Method and device for producing three-dimensional models

Abstract

The present invention relates to a method and a device for producing three-dimensional objects based on computer-provided data. Material is extruded on a surface of a workpiece (e.g., in two-dimensions). The workpiece is then moved incrementally so that additional material can be extruded on the new surface of the work piece. These steps are repeated until the 3-dimensional object is completed. The present invention also relates to a device including an extruder system for extruding a build material in multiple directions on a surface of a workpiece, and a conveying component for moving the workpiece incrementally for extruding additional material on the new surface. The method and device preferably allows for the continuous construction of three-dimensional objects.

Claims

1. A device comprising: i) an application system including an application device for laying a build material onto a surface of a workpiece, for constructing a 3-dimensional object based on computer-provided data; ii) a conveyance system for incrementally moving the workpiece in a generally horizontal direction so that additional build material can be laid onto the surface of the workpiece, wherein the surface of the workpiece is angled relative to the horizontal direction.

2. The device of claim 1, wherein the 3-dimensional object is constructed from a hot-melt material.

3. The device of claim 1, wherein the application system is an extrusion system, the application device is an extruder, and the extruder includes a nozzle.

4. The device of claim 1, wherein the nozzle is computer controlled and selectively dispenses molten material.

5. The device of claim 4, wherein the device includes a second nozzle for extruding a second material for supporting an area of the 3-dimensional object.

6. The device of claim 1, wherein the device includes an unpacking position and the 3-dimensional object is conveyed towards the unpacking position during the construction of the 3-dimensional object.

7. The device of claim 6, wherein a conveyance of the 3-dimensional object proceeds in steps.

8. The device of claim 1, wherein the 3-dimensional object is constructed in a heated atmosphere.

9. The device of claim 1, wherein the-application system provides one or more layers of the build material, wherein each layer is a section of the workpiece.

10. The device of claim 9, wherein the conveyance system engages the workpiece or an additionally laid support structure for moving the workpiece.

11. The device of claim 9, wherein each layer is a planar layer.

12. A method of building a 3-dimensional object with the device of claim 1, comprising steps of: i. extruding a build material on a surface of a workpiece; ii. moving the workpiece in a horizontal direction; iii. repeating steps i) and ii) until the 3-dimensional object is constructed.

13. The method of claim 12, wherein the workpiece is constructed on a build platform.

14. The method of claim 13, wherein a length of the 3-dimensional object is greater than a length of the build platform.

15. The method of claim 12, wherein the method includes constructing a support structure under the workpiece.

16. The method of claim 12, wherein the method includes a step of removing the 3-dimensional object from the workpiece.

17. The method of claim 12, wherein the 3-dimensional object is constructed suing a fused deposition modeling process.

18. The method of claim 12, wherein a second of the 3-dimensional object is constructed.

19. The method of claim 12, wherein the process is a continuous process wherein multiple 3-dimensional objects are constructed sequentially.

20. The method of claim 12, wherein a conveyance unit engages the workpiece and moves the workpiece forward.

Description

(1) In the drawing:

(2) FIG. 1 An isometric view of a device according to the state of technology;

(3) FIG. 2 A sectional view of a device according to the state of technology;

(4) FIG. 3 A sectional view of a build chamber according to the state of technology and an illustration of various component stabilities;

(5) FIG. 4 A sectional view of a preferred embodiment of the invention;

(6) FIG. 5 An illustration on the angle of repose and the transference to a preferred embodiment of the invention;

(7) FIG. 6 An isometric view of one preferred embodiment of the invention;

(8) FIG. 7 A sectional view of a further preferred embodiment of the invention;

(9) FIG. 8 An illustration of possible error sources of devices according to the invention;

(10) FIG. 9 A sectional view of a preferred embodiment of the invention;

(11) FIG. 10 A sectional view of a further preferred embodiment of the invention;

(12) FIG. 11 A sectional view of a further preferred embodiment of the invention for the automatic unpacking of the components;

(13) FIG. 12 An isometric view of a device according to the invention for the automatic removal of particulate material;

(14) FIG. 13 A sectional view of a device according to the invention;

(15) FIG. 14 A plate link belt as conveyance means for the usage according to a preferred embodiment of the invention;

(16) FIG. 15 A magazine belt as conveyance means for the usage according to a preferred embodiment of the invention;

(17) FIG. 16 A perspective view of a method according to a preferred embodiment, which uses film as material;

(18) FIG. 17 A perspective view of a method according to a preferred embodiment, which uses melted plastic as material;

(19) FIG. 18 A perspective view of a method according to a preferred embodiment, which uses a print head to apply build material;

(20) FIG. 19 A drive for layer positioning; and

(21) FIG. 20 A chain-connected extended drive in conjunction with FIG. 19.

(22) FIG. 1 shows a device according to the state of technology. A spreader device (2) applies a layer consisting of particulate material on a build platform (3). At the conclusion, with the aid of computer-provided data, the particulate material is selectively solidified to a component (4) using the solidification apparatus (1), in this case a print head. The vertical direction or also the direction of gravity, which is depicted here perpendicular to the build platform (3), is designated with arrow (5). After solidification the build platform (3) is lowered by one layer thickness and then another layer is created.

(23) In FIG. 2 the same device is depicted in sectional view. Several layers have already been created. A limiting factor during the method according to the state of technology is the build chamber depicted in the figure as (7), which is in this case also the process chamber. After a certain build height (6), the chamber (7) must be emptied or exchanged.

(24) If the solidification is not immediately effected, but rather with a certain time delay, then special circumstances are to be taken into consideration with the method according to the state of technology.

(25) As an example that can be derived from FIG. 3, during unpacking of component (4), the parts that were last created by the solidification apparatus (1) and the spreader device (2) are located above in the build chamber (7). These parts (8) are less solid than the parts (9) and (10) located further below in the build chamber (7). This necessitates a minimum waiting time that must be complied with before unpacking during such a process.

(26) FIG. 4 depicts the first of the preferred embodiments of the invention. FIG. 4 shows a sectional view comparable with FIG. 2. The method sequence is subdivided into sub-steps, namely, commissioning of the device, continuous production of components (4) and shutdown of the device. These phases are described in the following:

(27) Commissioning:

(28) Creation of a basic feedstockThe spreader device (2) applies one layer comparable to that shown in FIG. 1. The layer plane of the particulate material, however, which, with the state of technology, corresponds to a plane that is parallel to the build platform (3), is inclined at an angle in relation to a conveyor belt (11) here.

(29) This coating process is repeated until sufficient filling is present to obtain the desired dimensions for component (4) being manufactured. In this manner a feedstock results, which is smooth on the spreader device side and fissured on the opposite-facing side in accordance with the particulate material properties.

(30) Continuous Build Process:

(31) If a basic feedstock is created, then a continuous build process can begin that only requires termination when the device is stopped for maintenance purposes. The process is designed to a great degree along the lines of the state of technology.

(32) In a process chamber the spreader device (2) creates a layer that forms an angle in relation to the perpendicular (5). At the conclusion, a predetermined quantity of particulate material is selectively solidified using the solidification apparatus (1). The process chamber is in this sense not a delineated room, but rather the space in which the object is built; the object is subsequently removed from this area, respectively process chamber.

(33) The computer data processing must take this arrangement into consideration. The conveyor belt (11) is thereafter moved one layer thickness further so that the feedstock moves out from the spreader device plane and hereby gradually moves out of the process chamber. This process repeats itself until the device is shut down. Located in the feedstock are the components (4), which are ever further removed from the spreader device plane by the infeed movement.

(34) After a certain distance on the conveyor belt (11), the components can be unpacked, while the build process continues uninterrupted in the process chamber. The length of this distance of the conveyor belt (11) hereby depends on the process employed. For instance, cooling is relevant when dealing with sintering processes. The curing time is relevant in cases of chemical solidification mechanisms.

(35) In addition, the ejection of components (4) and the unbound particulate material from special areas may proceed in this area, such as, for example, protective gas atmospheres.

(36) The unpacking itself can take place manually on the device or via discharge of the particulate material.

(37) Shutting Down:

(38) If the device is to be shut down for maintenance purposes, the entire feedstock can be brought on the conveyor belt (11) and out of the process chamber by moving the conveyor belt (11).

(39) The angle (13) between the conveyor belt (11) and the spreader device plane is limited by the angle of repose of the particulate material (FIG. 5). Since an angle greater than the angle of repose (12) is accompanied by an increased risk of particulate material sliding off, the angle selected should be smaller than the angle of repose (12). In so doing, it can be guaranteed that a perfect surface is always available for the build process.

(40) FIG. 6 shows an isometric view of an especially preferred embodiment of the invention. Here can be seen the walls (14) mounted for lateral delimitation of the feedstock. The feedstock runs through and is subjected to frictional forces. These walls enable the device, at the same usable cross-section, to be built smaller than if the particulate material were allowed to laterally flow freely. Outside of the process chamber, the walls (14) can be dispensed with so that a portion of the work required for unpacking the components, namely removal of unbound particle material, can be carried out by allowing the particulate material to freely run off (15) by simply leaving these walls (14) absent.

(41) FIG. 7 shows another preferred embodiment of the invention. The illustration shows a sectional view. The conveyor belt (11) is inclined at a certain angle in relation to the perpendicular (5) here. Viewed horizontally, the plane on which the spreader device (2) and the solidification apparatus move now lies flatter than with the initially described device. On such an embodiment of the invention, particulate materials that exhibit a shallower angle of repose can also be economically processed. The steeper angle in the unpacking area does not disturb because a smooth surface area is not required here. The angle also favors the self-actuating unpacking of components (4).

(42) If the angle of repose (12) is exceeded by the device according to the invention, then the smooth surfaces in the particulate material areas (18) created by the spreader device (2) break out so that no defined surfaces exist any longer for the solidification process. One method to address this problem is described in the following:

(43) Another preferred embodiment of the invention is shown in FIG. 9. Protective structures or auxiliary structures (19) are created via the solidification apparatus (1). These artificially increase the angle of repose (12) of the particulate material. By so doing, difficult particulate materials can also be processed without modification of the device. The horizontal surfaces shown can be used for this purpose.

(44) However, there is no limit placed on usage of other structures, which could exhibit nearly any three-dimensional structure.

(45) FIG. 10 shows the above-described devices with the same corresponding arrangement. In this case, the material extrudate is discharged parallel to the perpendicular. So that the feedstock created by the spreader device (2) does not slip away, plates, represented by floor plates (20), are built by the solidification apparatus (1). These engage with at least two conveyor belts. The remaining walls can be implemented rigidly for delimitation of the particulate material feedstock. Shown below the actual device is another transfer conveyor belt (22) that enables a continuous production process as described in claim 1. The feedstock is taken over here and the components (4) can be removed as the device continues to produce.

(46) The described continuous production principle is also suitable for the construction of an entirely automated production system. This is represented in FIG. 11. In order to enable a robot (24) to grip the components (4), the option exists to attach auxiliary structures (23) with the solidification apparatus, thus facilitating grasping by the robot (24). The position of the components (4) in the feedstock is known from the production principle and can be used for the control of the robot (24).

(47) FIG. 12 shows a preferred embodiment of a conveyor belt (11) to move the feedstock. The conveyor belt (11) itself contains openings (26). Beneath the conveyor belt (11) is a guidance plate (25). This bears the weight of the feedstock and guarantees the accuracy of feedstock movement. The guidance plate (25) has no openings in the area in which the feedstock is created and in the area in which components (4) are subsequently solidified. In the unpacking area, the openings (26) and (27) correspond depending on the position of the belt (11). A portion of the particulate material thus runs off by itself and exposes the components (4).

(48) FIG. 13 shows that with a device according to the invention even components (4) that have very large sizes in one dimension can be produced. Such components must merely be supported if they are longer than the actual size of the device. To this end, additional simple conveyor belts (28) can be provided that take over the component or components (4) at the end of the device.

(49) Further conveyance means are depicted in FIGS. 14 and 15, showing how according to the invention they could be used instead of a conveyor belt.

(50) A plate-link belt is shown as a conveyance means in FIG. 14, while FIG. 15 shows a magazine belt. Plate-link belts have proven to be advantageous conveyance means since they can receive heavier loads than e.g. fabric-based belt conveyors and they additionally exhibit greater rigidity perpendicular to the conveyance direction. In FIG. 14, two various plate-link belts are depicted, which have linked plates (29). The build space (7) could be provided with such conveyance means for objects e.g. in the dashed line area.

(51) The use of magazine belts (see FIG. 15) in a device according to the invention proves advantageous if, in addition to high rigidity, modularity is also required in the conveyor chain. With the aid of such magazine belts, e.g. printed objects can remain on the respective section of the conveyor line, for instance, on the build platform (31), until further use in a magazine (32) after completion of the build-up process and in this manner be separated temporarily from the remaining conveyor chain. The conveyor length can also be relatively freely adapted to the requirements and local conditions by simply either adding additional link plates (31) in the magazine (32) or removing them from there. This can take place e.g. using a cylinder (30), which pushes a link plate out of the magazine and then moves this forward over the conveyor rollers (33). One possible arrangement of a build space (7) is shown again as a dashed line drawing.

(52) FIG. 16 shows a method according to a preferred embodiment of the invention. In this case, this is an endlessly continuous process for generative manufacturing methods, in which film layers (34) with cut-out contours are glued to a model (35).

(53) The film layers can be thin rolls (38) made of paper, metal as well as of plastic. They are applied on a workpiece being run (36), which is moved essentially horizontally on a conveyor belt (11).

(54) The application plane of the layer body proceeds with an angle less than 90 in relation to the movement direction.

(55) The films (34) are applied onto the layer body and thereupon connected by means of e.g. glueing, welding or similar means. The contour of the component is cut out of the respective layer e.g. with a laser (37). The cutting can either take place before or after the application step. If it takes place after the application step, then the depth of the cut must be checked. To facilitate unpacking, the aid of a hot-wire saw (39) can be employed for auxiliary cuts, which divide the surrounding film material into smaller units. The auxiliary cuts can, for example, be executed in the shape of rectangles. On complicated structures, the rectangles can be further reduced in size in order to better access the contour.

(56) If the current film layer (34) is applied and cut, then the infeed is actuated and the layer bodies are further transported by one layer thickness. The layer body should have reached a certain length in order to stably store the components or models (35) located there. If the layer body has reached this minimum length in the conveyor direction (11), then removal of the excess film can be begun on the end opposite the film application plane in order to break out the actual components. The removal can then proceed manually. The advantage of this build-up type lies in the quasi-infinite operation of the system.

(57) In order to start up the system, an angle or workpiece (36) is needed upon which the first layers (34) are applied. The angle is needed until the layer body (35) being built up with layers acquires sufficient inherent strength and can bear its own weight without deforming.

(58) FIG. 17 depicts a perspective view of a method according to a preferred embodiment, which uses melted plastic as material in nozzles (42).

(59) According to the embodiment shown, another nozzle (43) is provided for the application of support material (44). The whole unit is thereby moved forward again on a conveyor belt (11). Since such a method forms an endless block, the finished part areas must be separated for removal, for example, by means of a hot wire saw (39).

(60) The print heads (42, 43), which can generate individual drops of two different materials, are moved in a layer application plane over the layer body (35) and dispense the build material and support material (44) corresponding to the contour data issued by the computer. The support material (44) should hereby ensure that at least the layer body's (35) own weight can be supported on the conveyance unit (11).

(61) An endlessly continuous method for a 3D printing process, during which the material is directly deposited with a print head (45), is depicted in FIG. 18.

(62) A device used to accomplish this can be simplified for such a method.

(63) In contrast to devices according to the state of technology, the movement of the device for layer positioning must not proceed rapidly because positioning runs with long paths are no longer needed. As mentioned above, a consequence of such is that a discontinuous switching device may also be used. Possible embodiments are depicted in FIG. 19 and FIG. 20.

(64) A powder feedstock (46) is provided on a conveyor belt (11).

(65) In order to move one layer thickness after a coating process, the entire conveyor belt is moved in such a manner using the drive roller that the application plane approaches the drive roller as per the desired layer thickness. The torque required for this and the angle of rotation can be applied using a lever (48) that is connected with a drive roller via an overrunning clutch (47). The lever can be e.g. actuated by means of a pneumatic cylinder (49). The layer thickness itself is then specified by the travelling distance of the cylinder. This can be delimited by end stops.

(66) Other gear stages (51) may make sense depending on the required torque moments required. The layer thickness due to elasticity and slackness can be determined during commissioning and the desired target layer thickness can be set.

DESIGNATION LIST

(67) 1 Solidification unit

(68) 2 Spreader device

(69) 4 Building platform

(70) 5 Component

(71) 6 Vertical

(72) 7 Build height

(73) 8 Build chamber/Process chamber

(74) 9 Component (top from the build chamber)

(75) 10 Component (middle from the build chamber)

(76) 11 Component (lower from the build chamber)

(77) 12 Conveyor belt

(78) 13 Angle of repose

(79) 14 Angle of build plane relative to the conveyor belt

(80) 15 Solid delimitation wall

(81) 16 Run-off particulate material

(82) 17 End of device

(83) 18 Particulate material areas

(84) 19 Structures

(85) 20 Floor

(86) 21 Delimitation wall

(87) 22 Transfer conveyance means

(88) 23 Auxiliary structures

(89) 24 Robot

(90) 25 Guidance plate

(91) 26 Openings

(92) 27 Openings

(93) 28 Additional conveyor belt

(94) 29 Linked plates of the conveyor belt

(95) 30 Insertion unit

(96) 31 Rigid chain link

(97) 32 Magazine

(98) 33 Conveyor roller

(99) 34 Film layers

(100) 35 Model

(101) 36 Workpiece being run

(102) 37 Laser 1

(103) 38 Film rollers

(104) 39 Hot-wire saw

(105) 41 Job block

(106) 42 Nozzle for build material

(107) 43 Nozzle for support material

(108) 44 Support material

(109) 45 Print head

(110) 46 Powder feedstock

(111) 47 Overrunning clutch

(112) 48 Lever arm

(113) 49 Pneumatic cylinder

(114) 50 Frame

(115) 51 Chain-connected extended drive