Abrasive and cutting tools play a key role in metalworking processes. It is a tooling in the form of milling cutters, which are installed in machine chucks by means of shanks. The quality of processing is influenced by the characteristics of the tool, and the reliability of its fit is ensured by the collet. What is a clamp in processing equipment in principle? This fixture is an auxiliary part of the chuck, but due to differences between different types of shanks and machine designs, there are many variations and sizes of this element.
Collet design
The part is made in the form of a split spring sleeve with a truncated cone. There are also cuts on the surface of the body, which ensure the mobility of the clamping petals when removing or installing a milling head. Directly gripping the shank is carried out due to the force fromnuts. What is a collet in terms of interaction with a chuck? This is a component of the metal-cutting machine tool design, which is initially put on the working tool chuck and performs a kind of adapter function.
The setting tooling of the collet itself is generally universal. Different models can be used for the same group of machines. But the part that secures the milling shanks almost always caters to a limited range of sizes. As for the material of manufacture, the structural basis is formed by metal - usually tool steel. Unless in places of interfacing with a fixed cutter, inserts made of hard alloys and special ceramics can be used. This is necessary to increase the wear resistance of the working surfaces and prevent the hot shank from sticking to the collet.
Dimensional parameters of the product
The collet can be used in machines of various types, which determines the breadth of its size ranges. On average, we can talk about the following parameters:
- Length - from 35 to 70 mm. Moreover, 35.5 mm is considered the standard.
- Clamping head diameter - from 8 to 13 mm.
- Thread length - from 9 to 16 mm.
- Groove profile depth - regular format 2x0.8 mm.
- Boot diameter - from 6 to 22 mm.
The gradation of the size range does not in any way determine the dependence between different characteristics. For example, a typical turning collet for a 8 mm routercan have a length of 70 mm, and a part with a bore diameter of 10 mm - 45 mm. Much in size is determined by the nature of processing. Mechanical action can be performed at an angle on some machines, which, for example, complicates the use of long elements. The same applies to restrictions on combining clamping mechanisms with machine headstocks of different calibers.
Features of the collet chuck
This device is easily confused with a cam chuck, which is used not only in machine tools, but also as part of hand tools. They are united by the fact that they act as a universal means of capturing the nozzle. However, in both cases, universality is conditional, since we can talk about certain standard sizes of shank. The main feature of the collet chuck is the ability to adjust the clamp according to the diameter of the tool being used. Moreover, fastening can be provided in relation to shanks with different sections and shapes. Cylindrical and rectangular rods are commonly used, but there are special models for gripping triangular elements.
Classification of types of collets by purpose
The configuration and functionality of the collets varies depending on the place they occupy in the gripping mechanism. The most common elements are of two types:
- Clamping collet. The classic and most common sleeve style with multiple cushioning lugs for a versatile grip. howas a rule, such a collet for the machine is used in the processing of workpieces with a diameter of 30 to 80 mm.
- Feeding collet. It is also made in the format of a sleeve with springy petals formed due to three incomplete cuts along the body cylinder. When ready for use, the petals are pressed against each other.
Separately, it is worth noting split collets, which are used specifically in the processing of small format products. Such devices support the ability to disassemble and modularize - at least they allow updating inserts.
Classification by technical device
A typical collet differs from many cartridges in that it can be easily removed and, as noted above, even disassembled in some modifications. But collet fixtures also differ in the way they are combined with machine tools. In the same metalworking, static non-separable (fixed) and built-in removable models are used. Also, the collet chuck can be retractable and retractable. Belonging to a particular group is determined by the configuration of the grip of the processing tool, the range of angles of mechanical action and the control system, since there are manual and, to varying degrees, automated tooling setup nodes.
Fields of application for collets
Mostly, such devices find a place as an element of equipment for turning, drilling, rotary and longitudinal machines. This concerns one part of the installation, but what is a collet in terms of compatibility withprocessing tool? Among the target tools for gripping, taps, dies, drills and cutters can be distinguished. Specific compatibility will be determined by the type of shank. By the way, not only in machine tools such systems for fastening processing parts are used. Handheld power tools are also provided with screw-on nut spring-loaded chucks, only in a smaller format.
Collet manufacturers
Premium manufacturers include Metabo, Jet, Bosch, Makita and other manufacturers, which are also involved in the development of equipment for solid blanks. For example, the common collet for the 8 mm router in the Bosch line is also suitable for manual grinders of its own production. As for the cost, the products of the above brands are estimated at 700-1200 rubles. for the collet element. Kits with parts of different formats and additional equipment can cost 15-20 thousand rubles. Domestic products from the Zubr and Enkor enterprises are slightly inferior in quality, but cost 15-20% cheaper.
Conclusion
Using auxiliary adapters to secure processing tips does not in itself add to the reliability of the workflow. Intermediate nodes also reduce the level of security. What justifies the use of universal cartridges with spring segments? To answer, you need to turn to another question - what is a collet in the general technological process of processing? This is the element thatoperations of selection and change of the same cutters and taps are optimized. The operator does not need to select a nozzle for a cartridge strictly for a specific format for a long time. It is enough to complete the wiring of the collet and insert the part into the chuck. Of course, such a system also has its limitations, but the range of variations when combining a working tool with equipment is wide enough for complete universalization of equipment within an enterprise of a certain direction.
