Material supply device for a stereolithography apparatus

Abstract

In a stereolithography apparatus a material supply device for a printing material (16), in particular a photosensitive polymer, to be hardened is provided. The material supply device (10) accommodates a material cartridge (12) which in turn accommodates and completely surrounds the printing material (16). The material cartridge (12) can be connected liquid-tightly with an outlet valve unit (20) through which the printing material (16) can be discharged and which is at least partially accommodated in the material supply device (10) and is at least partially supported on or in the material supply device or is sealed with respect to the material supply device. The outlet valve unit (20) has a valve (100) which is opened and closed depending on the relative position, in particular the swivel position, of the material supply device (10) and the stereolithography apparatus.

Description

[0001] This application is a divisional application based on Chinese patent application No. 201910115251.7, filed on February 15, 2019, entitled "Material Supply Device for Stereoscopic Offset Printing Equipment". Technical Field

[0002] This invention relates to a material supply device and a stereolithographic printing apparatus. Background Technology

[0003] Rapid prototyping is increasingly being used to quickly and accurately manufacture components based on CAD / CAM data.

[0004] Among known methods, stereolithography stands out, particularly in the field of dental technology, where its application is becoming increasingly widespread. It involves constructing components layer by layer from a liquid, i.e., a printing material, through irradiation with a defined structure, in a manner known to exist.

[0005] Here, the layer thickness is between 0.05 and 0.25 mm, which correspondingly places higher demands on the drive device of the construction platform or on the supply of printing material bath.

[0006] On the other hand, different structures are required for the manufacture of different components. From the perspective of color selection alone, it is advantageous to be able to use different printing materials.

[0007] Therefore, it has been proposed to utilize active pools, each containing printing material of a desired color, and to move the desired pools with the corresponding desired printing material colors to an effective area, i.e., to the area where the component is manufactured.

[0008] Since the printing materials used are typically photosensitive, the pool is equipped with a suitable cover or other covering to prevent the printing materials from drying prematurely.

[0009] However, this solution is unsatisfactory because operating the pool usually results in or at least may result in the loss of printing material and environmental pollution, while also failing to prevent confusion.

[0010] Another stereolithographic printing method is known from WO 2010 / 45951 A1, in which a pool and a cylinder are mainly used. The disadvantage is that this method is particularly inflexible when changing printing materials. Summary of the Invention

[0011] In contrast, the object of the present invention is to provide a material supply device and a stereolithographic printing apparatus, wherein the material supply device enables the stereolithographic printing apparatus to be used more universally and to operate more reliably.

[0012] According to the present invention, a material supply device with a material cylinder, which can also be referred to as a box and is completely enclosed, is proposed. This enclosed design achieves an opaque material supply device, regardless of whether the material cylinder is placed within the material supply device.

[0013] The material supply device therefore includes a receiving frame that is openable and closable, particularly opaque. According to the invention, a bottle-shaped material cylinder can be mounted in this receiving frame. The material cylinder itself contains printing material and is designed to output the printing material for use in rapid prototyping devices, particularly stereolithographic printing equipment.

[0014] According to the present invention, the material supply device has a special material cylinder with an outlet valve unit. Printing material is output from the material cylinder through the outlet valve unit when needed. Whether printing material can be output also depends on the relative position of the material supply device with respect to the stereolithographic printing equipment.

[0015] In an advantageous embodiment, the valve is open when the material cylinder is above the outlet valve unit, and closed when the material cylinder is to the side of the outlet valve unit.

[0016] The material cylinder is preferably constructed as a bottle body. The outlet valve unit can be installed on an interface of the bottle body, such as a threaded interface.

[0017] When the material cylinder swings to a vertical position where the material cylinder extends downwards from the outlet, this movement of the portion of the outlet valve unit connected to the material cylinder causes the valve to open.

[0018] Therefore, a fluid connection is formed at this location, extending from the material cylinder to the outlet of the outlet valve unit. This fluid connection leads to a pool for containing printing material, allowing the printing material to flow from the bottle into the pool.

[0019] As the material cylinder swings laterally downwards, extending substantially horizontally, the portion of the valve unit connected to the bottle's outlet simultaneously swings. This movement closes the valve.

[0020] In a favorable design, the outlet valve unit can be removed from the receiving frame of the material supply device in this position. For this purpose, a sliding guide structure is provided, which allows for the upward removal of the relevant components of the outlet valve unit.

[0021] In this position, the bottle can be replaced with a new bottle along with the outlet valve unit. To do this, the new outlet valve unit can be screwed onto the new bottle, or the existing outlet valve unit can be unscrewed and screwed onto the new bottle.

[0022] Advantageously, according to the invention, a hinge is provided, which is integrated into the outlet valve unit and the outlet valve unit is divided into two parts that are oscillatingly connected to each other via the hinge.

[0023] The first hinge portion preferably has an interface for the material cylinder. When the material cylinder is constructed into a bottle body, the bottle body has a neck or bottle outlet. The bottle outlet may have external threads, and the first hinge portion can then be screwed onto the external threads.

[0024] It is understandable that, instead of a threaded interface, any other connection structure, such as a bayonet connection structure, can be implemented here.

[0025] Another hinged portion is preferably configured to also ensure connection to the material supply device.

[0026] Preferably, the second hinge portion has a sliding guide structure, such as a laterally protruding tenon that can be inserted into a corresponding slot on the receiving frame of the material supply device.

[0027] The hinge according to the invention allows the material cylinder to swing 90 degrees relative to the receiving frame. In the vertical position, the material cylinder is supported upside down and the valve is open.

[0028] In the flat position, the material cylinder extends to the side of the hinge and the outlet valve unit and valve are closed.

[0029] With the material cylinder in a horizontal position, the aforementioned sliding guide device is accessible, and the material cylinder, along with the outlet valve unit, is removable and can be fitted with a new material cylinder containing the outlet valve unit.

[0030] In contrast, in the vertical position of the material cylinder, the sliding guide structure is locked, so that the material cylinder will not be unintentionally pulled out when the valve is opened, which could lead to contamination of the stereolithography equipment.

[0031] The second hinged section extends downward in the form of a tube. This tube forms the outlet of the outlet valve unit and leads into the pool.

[0032] When implementing the rapid prototyping device into a stereolithographic printing apparatus, a pool is provided as described above, into which printing material can be output from a material cylinder to the pool. The material cylinder, according to the invention, has an outlet valve unit having a valve. The outlet valve unit is designed such that the printing material output therefrom is directly output into the pool.

[0033] The outlet of the outlet valve unit is preferably configured in such a length that the outlet terminates at the desired level of the printing material in the pool.

[0034] The level of the printing material in the tank is self-leveling, as is known, for example, from a drinking trough: once the level drops below the lower end of the outlet, air there may enter the material cylinder through the outlet and outlet valve unit, thus allowing the printing material to continue flowing out.

[0035] Alternatively, any other automatic regulating device can be used to maintain a constant liquid level in the pool: for example, a float valve, which is known in itself, can be cited. In contrast, the aforementioned drinking trough-type regulation is preferred because it better prevents cross-contamination.

[0036] In an advantageous embodiment, the printing material can be drawn back into the material cylinder when needed. Through gravity and / or hydrostatic effects, the printing material flows out of the material cylinder, thus ensuring the cylinder is always adequately filled.

[0037] A particular advantage is that, according to the invention, a one-to-one arrangement is achieved between the material cylinder and the pool. This can be ensured, for example, through corresponding coding, such as mechanical coding. Provided the material is specifically coded, the combination of the pool and the material cylinder then contains the same printing material.

[0038] "Material-specific" refers to both the type of printing material used, i.e., its chemical composition, and other characteristics of the printing material, such as its color.

[0039] In a favorable design, the spatial arrangement of the material cylinder and the pool is achieved in such a way that fluid communication exists between the material cylinder and the pool regardless of the state of the pool.

[0040] The desired level of the printing material in the pool is independent of the state of the molded part to be manufactured; that is, the liquid level can be ensured when constructing the molded part because the outlet of the outlet valve unit extends into the pool and maintains the level of the pool liquid.

[0041] Advantageously, the outlet terminates precisely horizontally, and the stereolithography equipment is set precisely horizontally.

[0042] To realize stereolithographic printing equipment, it is necessary to provide an accurate reference height during layer-by-layer construction. For this purpose, according to the present invention, a transparent auxiliary window is used, which can be constructed as a glass plate, the upper side of which serves as the reference height. The glass plate serves as a substrate for a film, which is disposed below on the pool. The film is stretched on the glass plate, thereby ensuring an accurate reference height in the pool regardless of guiding inaccuracies.

[0043] Therefore, in practical use, the material supply device, including the material cylinder and pool, is first installed into the stereolithographic printing equipment.

[0044] According to an alternative design, the glass plate can also be adjusted to the desired and pre-defined height, which constitutes the reference height.

[0045] At this moment, that is, when the glass plate comes into contact with the film, the pool is filled, but only when filling is required, that is, when the pool has not been filled beforehand. This can be achieved, for example, by opening the valve.

[0046] In another implementation, the liquid level can be adjusted based on the output signal of a sensor that detects the liquid level height.

[0047] Advantageously, according to the invention, the material cartridge and reservoir alignment is maintained during material replacement. This is ensured by proper coding. The material supply device can be removed from the stereolithography equipment and sent to a storage location. When the material cartridge is empty, it can only be replaced with a material cartridge containing exactly the same material. This is ensured by coding, because at this point, a material cartridge with a different printing material cannot be loaded due to the mechanically operated coding used to match the material cartridge and reservoir.

[0048] In principle, the pool is also replaceable, but only if its code matches the code of the material cylinder. The remaining components of the material supply device, namely the receiving frame, are, in principle, reusable and therefore reusable parts. This applies to all components of the material supply device except the material cylinder. The material cylinder is constructed as a disposable component. However, the material consumption for the material cylinder itself is very limited, especially when the material cylinder can be constructed as a simple bottle.

[0049] The pool itself is a reusable component. However, the bottom membrane has a limited lifespan and should be replaced after 5,000 or 10,000 removal processes, i.e., after the corresponding number of construction steps.

[0050] The material supply device with the loaded material cylinder is completely enclosed and sealed. As long as the pool is not full and the valve is in the closed position, the material supply device can be stored in any manner, including upside down. A mechanical locking mechanism ensures that the material cylinder with the outlet valve unit can only be removed when it is in a horizontal swing position, i.e., when it is contained within the material supply device.

[0051] The outlet preferably extends into the pool.

[0052] In a favorable design, a transparent auxiliary window, particularly a glass plate, can be provided below the pool, and the membrane of the pool can be stretched taut on the glass plate. In this case, the upper side of the glass plate plus the thickness of the membrane provides a reference height for construction or slicing using a stereolithography method.

[0053] In another design of the pool, a screen can be installed at one corner. Alternatively, multiple screens can be installed at each corner of the pool. Remaining printing material in the pool can be poured out through the screens and simultaneously filtered, thereby trapping contaminants and allowing for the recycling of the remaining printing material.

[0054] The printing material is preferably output to a pool with the same code, i.e., a pool specifically designated for the same printing material. The screen can be fixedly connected to the pool or operated separately. The screen aperture size can be adapted to requirements within a wide range; preferably, the aperture size is less than 500 μm, more preferably about 150 μm.

[0055] Advantageously, according to the invention, the material supply device can be opened from above. At this point, the material cylinder is horizontally exposed and can be replaced. For this purpose, the material cylinder, along with the outlet valve unit, is directly pulled out from its sliding guide structure, and the outlet valve unit is screwed onto the new material cylinder. Due to the mechanical locking structure, the material supply device can only be closed when the material cylinder is in its flat position.

[0056] The pool can also be replaced when needed, and for this purpose, for example, a snap-fit ​​connection structure is provided, which can be released to replace the pool.

[0057] Instead of the preferred single valve, multiple valves and corresponding valve housings can also be implemented as needed. Attached Figure Description

[0058] Other advantages, details and features will become apparent from the following description of several embodiments with reference to the accompanying drawings.

[0059] in:

[0060] Figure 1 A schematic perspective view showing a portion of one embodiment of the material supply device according to the invention, namely a schematic perspective view of the material cylinder, receiving frame and pool according to one embodiment of the invention;

[0061] Figure 2 Showing according to Figure 1 A cross-sectional view of the implementation form, with the material cylinder in another position;

[0062] Figure 3Showing according to Figure 2 A sectional view, but the material cylinder is in a flat position;

[0063] Figure 4 Showing according to Figure 1 A perspective view, in which the material cylinder has been removed;

[0064] Figure 5 Showing according to Figure 4 The implementation form shows a portion of the material cylinder;

[0065] Figure 6 A schematic perspective cross-sectional view showing another embodiment of the material supply device according to the invention; and

[0066] Figure 7 An exploded view of another embodiment of the material supply device according to the invention is shown. Detailed Implementation

[0067] Depend on Figure 1 A schematic perspective view of the material supply device 10 according to the present invention, which is part of a stereolithographic printing apparatus, is shown.

[0068] The material supply device 10 has a material cylinder 12 and a pool 14 below the material cylinder. The pool 14 is designed in a known manner to hold printing material and has a transparent bottom on which a similarly transparent film is adhered.

[0069] As is commonly seen in stereolithography equipment, the printing material is irradiated layer by layer from below.

[0070] The so-called construction platform, not shown here, is raised progressively, for example, at a resolution of 0.05 mm, in order to give the object to be made the desired shape. The material cylinder has a bottle body 17, which is essentially a rectangle with rounded corners 18.

[0071] The material cylinder is sized such that it is installed flat in the receiving frame 22, which is connected to the pool 14 above the pool and has a substantially the same flat rectangular cuboid shape, and also has rounded corners.

[0072] The material cylinder 12 also has an outlet valve unit 20.

[0073] The outlet valve unit 20 has a hinge 24, which allows the outlet valve unit to swing between a swing portion 26 and a fixed portion 28 about the hinge. The swing portion 26 is connected to the bottle body 17 in a sealed manner.

[0074] In contrast, the fixed portion 28 is inserted into the receiving frame 22 in such a way that no contamination is formed through the printed material, or such contamination does not enter areas where contamination is not desired.

[0075] Depend on Figure 2 Another embodiment of the material supply device 10 according to the present invention can be seen. Figure 2 The implementation form differs from that only in details according to Figure 1 The implementation form. For example, by Figure 2 As shown, in addition to the bottle body 17 and the outlet valve unit 20, the material cylinder 12 also has a valve 100, which is open at the 12 o'clock position shown in the material cylinder 12.

[0076] The bottle body 17 has a threaded interface 30, which is screwed into the swing portion 26 of the outlet valve unit 20 and sealed on the sealing surface 32.

[0077] As by Figure 2 As can be seen, the swing portion 26 partially surrounds the fixed portion 28. The two portions each have openings 36 and 38. If these two portions are aligned, as... Figure 2 As shown, valve 100 opens, and printing material can flow out from bottle 17 at the 12 o'clock position.

[0078] The fixed portion 28 has a specially shaped outlet 40. The outlet terminates downward at a downward-pointing annular surface 42, which extends horizontally accordingly.

[0079] Outlet 40 and annular surface 42 extend into pool 14.

[0080] The printing material 16 flowing out of the bottle 17 by gravity can only flow out to a level sufficient to replenish the incoming air. Self-leveling is achieved through the flat annular surface 42. Air can only enter the outlet 40 through the annular surface 42 and thus rise into the bottle 17 when the liquid level in the pool 14 decreases.

[0081] As long as the liquid level of the printing material drops to the height of the annular surface 42 or higher, the liquid surface is sealed relative to the annular surface 42, so that no more air flows into the bottle body 17 and thus no more printing material can flow out of the bottle body 17.

[0082] This principle can also be called the water tank principle.

[0083] exist Figure 2 The image also shows a guide element 44. The guide element 44 is connected to the swing portion 30 and is horizontal when the bottle body 17 is in the vertical position.

[0084] The receiving frame 22 has a sliding guide structure not shown here, which is laterally, i.e., according to Figure 2 In the view, the guide element 44 extends forward and accommodates the plane of the drawing. The sliding guide structure allows the guide element 44 to swing in the lower region, but is narrower at the top.

[0085] Accordingly, the guide element 44 is based on Figure 2 The material cylinder cannot pass through the sliding guide structure in the position, thereby preventing the material cylinder from being removed when it is in the vertical position.

[0086] As by Figure 3 It can be seen that the material cylinder 12 can rotate around the hinge 28 according to Figure 2 The vertical position swings to according to Figure 3 The material cylinder 12 is placed in a flat position. In this position, the guide element 44 extends vertically and can move via the guide rail, thereby allowing the material cylinder 12 to be removed.

[0087] Accordingly, bottle 17 is based on Figure 3 It can be removed from its position and replaced with a new bottle body 17 after the threaded connection of the threaded interface 30 is loosened.

[0088] In addition, according to Figure 3 In its position, opening 36 is offset from opening 38. This allows valve 100 to... Figure 3 The position is closed, so that the printing material contained in the bottle 17 cannot flow out from the outlet 40.

[0089] As by Figure 3 As can be seen, the housing frame 22 has a cover 50. The cover 50 opaquely houses the bottle 17 and can be removed when needed to allow for bottle replacement.

[0090] In addition, by Figure 3 As can be seen, the receiving frame 22 completely covers the pool 14. The printing material that may be located in the pool is thus protected by the receiving frame 22 from light penetration.

[0091] Depend on Figure 4 A perspective view of the housing frame 22 and the pool 14 is shown in part. In the material cylinder 12, only a portion of the outlet valve unit 20, namely the valve 100 with the opening 38 and the fixed portion 28, is visible.

[0092] As can be seen, the outlet 40 extends laterally beside and below the hinge 24.

[0093] As by Figure 5 As can be seen, the swing portion 26 on the hinge 24 surrounds the fixed portion 28.

[0094] Also by Figure 5As can be seen, the swing portion 26 has an internal thread 52, which is consistent with the internal thread in the swing portion 26. Figure 5 The threaded interface 30 of the bottle body 17, which is not shown in the figure, is matched.

[0095] The swing portion 26 also has a support frame 54 for better lateral and vertical support of the bottle body 17.

[0096] Figure 6 Another embodiment of the material supply device 10 according to the invention is shown. Here, as in the other figures, the same reference numerals indicate the same or similar parts.

[0097] As can be seen, outlet 40 extends downward into pool 14 and terminates at approximately half the height of pool 14 with plane 52.

[0098] according to Figure 6 The bottle body 17 is positioned in a flat position, in which valve 100 is closed.

[0099] In bottle 17 Figure 6 The printed material 16, as shown schematically, must not flow out of the bottle. The bottle can be replaced at this location.

[0100] Depend on Figure 7 As can be seen, the individual components of the material supply device 10 are configured to interact with each other in this embodiment.

[0101] In this embodiment, the cover 50 is a cap that flatly closes the receiving frame 22. The receiving frame 22 houses a material cylinder 12, which consists of a bottle body 17 and an outlet valve unit 20. The valve 100 in the outlet valve unit 20 is closed. The outlet 40 of the outlet valve unit 20 protrudes downward. The outlet can be inserted into the receiving frame 22 via a sliding guide structure 58, shown only schematically.

[0102] The receiving frame 22 is fitted onto the pool 14 and can be locked therein. For this purpose, a locking tenon 60 is provided, which engages with the locking recess 62 when the receiving frame 22 is fitted onto the pool 14.

[0103] The pool 62 has a transparent film 64 underneath, which adheres to the glass plate 66 during operation.

Claims

1. A material supply device for a stereolithographic printing apparatus for a printing material (16) to be hardened, characterized in that, The material supply device (10) includes a material cylinder (12) that contains and completely surrounds printing material (16). The material cylinder (12) has an outlet valve unit (20) through which printing material (16) can be output. The outlet valve unit is at least partially contained in the material supply device (10) and at least partially supported on or in the material supply device or sealed relative to the material supply device. The outlet valve unit (20) has a valve (100) that is open when the material cylinder (12) is above the outlet valve unit (20) and closed when the material cylinder is to the side of the outlet valve unit (20).

2. The material supply device according to claim 1, characterized in that, The printing material (16) to be hardened is a photosensitive polymer.

3. The material supply device according to claim 1, characterized in that, When the material cylinder (12) is above the outlet valve unit (20), the valve (100) is open, and the material cylinder (12) can swing laterally downward.

4. The material supply device according to any one of claims 1 to 3, characterized in that, The valve (100) is open when the material cylinder (12) is in a vertical position and closed when the material cylinder is in a horizontal position.

5. The material supply device according to any one of claims 1 to 3, characterized in that, The valve (100) has a hinge with a swing angle of at least 70 degrees.

6. The material supply device according to any one of claims 1 to 3, characterized in that, The valve (100) has a hinge with a swing angle of at least 90 degrees.

7. The material supply device according to any one of claims 1 to 3, characterized in that, The portion of the outlet valve unit connected to the outlet of the material cylinder can swing together with the material cylinder (12), and this movement closes the valve (100).

8. The material supply device according to any one of claims 1 to 3, characterized in that, In the vertical position, the material cylinder (12) is supported upside down and the valve (100) is open.

9. The material supply device according to any one of claims 1 to 3, characterized in that, The material cylinder (12) together with the outlet valve unit (20) is removable via a sliding guide structure (58).

10. The material supply device according to claim 9, characterized in that, In the vertical position of the material cylinder (12), the sliding guide structure (58) is locked, and the material supply device can only be closed in the flat position of the material cylinder due to the mechanical locking structure.

11. The material supply device according to any one of claims 1 to 3, characterized in that, The material supply device with the loaded material cylinder (12) is completely closed and sealed.

12. The material supply device according to any one of claims 1 to 3, characterized in that, The outlet valve unit (20) extends into the pool (14) containing liquid printing material (16) and is sealed by the liquid level of the pool to achieve self-leveling.

13. The material supply device according to any one of claims 1 to 3, characterized in that, When the valve (100) is in the open position, the material cylinder (12) with the outlet valve unit (20) is locked from being introduced into and removed from the frame (22) of the material supply device (10).

14. The material supply device according to claim 12, characterized in that, The material cylinder (12) and / or the pool (14) are constructed as disposable components and the receiving frame of the material supply device (10) is constructed as a reusable component, all of which are opaque.

15. The material supply device according to claim 12, characterized in that, A one-to-one configuration relationship is achieved between the material cylinder (12) and the pool (14) through corresponding codes.

16. The material supply device according to any one of claims 1 to 3, characterized in that, There are one or more pools (14) that can be used individually according to the user’s selection, wherein the code on the pool (14) matches the code on the material cylinder (12) and codes that are different from each other do not match each other.

17. The material supply device according to claim 12, characterized in that, The liquid level in the pool (14) can be adjusted based on the output signal of the sensor that detects the liquid level height.

18. The material supply device according to claim 12, characterized in that, A transparent auxiliary window is provided, and the upper side of the auxiliary window can be used as a reference height.

19. The material supply device according to claim 18, characterized in that, A glass plate is used as a substrate for a thin film (64), which is disposed from below on the pool (14) and stretched on the glass plate (66).

20. The material supply device according to claim 19, characterized in that, The upper side of the glass plate (66) and the thickness of the film (64) are reference heights when constructed or layered according to the stereolithography method.

21. The material supply device according to claim 9, characterized in that, When the material supply device is opened from above and the material cylinder (12) is exposed, the material cylinder (12) can be replaced in a flat position in such a way that the material cylinder together with the outlet valve unit can be pulled out from the sliding guide structure.

22. The material supply device according to any one of claims 1 to 3, characterized in that, The outlet of the outlet valve unit (20) is precisely horizontal at the end, and the stereolithography equipment is set to be precisely horizontal.

23. A stereolithographic printing apparatus, wherein the stereolithographic printing apparatus has a material supply device, characterized in that, The material supply device (10) of the stereolithographic printing equipment includes a material cylinder (12) that contains and completely surrounds printing material (16), and is provided with an outlet valve unit (20) through which printing material (16) can be output. The outlet valve unit is at least partially contained in the material supply device (10) and at least partially supported on or in the material supply device or sealed relative to the material supply device. The outlet valve unit (20) has a valve (100) that is open when the material cylinder (12) is above the outlet valve unit (20) and closed when the material cylinder is to the side of the outlet valve unit (20).

24. The stereolithographic printing equipment according to claim 23, characterized in that, The material supply device is the material supply device according to any one of claims 2 to 22.

Images