Laser rapid prototyping is a new manufacturing technology that integrates advanced technologies such as CAD, CAM, CNC, laser pointer, precision servo drives and new materials. Compared with the traditional manufacturing method, it has the reproducibility and high interchangeability of the prototype; the manufacturing process has nothing to do with the geometry of the manufacturing prototype; the advantages of short processing cycle and low cost, the general manufacturing cost is reduced by 50%, and the processing cycle is shortened by 70% Above; high degree of technical integration to realize the integration of design and manufacturing.
The LPRs that have recently developed mainly include: Stereo Optical Modeling (SLA) technology; Selective Laser Sintering (SLS) technology; Fuse Stacking (FDM) technology; Laser Cladding Forming (LCF) technology; Laser Proximity (LENS) technology; Laser laminate manufacturing (LOM) technology; laser induced thermal stress forming (LF) technology and three-dimensional printing technology.
The United States, Japan, Germany, Belgium, etc. have invested a lot of manpower and material resources in researching this technology, and new products have been coming out constantly. Jiaotong University has also successfully developed the LPS600a stereo modeling machine. At present, there are more than 10 factories all over the world producing this product.
The application of SLA technology in automobile body manufacturing can produce precision casting molds of the required proportions, thereby casting a certain proportion of body metal models, which can be used for wind tunnel and collision tests to complete the final evaluation of the body. To determine whether its design is reasonable.
The Chrysler Corporation of the United States has made a car body model with SLA technology and placed it in a high-speed wind tunnel for green laser pointer aerodynamic test analysis, which achieved satisfactory results and greatly saved test costs. It is used for the test of the intake pipe of automobile engine. The shape of the inner cavity of the intake pipe is composed of a very complicated free-form surface, which has a very important influence on the improvement of the intake efficiency and the combustion process.
In the design process, different air intake pipe schemes need to be tested for air passages. The traditional method is to manually process the air pipe wood mold or plaster mold described by dozens of cross-sections, and then cast the air intake pipe with sand molds. , Wood model workers’ understanding of drawings and their own technical level often lead to deviations of parts and design intent, and sometimes the impact of this error is significant.
Although the use of CNC machining can better reflect the design intent, its preparation time is long, especially when the geometric shape is complicated. British rover company uses rapid prototyping technology to produce the outer mold and inner cavity mold of the intake pipe, and has achieved satisfactory results.