Requirements for tools and tool holders for CNC lathes

1. Requirements for knives

CNC lathe can be used for both rough and fine turning. In order to make rough car can eat big knife, big knife, the requirements of rough car tool strength, good durability; Precision car is the first to ensure the processing accuracy, so the requirements of high precision cutting tools, good durability. In order to reduce tool change time and facilitate tool alignment, machine clamping should be used as much as possible. Using machine tool clamping can prepare the conditions for automatic tool alignment. If the use of machine tool clamping on the traditional lathe is only an initiative, then the use of machine tool clamping on the CNC lathe is a requirement. The tool body of machine clamping tool requires high manufacturing accuracy, and the way of clamping blade should be chosen reasonably. Because the machine clamping tool installed on the CNC lathe, generally do not add shim adjustment, so the high accuracy of the tip in manufacturing should be guaranteed. For the inner diameter cutter bar with larger ratio of length to diameter, it has better anti-vibration structure. It is better to introduce the coolant of the inner diameter knife into the body first and then spray it out from near the head. For blades, coated carbide inserts should be used in most cases. The advantage of the coating is demonstrated at a higher cutting speed (>100m/min). The cutting speed of the general lathe can not go up, so the use of carbide blades can not be coated. Blade coating cost less than one time, and in the use of CNC lathe durability can be more than two times. The use of coated blades in CNC lathes increases the cutting speed and hence the machining efficiency. Coating materials generally have titanium carbide, titanium nitride and alumina, etc., in the same blade can also be coated with several layers of different materials, become a composite coating. CNC lathe has higher requirements on chip breaking groove of the blade. The reason is very simple: high degree of automation CNC lathe, cutting often in a closed environment, so in the turning process is difficult to manual disposal of a large number of chips. If the chip is broken badly, it can become entangled in the tool head, which can either crush the blade or strain the cutting surface. The carbide blade used in the general lathe is a two - dimensional chip break groove, and CNC turning blades often use a three - dimensional chip break groove. There are many forms of three-dimensional chip slot, which is generally shaped into a number of standards in the blade factory. Its common characteristics are good chip breaking performance and wide chip breaking range. For specific material parts, in the cutting parameters set, pay attention to the selection of good blade groove. Some theoretical discussions can be made in the selection process, but the more important one is to carry out the real cutting experiment. In some cases, according to the existing blade groove to modify the cutting parameters. There is no doubt that the blade is required to be durable.

CNC lathes also require consistent blade durability to facilitate the use of tool life management functions. When using tool life management, the set principle of blade durability is based on the less durable blade in the batch. In this case, the consistency of blade durability is even more important than its average life. As for accuracy, the same requirements between the blade precision consistency.

2. Requirements for knife holder (clamp)

The knife (blade) is rarely mounted directly on the tool rest of the CNC lathe. The structure of the tool seat mainly depends on the shape of the tool body, the appearance of the tool rest and the configuration of the tool rest to the spindle. Nowadays, there are various kinds of knife blocks, which are of low standardization. The standardization degree of machine clamping tool body is relatively high, so the types and specifications are not too much; There are only a few ways to configure tool tool spindle. Only the shape of the tool rest (mainly refers to the part connected with the tool seat) is too many. When the user chooses a type, should reduce kind, type as far as possible, benefit management.