1.  Categories of Micro Mechanical Parts

According to the geometric characteristics of micro mechanical parts, micro mechanical parts mainly include micro shaft parts, micro three-dimensional structural parts, micro plate-type parts and micro gear-type parts. Various types of tiny parts are widely used in different occasions.

1.1 Micro shaft parts

Micro shaft parts are one of the typical parts often encountered in micro-miniature processing equipment. Micro-miniature shaft parts are mainly used to support tiny transmission parts, transmit torsional moments and bear external loads. From the perspective of its function, the processing of micro shaft parts requires high rotation accuracy and surface quality, so the processing consultation of micro-miniature parts has become increasingly important. When the micro-miniature shaft parts to be processed have a large aspect ratio, since the top support cannot be accepted during the machining process, the micro-miniature shaft parts to be processed are easily bent and deformed under the action of the radial cutting force during cutting, causing the tailing phenomenon of the processed parts. If the machined micro shaft parts have other features such as micro-planes, micro-grooves, micro-holes, etc. in addition to the typical features of shaft-type parts, it is impossible to complete such micro-miniature shafts by a single turning process. For the processing of similar parts, it is necessary to cooperate with other processing methods.

1.2 Micro 3D structural parts

The structural features of micro-miniature three-dimensional structural parts are relatively complex, and they do not only have simple rotary and plane features. Due to the complexity of its structural features and the unique process characteristics of the parts themselves, the difficulty of parts processing is increased. In the processing, it is necessary to reasonably control the processing technology according to the process characteristics of the part itself, and select micro-miniature processing equipment withelatively r small size, high precision and good flexibility for processing.

1.3 Micro-plate parts and gear parts

The main structural feature of micro and small board parts is the plane, in addition to some other structural features, such as stepped surfaces, micro holes, micro grooves and irregular contour appearance. Compared with micro-miniature three-dimensional structural parts, the structure of micro-miniature plate-type parts is relatively simple in processing. The application of micro-milling and micro-drilling processing technology can meet the technical requirements of such parts and complete the production of micro-miniature plate-type parts. If the thickness of the micro-miniature board parts is thin, the clamping method of the parts needs to be considered during processing to prevent the micro-clamps from exerting too much force on the parts during clamping and causing the parts to deform.

The difficulty and focus of micro gear processing is the processing of its tooth shape. The machining accuracy of the tooth shape is directly related to the meshing accuracy between the gears and the use effect after assembly. At present, there are mainly two kinds of micro-cutting processing methods, micro-forming milling and micro-hobbing, which are used for the processing of micro-miniature gears. In the process of using the micro-forming milling processing method to process the micro-miniature gears, the manufacturing accuracy of the forming tool itself has a great influence on the machining accuracy of the micro-miniature gears. The appearance error of the finished gear tooth profile is large, and the tooth profile is obviously distorted. Compared with the micro-forming milling, the micro-hobbing processing method is based on the forming process of the Fan Cheng method. During the processing, the multiple cutting edges of the hobbing tool continuously cut the workpiece, which is better than the micro-forming in terms of processing efficiency and processing quality.

2. Processing Method of Micro Mechanical Parts

The processing methods of micro-miniature parts include semiconductor-based manufacturing process technology, LIGA and quasi-LIGA technology, and the technology of conventional precision machine tools to process micro-miniature mechanical parts, as well as the use of micro-miniature processing equipment that is currently under discussion called micromachining. The material of semiconductor-based manufacturing process technology is relatively simple, and the application fields of the processed micro-miniature parts are mostly in the electronic field. The micro-miniature parts processed by LIGA and quasi-LIGA technology have a simple structure, mostly two-dimensional or quasi-three-dimensional micro-miniature mechanical parts, and the processing equipment is much expensive. The use of conventional precision machine tools to process micro and small parts has problems such as large space occupation, low processing efficiency, large energy consumption, and serious waste of resources. The micro-cutting processing technology that uses micro-miniature processing equipment to process micro-miniature parts has a wide range of processing materials, can process precise three-dimensional micro-miniature mechanical parts with complex structures, and can avoid the problems of the above processing methods. It is a discussion on the processing technology of micro-miniature parts focus.

Micro-cutting processing technology mainly includes micro-turning, micro-milling, micro-grinding and so on. Compared with conventional machining technology, the cutting amount of micro machining technology is small, and due to the small overall size of micro-miniature parts, if the machining process of conventional-scale parts is still accepted in the process of micro-cutting machining, it will not be able to meet the machining accuracy. The tiny cutting amount requires the processing equipment to have extremely high feed accuracy, positioning accuracy and spindle rotation accuracy. Micro-turning is mainly used for the machining of cylindrical surface, end surface and other external features of micro-small shaft parts. Micro-milling is mainly used for processing the planes, grooves and complicated surfaces of micro-small parts. At present, the processing of micro and small flat parts mainly relies on the processing technology of micro milling. Micro drilling is mainly used for the processing of micro holes on micro and small parts, and the processing aperture is restricted by the drill bit. Micro grinding is mainly used for the processing of micro and small parts with extremely high surface accuracy requirements, and is an important micro cutting technology.

3. Process analysis of micro-miniature mechanical parts

The overall size of micro-miniature mechanical parts is small, the machining accuracy and surface quality requestment are high. Therefore, the formulation of the processing technology of micro-miniature mechanical parts is much difficult than the processing technology of conventional scale parts. According to the geometric characteristics of micro-mechanical parts, the processing technology that should be included can be roughly determined. If the part has rotary features such as cylindrical surface and end surface, such parts should include turning process. If the part has structural features such as planes, micro-grooves, micro-holes, etc., such parts should include a milling process or a drilling process. In the process of processing micro-miniature mechanical parts, considering that the parts are prone to deformation, high machining accuracy and processing efficiency, the formulation of the processing technology of micro-miniature mechanical parts should focus on the following points.

3.1 The processing principle of roughing first and then finishing
In the processing of micro-miniature mechanical parts, the roughing process is given priority, and after the roughing process is completed, the semi-finishing and finishing processes of the parts are controlled. In the roughing process, under the condition of ensuring the rigidity of the system, the micro cutting tool with larger diameter should be selected as much as possible. It can shorten the processing time of parts and improve the processing efficiency. After the roughing process of the part is completed, it is necessary to control the finishing process of the part at a certain time interval. The purpose of this is to restore the deformation of the part after the roughing process to let the machining accuracy definitely improved.

3.2 Minimal calls to tools and accessories
In the process of processing micro-miniature mechanical parts, due to the different geometric characteristics of the parts, different types of tools such as turning, milling, drilling, etc. are often involved, and the pros and cons of the process route are largely affected by the order of the tools used. Therefore, the use of the tool should be reduced as much as possible to reduce the cumulative error caused by the tool during the installation process. During the use of the same tool, use it to process as many workpiece surfaces as possible, and reduce its installation on the machine tool. number of adjustments. The use of accessories in the process of processing should also follow the principle of least invocation. In one invocation of the accessories, it should be processed to the maximum extent.

3.3 Reduce the number of workpiece clamping
Due to the different geometric characteristics of micro-miniature parts, it is often necessary to perform multiple clampings to complete the machining of the parts. The size of micro-miniature parts is small, and many clamping times are time-consuming and laborious, and multiple clampings will cause errors and affect the machining accuracy of the parts. Therefore, the entire surface of the workpiece should be processed in one clamping process as much as possible. The machining accuracy of the workpiece.

At present, the micro parts demands is becoming more and more. As a professional CNC Machining Factory, Ningbo Tianhui also involve this business range to help our customers to complete more projects.

If you just have the request for micro parts demand, please contact us!