Broaching machines are a type of machine tool that uses a toothed tool, called a broach, to remove material from a workpiece. Broaching is a machining process that produces a smooth finish on cylindrical or tapered surfaces.
Advantages of Broaching Machines
There are several advantages to using broaching machines:
- High production efficiency and low processing cycle, can reduce the processing cost of a single product in mass production. Broaching machines can complete parts processing operations that require combined processing of gear hobbing machines, gear shaping machines, and milling machines in a short period of time. The broach is used for broaching. A broach is a multi-tooth tool. The number of teeth involved in the work is large, so the total cutting width is increased, and the roughing, semi-finishing, and finishing processes can be completed in one stroke of the broach. , so that the basic process time and auxiliary time are greatly reduced, so the broaching operation is faster than other metal cutting operations. When used in mass production, the processing cost per product is lower.
- Wide range of machining applications. Broaches can be used for both internal and external cutting operations， it can not only machine flat and unobstructed external surfaces, various shapes of internal holes can also be processed. In addition, broaching is used for the high-precision machining of difficult-to-cut materials, such as turbine disks used in the manufacture of generators and aircraft engines.
- The workpieces processed by broaching have a higher surface finish, higher dimensional accuracy, and smaller tolerances. The broach has a calibration part, whose function is to calibrate the size and trim the amount of light. In addition, the cutting speed of broaching is generally low (<18 m/min), and the cutting thickness of each cutting tooth is small, so the cutting process is relatively stable, and the adverse effect of a pseudo-chip edge can be avoided. Therefore, broaching can achieve high precision and low surface roughness. Generally, the dimensional accuracy tolerance level of broaching is IT7~IT8, and the surface roughness Ra is 0.4~0.8μ
- The structure of the broaching machine is simple, the broaching operation is simple, and the skill requirements for workers are low. There is only one main movement in broaching, that is, the linear movement of the broach. The feed movement is realized by the fact that the last tooth of the broach is higher than the previous one. The height of the tooth is called the tooth lift, so the broaching machine The structure is simple and the operation is convenient.
- The broach has a longer service life. The cutting speed during broaching is low, each tooth only needs a small incision in one operation, the tool wears slowly, and the sharpening once can process several dry workpieces, and one broach can be reground many times, so The broach has a long service life.
- The temperature of the workpiece is fairly constant, thus avoiding errors due to thermal stress.
7. The cutting force on the workpiece acts in the clamping direction, helping to hold the workpiece securely/in place.
Limitations of Broaching Machines
However, there are also some limitations to using broaching machines:
- The initial cost of custom broaches is high and not suitable for low-volume production. Although broaching has the above advantages, because the structure of the broaching tool is more complicated than that of the general hole machining tool, the manufacturing of the broach tool is more difficult and the cost is higher, so broaching machine is usually suitable for mass production. In single-piece and small-batch production, except for some processing applications that require high precision or special shapes, the cost of producing with a broaching machine is not cost-effective.
- The design, repair, and sharpening of broaches are expensive.
- The application range of broaching is also limited. Blind holes, deep holes, stepped holes, and obstructed outer surfaces cannot be broached.
- Broaching is only suitable for low chip load or light cutting.
- One broach can only be used for one program. A separate broach is required whenever the geometry of the workpiece changes.
In conclusion, broaching has many advantages and limitations. It can be used for high-efficiency large-scale workpiece processing, thereby improving product processing accuracy and reducing production costs. However, it also has some disadvantages, such as high cost and tool cost, making it unsuitable for single-piece or small-batch product processing. Therefore, before purchasing a broaching machine from any brochure machine manufacturer, it is important to consider your own processing needs to decide whether it is suitable for your production needs.