways to arrange the tool holder to the machine tool spindle; only the shape of the tool holder (mainly refers to the part connected with the tool holder) Too many types. When selecting users, users should minimize the types and types to facilitate management.