Patent Application
20250018659
The present application claims priority to Chinese Patent Application No. 202310106483.2 filed with the China National Intellectual Property Administration (CNIPA) on Feb. 13, 2023, the disclosure of which is incorporated herein by reference in its entirety.
The present application relates to the technical field of three-dimensional (3D) printing, for example, a top-down 3D printer and a 3D printing method.
A three-dimensional (3D) printer combines computer-aided design with material processing and molding technologies. By utilizing a control system and programming software, the 3D printer lays down various materials layer by layer to form a solid product. This solid product is generated through a bottom-to-top laying process on a printing platform in accordance with the projection of a light device. In the related art, stereolithography apparatus (SLA) 3D printers are mainly divided into two types, that is, bottom-up 3D printers and top-down 3D printers, depending on the placement of the light device.
When the top-down 3D printer in the related art performs 3D printing, the printing platform moves down, causing resin in a resin vat to adhere to the surface of the printing platform.
Then, the printing platform moves up to a designated position. Subsequently, a laser rangefinder on a scraper detects the liquid level of resin, and the scraper and the light device are adjusted to the designated positions. When the liquid level of the resin changes, the scraper and the light device are adjusted to move according to the detection data from the laser rangefinder on the scraper. It is to be understood that the material scraping operation of the scraper and the exposure operation are always based on the liquid level of the resin. However, this top-down 3D printer presents the following drawbacks when performing 3D printing.
The present application provides a top-down three-dimensional (3D) printer and a 3D printing method to improve the surface quality of a printed and molded model and improve the printing speed.
The present application uses a top-down 3D printer which includes a workbench, a light device, a first drive mechanism, a second drive mechanism, a scraper, a printing platform, a resin vat, a laser displacement sensor and a liquid level adjustment mechanism. The light device, the first drive mechanism, the second drive mechanism, the scraper, the printing platform, the resin vat, the laser displacement sensor and the liquid level adjustment mechanism are disposed on the workbench.
An output end of the first drive mechanism is connected to the printing platform, the first drive mechanism is configured to be capable of driving the printing platform to move up and down in a height direction of the workbench, an output shaft of the second drive mechanism is connected to the scraper, the second drive mechanism is configured to be capable of driving the scraper to move up and down in the height direction of the workbench and capable of driving the scraper to rotate around the output shaft of the second drive mechanism, the output shaft of the second drive mechanism is parallel to the height direction of the workbench, the laser displacement sensor is configured to monitor a liquid level of resin in the resin vat, and the liquid level adjustment mechanism is capable of feeding resin to or extracting resin from the resin vat.
The light device, the second drive mechanism, the scraper, the printing platform, the resin vat and the liquid level adjustment mechanism are disposed at intervals from top to bottom in the height direction of the workbench.
The present application uses a 3D printing method which is used for controlling the preceding top-down 3D printer. The 3D printing method includes steps described below.
A printing platform is controlled to acquire resin from a resin vat.
A scraper is controlled to rotate by a preset angle in a first rotation direction from a first initial position to flatten resin on the printing platform so that a thickness of the resin on the printing platform is a preset layer thickness.
The scraper is controlled to move up by a first preset distance.
The top-down 3D printer is allowed to stand for a preset standing duration.
A light device is controlled to expose a printed picture.
A liquid level of resin in the resin vat is acquired.
Whether the liquid level of the resin in the resin vat is within a preset liquid level range is determined.
In response to determining that the liquid level of the resin in the resin vat is within the preset liquid level range, controlling the scraper to return to the first initial position and controlling the printing platform to acquire resin again from the resin vat are simultaneously performed.
In response to determining that the liquid level of the resin in the resin vat is not within the preset liquid level range, controlling the scraper to return to the first initial position, controlling a liquid level adjustment mechanism to adjust the liquid level of the resin vat to be within the preset liquid level range and controlling the printing platform to acquire resin again from the resin vat are simultaneously performed.
Hereinafter the present application will be described in detail in conjunction with the drawings and embodiments. It is to be understood that the embodiments described herein are intended to illustrate the present application. Additionally, it is to be noted that for ease of description, only part, not all, of structures related to the present application are illustrated in the drawings.
In the description of the present application, unless otherwise expressly specified, the term “connected to each other”, “connected” or “secured” is to be construed in a broad sense, for example, as securely connected, detachably connected or integrated; mechanically connected or electrically connected; directly connected to each other or indirectly connected to each other via an intermediary; or internally connected between two elements or interaction relations between two elements. For those of ordinary skill in the art, specific meanings of the preceding terms in the present application may be construed according to specific circumstances.
In the present application, unless otherwise expressly specified, when a first feature is described as “on” or “below” a second feature, the first feature and the second feature may be in direct contact or be in contact via another feature between the two features instead of being in direct contact. Moreover, when the first feature is described as “on”, “above” or “over” the second feature, the first feature is right on, above or over the second feature, or the first feature is obliquely on, above or over the second feature, or the first feature is simply at a higher level than the second feature. When the first feature is described as “under”, “below” or “underneath” the second feature, the first feature is right under, below or underneath the second feature, or the first feature is obliquely under, below or underneath the second feature, or the first feature is simply at a lower level than the second feature.
In the description of this embodiment, the orientation or position relationships indicated by terms “above”, “below”, “right” and the like are based on the orientation or position relationships shown in the drawings, merely for ease of description and simplifying an operation, and these relationships do not indicate or imply that the referred device or element has a specific orientation or is constructed and operated in a specific orientation. In addition, the terms “first” and “second” are used only for distinguishing between descriptions and have no special meaning.
The present application provides a top-down three-dimensional (3D) printer. As shown in
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The present application further provides a 3D printing method. The 3D printing method is used for controlling the preceding top-down 3D printer. As shown in
In S100, the printing platform 6 is controlled to acquire resin from the resin vat 7.
The step in which the printing platform 6 is controlled to acquire resin from the resin vat 7 includes S110 and S120.
In S110, the printing platform 6 is controlled to move down from a second initial position by a second preset distance to be immersed in the resin vat 7.
The second preset distance is an empirical value obtained from a large number of previous experiments.
In S120, after the printing platform 6 is immersed in the resin vat 7 for first preset duration, the printing platform 6 is controlled to move up by the second preset distance to reach the second initial position, and the printing platform 6 is still immersed in the resin in the resin vat 7.
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In S200, the scraper 5 is controlled to rotate by a preset angle in a first rotation direction from a first initial position to flatten resin on the printing platform 6 so that the thickness of the resin on the printing platform 6 is the preset layer thickness.
It is to be understood that in the height direction of workbench 1, the first initial position is higher than the second initial position, and in the height direction of workbench 1, the distance between the first initial position and the second initial position is equal to the preset layer thickness.
Optionally, the output shaft of the second drive mechanism 4 is located at a middle position of the printing platform 6 in the length direction of the printing platform 6 and on a side of the printing platform 6 in the width direction of the printing platform 6. The preset angle is greater than or equal to 135 degrees. It is to be understood that the output shaft of the belt drive mechanism 43 is located at the middle position in the length direction of the printing platform 6 and on the side in the width direction of the printing platform 6. After the scraper 5 rotates around the output shaft of the belt drive mechanism 43 by the preset angle from the first initial position, the resin on the printing platform 6 is flattened and the thickness of the resin on the printing platform 6 is the preset layer thickness.
Optionally, in the embodiment, exemplarily, an example is illustrated where when the scraper 5 is located at the first initial position, the scraper 5 is parallel to the length direction of the printing platform 6, and the preset angle is equal to 180 degrees.
In S300, the scraper 5 is controlled to move up by a first preset distance.
This setting allows the scraper 5 to quickly rotate in a second rotation direction without touching the resin during rotation, reducing the risk of fluctuations of the liquid level of the resin.
At this time, the printing platform 6 is still located in the resin in the resin vat 7. It is to be understood that in the whole printing process, the printing platform 6 remains in the resin in the resin vat 7.
In S400, the top-down 3D printer is allowed to stand for the preset standing duration. The preset standing duration is an empirical value obtained from a large number of previous experiments. This setting is to ensure that the liquid level of the resin does not fluctuate and thus to improve the printing quality of 3D printing.
In S500, the light device 2 is controlled to expose a printed picture;
In S600, the liquid level of the resin in the resin vat 7 is acquired.
In S700, whether the liquid level of the resin in the resin vat 7 is within a preset liquid level range is determined.
In response to determining that the liquid level of the resin in the resin vat 7 is within the preset liquid level range, S800 and S900 are simultaneously performed.
In S800, the scraper 5 is controlled to return to the first initial position.
The step in which the scraper 5 is controlled to return to the first initial position includes S810 and S820.
In S810, the scraper 5 is controlled to rotate by the preset angle in the second rotation direction, where the second rotation direction and the first rotation direction are opposite rotation directions.
In S820, the scraper 5 is controlled to move down by the first preset distance.
In S900, the printing platform 6 is controlled to acquire resin again from the resin vat 7. In this manner, the upper surface of the molded model on the printing platform 6 can obtain resin.
Optionally, the step in which the printing platform 6 is controlled to acquire resin again from the resin vat 7 includes S910 and S920.
In S910, the printing platform 6 is controlled to move down from the second initial position by the third preset distance to be immersed in the resin vat 7.
In S920, after the printing platform 6 is immersed in the resin vat 7 for the first preset duration, the printing platform 6 is controlled to move up by the fourth preset distance, where the fourth preset distance equals the third preset distance minus the preset layer thickness.
It is to be understood that during 3D printing, when the first layer is printed, the printing platform 6 moves by the second preset distance and moves up by the second preset distance; then during each subsequent layer of printing, the printing platform 6 moves by the third preset distance and moves up by a distance which satisfies that the distance equals the third preset distance minus the preset layer thickness to ensure that the printed thickness of each time of printing is the preset layer thickness. It is to be understood that in response to determining that the liquid level of the resin in the resin vat 7 is within the preset liquid level range, S800 and S900 are simultaneously performed, so that the printing speed of the top-down 3D printer is improved.
In response to determining that the liquid level of the resin in the resin vat 7 is not within the preset liquid level range, S1000, S1100 and S1200 are simultaneously performed.
In S1000, the scraper 5 is controlled to return to the first initial position.
Optionally, the step in which the scraper 5 is controlled to return to the first initial position includes S1010 and S1020.
In S1010, the scraper 5 is controlled to rotate by the preset angle in the second rotation direction, where the second rotation direction and the first rotation direction are opposite rotation directions.
In S1020, the scraper 5 is controlled to move down by the first preset distance.
In S1100, the liquid level adjustment mechanism 9 is controlled to adjust the liquid level of the resin vat 7 to be within the preset liquid level range.
In response to determining that the liquid level of the resin in the resin vat 7 is greater than a maximum value of the preset liquid level range, the liquid level adjustment mechanism 9 is controlled to extract the resin in the resin vat 7 until the liquid level of the resin in the resin vat 7 is within the preset liquid level range. Optionally, the controller 10 controls the hydraulic pump 91 to operate, that is, to extract the resin in the resin vat 7.
In response to determining that the liquid level of the resin in the resin vat 7 is less than a minimum value of the preset liquid level range, the liquid level adjustment mechanism 9 is controlled to feed resin to the resin vat 7 until the liquid level of the resin in the resin vat 7 is within the preset liquid level range. Optionally, the controller 10 controls the hydraulic pump 91 to operate, that is, to feed resin to the resin vat 7.
In S1200, the printing platform 6 is controlled to acquire resin again from the resin vat 7.
Optionally, the step in which the printing platform 6 is controlled to acquire resin again from the resin vat 7 includes S1210 and S1220.
In S1210, the printing platform 6 is controlled to move down by the third preset distance to be immersed in the resin vat 7.
In S1220, after the printing platform 6 is immersed in the resin vat 7 for the first preset duration, the printing platform 6 is controlled to move up by the fourth preset distance, where the fourth preset distance equals the third preset distance minus the preset layer thickness.
It is to be understood that during 3D printing, when the first layer is printed, the printing platform 6 moves down by the second preset distance and moves up by the second preset distance; then during each subsequent layer of printing, the printing platform 6 moves down by the third preset distance and moves up by a distance which satisfies that the distance equals the third preset distance minus the preset layer thickness to ensure that the printed thickness of each time of printing is the preset layer thickness. It is to be understood that in response to determining that the liquid level of the resin in the resin vat 7 is not within the preset liquid level range, S1000, S1100 and S1200 are simultaneously performed, so that the printing speed of the top-down 3D printer is improved.
It is to be understood that after S920 is completed or after S1220 is completed, S200 to S700 are repeatedly performed. In response to determining that the liquid level of the resin in the resin vat 7 is within the preset liquid level range, S800 and S900 are simultaneously performed; in response to determining that the liquid level of the resin in the resin vat 7 is not within the preset liquid level range, S1000, S1100 and S1200 are simultaneously performed.
In this manner, the preceding top-down 3D printer is controlled by the 3D printing method to perform 3D printing, so that the problem in the related art that the printing speed and precision are affected by the movement of the light device 2 and the laser displacement sensor 8 is effectively avoided, and thus the printing speed and precision of the top-down 3D printer are improved.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202310106483.2 | Feb 2023 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2023/107703 | 7/17/2023 | WO |
