原文：
The rapid development of quickly modeling manufacturing techonology
In recent years, the manufacturing sector of the manufacturing market is undergoing a strategic focus from cost and quality time with the response to a major shift. Rapid diversification of the product into the market to manufacturers grasp market opportunities for the sake of the survival of important support, and rapid response manufacturing has become a hot international research, the right moment rapid prototyping / rapid tooling / Rapid Manufacturing technology enterprises to improve competitiveness to provide an advanced means of gradually become the focus of the industry.
According to media reports, the strategy is the traditional manufacturing economies of scale first, and the 20th century to the 1980s prices and quality first, since the 1990s, has been developed as a response to market first. In the manufacturing sector growing international circumstances, shorten product development cycles and reduce investment risks and development of new products, as for the survival of key enterprises.
Rapid Prototyping / rapid tooling / manufacturing technology is based on the rapid accumulation of forming a high-tech manufacturing technology, and is regarded as the 20th century created a revolutionary breakthrough in the field, can produce injection mold, die-casting mould, Die, and other sophisticated Die, Fan has been widely used in the automotive, aerospace, shipbuilding, electrical household appliances, industrial design, medical, construction, crafts, as well as children's toys, and other fields, and with the technology itself to continuously develop and improve, its scope of application will continue Extension.
In the automotive, appliance manufacturing industry, forming mold parts manufacturers account for 50 per cent of working hours to 70 per cent. Mould Manufacturing is constraining our automobiles, household appliances, light industry and the development of key bottleneck, with the rapid prototyping software, hardware, and rapid prototyping materials continuous development and improvement, rapid prototyping of the intensity and precision of continuous improvement, rapid prototyping technology has been gradually into the field of rapid tooling, rapid prototyping based on the simple method of manufacturing various types of rapid economic Die RP & M has become a hot issue Application
first, rapid manufacturing mold
Although rapid prototyping technology was first time is not long, but because of its manufacturing sector makes the tremendous benefits this technology becomes more widely available, especially to the design and manufacture of molds brought a leap. Rapid prototyping technology can accurately type heart and mold cavity, and can be used directly in the production process of plastic injection sample, in order to identify and correct the mistakes. Because rapid prototyping and manufacturing applications of this new technology, mold design and manufacturing becoming increasingly digital, and rapid, so a reduction in the mould manufacturing cycle, and reduce their costs in the process, a step forward significantly.
Rapid Tooling Technology are based on rapid prototyping model that is produced by entities like mode (the mother mode) used copy format (such as metal coating, plating, composite materials casting, casting, etc.) to quickly manufacture key parts Die (convex and concave die or cavities, core), and its general manufacturing cycle for the traditional method of CNC cutting 1 / 5 to 1 / 10, while its costs are only 1 / 3 to 1 / 5
According to mold materials, the cost of production, RP prototype materials, production volume, the accuracy of mold has developed a wide range of Process. The current rapid tooling methods generally have an indirect and direct modelling of the system model, based on the RP rapid manufacturing mold for more indirect methods of modelling. Based on different materials, indirect modelling produced by molds are soft mode, and hard-bridge module. Soft mode (softtooling) usually refers to the silicone rubber mold. By SLA, FDM, SLS or LOM technologies such as the production of prototype and then translated into silicon rubber mold, the mold reperfusion bicomponent polyurethane curing after the necessary parts. Bridge mode (bridgetooling) usually refers to the direct production of epoxy resin for injection molds. Using epoxy resin mold compared with the traditional injection mold, cost only a fraction of the traditional methods, production cycle is greatly reduced. Die life than steel form, but high-silica ratio, up to 1000 ~ 5000 to meet the needs of small batch production. Die Hard (hard tooling) usually refers to the steel mold, which uses indirect way in manufacturing metal molds and directly processed by rapid prototyping tool.
Enterprises increased competition, product development cycle shorter growing demand for rapid tooling technology offers opportunities for development and development space. With the development of industrial production, rapid tooling technology developers and more and more products Die extensive attention, their research is in full swing, new technologies have emerged results, showing a trend of the development of vibrant, it has great vitality.
Second, rapid injection mold manufacturing technology - Metalizing molding method
1, Metalizing molding method Profile
Metalizing modelling method is rapid prototyping and thermal spraying, such as rapid solidification method with the indirect model of the system, the process is molten or semi-molten metal particles to spray through the SLA, SLS, or LOM prototype manufacturing, Thin metal production, and then back reinforcement lining and remove mold get prototype products. At present, there are two forms, namely, aerosol spray (rapid solidification process RSP), the spraying method. When asked die in the life of the following 3000, the general RP prototype for the mother to die, the molten metal of low melting point (such as the zinc-aluminum alloy) after full atomization of a certain level of the mother-speed jet to the surface, forming Die cavity surface, filling back lining composite materials, the production of zinc-aluminum alloy die. Metalizing molding die for the kind of a standard mold cavity size, geometric accuracy depends entirely on-die, cavity surface and a fine pattern forming at the same time, the molding speed, short manufacturing cycle, mold, long life, low cost , the only stop in NC machining of 1/3-1/5. Die good surface finish, the process is simple, low equipment requirements, more suitable for the injection molding die, die-casting mould, sheet metal rolling mode of rapid manufacturing.
2, metal spraying process modelling method
Metalizing molding processes can be broadly divided into five steps:
(1) model preparation
Model can be made of many materials, including plastic, plaster, rubber, and timber. First a three-dimensional model, and then Slicing them by the rapid prototyping mechanism-like mode. Model preparation is the most important clean-up of the surface and apply release agent.
(2) metal spraying model
Release Agent drying, select the best spray parameters can begin spraying metal mold, spray gun should be to ensure that continuous campaigns to prevent overheating deformation coating, coating thickness could be controlled in the 2 to 3 mm.
(3) Production Die Frame
If die in work or be subject to pressure in the mold must be installed on the machine, mold must have a skeleton structure of the skeleton and should be made with fillers.
(4) casting mold filling material
Materials should be filled with high thermal conductivity and lower solidification shrinkage rates and higher compressive strength and wear resistance. General choice of filling material for epoxy resin and aluminum, aluminum and other metal particle powder mixture.
(5) Stripping and the mold cavity surface polishing treatment
Stripping after the metal should remain in the release agent on the surface clean, and then in accordance with their different needs, such as polishing die for post-production.
(6) test module assembly
3, spraying equipment and spraying materials
Metal arc spraying systems generally work by spraying power supply, wire feeder, Lance and compressed gases such as system. XDP-5 arc spraying equipment stable and reliable work, the use of maintenance convenience, equal to the heavy spraying work, and the basic parameters:
Power supply voltage: 380 V
Rated input capacity: 12 KVA
Current Rating: 300 A
The use of compressed air pressure: 0.6 Mpa
Compressed air consumption: 1.6 ~ 2 m3/min
Wire feed rate: 0 ~ 4.8 m / min
Die arc spraying system for the material to meet the low melting point, low shrinkage rate of circumstances, as far as possible should have better mechanical properties and more dense coating. At present the market with wire arc spray materials are aluminum, zinc, copper, nickel, stainless steel, aluminum bronze, Babbit, composite wire, and many other varieties. But high melting point metal, such as steel, nickel, copper, etc., in the spray coating shrinkage rate, heat stress, greater than the porosity of the coating-cracking, warping, peeling, so only low melting point of zinc, wood Lvsi suitable for mold making.
Third, Metalizing rapid manufacturing injection mold technology applications and development paradigm
Metalizing mold manufacturing method particularly suitable for the production of reaction injection molding of polyurethane components in the production of plastic widely used in the processing reaction injection molding, blow molding, structural foam, as well as a number of other processes such as injection molding , such as car manufacturers can be used in the production of the steering wheel, car dashboards, upholstery, head Cushion, Baffles boards, automotive interior Roof, in the light can be used to make polyurethane soles, Metalizing Rapid Tooling more rapid silicone rubber mold longer life expectancy, can be used in the injection molding machine for the production of small quantities of products. Injection in the application process should take into account the low melting point metal alloy spraying mold cavity, as well as the performance of the life limit. To prevent damage to die prematurely, the injection pressure should not be too high, it must also be able to ensure that products forming the minimum injection pressure, otherwise they will have a note with the phenomenon.
Metalizing injection mold examples of the successful application of:
1. Flowerpots injection mold base
If the EDM using traditional methods, and the cost about 5,000 yuan in 4000 to between production for about a month or so, and with rapid tooling arc spraying method to produce, the cost is about 1,100 yuan about working hours 60h around. This is exactly what the arc spraying rapid tooling receive widespread one of the reasons.
Flowerpots base injection moulding processes: machining Spray bottom → concave shell model cavity preparation → spraying spraying metal die → epoxy resin and aluminum shell configuration and filled with epoxy curing → spraying → mother die → surface cleaning of metal spraying punch → epoxy resin and aluminum shell configuration and filled with epoxy curing → → convex and concave die separation and surface cleaning → mold machining mould parts → assembly test mode.
2. Drip emitter using rapid tooling
Centre national water-saving irrigation drip emitter rapid tooling is used in the production emitter RP model, using metal spraying system of manufacturing zinc-aluminum alloy soft molds, injection molding 1000 emitter products for agricultural water-saving irrigation test. State water-saving irrigation center to RP & M prototype up for the mother-to-use drip irrigation emitters molds, rapid prototyping play to the advantages of technology, rapid realization of the prototype-a new, including RP prototype, the production cycle for the production of only 2 week.
3, Idaho injection mold
United States Idaho National Engineering and Environmental Test Center using rapid solidification process that RSP technology to realize rapid economic injection mold manufacturing. The method uses rapid prototyping technology produced as a kind of model mother, the mother model to spray through the metal or alloy droplet deposition manufacturing mold. Process: molten alloy tool steel or other pressure was all nozzle, and high-speed flow of inert gas incurred by the formation of a diameter of about 0.05 mm mist droplet, Fenxiang and deposition model to the mother, a mother-like reproduction shape of the surface structure, with a release agent to the deposition of steel mold samples from the mother and can be quickly produced for mold.
Recently, Xi'an Jiaotong University Institute of Mechanical Engineering, Advanced Manufacturing Technology Research Institute successfully used "electric arc spraying and brush integration Mould Manufacturing Technology" for the development of new models of cars large stamping dies rapid manufacturing, the technology has been rapid prototyping arc spraying and technologies such as electric brush using arc spraying of the mother-in the mold surface rapid deposition of a layer of dense low melting point metal shell, thereby producing a mold cavity in the back filled with the appropriate lining materials and stripping, use a brush technology in the die surface coating brush strengthen, then the rapid completion of mold manufacturing.
Use of the technology and equipment, with rapid prototyping and manufacturing technology, and high-speed CNC machining technology can be a cost-efficient manner for large, sophisticated, complex and long-life die rapid manufacturing.
Using electric arc spraying and brush manufacturing technology integration Die Die Manufacturing coverage, cost only traditional mold machining steel 1 / 10, the manufacturing cycle for the latter's 1 / 4 to 1 / 5, and economic benefits are substantial, it is ideal for in the development of new models of cars Preparation and small-batch production. The technology can also be used for rapid manufacturing injection mold.
