KR20020032008A - Method and apparatus for rapidly manufacturing 3-dimensional shaped products using machining and filling process - Google Patents

Abstract

PURPOSE: An apparatus and a method for rapidly manufacturing a three dimensional article are provided to rapidly fabricate the three dimensional article or samples by performing milling and filling processes. CONSTITUTION: A workpiece is mounted(601). Front and rear portions of the workpiece are fixed(603) and the left and right portions of the workpiece are fixed(605). Then, an upper surface of the workpiece is subject to a milling process. After pressing a gate plate towards the workpiece(609), filling material is filled and cured(611). The front and rear portions of the workpiece fixing device is released(615) and the workpiece is rotated by 180 degrees about an axis line(617). Then, the front and rear portions of the workpiece fixing device is again fixed(619). In this state, a lower surface of the workpiece is processed. After milling the lower surface of the workpiece(621), the workpiece is released. After that, the filling material is withdrawn(625) and a sample is achieved.

Description

Rapid manufacturing method and apparatus for three-dimensional products using cutting and filling processes {METHOD AND APPARATUS FOR RAPIDLY MANUFACTURING 3-DIMENSIONAL SHAPED PRODUCTS USING MACHINING AND FILLING PROCESS}

The present invention relates to a method and apparatus for manufacturing a three-dimensional product using a cutting process.

Rapid production of three-dimensional products refers to the rapid production of the same materials as the materials actually used for the products. Products manufactured according to this manufacturing process are called rapid products. This includes prototypes (mock-ups) that have been built before. If the mass production product requires complex geometric shapes and precision, the rapid product, which is a prototype, must also have a complicated geometric shape, and the precision of the prototype is also very strictly required.

The existing processing method for manufacturing such rapid products is to perform rapid molding process by using Rapid Prototyping (RP). This processing method is a method of hardening a liquid photocurable material by irradiating a laser beam to produce a three-dimensional shape, and a method of joining granular or layered solid materials in a desired shape. It can be divided into two types. (For reference, the rapid molding process refers to a process of directly forming a prototype or mold of a three-dimensional shape directly from three-dimensional CAD data using various non-metallic and metal materials such as paper, wax, ABS, and plastic. Various processes are being developed using metal powder and metal wire.)

Stereolithography (SLA; 3D Systems) is a method of stacking layer by layer by selectively irradiating and solidifying a laser beam onto a liquid photopolymer. In this method, the laser beam is locally irradiated (3D Systems Inc.-SLA, Quadrax Inc., Sony Inc., Dupont Inc., etc.), or one layer at a time using an ultraviolet lamp (Cubital Inc.-SGC, Light Sculpting Inc., etc.). There are two methods and it is the most commonly used rapid rapid molding process. However, the cured photocurable resin shrinks during curing, which may cause warpage. In the case of manufacturing a part having protrusions, the cured resin may be formed in a liquid resin container. You need a support to prevent it from falling. Since the material used is resin, its strength is low and it is difficult to use as a functional material.

Methods for manufacturing shapes using powder materials include selective laser sintering (SLS; DTM) and 3D printing (3DP; Solingen, Z Corp., etc.-MIT development). have. In the selective laser sintering molding process, a powder material of plastic resin is applied, and a product is manufactured by bonding a powder by irradiating a laser beam. Metal parts or molds may be manufactured using iron powder coated on the surface of plastic resin. However, post-treatment such as sintering, copper infiltration, etc. is required in the production of metal parts and molds. Shrinkage due to thermal deformation occurs during the post-treatment process, making it difficult to achieve dimensional accuracy.

In the 3D printing process, the product is made by selectively spraying a liquid binder onto the applied powder. Currently, ceramic shells for investment casting can be directly made from ceramic powders, or parts can be manufactured using powder materials based on starch components. In this process, post-treatment is essential to increase the density and strength of the product, so shrinkage due to thermal deformation occurs.

Laminated Object Manufacturing (LOM; Helisys) manufactures parts by repeating the process of bonding thin paper using a heated roller and cutting it with a laser. This method has the advantage of low cost because the material is paper, but has the disadvantage that it takes a lot of time to remove the parts after manufacturing. Currently, plastic sheet material is developed to produce plastic parts, but it is difficult to remove parts like paper.

Fused Deposition Manufacturing (FDM; Stratasys, Inc.) manufactures components by filament-like plastic resin materials that pass through a heated nozzle, similar to an extrusion die, to be melted and glued together. . The disadvantage is that the surface is rough because of the use of filamentary materials.

Rapid forming processes for directly manufacturing parts or molds of functional materials such as metals are as follows. Recently commercialized Laser Engineered Net Shaping (LENS ^™ ; developed by Optomec, Sandia National Lab.) Locally uses a laser beam to locally heat the metal substrate to create a small melt pool where the metal powder is located. The parts are manufactured by dropping them with gas. In this case, since the parts are manufactured by completely melting the metal, there is a disadvantage in that the dimensional accuracy is lowered due to the severe deformation during solidification. In addition, it is impossible to make parts with protrusions or cantilever shapes.

Shape Deposition Manufacturing (SDM; Stanford Univ, Carnegie Mellon Univ) combines metal deposition and CNC machining. In this method, metal is first welded and then processed using multi-axis CNC cutting to have the desired thickness and boundary shape, and the remaining part of the same layer is filled with another metal material, and then CNC machining is completed to complete one layer. After one layer is completed, shot peening is performed to remove residual stress. This process is repeated to produce the desired parts. This method has a drawback in that it takes a lot of time to manufacture the part because it involves a number of processes.

Such molding methods are complicated in their processes. It is only possible to manufacture precise final products through various processes with expensive equipment (especially foreign equipment). Perfect three-dimensional shape machining also has its limitations, and this method of processing must be followed by post-production. There is a problem that can cause environmental problems due to the limitation of the material used.

It is an object of the present invention in view of this point to provide a method and apparatus capable of rapidly manufacturing a three-dimensional product capable of producing a prototype or producing a small quantity of various kinds.

Another object of the present invention is to manufacture a three-dimensional shape of a plastic or metal by using a cutting and filling process, to provide a manufacturing method that is simple and does not require a post-process.

1 is a process flow diagram for explaining the principle of rapid production of three-dimensional products

Figure 2 is a perspective view showing a rapid manufacturing apparatus according to an embodiment of the present invention

Figure 3 is a block diagram of a charging device provided in the rapid manufacturing apparatus according to the embodiment of the present invention

Figure 4 is a perspective view showing a workpiece installation apparatus provided in the rapid production apparatus according to an embodiment of the present invention

5 (a), 5 (b) and 5 (c) are conceptual views shown for explaining various work installation devices.

6A and 6B are flowcharts of rapid manufacturing methods of a three-dimensional product according to an embodiment of the present invention.

7 is a flowchart showing each process of the rapid manufacturing method of the three-dimensional product (fan) according to another embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

10: Rapid Producing Device 16: Machining Tool W: Workpiece F: Filling Material

In order to achieve the above object, the present invention provides a method of manufacturing a three-dimensional article,

As a method of manufacturing a three-dimensional article,

(1) mounting the workpiece to the workpiece installation apparatus so that the portion to be cut is directed to the cutting tool;

(2) cutting the portion to be cut with a cutting tool;

(3) filling the filling material into the space formed by cutting;

(4) moving the workpiece such that the other part to be cut is directed toward the cutting tool;

(5) cutting other parts with a cutting tool;

(6) comprising the step of separating the filler,

Steps (2), (3) and (4) provide a method of manufacturing a three-dimensional article that is performed once or repeated two or more times.

According to another aspect of the present invention, an apparatus for manufacturing a rapid product using a cutting tool, the processing apparatus provided with a cutting tool, the transfer table device, the workpiece installation device provided on the transfer table device, the transfer table device and the A control device for controlling the relative movement of the cutting tool is provided, the transfer table device to transfer the workpiece in synchronization with the cutting tool, the workpiece installation device mounted to the transfer device and the rotating shaft portion coupled to the transfer device; And a workpiece fixing portion for holding a workpiece is provided.

In general, the cutting process is large, the processing time is short, the product processing surface is uniform, it is possible to remove the styrofoam, wood, plastic and metal.

In the cutting process, the removal of the workpiece is dependent on the type of tool used, but almost no heat affected zone near the cutting surface boundary is achieved by using cutting oil. Therefore, by controlling the machining speed and the moving speed, it is possible to control the machining depth and direction of the three-dimensional shaped part. In addition, in recent years, high-speed processing technology is generalized, it is desirable to use it. However, in the conventional processing method using cutting, only one surface can be processed like the mold surface, and thus it is impossible to process a three-dimensional prototype in the full sense. Therefore, in the present invention, the processed surface is filled with a filler to overcome such limitations, and it is possible to repeatedly process another processing surface using its bonding force. By repeating this procedure, machining of complete three-dimensional complexities is possible in a short time and with high precision.

A representative example of the manufacturing process of the present invention is briefly described as shown in FIG. That is, ① fix the stock to the workpiece installation device. ② First, cut the upper surface (roughing, finishing). ③ Fill the first processed upper surface with filler (FILLER; also referred to herein as filler). ④ Rotate the second back side in the cutting direction (ie to face the tool). (5) Perform cutting (roughing, finishing), and filling of the filler. ⑥ Separate the filler and complete the final prototype.

Referring to Fig. 2, a manufacturing apparatus 10 for processing a rapid product is shown centering around the cutting apparatus 12 and the workpiece mounting apparatus 14. The cutting device 12 of the rapid production device 10 includes a cutting tool 16. The cutting tool 16 can move in up, down, front, back, left and right directions. This movement of the cutting tool 16 is controlled by the controller 18. The production apparatus 10 is further provided with a workpiece transfer table apparatus 20 capable of transferring the workpiece, and a workpiece mounting apparatus is mounted on the table 20.

The cutting device 12 is a general NC cutting device. Use a CAM program created using CAD data for NC cutting. Cutting tools also vary widely for tool diameters used for general light and heavy cutting, depending on the material and conditions. Spindles used are also commercialized for low speed, medium speed and high speed. Especially in the case of high speed machining, the diameter of tool (eg end mill) is mainly used in 0.1 to 6.0 mm, and the spindle speed is mostly in the range of about 8,000 to 40,000 rpm, but some parts are developed up to 150,000 rpm.

As the control apparatus 18, Japanese Fanak and German HEIDENHAIN are typical, but any can be used according to a cutting machine. Preferably, it can be used as a direct operation from a PC. Although the degree of control depends on the processing environment and the required precision, the PC-based control system is somewhat uniform and the device is simple.

The workpiece transfer table apparatus 20 can use a normal thing which can linearly move a workpiece or rotate (rotate) a workpiece. The work transfer table apparatus 20 is provided with a work set-up equipment 14.

Referring to Fig. 3, the filling device 22 is provided on the workpiece mounting device 14 to fill the cut portion of the workpiece after cutting. The filling device 22 melts the filling material and supplies it to the workpiece. The filling device 22 has a filler tank 24, a supply tube 26 and a heating wire which is a heating device 28. In addition, the injection device 30 is provided to inject the filler to fill the processed surface of the workpiece. The injection device 30 is provided with a cylinder 32 and a piston 34. At the end of the tube 26 is a reservoir (to provide a generally large space between the tube and the gate plate, which will be described later, which is widened to supply filler through the gate plate. In general, the outlet area corresponds to the area of the gate plate. 36 is provided, and a plurality of holes are provided as gate plates 38 (flat plates, which uniformly flow out the injection (injection) from the reservoir 36, through which the filler material is provided). Is supplied). The heated heater 28 is disposed around the filling tank 24, the tube 26, the reservoir 36 to supply heat to the filler material in the apparatus to improve fluidity.

Workpiece installation device 14 shown in Figures 2 and 3 is shown in detail in Figure 4. The illustrated transfer table 20 includes a left and right fixing device 40 and a front and rear fixing device 44. The workpiece | work W is provided in the center.

5A to 5C are diagrams illustrating the concept of a workpiece mounting apparatus (also referred to as mounting jig and mounting jig). Referring to Fig. 5A, an installation jig 128 is shown. The jig 128 has a rotation shaft 130 and the workpiece fixing part 132. The workpiece W is fixed to the workpiece fixing part 132. In Fig. 5A, the upper surface Wa and the lower surface Wb of the work W are machined. First, the front, rear, left, and right directions of the work W are fixed to the transfer table device 20, and then one surface Wa is cut. When the machining of one side is completed, the filling is rotated 180 ° around the rotation shaft 130. Then, the other surface Wb is cut.

Referring to Fig. 5B, an installation jig 138 is shown. The jig 138 has a rotation shaft portion 140 and the workpiece fixing portion 142. The workpiece W is fixed to the workpiece fixing part 142. In Fig. 5B, four surfaces Wa, Wb, Wc, and Wd forming 90 degrees of the workpiece W are machined. First, the front, rear, left and right directions of the workpiece are fixed to the transfer table device 20, and then one surface Wa of the workpiece W is moved along the x-axis and the y-axis. When the processing (cutting and filling) of the one surface is completed, rotate the 90 ° around the rotating shaft portion 140. Then, the workpiece is processed by repeating the steps of machining and rotating the other surfaces Wb, Wc, and Wd.

5C, jig 148 is shown. The jig 148 has a rotating shaft portion 150 and the workpiece fixing portion 152. The workpiece fixing part 152 is provided with a jaw 152a. The cylindrical workpiece 154 is fixed by the jaw 152a. In Fig. 5C, the workpiece W is machined (cut and filled) at any position, and then rotated by a designated angle and then stopped (machined and cut). This is repeated to machine the workpiece (W).

6A and 6B are flowcharts illustrating a method of manufacturing a product by processing and filling the upper and lower sides fixed to an installation jig having the same concept as that of FIG. 5A.

Fig. 6A shows a procedure of manufacturing the filler F by supplying it from the upper surface side. First, the workpiece (W) is mounted (601). The front-back direction of the workpiece | work W is fixed (603), and the left-right direction is fixed (605). Then, the upper surface is cut (607). The gate plate 38 is pressed (609) toward the work W (to apply force so that the filler does not leak out). Then, the filler F is charged 611 through the gate plate 38 to be cured, and the gate plate 38 is separated. The front and rear directions of the workpiece holding device are separated (615), and the workpiece is rotated (1801) by 180 degrees with respect to the horizontal axis. Again, the front and rear directions are fixed (619). Then, the back surface will be in the state which can be cut. After cutting the back surface 621, the fixed thing in all directions are separated (623) to separate the workpiece (W) from the machine. Thereafter, the filler is separated (625) in an appropriate manner to complete the prototype (627).

Fig. 6B shows a flowchart of a method of rotating and then filling a workpiece after machining the front surface (top surface). First, the gate plate 38 is mounted 649 below. The workpiece W is mounted on the gate plate and installed in the workpiece mounting apparatus (651). The front and rear directions of the work W are fixed (653), and the left and right directions are fixed (655). Then, the upper surface is cut (657). Then, in order to be able to rotate the work W, the gate plate 38 supporting the work is lowered and separated (659). The front and rear directions of the work holding device are separated 661, and the work is rotated 663 degrees 180 degrees about the horizontal axis. Again, the front-rear direction is fixed (665). Thereafter, the gate plate 38 is compressed (667) from the bottom upward. The filler F is then charged 669 through the gate plate to cure. Filling material is supplied from the bottom to the upper space in the upper surface during machining. After cutting the back surface 671, the fixed ones in all directions are separated 673 to separate the work W from the machine. The filler is then separated (675) in an appropriate manner to complete the prototype (677).

Referring to FIG. 7, there is shown a fan, which is an example of a rapid product to be processed. Both sides of the fan have a complex three-dimensional shape. Three-dimensional machine coordinate data for the machined surface of this type of fan can be obtained in the three-dimensional design of the fan. This fan is intended to help the understanding of the present invention and is introduced as an example of a rapid product for the purpose of illustrating the present invention. Therefore, the present invention is not limited only to the processing of the fan. It is a matter of course that other rapid-shaped products can be produced according to the production method of the present invention.

Referring to FIG. 7, there is shown a method of manufacturing a fan, in accordance with an embodiment of the present invention. As shown in Fig. 7A, the workpiece W is fixed to the workpiece mounting apparatus. This workpiece is made of a plastic resin that is actually injected and used, for example, acrylic resin. As already explained in Fig. 2, the cutting tool attached to the NC cutting device can be cut according to the instructions of the machining program. The workpiece, that is, the table feeder on which the workpiece is mounted, is controlled by the position control device. At this time, the workpiece (workpiece) is synchronized with the tool under the control of the control device that controls the feed (ie position). ('Synchronized' here means that the table holding the workpiece in the cutting machine (eg NC milling machine) moves simultaneously in the xy axis, so that the machining tool is automatically machined as long as it rotates.) Yes, the workpiece is cut when the tool is rotated and simultaneously controlled and moved on the xy axis.)

Next, as shown in Fig. 7B, the system is operated. In addition, by selecting a tool according to the workpiece material and precisely positioning the cutting depth and the feed rate to be optimal. As shown in Fig. 7 (b), all regions corresponding to the first machining surface are cut while adjusting the position of the workpiece. At this time, synchronize the position of the workpiece. By synchronously machining these machining positions, complete three-dimensional machining is possible. As shown in Fig. 7 (c), the filled space F is filled in the processed space on the processed surface side. In this case, the filler (F) is a thermoplastic resin, a wax or water that is more easily melted, for example, a soluble support resin (e.g., a soluble support resin) than the plastic resin used as the workpiece (W), for example. Use resins that are soluble in water at room temperature. Alternatively, in the case of a metal workpiece, a material having a lower adhesion temperature than that of the workpiece and having excellent adhesion force (for example, a bismuth alloy material in the case of aluminum) is used.

As shown in Fig. 5 (d), the workpiece mounted on the workpiece mounting apparatus is rotated 180 degrees. In other words, the second surface to be machined is rotated and fixed by the workpiece installation device to position the cutting surface. Thereafter, as shown in Fig. 5E, the second surface is cut as in the previous step. Then, all the surfaces to be processed are cut. At this time, the workpiece is processed to be a complete three-dimensional fan. Thereafter, the filler is separated to complete a fan, which is the final product (P). The filler can be removed from the processed pan by dissolving in water when using the above-mentioned resin. The filler in the above embodiment serves as a general jig that allows the workpiece to maintain its shape until processing is complete.

On the other hand, it may be easy to separate between the filler and the workpiece in a manner different from melting. For example, in the embodiments described above, the cotton to be left as a fan and the filler may be applied before the separation chemical is filled. Then, the filler and the finished pan can be easily separated later.

Although the present invention has been described with reference to the above embodiments, the present invention is not limited thereto. Those skilled in the art may make modifications, changes, and the like without departing from the spirit and scope of the present invention, but it will be understood that such modifications and changes also belong to the present invention.

According to such a structure of this invention, a three-dimensional rapid product can be processed using a cutting process and a filling process. In particular, the manufacturing method of the present invention is suitable for producing plastic or metal prototypes or producing small quantities of various kinds quickly. The process of manufacturing a three-dimensional rapid product is simplified, and a prototype of a three-dimensional plastic resin or metal can be manufactured without a separate mold. In addition, by using the workpiece mounting apparatus of the present invention, it is possible to easily produce three-dimensional prototypes by processing each side of the rapid product.

Claims (8)

As a method of manufacturing a three-dimensional article, (1) mounting the workpiece to the workpiece installation apparatus so that the portion to be cut is directed to the cutting tool; (2) cutting the portion to be cut with a cutting tool; (3) filling the filling material into the space formed by cutting; (4) moving the workpiece such that the other part to be cut is directed toward the cutting tool; (5) cutting other parts with a cutting tool; (6) comprising the step of separating the filler, The steps (2), (3) and (4) are performed once or repeated two or more times. The method of claim 1, wherein the workpiece is transferred but synchronized with the cutting of the tool. The method of claim 1, wherein in the filling step, a filler is supplied at an upper portion of the cut space in the cut portion. The method of claim 1, wherein in the filling step, a filler is supplied from the uncut portion to the processed space. The method of claim 1, wherein the workpiece is a plastic article, and the filler is a thermoplastic resin, a wax or a resin that easily dissolves in water. The method according to any one of claims 1 to 4, wherein the workpiece is an aluminum or aluminum alloy article and the filler is a bismuth alloy. An apparatus for manufacturing a rapid product using a cutting tool, comprising: a processing apparatus provided with a cutting tool, a transfer table apparatus, a workpiece installation apparatus installed on the transfer table apparatus, and a relative movement of the transfer table apparatus and the cutting tool; A control device is provided, and the transfer table device transfers the workpiece in synchronization with the cutting tool, and the workpiece mounting apparatus mounted to the transfer apparatus includes a rotating shaft portion coupled to the transfer apparatus, and a workpiece fixing portion holding the workpiece. An article manufacturing apparatus having a three-dimensional shape comprising a. The method of claim 7, further comprising a filler supply for supplying a filler to the workpiece fixed to the workpiece installation apparatus, The filler supply device is a filler container, a supply tube connected to the container and forming a filler supply path, an injection device provided on the filler supply path, and a flow of the filler material installed near the workpiece and supplied to the workpiece through the tube. A three-dimensional article manufacturing apparatus characterized by comprising a gate member for uniformizing.