3D printing system and 3D printing method

Abstract

The invention relates to a 3D printing system and a 3D printing method, the 3D printing system comprises a 3D printing device and a temperature adjusting system, the 3D printing device comprises a light source and a material tray for bearing a printing material, and the temperature adjusting system comprises a temperature sensor configured to detect the temperature of the material tray; the temperature adjusting unit is configured to adjust the temperature of the charging tray to a target temperature; and the controller is configured to control the operation of the temperature adjusting unit at least based on the temperature of the charging tray. In this way, the temperature adjusting assembly can be controlled to be in the open state based on the temperature of the material disc, low-temperature gas exchanges heat with the material disc, efficient heat dissipation of resin is achieved, materials in a non-projection area are prevented from being solidified, and therefore the printing precision and the printing quality are guaranteed.

Description

Technical Field

[0001] This application relates to the field of 3D printing technology, and particularly to a 3D printing system and a 3D printing method. Background Art

[0002] Stereolithography 3D printing technology is a three-dimensional manufacturing technology based on the photocuring reaction of photosensitive resin under the irradiation of a light source with a specific wavelength, and is formed by layer-by-layer stacking. During the printing process, the light will continuously or intermittently irradiate the resin to cure the resin, but this will cause the temperature of the resin to rise. If the heat cannot be dissipated in time, it may cause local overheating of the resin, resulting in problems such as uneven curing, deformation of the printed part, and aging and deterioration of the photosensitive resin, seriously affecting the printing accuracy and forming quality. Therefore, how to control the efficient heat dissipation of the material tray has become an urgent problem to be solved. Summary of the Invention

[0003] This application provides a 3D printing system and a 3D printing method to solve the technical problem of how to control the efficient heat dissipation of the material tray.

[0004] In a first aspect, this application provides a 3D printing system, including a 3D printing device and a temperature regulation system. The 3D printing device includes a light source and a material tray for carrying printing materials. The temperature regulation system includes:

[0005] A temperature sensor configured to detect the temperature of the material tray;

[0006] A temperature regulation unit configured to adjust the temperature of the material tray to a target temperature; and

[0007] A controller configured to control the operation of the temperature regulation unit at least based on the temperature detected by the temperature sensor.

[0008] In a possible implementation, the temperature regulation system further includes a material identification device. The controller is electrically connected to the material identification device. The material identification device is configured to identify the currently used printing material and send a signal to the controller, and the signal is associated with the target temperature of the currently used printing material.

[0009] In a possible implementation, the temperature regulation unit is configured to direct a gas to the material tray, and the controller is configured to adjust the process parameters of the temperature regulation unit. The process parameters include any one of the following: gas flow rate, gas temperature, gas flow.

[0010] In a possible implementation, the temperature regulation system further includes a humidity sensor configured to detect the humidity of the environment where the material tray is located; the controller is configured to control the temperature regulation unit to increase the gas temperature when the humidity exceeds the humidity threshold.

[0011] In a possible implementation, the 3D printing system further includes a fluid channel disposed on a side of the material tray close to the light source. The fluid channel includes a transparent channel portion, and a gas is disposed in the fluid channel. The gas is configured to perform heat exchange with the printing material in the material tray;

[0012] The temperature adjustment unit includes a fluid driving device configured to drive the gas to move in the fluid channel. Wherein, the light projected by the light source passes through the transparent channel portion and cures the printing material.

[0013] In a possible implementation, the transparent channel portion is at least defined by a first transparent portion and a second transparent portion. The first transparent portion and the second transparent portion are spaced apart, and the light projected by the light source can pass through the second transparent portion and the first transparent portion.

[0014] In a possible implementation, the temperature adjustment unit includes a refrigeration module, a radiator, and a blower. The refrigeration module is configured to provide cooling capacity to the gas. The radiator is connected to the refrigeration module, and the air outlet of the blower faces the radiator.

[0015] In a possible implementation, the refrigeration module includes a thermoelectric cooler disposed on the wall surface of the fluid channel. The thermoelectric cooler has a refrigerating surface and a heating surface disposed opposite to each other. Wherein, the refrigerating surface faces the inside of the fluid channel, and the heating surface faces away from the fluid channel and is connected to the radiator.

[0016] In a second aspect, the present application provides a 3D printing method. The 3D printing method includes:

[0017] Exposing the printing material in the material tray continuously or intermittently using a light source;

[0018] Using a temperature sensor to detect the temperature of the material tray;

[0019] At least based on the temperature detected by the temperature sensor, using a controller to control the operation of the temperature adjustment unit to adjust the temperature of the material tray to a target temperature.

[0020] In a possible implementation, the at least based on the temperature detected by the temperature sensor, using a controller to control the operation of the temperature adjustment unit includes:

[0021] Based on the difference between the temperature of the material tray and the target temperature being greater than or equal to a temperature difference threshold, starting the temperature adjustment unit; and / or

[0022] Based on the difference between the temperature of the material tray and the target temperature being less than the temperature difference threshold, turning off the temperature adjustment unit.

[0023] In a possible implementation, it further includes: controlling the temperature adjustment unit to be in a closed state based on a second signal for turning on the light source for exposure.

[0024] In a possible implementation, it further includes: controlling the temperature adjustment unit to be in an open state based on a third signal for curing the last layer of the currently printed object by exposure curing.

[0025] In a possible implementation, controlling the operation of the temperature adjustment unit includes: adjusting the process parameters of the temperature adjustment unit, where the process parameters include any one of the following: gas flow rate, gas temperature, gas flow.

[0026] In a possible implementation, it further includes reducing the power of the temperature adjustment unit using a controller based on the decreasing rate of the temperature drop of the tray becoming smaller with respect to the real-time temperature of the tray.

[0027] In a possible implementation, it further includes adjusting the temperature adjustment unit using a controller to increase the temperature of the tray based on the humidity of the environment where the tray is located exceeding a humidity threshold.

[0028] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:

[0029] The 3D printing system and the 3D printing method provided by the embodiments of the present application, the 3D printing system includes a 3D printing device and a temperature adjustment system, the 3D printing device includes a light source and a tray for carrying printing materials, the temperature adjustment system includes a temperature adjustment component, and can control the temperature adjustment component to be in an on state based on the temperature of the tray, enabling heat exchange between the low-temperature gas and the tray, realizing efficient heat dissipation of the resin, avoiding curing of the materials in non-projected areas, and thus ensuring the printing accuracy and printing quality. Description of the Drawings

[0030] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0031] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplary illustrations do not limit the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, unless otherwise stated, and the drawings in the figures do not constitute a proportional limitation.

[0033] Figure 1 It is a schematic structural diagram of a 3D printing system provided by the embodiments of the present application;

[0034] Figure 2 is Figure 1 a side view of the 3D printing system shown;

[0035] Figure 3 is a cross-sectional view along the Figure 2 A-A direction in [reference], where the arrow direction shows the gas flow direction;

[0036] Figure 4 is a cross-sectional view of the 3D printing system provided by another embodiment of the present application, where the arrow direction shows the gas flow direction;

[0037] Figure 5 is Figure 1 a structural connection block diagram of the temperature regulation system of the 3D printing system shown;

[0038] Figure 6 is a flowchart of a 3D printing method provided by an embodiment of the present application.

[0039] Explanation of reference numerals:

[0040] 1. 3D printing device; 11. Light source; 12. Material tray; 13. Substrate; 131. Hollow channel; 132. First side; 133. Second side;

[0041] 2. Temperature regulation system; 21. Temperature regulation unit; 211. Fluid driving device; 212. Refrigeration module; 213. Radiator; 214. Fan; 22. Temperature sensor; 23. Fluid channel; 231. First transparent part; 2311. First transparent element; 2312. Second transparent element; 232. Second transparent part; 2321. Third transparent element; 2322. Fourth transparent element;; 24. Humidity sensor; 25. Controller;

[0042] 3. Material identification device. Detailed implementation manners

[0043] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0044] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present application. In addition, the present application may repeat reference numerals and / or letters in different examples. This repetition is for the purpose of simplicity and clarity and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0045] For ease of description, spatially relative relationship terms may be used in the text to describe the relative positional relationship or movement of one element or feature shown in the figure relative to another element or feature. These relative relationship terms are, for example, "inside", "outside", "inner side", "outer side", "below", "beneath", "above", "over", "front", "rear", etc. Such spatially relative relationship terms are intended to include different orientations of the device in use or operation other than the orientation depicted in the figure. For example, if the device in the figure undergoes a position flip or attitude change or motion state change, then these directional indications will change accordingly. For example, an element described as "below other elements or features" or "beneath other elements or features" will subsequently be oriented as "above other elements or features" or "over other elements or features". Therefore, the exemplary term "below" can include both upward and downward orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions) and the spatially relative relationship descriptors used in the text are interpreted accordingly.

[0046] First, the professional terms proposed in the present application are explained as follows:

[0047] SLA 3D printing technology: Using photosensitive resin as the raw material, by irradiating the photosensitive resin with ultraviolet light, the liquid material is solidified layer by layer into a solid state, and the required object is constructed. Layer by layer stacking: Once a layer is cured, the printing platform will rise upward, allowing the liquid material of the next layer to be cured. This process is repeated layer by layer until the entire model is printed.

[0048] Such as Figure 1As shown, the present application provides a 3D printing system, including a 3D printing device 1 and a temperature regulation system 2. The 3D printing device 1 includes a light source 11 and a tray 12 for carrying printing materials. The light source 11 emits light towards the tray 12 to expose the printing materials in the tray 12. When the light source 11 operates continuously, the tray 12 (especially the film assembly of the tray 12) will heat up due to light radiation, for example, heating up to 40°C to 80°C. For some printing materials in a high-temperature environment (such as 70°C), when curing a layer, the materials in the projected area are expected to be cured, while the materials in the non-projected area have the risk of being undesirably cured. The printing material can be a liquid photosensitive resin. Therefore, it is necessary to cool down the resin in the tray 12. Specifically, the higher temperature of the resin in the tray 12 is concentrated in the part of the liquid resin close to the film assembly of the tray 12.

[0049] As Figure 5 shown, the temperature regulation system 2 includes a temperature sensor 22, a temperature regulation unit 21, and a controller 26. The temperature sensor 22 is configured to detect the temperature of the tray 12; the temperature regulation unit 21 is configured to adjust the temperature of the tray 12 to a target temperature; the controller 26 is electrically connected to the temperature sensor 22 and the temperature regulation unit 21, and the controller 26 is configured to control the operation of the temperature regulation unit 21 at least based on the temperature of the tray 12.

[0050] Specifically, the present application provides a temperature sensor 22, which can detect the temperature of the tray 12 in real time. For example, when the detected real-time temperature of the tray 12 (such as 70°C) is greater than or equal to the target temperature (such as 60°C), it indicates that the polymerizable liquid in the tray 12 cannot be effectively cooled by natural convection heat dissipation at this time. The temperature sensor 22 sends a signal to the controller 26, and then the controller 26 sends a control signal to control the operation of the temperature regulation unit 21. At this time, the temperature regulation component is controlled to be in an open state, and the low-temperature gas exchanges heat with the tray 12 to achieve efficient heat dissipation of the resin, avoiding the curing of the materials in the non-projected area, thereby ensuring the printing accuracy and printing quality.

[0051] In some embodiments, as Figure 1 shown, the temperature regulation unit 21 can guide the gas with a lower temperature to the tray 12 to exchange heat with the tray 12, thereby reducing the temperature of the tray 12. The temperature regulation unit 21 includes, for example, a fan and / or a fluid channel 23 for delivering room-temperature air to the tray 12. Alternatively, the temperature regulation unit 21 includes, for example, a fan and / or a fluid channel 23 for delivering the refrigerated gas to the tray 12.

[0052] In some embodiments, the power or process parameters of the temperature regulation unit 21 are adjustable. For example, the controller 26 adjusts at least one of the gas flow rate, gas temperature, and gas flow of the temperature regulation unit 21.

[0053] After starting the temperature regulation unit 21, obtain the temperature rising rate of the tray 12; if the temperature rising rate of the tray 12 is greater than the temperature rising rate threshold, control the air flow velocity to increase, or the gas temperature to decrease, or the gas flow rate to increase. For example, the temperature rising rate threshold can be set at 5 °C / s, and the temperature of the tray 12 rises by 6 °C per unit time, that is, the temperature rising rate of the tray 12 is 6 °C / s. Then control the air flow velocity to increase, or the gas temperature to decrease, or the gas flow rate to increase, so as to reduce the speed and / or amplitude of the tray temperature rise.

[0054] In some embodiments, as Figure 5 shown, the 3D printing system further includes a material identification device 3. The controller 26 is electrically connected to the material identification device 3. The material identification device 3 is configured to identify the currently used printing material and send a first signal to the controller 26, and the first signal is associated with the target temperature of the currently used printing material.

[0055] The target temperatures applicable to different printing materials may be different. For example, the first type of material A is easily exposed to stray light and cured by light at 50 °C, the second type of material B is easily exposed to stray light and cured by light at 60 °C, and the third type of material C is thermally cured at 80 °C. The present application can identify the category of the currently used printing material and thus determine the target temperature. For example, the present application obtains the material information on the resin bottle through, for example, an RFID reader, and determines the target temperature corresponding to the material through the data stored in the memory or processor (these data are pre-entered). Alternatively or additionally, the target temperature is directly recorded on the resin bottle, and this information is identified through, for example, OCR. The identification device can be, for example, an RFID identifier, a two-dimensional code scanner, a bar code scanner, etc.

[0056] In some embodiments, when it is detected that the difference between the temperature of the tray 12 and the target temperature is greater than or equal to the temperature difference threshold, control the temperature regulation unit 21 to be in the on state. For example, the target temperature is 50 °C, the temperature difference threshold can be set at 5 °C, and the real-time temperature detected by the temperature sensor 22 gradually rises from 50 °C to 55 °C. At this time, the difference between the real-time temperature (55 °C) and the target temperature is 5 °C, and the temperature regulation unit 21 is started to reduce the temperature.

[0057] In some embodiments, when the difference between the temperature of the tray 12 and the target temperature is less than the temperature difference threshold, the temperature adjustment unit 21 is controlled to be in the off state. For example, if the target temperature is 50 °C and the temperature difference threshold can be set to 5 °C, and the real-time temperature detected by the temperature sensor 22 is 60 °C, the temperature adjustment unit 21 has been started to lower the temperature at this time. As the temperature adjustment unit 21 operates, the real-time temperature detected by the temperature sensor 22 gradually decreases to 53 °C. At this time, the difference between the real-time temperature (53 °C) and the target temperature is 3 °C, and the temperature adjustment unit 21 is turned off. The residual cold of the gas of the temperature adjustment unit 21 can be used to cool the resin on the tray 12, thereby saving energy consumption.

[0058] The power of the temperature adjustment unit 21 can also be adjusted according to the temperature change rate of the tray 12. If the temperature drop rate of the tray 12 decreases, it indicates that the temperature of the tray 12 is gradually decreasing and approaching the target temperature at this time, then the power of the temperature adjustment unit 21 is controlled to decrease. For example, if the temperature of the tray 12 drops by 3 °C within a unit time period T and then drops by 2 °C within the next unit time period T, the power of the temperature adjustment unit 21 can be reduced at this time. The greater the power, the greater the operating noise. Therefore, the power of the temperature adjustment unit 21 can be reduced according to the temperature drop rate of the tray 12 within a unit time, thereby reducing the operating noise.

[0059] To reduce the risk of the influence of the air flow on the exposure curing, the gas flow rate is reduced or stopped during the exposure. For example, in response to the signal for the light source 11 to perform the exposure, the temperature adjustment unit 21 is immediately or in advance turned off. For example, 1 s, 1.5 s before the light source 11 projects light or when the light source 11 projects light, the temperature adjustment unit 21 is turned off or the power of the temperature adjustment unit 21 is reduced. Those skilled in the art can understand that when printing a single object (which includes multiple layers), the exposure operation occurs for each layer.

[0060] In some embodiments, when constructing a single object, the time between exposing the nth layer and exposing the (n + 1)th layer is short (for example, 2 s to 5 s), and multiple exposures are required, so that the adjustment frequency of the temperature adjustment unit 21 is high, which poses a challenge to the control strategy. In an alternative or additional solution, based on the signal of exposing the last layer (or completing the last layer) of the currently printed object by exposure curing, the temperature adjustment unit 21 is turned on to lower the temperature of the tray 12. Thereafter, the printed object on the forming platform needs to be removed to prepare for printing the next object, which provides a relatively long time (for example, 3 minutes to 30 minutes) to cool the resin on the tray 12.

[0061] Since condensation is likely to occur on the tray 12 when the environmental humidity where the tray 12 is located is high, the embodiment of the present application is also provided with a humidity sensor 25 to detect the environmental humidity where the tray 12 is located. Of course, an existing temperature and humidity sensor 25 can also be used, and the specific design is described as follows.

[0062] In some embodiments, as Figure 5 shown, the temperature regulation system 2 further includes a humidity sensor 25 configured to detect the humidity of the environment where the tray 12 is located; a controller 26 is electrically connected to the humidity sensor 25, and the controller 26 is configured to control the temperature regulation unit 21 to increase the gas temperature when the humidity exceeds the humidity threshold. For example, the humidity threshold can be set to 70% RH. When the detected humidity of the environment where the tray 12 is located is 80% RH, then control the temperature regulation unit 21 to increase the gas temperature, for example, increase it by 2 °C, to reduce the amount of condensation.

[0063] In some embodiments, as Figure 2 and Figure 3 shown, the 3D printing system further includes a fluid channel 23 disposed on one side of the tray 12 close to the light source 11. The fluid channel 23 includes a transparent channel portion, and a gas is disposed in the fluid channel 23. The gas is configured to perform heat exchange with the printing material in the tray 12; the temperature regulation unit 21 includes a fluid driving device 211 configured to drive the gas to move in the fluid channel 23; wherein, the light projected by the light source 11 passes through the transparent channel portion and cures the printing material.

[0064] The fluid channel 23 is a sealed channel, and the gas circulates in the fluid channel 23 and continuously performs heat exchange with the resin at a higher temperature. Since the fluid channel 23 is sealed, for example, dust from the air will not or is difficult to enter the fluid channel 23. The 3D printing system provided by the embodiments of the present application can efficiently dissipate heat for the heat-concentrated area (such as the bottom of the tray 12) of the tray 121, avoid introducing dust to interfere with the optical path, take into account the heat dissipation efficiency and optical compatibility, thereby improving the printing accuracy and forming quality of the three-dimensional object and reducing the optical path cleaning and maintenance frequency.

[0065] The fluid driving device 211 can be a fan or the like. When the fan works, it can pressurize the gas, thereby realizing the circulation of the gas in the fluid channel 23.

[0066] For example, when it is detected that the temperature of the tray 12 (for example, 70 °C) is greater than or equal to the target temperature (for example, 60 °C), the temperature sensor 22 sends a signal to the controller 26, and then the controller 26 sends a control signal to control the operation of the fluid driving device 211, for example, increasing the operating power of the fan to increase the gas flow rate and gas flow.

[0067] In some embodiments, as Figure 4 shown, the transparent channel portion is at least defined by a first transparent portion 231 and a second transparent portion 232. The first transparent portion 231 and the second transparent portion 232 are spaced apart, and the light projected by the light source 11 can pass through the second transparent portion 232 and the first transparent portion 231.

[0068] The 3D printing system further includes a substrate 13. The substrate 13 has a first side 132 and a second side 133 which are oppositely arranged. The material tray 12 is fixedly installed on the first side 132 of the substrate 13. A hollow channel 131 may be provided on the substrate 13, and the hollow channel 131 extends from the first side 132 of the substrate 13 to the second side 133 of the substrate 13.

[0069] In some embodiments, the first transparent part 231 includes at least one of the following: a first transparent element 2311 fixed to the material tray 12; a second transparent element 2312 located between the material tray 12 and the second transparent part 232.

[0070] In some embodiments, the second transparent part 232 includes at least one of the following: a third transparent element 2321 fixed to the substrate 13; a fourth transparent element 2322 located between the third transparent element 2321 and the first transparent part 231.

[0071] Furthermore, at least one of the first transparent part 231 and the second transparent part 232 is selected from: glass, acrylic plate.

[0072] Specifically, in an exemplary embodiment, as Figure 4 shown, the first transparent part 231 may be the first transparent element 2311 fixed to the material tray 12, and the first transparent element 2311 is the glass of the material tray 12. The material tray 12 includes a construction surface (e.g., a film), and the resin will be cured on the construction surface. The glass of the material tray 12 is arranged on the side of the film of the material tray 12 close to the optical unit, so that the amplitude of the deformation of the film towards the glass is limited by the glass. The second transparent part 232 may be the third transparent element 2321 (acrylic plate or glass plate) fixed to the second side 133 of the substrate 13, and the third transparent element 2321 is recessed in a direction away from the material tray 12. At this time, the light projected by the optical module can sequentially pass through the third transparent element 2321 and the first transparent element 2311, and cure the polymerizable liquid. The refrigeration module 212 makes the gas form a low-temperature gas (e.g., 10°C - 30°C), and the fluid driving device 211 drives the low-temperature gas to circulate in the fluid channel 23. The low-temperature gas exchanges heat with the polymerizable liquid in the material tray 12, thereby realizing efficient heat dissipation of the polymerizable liquid. The gas does not interfere with the path of the light projected by the optical module. The first transparent element 2311, the third transparent element 2321, and the substrate 13 form a sealed channel part, and it is difficult for dust in the external environment to enter this channel part, which can avoid dust accumulation on the glass at the bottom of the material tray 12 and interfering with the optical path.

[0073] In an exemplary embodiment, the first transparent part 231 may further be a second transparent element 2312 (acrylic plate or glass plate) disposed below the tray 12. The second transparent element 2312 is fixed to the first side 132 of the substrate 13. The second transparent part 232 may be a third transparent element 2321 fixed to the second side 133 of the substrate 13. The second transparent element 2312 is located between the tray 12 and the third transparent element 2321. With such an arrangement, the light projected by the optical module can sequentially pass through the third transparent element 2321 and the second transparent element 2312 to cure the polymerizable liquid.

[0074] In an exemplary embodiment, as Figure 4 shown, the first transparent part 231 includes a first transparent element 2311 and a second transparent element 2312. The first transparent element 2311 is fixed to the bottom of the tray 12, and the second transparent element 2312 is fixed to the first side 132 of the substrate 13. The second transparent part 232 includes a third transparent element 2321 and a fourth transparent element 2322. The fourth transparent element 2322 is disposed on the second side 133 of the substrate 13, and the fourth transparent element 2322 is located between the third transparent element 2321 and the second transparent element 2312. With such an arrangement, the light projected by the optical module can sequentially pass through the fourth transparent element 2322, the third transparent element 2321, the second transparent element 2312, and the first transparent element 2311 to cure the polymerizable liquid. To enable better heat exchange between the low-temperature gas and the tray 12, through grooves can be provided on both the third transparent element 2321 and the second transparent element 2312.

[0075] In some embodiments, as Figure 3 shown, the temperature adjustment unit 21 includes a refrigeration module 212, a radiator 213, and a blower 214. The refrigeration module 212 is configured to provide cooling capacity to the gas. The radiator 213 is connected to the refrigeration module 212, and the air outlet of the blower 214 faces the radiator 213.

[0076] Optionally, the refrigeration module 212 may employ refrigeration devices such as a loop heat pipe or a thermoelectric cooler. A loop heat pipe generally consists of an evaporator, a condenser, a reservoir, and vapor and liquid pipelines. Its working principle is as follows: A heat load is applied to the evaporator, and the working fluid evaporates on the outer surface of the evaporator wick. The generated vapor flows out from the vapor channel into the vapor pipeline and then enters the condenser to condense into a liquid and subcool. The reflux liquid enters the liquid main pipeline through the liquid pipeline to replenish the evaporator wick. Thus, a cycle is formed, and the cycle of the working fluid is driven by the capillary pressure generated by the evaporator wick without an external power source.

[0077] In some embodiments, the refrigeration module 212 includes a thermoelectric cooler disposed on the wall surface of the fluid channel 23. The thermoelectric cooler has a refrigerating surface and a heating surface disposed opposite to each other, wherein the refrigerating surface faces the interior of the fluid channel 23, and the heating surface faces away from the fluid channel 23 and is connected to the radiator 213.

[0078] The radiator 213 can adopt an existing air-cooled radiator 213. The heat of the heating surface of the thermoelectric cooler is transferred to the radiator 213 by heat conduction. The air outlet of the fan 214 faces the radiator 213, so that the air in the external environment forms forced convection, thereby improving the heat dissipation efficiency. That is to say, the heat of the polymerizable liquid is conducted to the bottom through the material tray 12. This part of the heat is then transferred to the heat exchange chamber through heat convection in the first heat exchange chamber, and finally transported to the external environment through heat convection by the heating surface of the thermoelectric cooler and the radiator 213. The entire cycle of heat dissipation only exchanges heat with the external environment, forming a closed independent heat dissipation system, effectively preventing external dust from entering the optical path and affecting the light projection of the light curing optical path.

[0079] In this embodiment, when it is detected that the temperature of the material tray 12 (for example, 70 °C) is greater than or equal to the target temperature (for example, 60 °C), the temperature sensor 22 sends a signal to the controller 26, and then the controller 26 sends a control signal to control the thermoelectric cooler to be in an on state to reduce the temperature of the gas flowing inside the fluid channel 23. When it is detected that the temperature drop rate of the material tray 12 decreases, the refrigeration power of the thermoelectric cooler is controlled to decrease. For example, if the temperature of the material tray 12 drops by 3 °C within a unit time period T and then drops by 2 °C within the next unit time period T, the refrigeration power of the thermoelectric cooler is controlled to decrease to save energy consumption.

[0080] As Figure 6 shown, the embodiment of the present application also provides a 3D printing method applied to the 3D printing system as described above. The 3D printing method includes the following steps:

[0081] S1. Continuously or intermittently expose the printing material in the material tray 12 using the light source 11.

[0082] S2. Use the temperature sensor 22 to detect the temperature of the material tray 12; as Figure 5 shown, the temperature sensor 22 is connected to the controller 26.

[0083] S3. Based on the temperature detected by the temperature sensor 22, use the controller 26 to control the operation of the temperature adjustment unit 21 to adjust the temperature of the material tray to the target temperature.

[0084] For example, when the detected real-time temperature of the tray 12 (e.g., 70 °C) is greater than or equal to the target temperature (e.g., 60 °C), it indicates that the polymerizable liquid in the tray 12 at this time cannot be effectively cooled by natural convection heat dissipation. At this time, the temperature adjustment component is controlled to be in the on state, and the low-temperature gas exchanges heat with the tray 12, thereby achieving efficient heat dissipation and ensuring printing accuracy and printing quality.

[0085] In one example, based on the temperature detected by the temperature sensor 22, controlling the operation of the temperature adjustment unit 21 using the controller 26 includes: if the difference between the temperature of the tray 12 and the target temperature is greater than or equal to the temperature difference threshold, controlling the temperature adjustment unit 21 to be in the on state.

[0086] For example, the target temperature is 50 °C, the temperature difference threshold can be set to 5 °C, and the real-time temperature detected by the temperature sensor 22 gradually rises from 50 °C to 55 °C. At this time, the difference between the real-time temperature (55 °C) and the target temperature is 5 °C, and the temperature adjustment unit 21 is started to lower the temperature.

[0087] In one example, based on the temperature detected by the temperature sensor 22, controlling the operation of the temperature adjustment unit 21 using the controller 26 includes: if the difference between the temperature of the tray 12 and the target temperature is less than the temperature difference threshold, controlling the temperature adjustment unit 21 to be in the off state.

[0088] For example, the target temperature is 50 °C, the temperature difference threshold can be set to 5 °C, and the real-time temperature detected by the temperature sensor 22 is 60 °C. At this time, the temperature adjustment unit 21 has been started to lower the temperature. As the temperature adjustment unit 21 works, the real-time temperature detected by the temperature sensor 22 gradually decreases to 53 °C. At this time, the difference between the real-time temperature (53 °C) and the target temperature is 3 °C, and the temperature adjustment unit 21 is turned off. The residual cold of the gas of the temperature adjustment unit 21 can be used to cool the resin of the tray 12, thereby saving energy consumption.

[0089] In some embodiments, the 3D printing method further includes: based on the second signal for exposing by turning on the light source 11, controlling the temperature adjustment unit 21 to be in the off state. To reduce the risk of the airflow affecting the exposure curing, the gas flow rate is reduced or stopped during exposure. For example, in response to the second signal for exposing by the light source 11, the temperature adjustment unit 21 is immediately or prematurely turned off. For example, the temperature adjustment unit 21 is turned off or the power of the temperature adjustment unit 21 is reduced 1 s, 1.5 s before the light source 11 projects light or when the light source 11 projects light. Those skilled in the art can understand that during the printing of a single object (which includes multiple layers), the exposure operation occurs at each layer.

[0090] In some embodiments, it further includes: controlling the temperature regulation unit 21 to be in an open state based on a third signal for curing the last layer of the currently printed object by exposure. When building a single object, the time between exposing the nth layer and the (n + 1)th layer is short (e.g., 2 s to 5 s), and multiple exposures are required, resulting in a high adjustment frequency of the temperature regulation unit 21. Based on the third signal for curing the last layer (or completing the last layer) of the currently printed object by exposure, the temperature regulation unit 21 is turned on to lower the temperature of the material tray 12. Thereafter, the printed object on the forming platform needs to be removed to prepare for printing the next object, which provides a relatively long time (e.g., 3 minutes to 30 minutes) for cooling the resin in the material tray 12.

[0091] In some embodiments, controlling the operation of the temperature regulation unit 21 includes: adjusting the process parameters of the temperature regulation unit 21, where the process parameters include any one of the following: gas flow rate, gas temperature, gas flow.

[0092] After starting the temperature regulation unit 21, obtain the temperature rise rate of the material tray 12; if the temperature rise rate of the material tray 12 is greater than the temperature rise rate threshold, then control the gas flow rate to increase, or the gas temperature to decrease, or the gas flow to increase. For example, the temperature rise rate threshold can be set to 5 °C / s, and the temperature of the material tray 12 rises by 6 °C per unit time, that is, the temperature rise rate of the material tray 12 is 6 °C / s, then control the gas flow rate to increase, or the gas temperature to decrease, or the gas flow to increase.

[0093] In some embodiments, obtain the temperature drop rate of the material tray 12; the temperature of the material tray 12 can be collected in real time through the temperature sensor 22, and the sampling frequency of the temperature sensor 22 is set to calculate the temperature drop rate of the material tray 12. If the temperature drop rate of the material tray 12 decreases, then control the power of the temperature regulation unit 21 to decrease.

[0094] For example, the temperature of the material tray 12 drops by 3 °C within a unit time period T and then drops by 2 °C within the next unit time period T. At this time, the power of the temperature regulation unit 21 can be reduced. The greater the power, the greater the operating noise; therefore, through the above control method, the power of the temperature regulation unit 21 can be reduced according to the temperature drop rate of the material tray 12 per unit time, thereby reducing the operating noise on the premise of meeting the cooling requirements of the material tray 12.

[0095] In some embodiments, obtain the ambient humidity where the material tray 12 is located; if the humidity exceeds the humidity threshold, then control the gas temperature of the temperature regulation unit 21 to increase by a preset temperature. For example, the humidity threshold can be set to 70% RH. When it is detected that the ambient humidity where the material tray 12 is located is 80% RH, then control the gas temperature of the temperature regulation unit 21 to increase by 2 °C to reduce the amount of condensation.

[0096] It should be understood that the terms used herein are for the purpose of describing particular example embodiments only and are not intended to be limiting. Unless the context clearly dictates otherwise, the singular forms "a", "an", and "the" as used herein may also include the plural forms. The terms "comprising", "including", "containing", and "having" are inclusive and thus specify the presence of the stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless an order of performance is explicitly stated. It should also be understood that additional or alternative steps may be used.

[0097] Although the terms first, second, third, etc. may be used herein to describe multiple elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or section from another. Unless the context clearly indicates otherwise, terms such as "first", "second", and other numerical terms when used herein do not imply an order or sequence. Thus, a first element, component, region, layer, or section discussed below may be referred to as a second element, component, region, layer, or section without departing from the teachings of the example embodiments.

[0098] The above description is only a specific embodiment of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but rather will be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A 3D printing system, comprising a 3D printing device and a temperature control system, wherein the 3D printing device comprises a light source and a tray carrying printing materials, characterized in that: The temperature regulation system comprises: a temperature sensor configured to detect the temperature of the tray; a temperature regulating unit configured to regulate the temperature of the material tray to a target temperature; and The controller is configured to control the operation of the temperature adjustment unit based at least on the temperature detected by the temperature sensor.

2. The 3D printing system according to claim 1, characterized in that: The 3D printing system further includes a material identification device configured to identify a currently used printing material and send a signal to the controller, wherein the signal is associated with a target temperature of the currently used printing material.

3. The 3D printing system according to claim 1, characterized in that: The temperature regulating unit is configured to guide the gas to the material tray, and the controller is configured to adjust the process parameters of the temperature regulating unit, and the process parameters include any one of the following: gas flow rate, gas temperature, and gas flow rate.

4. The 3D printing system according to claim 3, characterized in that: The temperature regulation system further includes a humidity sensor, which is configured to detect the humidity of the environment where the material tray is located; the controller is configured to control the temperature regulation unit to increase the gas temperature when the humidity of the environment exceeds a humidity threshold.

5. The 3D printing system according to claim 1, characterized in that: The temperature adjustment system further comprises a fluid channel, which is arranged on a side of the material tray close to the light source, the fluid channel comprises a transparent channel portion, a gas is arranged in the fluid channel, and the gas is configured to perform heat exchange with the printing material in the material tray; The temperature regulating unit includes a fluid driving device configured to drive the gas to move in the fluid channel; wherein the light projected by the light source passes through the transparent channel portion and solidifies the printing material.

6. The 3D printing system according to claim 5, characterized in that: The transparent channel portion is defined by at least a first transparent portion and a second transparent portion, the first transparent portion and the second transparent portion are spaced apart, and the light projected by the light source can pass through the second transparent portion and the first transparent portion.

7. The 3D printing system according to claim 5, characterized in that: The temperature regulating unit comprises a refrigeration module, a radiator and a fan. The refrigeration module is configured to provide coldness to the gas. The radiator is connected to the refrigeration module. The air outlet of the fan faces the radiator.

8. The 3D printing system according to claim 7, characterized in that: The refrigeration module includes a semiconductor refrigeration plate, which is arranged on the wall surface of the fluid channel. The semiconductor refrigeration plate has a cooling surface and a heating surface that are relatively arranged, wherein the cooling surface faces the inside of the fluid channel, the heating surface faces away from the fluid channel, and is connected to the radiator.

9. A 3D printing method, characterized in that: The 3D printing method comprises: Use a light source to continuously or intermittently expose the printing material in the tray; Use a temperature sensor to detect the temperature of the tray; Based at least on the temperature detected by the temperature sensor, a controller is used to control the operation of the temperature adjustment unit to adjust the temperature of the material tray to a target temperature.

10. The 3D printing method according to claim 9, wherein the step of controlling the operation of the temperature regulating unit using a controller based at least on the temperature detected by the temperature sensor comprises: Based on the difference between the temperature of the material tray and the target temperature being greater than or equal to a temperature difference threshold, starting the temperature adjustment unit; and / or Based on the fact that the difference between the temperature of the material tray and the target temperature is less than the temperature difference threshold, the temperature adjustment unit is turned off.

11. The 3D printing method according to claim 9, further comprising: The temperature adjustment unit is turned off based on a signal to turn on the light source for exposure.

12. The 3D printing method according to claim 9, further comprising: The temperature regulating unit is turned on based on a signal for exposing and curing the last layer of the currently printed object.

13. The 3D printing method according to claim 9, wherein the step of controlling the operation of the temperature regulating unit using a controller comprises: The process parameters of the temperature regulating unit are adjusted, and the process parameters include any one of the following: gas flow rate, gas temperature, and gas flow rate.

14. The 3D printing method according to claim 9, further comprising reducing the power of the temperature regulating unit using a controller based on a decrease in the temperature drop rate of the real-time temperature of the material tray.

15. The 3D printing method according to claim 9, further comprising using a controller to adjust the temperature adjustment unit to increase the temperature of the material tray based on the humidity of the environment where the material tray is located exceeding a humidity threshold.

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