Three-dimensional printing apparatus and three-dimensional printing method

A 3D printing apparatus and a method thereof are provided. The apparatus includes base, forming platform, nozzle module, curing module, first sensor and second sensors and control module. The forming platform is movably disposed on the base along an axial direction. The nozzle module and the curing module are disposed on the base and located above the forming platform. The first and second sensors are movably disposed on the base and located at two opposite sides of the nozzle module and the curing module along the axial direction. A predetermined range of the 3D object on the forming platform has first and second endpoints along the axial direction, and the first and second sensors respectively correspond to the first and second endpoints. The control module determines whether the nozzle module impacts the 3D object according to a sensing time difference of the first and second sensors.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of China application serial no. 201710061714.7, filed on Jan. 26, 2017. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

Technical Field

The disclosure relates to a three-dimensional (3D) printing apparatus and a 3D printing method.

Description of Related Art

Along with quick development of technology, different methods for constructing three-dimensional (3D) models by using additive manufacturing technology such as layer-by-layer model constructing, etc. have been developed. Generally, the additive manufacturing technology converts design data of a 3D model constructed by software of computer aided design (CAD), etc. into a plurality of thin (quasi two-dimensional) cross-section layers that are stacked in sequence.

Presently, methods for forming a plurality of thin cross-section layers have been developed. For example, a liquid forming material is sprayed on a moving platform according to X-Y-Z coordinates constructed based on the design data of the 3D model, and a light source is driven to move along X-Y coordinates to irradiate the liquid forming material, so as to cure the liquid forming material to form a correct cross-section layer shape. Then, as the moving platform or a spray nozzle assembly is moved along a Z-axis, the liquid forming material is cured layer-by-layer and stacked on the forming platform to form the 3D object.

SUMMARY

The disclosure is directed to a three-dimensional (3D) printing apparatus and a 3D printing method, by which whether components have an impact during a printing process is detected, and an impact warning is announced to a user.

An embodiment of the disclosure provides a 3D printing apparatus includes a base, a forming platform, a nozzle module, a first sensor, a second sensor and a control module. The forming platform and the nozzle module are respectively disposed on the base, and the forming platform and the nozzle module are adapted to move relative to each other along an axial direction, so that when the forming platform and the nozzle module pass by each other, the nozzle module prints the 3D object on the forming platform. The first sensor and the second sensor are respectively and movably disposed on the base along the axial direction and are located adjacent to the forming platform. The control module is electrically connected to the first sensor and the second sensor. A predetermined range of the 3D object on the forming platform has a first endpoint and a second endpoint along the axial direction, a position of the first sensor on the base corresponds to the first endpoint, and a position of the second sensor on the base corresponds to the second endpoint. During a printing process, the control module determines whether the nozzle module impacts a forming layer or the 3D object according to sensing signals produced by the first sensor and the second sensor for sensing the 3D object.

An embodiment of the disclosure provides a 3D printing method adapted to a 3D printing apparatus to print a 3D object. The 3D printing apparatus includes a base, a forming platform and a nozzle module, wherein the forming platform and the nozzle module are respectively disposed on the base, and the forming platform and the nozzle module are adapted to move relative to each other along an axial direction, so that when the forming platform and the nozzle module pass by each other, the nozzle module prints the 3D object on the forming platform. The 3D printing method includes: providing design data of the 3D object and converting the design data into coordinate data corresponding to the forming platform, so as to produce a predetermined range on the forming platform, where the predetermined range has a first endpoint and a second endpoint along the axial direction; providing a first sensor on the base to be located adjacent to the forming platform, driving the first sensor to move along the axial direction and positioning the first sensor to be corresponding to the first endpoint; providing a second sensor on the base to be located adjacent to the forming platform, driving the second sensor to move along the axial direction and positioning the second sensor to be corresponding to the second endpoint; and during the printing process, monitoring a sensing time difference of the first and the second sensors to determine whether the nozzle module impacts the 3D object or a forming layer of the 3D object.

According to the above description, in the 3D printing apparatus and the 3D printing method, by setting sensors beside the forming platform to indicate the endpoints of the predetermined range of the 3D object or the forming layer on the forming platform, during the printing process, it is determined whether an abnormal situation is occurred by monitoring the sensing time difference of the sensors caused by the forming layer or the 3D object on the forming platform. In other words, the user may determine that the nozzle module and the forming layer (the 3D object) are impact through prolonging of the sensing time difference, and the user is warned to avoid damaging the nozzle module or the forming layer (the 3D object).

In order to make the aforementioned and other features and advantages of the disclosure comprehensible, several exemplary embodiments accompanied with figures are described in detail below.

DESCRIPTION OF EMBODIMENTS

FIG. 1is a top view of a three-dimensional (3D) printing apparatus according to an embodiment of the disclosure, in which only partial related components are illustrated, and the other components can be learned according to the known technique, and details thereof are not repeated.FIG. 2is a schematic diagram illustrating a coupling relationship of partial components of the 3D printing apparatus. Referring toFIG. 1andFIG. 2, and Cartesian coordinates X-Y-Z are provided to facilitate describing the components. In the present embodiment, the 3D printing apparatus100includes a base140, a forming platform120, a nozzle module110, a curing module150and a control module130, where the control module130is electrically connected to the forming platform120, the nozzle module110and the curing module150, the forming platform120is movably disposed on the base140along an X-axis, and the nozzle module110and the curing module150are disposed on the base140and located on a moving path of the forming platform120. The 3D printing apparatus100is, for example, a stereolithography (SL) device or a digital light processing (DLP) device, in which the control module130drives the nozzle module110to provide (spray) a liquid forming material, for example, photosensitive resin on the forming platform120, and then the control module130drives the curing module150, for example, an (ultraviolet) light curing device to irradiate the liquid forming material on the forming platform120, such that the liquid forming material is cured (solidified) to be a forming layer, and as the forming platform120moves along the X-axis back and forth, the cured forming layers are stacked layer-by-layer until a 3D object is formed, so as to complete the 3D printing operation of the present embodiment. It should be noted that a moving mode of the forming platform120and the nozzle module110is not limited by the disclosure, and in another embodiment that is not illustrated, a moving mode that the forming platform120is fixed and the nozzle module110is driven can also be adopted, i.e. any moving mode adapted to move the forming platform120and the nozzle module110along the X-axis relative to each other can be adopted.

Under the existing device structure, since a situation of printing abnormity that causes impact between the nozzle module and the forming layer or the 3D object cannot be warned to the user during the printing process, the user generally learns the above situation only when the printing process is completed or the nozzle module is damaged and cannot implement the printing operation. Therefore, the 3D printing apparatus100of the present embodiment further includes a first sensor S1and a second sensor S2, which are used for detecting the impact occurred during the printing process and announcing a warning message to the user.

In detail, as shown inFIG. 1, the nozzle module110and the curing module150are disposed on a gantry structure180of the 3D printing apparatus100, as shown inFIG. 2, a fourth motor M4is connected to the nozzle module110and/or the curing module150and electrically connected to the control module130to drive the nozzle module110and/or the curing module150to move along a Y-axis and a Z-axis, i.e. the nozzle module110and the curing module150of the present embodiment are in a fixed and non-moving state along the X-axis. Moreover, a third motor M3is connected to the forming platform120and electrically connected to the control module130, such that the control module130drives the forming platform120to move back and forth along an axial direction of the X-axis, so as to achieve a basic structure of the aforementioned 3D printing operation.

FIG. 3is a flow chart of a 3D printing process of the disclosure.FIG. 4AandFIG. 4Bare respectively schematic diagrams depicting steps ofFIG. 3.FIG. 5AandFIG. 5Bare respectively schematic diagrams depicting other steps ofFIG. 3. Referring toFIG. 3in comparison withFIG. 4A,FIG. 4B,FIG. 5AandFIG. 5B, in the present embodiment, in step ST1, design data of a 3D object is firstly provided, and the design data is converted into coordinate data corresponding to the forming platform120, so as to produce a predetermined range200on the forming platform120, where the predetermined range200has a first endpoint E1and a second endpoint E2on the X-axis. Comparing toFIG. 2, dot lines are adopted to describe a driving relationship between the first motor M1and the first sensor S1and a driving relationship between the second motor M2and the second sensor S2. In step ST2, the first sensor S1is provided on the base140, and the first motor M1drives the first sensor S1along the X-axis, so as to locate a position of the first sensor S1on the base140. The aforementioned “location” refers to that the first sensor S1may correspond to a position of the first endpoint E1of the predetermined range200, i.e. as shown inFIG. 4A, when the nozzle module110sprays the liquid forming material at the second endpoint E2, the first sensor S1corresponds to the position of the first endpoint E1on the X-axis. In other words, the first sensor S1is used for defining a boundary of the predetermined range200of the 3D object (the forming layer) at one side of the X-axis. Then, in step ST3, the second sensor S2is provided on the base140, and the second motor M2drives the second sensor S2along the X-axis, so as to locate a position of the second sensor S2on the base140. The aforementioned “location” refers to that the second sensor S2may correspond to a position of the second endpoint E2of the predetermined range200, i.e. as shown inFIG. 4B, when the nozzle module110sprays the liquid forming material at the first endpoint E1, the second sensor S2corresponds to the position of the second endpoint E2on the X-axis. In other words, the second sensor S2is used for defining a boundary of the predetermined range200of the 3D object (the forming layer) at another side on the X-axis. In the present embodiment, the first sensor S1and the second sensor S2are respectively infrared sensors, and the first motor M1and the second motor M2are respectively stepper motors.

In this way, the first sensor S1and the second sensor S2can be adopted to complete boundary setting of the predetermined range200on the X-axis, and the control module130may control the third motor M3to drive the forming platform120to move on the base140, and then the printing operation of a step ST4is started.

Then, in step ST6, the control module130determines whether the nozzle module110impacts the 3D object (or the forming layer thereof) by receiving sensing messages of the first sensor S1and the second sensor S2. A sensing waveform Ta illustrated inFIG. 5Ais a sensing waveform generated when the 3D object (or the forming layer) passes by the first sensor S1and the second sensor S2and is sensed by the same under a normal state. As shown inFIG. 5A, when no impact is occurred, a sensing time difference Δt1between the first endpoint E1and the second endpoint E2sensed by the first sensor S1and the second sensor S2is a fixed value. Once the impact is occurred, it represents that the time difference between the first endpoint E1and the second endpoint E2of the predetermined range200that is sensed by the first sensor S1and the second sensor S2is prolonged, as shown inFIG. 5B, the time difference is prolonged to a sensing time difference Δt2(Δt2>Δt1). Therefore, through determination of the sensing time difference of the first sensor S1and the second sensor S2, whether the impact is occurred can be determined.

Meanwhile, the control module130may further execute a step ST5to serve as an auxiliary reference to determine whether the impact is occurred. Referring toFIG. 2andFIG. 3, in the present embodiment, the third motor M3used for driving the forming platform120to move along the X-axis has an encoder C1, which serves as the control module130to control a moving mode of the third motor M3. In the step ST5, the control module130also monitors waveform data of the encoder C1, referring toFIG. 5AandFIG. 5B, the sensing waveform Tb shown inFIG. 5Ais in the normal state, which represents that a moving process of the forming platform120has no obstacle, and inFIG. 5B, the sensing waveform Tb obviously has an abnormal waveform ER within a predetermined time, which represents that the third motor M3has abnormity during the process of driving the forming platform120, so that the control module130may accordingly determine whether the impact is occurred.

In general, in step ST6, the control module130may determine whether the nozzle module110impacts the 3D object (or the forming layer) according to the sensing time difference between the first sensor S1and the second sensor S2and whether the encoder C1of the third motor M3has an abnormal waveform in the step ST5.

Then, in step ST7, after the impact is occurred, the control module130sends a visual and/or audio warning message to the user through a warning system (not shown), and in step ST8, the user makes further confirmation. When it is confirmed that the impact is occurred, in step ST9, the current printing operation is stopped to facilitate implementing troubleshooting. If it is confirmed that the impact is not occurred, the printing operation of the aforementioned step ST4is continued.

Moreover, if the control module130determines that the impact is not occurred, the printing operation of the step ST4is continued until a step ST10to complete printing the 3D object.

It should be noted that the predetermined range200shown inFIG. 4AandFIG. 4Bis only an orthogonal projection profile of one of the forming layers on the forming platform120, and along with continuous stacking of the forming layers, different profiles and forming layers of different ranges are presented, and values of the coordinates of the first endpoint and the second endpoint on the X-axis are accordingly changed, and the positions of the first sensor S1and the second sensor S2are certainly adjusted accordingly.

Moreover, determination frequency of the step ST6can be properly set according to a printing environment. For example, the user may set that the determination is performed for each of the forming layers, or one detection or determination is performed every a fixed layer number of the forming layers or a fixed thickness of the forming layers.

FIG. 6is a top view of a 3D printing apparatus according to another embodiment of the disclosure.FIG. 7is a schematic diagram of partial components of the 3D printing apparatus ofFIG. 6. It should be noted that inFIG. 7, related structure is illustrated in a single viewing angle, and a transmission manner thereof is simply illustrated, and technical features of the present embodiment are not limited thereto. Referring toFIG. 6andFIG. 7, in the present embodiment, the same to the aforementioned embodiment, the 3D printing apparatus300includes the base140, the nozzle module110, the curing module150(including a fourth motor M4driving the curing module150), the gantry structure180, the forming platform120(including the third motor M3driving the forming platform120), and the first sensor S1and the second sensor S2, and a difference there between lies in the method of driving the first sensor S1and the second sensor S2. The 3D printing apparatus300further includes a transmission assembly and a switching assembly, where the transmission assembly includes a first motor M1and a gear set G1, and the switching assembly includes a second motor M2, a swing arm162and a gear set G2, which is used for connecting between the first motor M1and the first sensor S1or between the first motor M1and the second sensor S2, so as to switch between a first state and a second state.

Further, when the switching assembly is in the first state, as shown by the swing arm162in solid lines and the gear set G2ofFIG. 7, the second motor M2drives the swing arm162and the gear set G2thereon for coupling between the gear set G1and the gear set G3, such that the power of the first motor M1is transmitted to drive the first sensor S1. Comparatively, when the switching assembly is in the second state, as shown by the swing arm162in dot lines and the gear set G2ofFIG. 7, the second motor M2drives the swing arm162and the gear set G2thereon for coupling between the gear set G1and the gear set G4, such that the power of the first motor M1is transmitted to the gear set G4through the gear set G1and the gear set G2, so as to drive the second sensor S2. The first motor M1is a stepper motor, the second motor M2is a direct current (DC) motor, based on the characteristic that the second motor M2is only required to provide a switching operation without achieving a precise positioning, convenience of the user for selecting the motors is improved, so as to effectively decrease the component cost.

In summary, in the 3D printing apparatus and the 3D printing method, by setting sensors beside the forming platform to indicate the endpoints of the predetermined range of the 3D object or the forming layer on the forming platform, during the printing process, it is determined whether an abnormal situation is occurred by monitoring the sensing time difference of the sensors caused by the forming layer or the 3D object on the forming platform. Meanwhile, it is monitored whether the waveform of the encoder of the motor used for driving the forming platform is abnormal, which can be used as a reference in collaboration with the aforementioned sensing time difference to determine whether the impact is produced, such that the user can be opportunely warned when the impact is produced, so as to facilitate implementing troubleshooting to avoid component damage. Moreover, besides that the one-to-one manner can be adopted to use the first motor and the second motor to respectively drive the first sensor and the second sensor, the switching assembly can also be adopted to switch the transmission assembly used for driving the sensors, so as to improve convenience of the user for selecting motors, and effectively decrease the component cost.