The process and flow of impeller machining of five-axis machining center
One,Difficulties in processing the integral impeller
1. The shape of the ternary integral impeller is complex, and its blades are mostly non-developable and twisted ruled surfaces, which can only be processed by machine tools with five coordinates or more;
2. The space between adjacent blades of the integral impeller is small, and the channel becomes narrower and narrower as the radius decreases. Therefore, when processing the curved surface of the impeller blade, in addition to the interference between the tool and the processed blade, the tool pole Easy to interfere with adjacent blades;
3. Due to the thin thickness of the integral impeller blades, there are relatively serious elastoplastic deformations during processing;
4. There are many constraints in tool location planning, and it is difficult to automatically generate non-interference tool location trajectories.
Second, the choice of impeller processing tools and tool holders
1. Tool selection
In order to improve the processing time, a large ball-end cutter should be used to rough the blades, and a multi-edge milling cutter should be used, which can improve the processing efficiency;
In the choice of tool structure type, in order to improve the rigidity of the tool, in addition to using large-diameter tools as much as possible, ball-end tools with taper should also be used as much as possible;
The choice of tool material needs to determine the material of the machining tool according to different workpiece materials, whether it is necessary to use coated tools, and so on.
2. The choice of handle
The structure of CNC machine tool holders is divided into two types: integral type and modular type. The working part of the integral tool holder for clamping the tool is integrated with the shank used for installation and positioning on the machine tool. This kind of tool holder has poor adaptability to the transformation of machine tools and parts. In order to adapt to the change of parts and machine tools, users must reserve tool holders of various specifications, so the utilization rate of tool holders is low. The modular tool system is a more advanced tool system. Each tool holder can be assembled through various serialized modules. According to different processing parts and machine tools, different assembly schemes are adopted to obtain a variety of tool holder series, thereby improving the adaptability and utilization of tool holders.
The selection of the structure of the tool holder should take into account advanced technology and reasonable economy. The choice of impeller processing tool holders can be divided into collet chuck holders and side-fixed holders. The clamping force of the collet chuck holders is increased by the nut sleeve. The force action produces a large enough axial pushing force on the spring to realize the clamping of the tool, so that in the case of relatively large chip force, the spring may loosen and cause the phenomenon of tool drop. Since the side-fixed tool holder produces a lateral locking force, there will be no overcutting caused by loosening of the tool during the machining process.
Three, impeller processing process
The impeller processing process is divided into several processing strategies such as impeller rough machining, blade surface middle processing, blade surface finishing and runner surface finishing. The purpose of rough machining is to quickly and efficiently remove the blank margin, and it is also the strategy that best reflects the efficiency of impeller machining. The purpose of semi-finishing is to make the margin of the blade surface uniform and prepare for the next finishing. The purpose of finishing is how to obtain a good surface quality, which has a great relationship with the selection of tools, the combination of machine speed and feed.
The improvement of impeller processing efficiency is mainly the improvement of roughing efficiency. Using the five-axis impeller roughing mode, the five-axis roughing of the impeller can be realized, and the material can be retained uniformly, the processing path is relatively smooth, and the processing efficiency is improved.
Fourth, the impeller processing process
The impeller processing process is divided into several processing strategies such as impeller rough machining, blade surface middle processing, blade surface finishing and runner surface finishing. The purpose of rough machining is to quickly and efficiently remove the blank margin, and it is also the strategy that best reflects the efficiency of impeller machining. The purpose of semi-finishing is to make the margin of the blade surface uniform and prepare for the next finishing. The purpose of finishing is how to obtain a good surface quality, which has a great relationship with the selection of tools, the combination of machine speed and feed.
The improvement of impeller processing efficiency is mainly the improvement of roughing efficiency. Using the five-axis impeller roughing mode, the five-axis roughing of the impeller can be realized, and the material can be retained uniformly, the processing path is relatively smooth, and the processing efficiency is improved.