Xi'an Aviation Power Control Company Liu Wenyi
In recent years, with the country's high attention to the development of the mold industry and the training of talents, the mold technology in the aerospace industry has also developed rapidly. The aerospace products are constantly diversified and high-performance development, which means that the mold manufacturing unit is required in a short time. Provide high-precision molds for the development and commissioning of production units. In order to meet this requirement, the company made full use of technologies such as CNC machining and mold computer-aided manufacturing to apply digitalization to the whole process of mold manufacturing, including digital design, processing, analysis and information collection in the manufacturing process, thus achieving rapid prototyping. High-speed machining to ensure the completion of product tasks.
Milling of thin-walled parts
In the production process of the mold, CNC milling of thin-walled parts is a common processing method. Through the analysis of the NC machining process of the thin plate bracket parts and the routing route in the UG software, the law of the deformation of the thin-wall milling machining is summarized, and the compensation method of the machining deformation of the thin-walled parts is proposed. Thin-walled structural parts are mainly composed of side walls and webs. Due to their simple structure, large machining allowance and low relative rigidity, the machining process is poor, and it is easy to be affected by various factors such as cutting force, cutting heat and cutting vibration. The machining deformation occurs, which makes it difficult to guarantee the machining accuracy, and the efficiency is low, which becomes an important constraint for the processing of thin-walled mold parts.
The illustrated part is a thin plate-shaped bracket made of forged aluminum alloy LD5, which has a complicated structure and is a typical thin-walled part suitable for CNC milling.
Thin wall parts
The machining contour of the part consists of a list of curved arcs and straight lines. The structure is complex, the geometric tolerance is IT14, and the surface roughness value is Ra=6.3 mm. It is easy to generate vibration during machining, resulting in the wall thickness tolerance of the part. Surface roughness and the like are difficult to meet the requirements. The blanks of the products are similar to the parts, and there are machining allowances of not less than 5 mm everywhere. The parts have large difference in size before and after machining, and the rigidity is not good during processing. During the machining process, large deformation errors occur before and after milling. Therefore, the choice of cutting tool materials should be based on the use of chemical vapor deposition coatings with good wear resistance, good impact resistance, high hardness and low affinity with working materials. Tool. The requirements for dynamic balance characteristics, geometric accuracy, repetitive clamping accuracy and clamping rigidity of the tool holder are high during cutting, so a 1:10 HSK vacuum tool holder is used; in the milling process, a two-hole positioning is used. The fixture uses a special transitional vacuum platform to vacuum the workpiece with a large clamping area and good rigidity. It is not easy to generate vibration during milling. It is especially suitable for thin plate clamping and auxiliary clamping device to avoid loose workpiece.
For the problem of milling deformation of thin-walled parts, the usual method is to cut several times without the feed amount after finishing. This method can remove some residual materials, but affects the processing efficiency of the parts. In this example, the method of actively optimizing the tool path to compensate for the deformation of the milling process is used in the machining. The deformation amount of the workpiece is calculated by the finite element model, and the deformation amount data is loaded into the UG software to form a numerical control machining program with a compensation function. The so-called tool path compensation function is based on the finite element analysis, according to the amount of machining deformation, in the NC programming, the tool is added according to the deformation amount in the original path, to compensate for the amount of tooling caused by the deformation. Through the tool compensation, the residual material of the knife can be removed, and the precision of the wall thickness of the thin-walled part can be ensured in one pass, thereby achieving the purpose of processing the thin-walled part. Since the processing of thin-walled parts is a dynamic and complex process, there are still many factors affecting the processing. Therefore, the research on the deformation of thin-walled parts needs further research.
CNC electric discharge machining
CNC EDM technology is used in the mold manufacturing, electronics, instrumentation and other departments to deal with the processing of various complex shape parts and difficult materials. Before the manufacturing of the mold parts, according to their own characteristics, processing requirements to determine a reasonable processing. In order to make the mold parts processed in the shortest possible time, reduce the processing cost and improve the processing efficiency, the machining process should be selected by milling, wire cutting and other processes. EDM is used when milling, wire cutting, etc. are not processed or the workpiece has special requirements. For example, the complex appearance that the tool is difficult to reach, the center of the deep cutting, the center of the long diameter ratio, and the fine Small cavities, narrow slits, grooves and corners are not convenient for cutting and clamping, and the material hardness is very high. According to the requirements of processing object, precision and appearance roughness, and the machine tool function, a suitable EDM process is adopted.
The use of a fast clamping positioning system to manufacture electrodes is an advanced process of EDM. It is manufactured by clamping the electrode blanks on the clamping system of the processing machine. After the manufacturing is completed, the electrodes can be directly mounted on the EDM. The electric discharge machining is stopped on the fast clamping system of the machine tool, which brings great convenience to the machining operation, improves the manufacturing efficiency of the electrode, and ensures the clamping and positioning accuracy of the electrode.
Electrical discharge machining begins with the design and manufacture of electrodes. Current computer-aided design and manufacturing (CAD/CAM) technology has been widely used in the mold manufacturing industry. The company uses the powerful electrode design and programming functions provided by UG and MasterCAM software, and uses wire-cutting electrodes. It is very suitable for the manufacture of 2D electrodes. It can be used to manufacture the entire electrode separately or to clean the corners of the electrodes. In addition, the sheet-like electrode is difficult to stop by mechanical cutting, and the wire cutting process can achieve high processing efficiency and machining accuracy. With the slow wire cutting machine, it is possible to process complex electrodes with slopes and upper and lower profiles. High machining accuracy and appearance quality.
In the process of electric spark machining, the choice of electrical parameters directly affects the various process indicators of processing. The ultimate goal of selecting electrical parameters is to achieve the desired processing dimensions and surface roughness requirements. When selecting electrical parameters, fundamentally consider the number of electrodes, electrode loss, working fluid disposal, processing surface roughness requirements, electrode scaling, processing area and processing depth. The main basis for the selection of roughing parameters is the size of the electrode scaling. The scaling dimensions of the roughing electrodes are generally larger, and the safety parameters can be selected to achieve electrical parameters close to the scale of the electrodes. The main basis for the selection of finishing parameters is the final appearance roughness requirement. Multiple sets of electrical parameters are selected, and the discharge energy is stopped from large to small to achieve the surface roughness and processing size requirements. CNC EDM machines have many optimal sets of electrical parameters that are configured. When the electrical parameters are automatically selected, the electrical parameters can be automatically configured by simply inputting the required input conditions.
Application of mold manufacturing technology in aerospace manufacturing
With the development of aerospace industry, advanced digital technology has been applied to mold manufacturing, and it has developed rapidly in recent years. With good performance, it has begun to take orders from the European and American markets. However, the popularity of digital technology has yet to be deepened. The development level of the mold industry, especially complex and large-scale high-precision molds, is still far behind that of some countries in Europe and America. Research and development of mold digital manufacturing technology should be vigorously carried out, so that digital manufacturing technology is widely used in the mold industry to transform the traditional mold industry.
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DTMADE provides excellent service to each OEM customer, and every project is assigned to a dedicated project manager. It takes only 6-12 months from project inception to production launch.
Cooperating with us shift your business!DTMADE has been committed to manufacturing cost-effective products for many years. The product line covers four major product series, snowblower, lawnmower, leafblower, gardentools.
DTMADE product is designed to keep up with the derivation of the market, innovation and quality stablization always become the first goal we pursue.
DTMADE provides excellent service to each OEM customer, and every project is assigned to a dedicated project manager. It takes only 6-12 months from project inception to production launch.
Cooperating with us shift your business!
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