CN1060698C - Multifunctional equipment capable of fast completing various model making technique - Google Patents

Abstract

The equipment of the present invention is mainly composed of a processing room, a computer and a corresponding control unit. The processing room includes a laser, a scanning unit for XYZ three-way movement, a height measuring unit, a synchronous toothed belt and the heating roller driven by it, and a Z-direction movement. The basic working platform and the foil conveying device are characterized in that the processing chamber is a closed box with air supply and exhaust devices inside, and the heating roller is a multi-layered roller and shell that can be rotated by a motor and a transmission device. Functional roll. The equipment of the present invention can complete a variety of rapid prototyping processes, which can meet the various needs of users in industries such as aerospace, automobiles, electronics, home appliances, machinery, medical treatment, toys, etc.; research and integration of new forming processes can be carried out on the equipment, The performance and price ratio of this equipment is higher than that of other existing rapid prototyping equipment.

Description

Versatile equipment capable of performing multiple rapid prototyping processes

The invention belongs to the field of mechanical manufacturing, in particular to the improvement of the structure of a rapid prototyping machine.

Rapid prototyping technology is based on the idea of discrete/stacking forming, and comprehensively utilizes high-tech disciplines such as laser, numerical control, CAD and new materials, and forms a high-tech integrated from conceptual design to three-dimensional solid model manufacturing. This technology was successfully studied for the first time in the United States in 1986. Rapid prototyping technology is based on the idea of layered manufacturing (discrete/accumulation forming). First, the required three-dimensional CAD model is designed by CAD software, and then it is layered according to a certain thickness, and the plane profile information is obtained by layering, and then transmitted to the CNC. The system, under the control of the computer, uses a specific stacking method to process materials according to the trajectory determined by the layered information, so as to obtain a three-dimensional entity (prototype). In the past ten years, rapid prototyping technology has developed rapidly, and there are nearly ten kinds of commercial rapid prototyping technologies so far. The following are brief introductions respectively: 1) Layered entity manufacturing (LOM)

Layered entity manufacturing was invented by Chicago Helisys, Incin Michael Feygin in 1987, and obtained a US patent in 1988. The schematic diagram of the LOM system is shown in Figure 1. The LOM system is mainly composed of computer and corresponding control system, laser and X-Y direction movement optical scanning system, Z direction movement working platform, heating roller, paper feeding device, and forming paper. The working process of the LOM system is as follows: firstly, the heating roller moves to heat and press the paper on the current layer and the paper below to make them stick together, and then the heating roller returns to its original position; the next step is to control the optical scanning system on the focus plane of the current layer by the computer. The material is scanned and cut to obtain the plane outline of the current layer of the part, and the remaining unnecessary parts are cut into small grids; next, the working platform is lowered to a certain height H to separate the laser-cut formed part from the paper roll, and then The paper feeding device works to send new paper to the working platform, and the working platform rises to the height of (H minus the thickness of a layer of paper). In this way, a processing is completed, and then the above process will be repeated until the parts of the required height are completed. 2) Stereolithography (SLA)

Stereolithography is the United States C. Hull successfully developed it in 1986, obtained a US patent in 1987, and launched the first commercial machine SLA-1 in 1988. The three-dimensional printing technology is based on the photosensitive polymer as the forming material. The laser beam moves in the X-Y plane, scans a plane figure on the material, forms continuous solidification points, and obtains a three-dimensional entity through the cooperative movement of the Z axis. Model. 3) Selective Laser Sintering (SLS)

Selective laser sintering was invented by Carl Deckard at the University of Texas at Austin during his graduate studies. The University of Texas and DTM have jointly developed the commercial machine SLS Model 125. SLS uses laser beam sintering of resin-coated powder materials to complete the processing of the plane model. Theoretically speaking, since the powder materials used by SLS can be metal, ceramics, Wax powder, ABS plastic, etc., thus has the potential to directly manufacture parts. 4) Fused deposition molding (FDM)

Fused deposition molding (FDM) was invented by American Minneapolis engineer Scott Crump in 1988 and has applied for a patent. Instead of using a laser, this method uses a heated nozzle to build up the thermosetting material layer by layer. The biggest advantage of this method is that it is non-polluting and can be used in office environments.

Due to the advantages of shortening the time from product design to processing, increasing productivity, improving product quality, and accelerating optimal design, rapid prototyping technology has received great attention from the industry and academia since its birth. Aerospace, automotive, electronics, home appliances, machinery, medical, toys and other industries have been widely used and achieved great results. 1). Application in new product development

Since the rapid prototyping technology can manufacture the conceptual model in a relatively short period of time, it plays an extremely important role in the development of new products. With the physical model, the designer can quickly judge the aesthetics and novelty of the design, and Quickly modify inappropriate design schemes until a satisfactory product is designed. Other applications such as functional testing, feel and appearance testing, assembly inspection, product promotion, etc. 2) Rapid part/mold manufacturing

The model manufactured by rapid prototyping technology can be combined with the traditional part/mold manufacturing method to quickly manufacture parts and models. 3) Test model

For products that require streamlined body wind tunnel tests (such as aircraft, automobiles, ships, etc.), rapid prototyping technology can quickly and accurately manufacture test models to speed up the test process of these products. 4) Medicine

Using CT technology and rapid prototyping technology, the shape of human bones or tumors can be quickly copied to assist in diagnosis, determine major surgical plans, and design and manufacture artificial limbs. 5) Engineering analysis model

Carry out numerical simulation for the analysis of engineering structures in civil engineering, machinery, water conservancy and other industries, so as to determine the dangerous parts and optimize the design. Rapid prototyping technology can also be used in the production of architectural models, the production of artworks and so on.

In today's RP field, there are dozens of forming equipment based on different forming methods, and there are more than ten most representative ones. Various rapid prototyping methods and commercial equipment emerge in endlessly, but all kinds of forming machines are expensive (all around hundreds of thousands of dollars), and their performances are quite different from each other. Comparing the SLA forming machine of American 3D System Company with the LOM forming machine of HELISYS Company, there are great differences in the materials used, processing accuracy and forming range. In this way, the advantages and disadvantages between each other are difficult to make up, the forming method is single, the forming material is single, and the system is not open. One RP forming equipment can only complete one process, so the performance-price ratio is very low. At the same time, the demand for RP technology in industry and scientific research and teaching is multifaceted. Different product development requires different RP processes. Large enterprises and research Units often need to purchase multiple single-function RP equipment with different processes, which reduces the utilization rate of the equipment and causes huge waste.

Based on the inventor's years of research in the RP field, an important conclusion has been drawn, that is, the unit technology in RP technology: CAD modeling technology, discrete stacking and layered software technology, numerical control scanning technology, temperature control technology, feeding unit, The height measurement system is the key technology in RP technology, and they have universal applicability to all RP forming technologies.

The purpose of the present invention is to develop a multi-functional RP device. By integrating those key technologies with universality and supplementing relevant technical support, a multi-functional and open RP device can be completed. This equipment can not only complete a variety of RP processes, but also conduct research and re-integration of new forming processes, and has a high performance-price ratio, which can meet various needs of users, thus overcoming the shortcomings of existing equipment.

The present invention designs a multi-functional equipment capable of completing various rapid prototyping manufacturing processes. The equipment is mainly composed of a processing room, a computer for regulating and controlling the functions of each component in the processing room, and a corresponding control unit. The chamber at least includes a laser and a scanning unit moving in the X-Y direction, a height measuring unit, a synchronous toothed belt and the heating roller driven by it, a basic working platform moving in the Z direction, and a foil conveying device. It is characterized in that the processing chamber is A closed box-type multi-functional processing room is equipped with air supply and exhaust devices, and also includes a horizontally placed optical platform, a reference platform and a Z guide rail fixed on the side wall of said processing room, and all components are installed on the optical platform. Said laser and X-Y guide rail, on the optical platform and on the slider of X-Y guide rail, an optical path composed of multiple optical lenses and focusing mirrors is installed to form the scanning unit, and the Z guide rail slider is installed on the said The basic working platform is to install the synchronous gear belt and the heating roller on the reference platform. The said heating roller is a multifunctional roller composed of a roller and a shell that can be rotated by the motor and the transmission device. The shell has a long slot at the bottom. The outer wall of the shell is equipped with a hooking device and a height measuring device at an appropriate part, the roller is installed in the shell, the radial side wall of the roller is exposed from the notch of the shell to an appropriate width, and the heating element and temperature measuring device are installed inside the roller. element.

The above scheme of the present invention can meet the LOM process, if the process requirements are changed, the required feeding device can be easily articulated at the joint of the shell of the said multifunctional roller, such as the SLS process can be realized by articulated powder spreading box, The hooking of the scraping device can realize the SLA process. Correspondingly, in order to adapt to the forming of different processes, the basic workbench of the present invention can be a frame structure, which can be easily matched with various special workbenches required by different processes. The above-mentioned structural design ensures fast and convenient replacement of process .

The control unit of the present invention is mainly based on the industrial computer, and the drivers connected to each interface of the industrial computer are connected with X, Y, Z motors, paper feeding motors, multi-functional roller motors, FDM wire feeding motors, and FDM auxiliary wire feeding motors , laser, temperature control unit, height measurement and control unit, laser shutter and other components. In order to ensure the quality and precision of prototyping under different processes, the temperature control of the present invention adopts two-level control, that is, the temperature control of the multi-functional processing chamber and the temperature control of the multi-functional roller. The temperature control of the processing chamber as a small environment temperature control is a key condition in RP technology. For the FDM process, if the molding room temperature is too low, it is easy to cause interlayer peeling; if the molding room temperature is too high, it is easy to cause surface wrinkling. For the SLS process, a certain temperature is also required to ensure that the powder has a certain temperature to reduce the stress between layers during powder sintering.

Height measurement control is designed for real-time detection of the height of each layer of powder, filament or sheet material after forming. The Z-axis table moves a fixed displacement value for each layer according to the layered data, but there is some error between the thickness of each layer of material and this displacement value. After dozens of layers, the error accumulation in height may reach the value of one layer thickness, that is, several Ten microns. The measurement accuracy of the altimeter can reach the micron level, and the repeatability is good. It measures the error between the displacement value of the Z-axis table and the height of the mold and converts it into a voltage value.

The computer is controlled by the program, and the A/D conversion is started according to the needs, and the height signal value is collected, so that the computer can correct the height, so as to ensure the high precision of the height of the formed part.

The height measurement control unit of the present invention includes a displacement sensor, a displacement-voltage transmitter, a PC bus 12-bit conversion board and other components installed in one body to form a height measuring device, which is installed on the shell of the multifunctional roller.

In order to meet the requirements of different processes, the lasers described in the present invention can be He-Cd lasers, CO2 lasers and lasers with other wavelengths, and the output power depends on the process requirements. The multiple reflecting mirrors and focusing mirrors of the optical path can be replaced according to the lasers with different wavelengths.

The working principle of the present invention is briefly described as follows: firstly, according to the needs of the user, select the appropriate process mode, install the feeding device of the corresponding process, a special workbench, as well as the laser and the corresponding optical lens, and use the computer to determine the structure of the parts to be formed. And process parameters are set, and through corresponding software processing, computer instructions for controlling the numerical control system and corresponding control units are obtained, real-time processing is controlled, and the pre-set process is automatically realized.

The invention can complete various RP processes such as LOM, FDM, SLS, and SLA. Like other RPM molding systems, the software system of the present invention is also composed of three parts: CAD modeling software, data inspection and processing software and monitoring system software, CAD modeling software is responsible for the geometric modeling of parts, support structure design and STL file output, etc.; The data inspection and processing software inputs STL files, checks its rationality, corrects errors, performs geometric transformation, selects the forming direction, and performs entity layering; the monitoring system software completes layering information input, processing parameter setting, part layout merging, and generation NC code, control real-time processing, etc. The software system of the present invention should comprehensively consider the forming requirements and characteristics of various RP processes, and automatically realize various RP processes. The present invention has the following remarkable features: 1) The performance-price ratio of the equipment is higher than that of any existing forming equipment (the cost of integrating a new process is less than 20% of the equipment cost), which greatly reduces the investment level of users. 2) A variety of RP processes can be completed on one multifunctional equipment to meet the various needs of users. 3) Research and integration of new forming processes can be carried out on this equipment.

Description of the drawings: Figure 1 is a schematic diagram of the existing LOM technology structure Figure 2 is a schematic diagram of the overall structure of an embodiment of the present invention Figure 3 is a schematic diagram of the principle of the control system of this embodiment Figure 4 is the temperature regulation of the control system of this embodiment Unit schematic diagram Figure 5 is a schematic diagram of the height measurement and control unit of the control system of this embodiment Figure 6 is a schematic diagram of the X-Y scanning unit and Z-direction feed unit of this embodiment Figure 7 is a structural schematic diagram of the multifunctional roller of this embodiment Figure 8 is a schematic diagram of this embodiment Figure 9 is a schematic diagram of the multifunctional roller of this embodiment working in the SLS process Figure 10 is a schematic diagram of the multifunctional roller of this embodiment working in the LOM process 11 is a schematic diagram of the multifunctional roller of this embodiment working in the SLA process. FIG. 12 is a schematic diagram of the automatic wire feeding device of this embodiment. FIG. 13 is a schematic diagram of the automatic paper feeding device of this embodiment. FIG. 14 is a schematic diagram of the assembly of the optical path system of this embodiment Fig. 15 is a schematic diagram of the structure of the focusing mirror base in the optical system of this embodiment. Fig. 16 is a schematic diagram of the structure of the optical mirror base in the optical system of this embodiment. Fig. 17 is a schematic diagram of the electromagnetic shutter in the optical system of this embodiment. Basic workbench and special workbench assembly diagram The descriptions of the symbols in the drawings are as follows: 1. Benchmark platform 2. Optical platform 3. Optical mirror holder 4. Electromagnetic shutter 5. Auxiliary feed roller 6. Wax feeding roller 7. FDM nozzle (non-working state) 8. FDM nozzle (working state) 9. X guide rail slider 10． Y rail motor 11. Y guide rail12. X-rail 13. Y guide rail slider 14. Focusing mirror 15. X rail motor 16. Powder box 17. Multifunctional roller 18. laser19. Synchronous toothed belt 20． control button 21. Computer monitor 22. mouse23． Computer keyboard 24 computer mainframe 25. Driven paper roller 26. Multifunctional workbench 27. Active delivery roller 28. Z guide rail 29． Z guide rail slider 30． Processing room door 31. Auxiliary toolbox 32. Insulation board 33. air intake hole 34． Vent 35. Processing room observation window 36. SLS auxiliary workbench37. piston38． SLS standard accessories 39． Foil material (paper, plastic film, etc.) 40 Transmission motor 41 of multifunctional roller Fastening screw 42. Main drive gear 43. Clutch handle 44. Reduction gear 45． Bearing 46． Multifunctional roller base 47． Temperature measuring element 48. Heating element 49. The hanging place of the powder box 50 The fixing place of the altimeter 51. Bearing 52． Powder for SLS53. Electromagnet 54． Block 55． altimeter 56． Roller 57． Paper receiving motor 61. Optical mirror base 62 . Hold the nut 63． Support sleeve 64. Optical lens holder 65． Mirror frame fixing nut 66． Optical lens seat 67． Optical lenses68． Optical lens seat fixing nut 69. Auxiliary workbench 70． Fastening screw 71. SLA standard workbench 72． Solidified shaped objects 73. Scraper 74． Processing table positioning device 75. Scraper connecting plate 76. 77 Resin tank 78 at the connection between the connecting plate and the multi-functional roller. Resin discharge port 79 Resin 80. Wax silk 81． Wire feed wheel 82． Liquefier 83． Nozzle 84． Formed wax layer 85 . Formed paper 86． Standard parts of LOM (200×200mm) 87. Standard parts of LOM (150×150mm) 88. Standard parts of LOM (250×250mm) 89. FDM's standard work platform 90SLS with standard accessories 91 support plate 92. Optical lens holder 93 . Connection sleeve 94． Tighten the nut 95． Support long sleeve 96． Focus lens cover 97． Focus on the environment 98． Optical lens seat 99. Optical lens cover 100． Optical lens101． Nut 108． Upper iron core 109． Upper electromagnetic coil 110． Electromagnetic block 111 . Lower electromagnetic coil 112 . Lower iron core 201． Delivery roller 202 . Layer perimeter and crosshatching 203 . Focusing device 204 . lens 205． Laser 206． Heating roller 207． computer 208． paper209． Feed roller

The present invention designs a multi-functional equipment embodiment that can complete multiple rapid prototyping processes, as shown in Figure 2, a schematic diagram of the overall structure of an embodiment of the present invention, and is described in detail in conjunction with the accompanying drawings as follows: 1. The overall structure

Present embodiment is a large box body structure, overall structure as shown in Figure 2, box body is separated into left and right two parts with dividing plate in the box, and right part is an open structure, places computer monitor 21 respectively, main computer 24 and Auxiliary tool box for special workbench, feeding unit, etc. The left part is a multifunctional processing room with a closed structure. Two planar supports are set in the processing room to divide the indoor space into upper, middle and lower parts. The upper support is equipped with an optical platform 2, and a laser 18 is installed. Optical lenses, X-Y-Z three-way guide rail system, wax supply device 6, FDM nozzle 7, etc.; the middle bracket is equipped with a synchronous toothed belt 19 transmission device and a multi-functional roller 17, and the powder spreading box 16 is mounted on the roller; Paper device, basic working platform 26 is installed on the slide block of Z guiding rail 28.

This embodiment needs to meet the requirements of various forming processes. In fact, the basic requirements of the overall parameters of various forming processes are the same. Therefore, under the premise of ensuring the basic requirements, taking into account the special requirements of some forming processes, the overall parameters are determined as follows: a) The forming size is determined as: 250mm×250mm×250mmb) The requirements for the scanning speed of the CNC system are slightly checked by different processes Different, determine the highest scanning speed: 500mm/sc) Many processes require CO2 lasers and corresponding optical path systems. Considering the matching of scanning speed and laser power, the system uses 40W CO2 lasers and corresponding power supply and cooling systems. two. System Control Circuit

Fig. 3 is a schematic diagram of the control circuit of this embodiment. The 486 industrial computer controls the X and Y motors that complete the plane scanning and the Z motor that lifts the worktable through the OEMAT6400 numerical control card. In addition, the control signal sent by the numerical control card is converted into the control signal sent by the multiplexer through the I/O port of the industrial computer. Perform gating to control the paper feeding motor, heat press motor, laser control system, FDM wire feeding motor and auxiliary wire feeding motor respectively. The computer also sends signals through the I/O port to control the total power supply, lasers, etc., controls the WEST temperature controller through the 485 interface, and performs height measurement control through the 12-bit A/D port.

The temperature control circuit of this embodiment includes: a Pt-100 platinum resistance temperature sensor, a solid state relay switch of a resistive heating actuator, a West temperature controller (including setting, display, etc.) and corresponding interface circuits. As shown in Figure 4. The West thermostat itself has the function of PID self-tuning and self-regulation. In order to get a better temperature control effect, choose the combination of fuzzy control and PID (FUZY&PID). At the same time, for unified and coordinated control, the upper computer must be able to easily query and modify parameters, such as setting temperature values. Therefore, the management software of the upper PC needs to realize the control of the lower West table through the communication interface.

The height measuring device of this embodiment includes a displacement sensor, a displacement-voltage transmitter, and a PC bus 12-bit A/D conversion board. Mounted on a multipurpose roll stand. As shown in Figure 5: when there is a change in displacement, the detection transformer in the displacement sensor produces a certain voltage change, and the displacement-voltage transmitter converts this signal through A/D to obtain the displacement change value, according to The change of this displacement is used to control and ensure that the current processing layer is always on the focus plane. three. multifunctional processing room

A schematic diagram of the processing chamber is shown in Figure 2. The shaping of the prototype is done in the processing room. Each forming process requires a specific environmental requirement, and the multifunctional processing chamber of this embodiment provides the following necessary conditions for various forming processes. a) Temperature conditions When forming, the material should be preheated, and at the same time, in order to reduce the temperature difference between the formed material and the unformed material to prevent warping and deformation, the temperature in the forming room should be appropriate. If the temperature is too high, it will affect the normal operation of the motor, small guide rail and lead screw; if the temperature is too low, the work efficiency will be reduced. Therefore, the processing room uses heat insulation boards for heat insulation and heat preservation, and a temperature control unit is required to control and adjust the temperature. The temperature of the multifunctional processing chamber is generally controlled within the range of 40-50°C. b) Atmospheric conditions When high energy density CO2 laser is used for forming processing, it is often accompanied by strong oxidation reaction, which is very detrimental to the surface quality of parts after forming. To avoid this, it is necessary to control the atmosphere in the processing room . This embodiment adopts the method of passing nitrogen to the processing chamber, so the processing chamber is an airtight structure and has an inflating device. c) Exhaust gas The forming process is often accompanied by some gas with pungent odor. In order to ensure the normal processing conditions in the processing room, the waste gas should be discharged in time. Therefore, an air extraction device is designed in the processing chamber. Four. X-Y scanning system and Z-direction feeding system

The X-Y scanning system and the Z-direction feeding system of this embodiment are composed of X, Y, and Z three-way guide rails. As shown in Figure 7, the X-Y scanning system is composed of two guide rails driven by ball screws. When the motor 15 rotates, the transmission of the ball screw makes the slider 9 move in the X direction. Since the motor 10 and the guide rail 11 are fixed on the slider 9, the guide rail 11 also moves in the X direction; when the motor 10 rotates, the slider The block 13 moves along the Y direction, and a laser focusing mirror or a nozzle for FDM process can be installed on the slider 13 . Control the joint movement of motor X and Y to drive the laser focusing head or nozzle to scan the plane along the predetermined path to form a physical layer of the prototype. The Z-direction feed system is composed of motor Z, ball screw and slider. The workbench is installed on the slide block. When the motor Z rotates, the slide block Z moves along the Z direction through the transmission of the ball screw, thereby completing the lifting movement of the workbench. When Z feeds (drops) the thickness of one layer of forming material to the worktable, another layer of processing can be carried out. The basic workbench is fixed on the slider of the Z axis, driven by a stepping motor, and driven by a high-precision ball screw to move the workbench along the Z direction (height direction). It has good rigidity on the one hand and high positional accuracy on the other hand. five. Integrated rolling, scraping, feeding device

Although the forming materials of various rapid prototyping processes are diverse, they can be divided into four types according to the form of materials: filamentous, powdery, flake, and liquid. The comprehensive action process on materials can be roughly divided into: material conveying, paving (powder material), compaction (sheet material), heating (powder material or sheet material), and scraping of the liquid surface. Therefore, an integrated rolling, scraping and feeding device is required, which are installed on the datum platform. 1) Multifunctional roller:

The structural diagram of the multifunctional roller is shown in Figure 7, which integrates functions such as rotation, heating, pressing, and scraping. The rotating speed of motor 40 in the figure can be controlled by computer, and motor 40 drives roller 56 to rotate through deceleration transmission system, and there are heating element 48 and temperature measuring element 47 inside the roller, so that the roller can keep a certain temperature, by adjusting roller 56 and workbench The gap can realize the pressurization effect on the material. Some detachable mechanisms are also designed on the roller, such as the hook-type structure for installing the powder spreading box 16 and the height gauge 55, as shown in Figure 8, which can be installed on the upper end surface of the roller shell for the SLA process The scraping device, as shown in Figure 7.

For the SLS process, the multifunctional roller provides powder feeding, rotation and pressing functions. As shown in Figure 9, the upper powder box can be mounted on the front portion of the multifunctional roller. When the synchronous toothed belt drives the multifunctional roller 17 and the powder box 16 to reach the work surface, the computer controls the electromagnet 53 Action, open the baffle 54 of powder spreading box, powder is spread on the workbench. Subsequently, the clockwise-rotating roller 56 reaches the working surface, and the powder is paved and compacted (the clockwise-rotating roller has an upward effect on the powder, which can ensure that the powder is evenly spread). In order to ensure that the powder of this layer has normal processing conditions.

For the LOM process, the function of the multifunctional roller is to heat and press the paper, as shown in Figure 10, to ensure that this layer of paper is firmly adhered to the previous layer of paper and when the leveling roller is working, the powder spreading device 16 can be removed. At the same time, the clutch handle 43 is opened, so that the motor 40 and the roller 56 lose the transmission and clutch relationship, and the heating element 48 and the temperature measuring element 47 in the roller are controlled to work (the temperature measuring element can also be installed outside the roller), and the roller is adjusted. The gap between the cylinder 56 and the workbench is installed, and the altimeter 55 is installed, and the LOM process can be carried out.

For the SLA process, after the current liquid surface is cured for one layer, due to the lifting movement of the worktable, bubbles and other defects that are not conducive to the laser curing of the next layer will appear. Thereby it is necessary to scrape the liquid surface. As shown in Figure 11, the scraping device is fixed on the multifunctional roller 17. When the synchronous toothed belt 19 drives the multifunctional roller 17 to move, the scraper 73 will smooth the liquid surface. Scraping treatment.

For the FDM process, the surface does not need to be treated, but the height of the material surface is only required to be inspected. Therefore, when the multi-function roller moves to the worktable, the height measuring device 55 detects the height of the formed material to ensure the height of the parts. 2) Automatic wire feeding device The automatic wire feeding device is the key to the FDM (wax deposition forming) technology, as shown in Figure 12. The automatic wire feeding device includes a wire coil, an auxiliary wire feeding roller 6, a nozzle 7, and the like. The driving force of wire feeding comes from the wire feeding wheel 81 driven by the motor on the spray head. When the wire feed wheel 81 moves, the wax wire 80 on the silk roll is sent into the FDM nozzle. When carrying out the FDM process, take off the fixed focusing mirror base 14 on the Y guide rail slider 13 and replace it with the FDM nozzle 8 and fix it and connect the wax wire to carry out the FDM process. 3) Automatic paper feeding device The automatic paper feeding device consists of a driven paper roller 25, an active paper delivery roller 27, an auxiliary paper feeding roller 5, a paper delivery motor 57 and corresponding control circuits. As shown in Fig. 13, the paper roll is contained on the driven paper roller 25, and the paper is passed through the auxiliary paper feeding roller 5, the workbench, the auxiliary roller 5, and onto the driving paper delivery roller 27. After each layer of paper is processed, the paper delivery motor 57 rotates an angle under the control of the computer (this angle decreases proportionally with the increase of the radius of the paper delivery roll). six. The multi-functional laser optical path system needs laser as the processing source in many rapid prototyping processes. Therefore, the optical path system must not only ensure that the laser beam can scan the X-Y plane, but also meet the general requirements of being able to adapt to different wavelength lasers. The optical path system is installed on the optical platform. Above, as shown in Figure 14.1) Optical mirror mounts suitable for various lasers

In FIG. 14 , the optical mirror base 3 is respectively installed on the optical table 2 , the X guide rail slider 9 and the Y guide rail slider 13 of the numerical control system. The optical mirror seat is used to lay the optical reflector, and the reflector and the focus mirror will be placed on the focusing mirror seat 14. The laser beam is reflected by the mirror and focused on the processing plane (focal plane) by the focusing mirror. By controlling the coordinated movement of the sliders on the X and Y of the numerically controlled guide rails, the optical mirror seat on it is made to move accordingly, so that the focused laser can complete the predetermined planar movement on the processing plane. For LOM and SLS processes, CO2 lasers (laser wavelength of 10.6 microns) are required; for SLA processes, He-Cd (helium cadmium) lasers (laser wavelength of 325 nm) are required. Therefore, it is necessary to be equipped with total reflection mirrors and focusing mirrors suitable for different wavelength lasers. In the design of the mirror base, the structure that facilitates the installation of different lenses is considered. As shown in Figures 15 and 16, Figure 15 is a schematic view of the focusing lens holder, the focusing lens holder 14 is fixed on the slider 13 of the guide rail Y through the support plate 91, the optical lens 100 is placed in the optical lens holder 98, and the optical lens cover 99 Tighten; focusing lens 97 is placed on the bottom of supporting long sleeve 95, and is tightened with focusing lens cover 96. The optical lens frame 92 and the connecting sleeve 93 are locked by threaded connection, and the supporting long sleeve 95 has a certain range of movement in the axial direction in the connecting sleeve 93, so as to ensure that the position of the focus lens can be adjusted after the laser beam is focused to ensure that the focus is at Utilize the hold nut 94 on the working table to lock the long supporting sleeve 95 and the connecting sleeve 93. The adjusted optical path should ensure that the reflection of the laser beam by the mirror 100 is focused on the working plane through the focusing mirror 97 along the axial direction of the connecting sleeve 93 and the supporting long sleeve 95 . The structural diagram of the optical mirror base is shown in Figure 16. 2) Electromagnetic shutter

In the optical path system, we also have an electromagnetic shutter 4, as shown in Figure 17. The iron core is magnetized by energizing the electromagnetic coil to form an electromagnet, which is controlled by the relay to energize the upper electromagnetic coil 109 to generate magnetic attraction to the electromagnetic stopper 110, so that the electromagnetic stopper moves upward rapidly, even if the laser beam passes through; the lower electromagnetic coil is controlled 111 is energized, and when the upper electromagnetic coil 109 is de-energized, the electromagnetic block 110 moves downward rapidly to cut off the laser beam. Therefore, by controlling the movement of the electromagnetic stopper, the on and off of the laser beam can be controlled. On the one hand, this is the requirement of some forming processes. When the laser cutting and scanning process stops, the laser beam is quickly turned off to ensure good forming quality. ; At the same time, it can also avoid the reduction of laser life due to frequent switching of the laser; in addition, under non-forming conditions, the laser beam is controlled to turn off to ensure the safety of the operator. seven. multifunctional workbench

According to the principle of layered discrete stacking of rapid prototyping, each time a layer is processed on the workbench, the workbench must be moved along the direction of layering (height direction) to produce a single-layer feed motion. For different processes, the properties of the material are different. For example, the material of LOM is lamellar, the material of SLS is powdery, the material of FDM is filamentous, and the material of SLA is liquid. Therefore, we have invented a multifunctional The workbench is suitable for different forming processes.

As shown in Figure 18, the workbench is a hollow frame, on which different standard platforms (accessories of different standards) can be placed, so as to assemble forming platforms suitable for different rapid prototyping processes. The multifunctional workbench has the advantages of standardized accessories and convenient disassembly and assembly. After the processing and forming are completed, the standard fitting and the formed parts on it can be taken out from the workbench. Installing the standard accessories 86, 87 and 88 on the workbench constitutes the forming platform required for different parts forming sizes (respectively 150×150mm, 200×200mm, 250×250mm) in the layered solid manufacturing technology . Standard accessories 89 are installed on the workbench to form the required forming platform in the melting wax accumulation forming process. The standard accessory 90 is installed on the workbench and matched with the piston to constitute the required forming platform in the laser sintering forming process. Main performance indicators of this embodiment 1. Maximum forming part size: 250×250×250mm2. Two-dimensional scanning speed (maximum): 500mm/sec. 3. Two-dimensional scanning and lifting platform stop accuracy: <0.01mm/100mm4. Realization of temperature control: multi-point preset, adjustable from room temperature to 300±2℃ 5. RP process that can be completed automatically: LOM (SSM), SLS, FDM6. Other processes can be integrated: such as SLA, 3DP, etc.

Claims (10)

1. A multi-functional equipment that can complete a variety of rapid prototyping manufacturing processes. It is mainly composed of a processing room, a computer that regulates the functions of each component in the processing room, and a corresponding control unit. The processing room includes at least a laser and X-Y The scanning unit moving in the Z direction, the height measuring unit, the synchronous toothed belt and the heating roller driven by it, the basic working platform moving in the Z direction, and the foil conveying device are characterized in that the processing chamber is a closed box type multiple The functional processing chamber is equipped with air supply and exhaust devices, and also includes a horizontally placed optical platform, a reference platform and a Z guide rail fixed on the side wall of the processing chamber, and the laser and the X-Y direction are installed on the optical platform. The guide rail, on the optical platform and the slider of the X-Y guide rail, is equipped with an optical path composed of multiple optical lenses and focusing mirrors to form the scanning unit, and installs the basic working platform on the Z guide rail slider. A synchronous gear belt and a heating roller are installed on the platform. The heating roller is a multifunctional roller composed of a roller driven by a motor and a transmission device and a shell. The shell is a shell with a long slot at the bottom. Appropriate parts are provided with a hooking device and a height measuring device. The roller is installed in the shell, and the radial side wall of the roller exposes a proper width from the notch of the shell. The roller is equipped with a heating element and a temperature measuring element. 2. The multifunctional equipment capable of completing multiple rapid prototyping manufacturing processes as claimed in claim 1 is characterized in that feeding devices suitable for different process requirements can be installed through the hooking device of the outer shell of said multifunctional roller. 3. The multifunctional equipment capable of completing multiple rapid prototyping manufacturing processes as claimed in claim 2 is characterized in that said feeding device at least includes a powder spreading device and a scraping device. 4. The multifunctional equipment capable of completing multiple rapid prototyping manufacturing processes as claimed in claim 1 is characterized in that it also includes an FDM nozzle fixed on the Y guide rail slider. 5. As claimed in claim 1, 2 or 3, the multi-functional equipment capable of completing multiple rapid prototyping processes is characterized in that said basic working platform is a frame structure, which can be installed with multiple special-purpose equipment suitable for different process requirements For the workbench, a backing plate is combined under the bottom plate of each special workbench, and the size of the backing plate matches the frame size of the basic working platform. 6. The multi-functional equipment capable of completing multiple rapid prototyping manufacturing processes as claimed in claim 1, wherein said control unit includes an industrial computer as the main body, and is connected to X, Y, and Z three-way through the interfaces of the industrial computer. Guide rail motor drive control unit, feeding device motor drive unit, temperature control unit, forming material height measurement control unit, laser control unit. 7. The multifunctional equipment capable of completing multiple rapid prototyping processes as claimed in claim 1 or 6 is characterized in that said temperature control circuit includes temperature sensors respectively installed in the multifunctional roller and in the working room, and resistive heating actuators, and temperature control units. 8. The multifunctional equipment capable of completing multiple rapid prototype manufacturing processes as claimed in claim 1 or 6 is characterized in that said height measurement control unit includes a displacement sensor, a displacement-voltage transmitter, and an A/D conversion board. 9. The multifunctional equipment capable of completing multiple rapid prototyping processes as claimed in claim 1 is characterized in that said optical mirror mounts are respectively installed on the slide blocks of the optical table and X guide rail, and said focusing mirror mounts are installed On the slider of the Y rail. 10. The multifunctional equipment capable of completing multiple rapid prototyping processes as claimed in claim 1, 2, 3, 4, 6 or 9 is characterized in that multiple rapid prototyping processes can be completed in the multifunctional processing chamber.

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