Industrial additive manufacturing temperature control method

Abstract

The invention provides an industrial additive manufacturing temperature control method which comprises a box body, a first containing cavity is formed in the box body, the upper end of the box body is communicated with one end of a main air pipe, the main air pipe is communicated with the first containing cavity, the other end of the main air pipe is communicated with a bottom diffusion disc, and the bottom diffusion disc is communicated with the first containing cavity. A heating pipe and a cooling pipe are arranged along the main air pipe in a communicating mode, the heating pipe is provided with a heating device, the heating device comprises a first heating pipeline and a heating mechanism, and the first heating pipeline is sleeved with the heating mechanism. The cold air pipe is provided with a cooling device, the feed-forward heating requirement and the printing steady-state control stage are met through the temperature rising process, the temperature is accurately controlled through the feed-forward heating requirement and feedback adjustment, and the product forming effect is good.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and particularly to an industrial additive manufacturing temperature control method. Background Art

[0002] In current industrial additive manufacturing applications, one is an open environment where the printing platform is relatively open to the surrounding environment and there is no external enclosure; the other is a closed environment where the outside of the printing platform is also covered with a box to achieve a constant temperature effect. However, in either of the above environments, the temperature control of the printing environment is not good. Therefore, in some requirements for continuous printing operations at high temperatures, such as between 250°C and 500°C, the printed part has cooled while the unprinted part is still at a high temperature, resulting in the industrial application problem of uneven condensation.

[0003] Especially in the process of additive manufacturing of engineering materials for non-metallic materials, such as when printing PEEK materials, strict requirements are imposed on the 3D printing environment. Due to the temperature sensitivity of PEEK materials, ensuring the temperature stability during the printing process is crucial. Therefore, it is necessary to use a constant temperature box to provide a stable environment for the 3D printing equipment, reduce large temperature fluctuations, and thus ensure the printing quality to meet the needs of industrial fields with strict requirements such as aerospace, medical, automotive, and electronics. Therefore, a temperature control box needs to be set on the printing platform.

[0004] For example, in the patent document with the patent application number 202410498362.1 and the publication date of July 23, 2024, a 3D printing temperature control device and method for reducing the deformation of the formed part are disclosed. It includes a printing point temperature control unit, an ambient temperature control unit, a printed part heat dissipation unit, and a formed entity surface temperature acquisition unit; the printing point temperature control unit is used to regulate the temperature of the formed entity surface at the printing point; the ambient temperature control unit is used to regulate the ambient temperature outside the formed entity, and the formed entity is placed above the hot bed; the printed part heat dissipation unit is used to uniformly and synchronously dissipate heat from each area of the printed and formed entity; the formed entity surface temperature acquisition unit is used to collect and output the surface temperature of the formed entity. The device and method can perform real-time and accurate compensation for the temperature during 3D printing, reduce warping deformation caused by uneven interlayer temperature, sudden cooling of the molten filament, and inconsistent cooling rates of each area of the formed part, and improve the accuracy of the fused deposition modeling 3D printing technology.

[0005] In the above literature, before the printing starts, the telescopic rod adjusts the quartz heating tube to the initial position to ensure that the heating area covers the printing area. During the printing process, according to the needs, the telescopic rod can adjust the position of the quartz heating tube in real time to adapt to the shape and size of the printed part. If there are problems with synchronous control, it may cause changes in the relative position between the heating area and the printing area, affecting the printing effect; and it only dissipates heat and reduces the temperature through the ventilation duct and the refrigeration fan, and realizes the heating temperature control through the heating tube; for the heating process, if the heating tube is directly started for temperature increase control when the temperature is not enough, it is easy to directly control the temperature from a relatively low temperature to a high temperature, resulting in large temperature fluctuations and ultimately affecting the printing effect; in addition, due to the layout of the ventilation duct and the unevenness of air flow, it may cause uneven local heat dissipation of the printed part, thus affecting the forming quality. Summary of the Invention

[0006] The present invention provides an industrial additive manufacturing temperature control method, which can accurately control the temperature and has a good forming effect.

[0007] To achieve the above object, the technical solution of the present invention is: an industrial additive manufacturing temperature control method, which is realized through a temperature control device. The temperature control device includes a box body. A first cavity is arranged in the box body. One end of the main air pipe is communicated with the upper end of the box body. The main air pipe is communicated with the first cavity. The other end of the main air pipe is communicated with the bottom diffusion disk. The bottom diffusion disk is communicated with the first cavity. A heating pipe and a cooling pipe are arranged along the main air pipe. The heating pipe is provided with a heating device and a heating valve. The cold air pipe is provided with a cooling device and a cooling valve. A 3D printing nozzle is arranged in the box body.

[0008] The specific steps include: S1 heating-up stage, calculating the feedforward heating demand according to the preset target temperature, the actual temperature difference, the heat storage capacity coefficient of the box body and the set time ; then calculating the opening degree of the heating valve according to the feedforward heating demand and the maximum heating amount ; adjusting the opening degree of the heating valve from the preset opening degree size to the opening degree of the heating valve at a preset rate ; determining the opening degree of the cooling valve to be opened according to the heat generated by the printing nozzle, the maximum heat dissipation power of the cooling device and the minimum value of the set opening degree; adjusting the opening degree of the cooling valve from the closed state to the opening degree of the cooling valve to be opened according to the preset valve opening degree rate; S2 steady-state control stage during printing, determining the opening degree of the heating valve according to the heat generated by the printing nozzle, the current opening degree of the cooling valve, the maximum heat generated by cooling and the maximum heat generated by heating ; then through PID feedback adjustment, adjusting the opening degree of the cooling valve according to the increased heat generated by printing; S3 maintenance control stage after printing ends, calculating the heat dissipation power ; and determine the opening degree of the heating valve according to the heat dissipation power and the maximum heat generated by the heating valve, and keep the cooling valve in the closed state; In the non-printing state maintenance stage, the heating valve is closed at a preset rate.

[0009] With the above settings, a first cavity is provided in the box body, which can be used to place the 3D printing nozzle. A heating pipe is connected and arranged on one side of the main air pipe. When the temperature in the first cavity is lower than the set temperature, the heating valve in the heating pipe controls the gas in the main air pipe to enter the first heating pipeline. The heating device heats the gas in the first heating pipeline to complete the heating of the gas. The heated gas continues to flow downward into the main air pipe and then enters the bottom diffusion plate from the main air pipe; the cooling pipe is provided with a first cooling pipeline, and a number of second cooling pipelines are arranged in the first cooling pipeline. When the temperature in the first cavity is higher than the set temperature, cooling is achieved by opening the cooling valve; the heated or cooled gas flows through the main air pipe to the bottom diffusion plate, and the gas flows from the bottom diffusion plate into the first cavity to complete the temperature adjustment of the box body.

[0010] During the temperature control process, in the heating-up stage, first determine the feed-forward heating demand based on the difference between the target temperature and the actual temperature, and determine the opening degree of the heating valve according to the feed-forward heating demand. Determine the opening degree of the cooling valve according to the heat generated by the printing nozzle and the maximum cooling temperature. Then adjust the heating valve from the starting opening degree to the opening degree of the heating valve at a preset rate, and adjust the cooling valve from the closed state to the opening degree of the cooling valve at a preset speed. This can ensure that the heating valve and the cooling valve are adjusted at a certain rate, and make the heating valve meet the feed-forward heating demand after opening, so that there is no linear heating in the printing area, and the temperature change process in the heating-up stage is well controlled. When in the printing steady state, determine the opening degree of the feed-forward heating valve through the heat generated by the heating valve and the cooling temperature generated by the cooling valve at the current opening degree and the maximum heating temperature, initially determine the opening degree of the heating valve, and then adjust the dynamic opening degrees of the heating valve and the cooling valve through the PID algorithm, so as to reliably maintain at the preset temperature in the steady state. In addition, after printing is completed, close the cooling valve, and determine the opening degree of the heating valve according to the heat dissipation power to maintain a certain temperature of the box body, preventing direct cooling from causing the formed part to change from a hot state to a cold state, resulting in depressions in some positions and affecting the forming effect. In addition, when maintaining the non-printing state, the heating valve is directly closed, reducing energy consumption and ensuring the cooling effect of the formed product at the same time. Ensure good temperature control effect and good forming effect through different temperature control methods in different stages.

[0011] Further, in step S1: Feed-forward heating demand , C is the preset heat storage capacity of the box body, T set is the target temperature, T0 is the normal temperature, and △t is the set time; the opening degree of the heating valve ; The maximum heating power provided for the heating device, the opening degree of the cooling valve ; P cool_max Is the maximum heat dissipation power of the cooling device, P print Is the heat generation power of printing.

[0012] With the above settings, during the heating-up stage, the feed-forward heating demand is determined by setting the ratio of the difference between the target temperature and the actual temperature, the heat storage capacity of the box body, and the set time, so as to ensure that the feed-forward heating demand can meet the requirements of the target temperature value. And the opening degree of the heating valve is determined by the ratio of the feed-forward heating demand to the maximum heating heat of the heating valve, so that the heating valve can reach the preset heating temperature at the opening degree of the heating valve. In order to prevent the cooling valve from directly changing from the closed state to the open state when cooling is required, resulting in a large temperature fluctuation range, the opening degree of the cooling valve is set to take the minimum value between the ratio of the heat generated by the print head to the maximum heat of the cooling valve and the preset 5%, so that the opening degree of the cooling valve will not be too large or too small.

[0013] Furthermore, in step S2, the opening degree of the heating valve ; And step S2 also includes that when the film thickness exceeds the preset value, the opening degree of the cooling valve is adjusted, and the opening degree of the cooling valve ; Is the heat that the print head needs to generate for the increased film thickness.

[0014] With the above settings, the opening degree of the heating valve is determined by the ratio of the heat generated by the heating valve, the opening degree of the cooling valve, and the difference between the heat generated by the cooling valve and the maximum heat generated by the heating valve, so that the opening degree of the heating valve is determined according to the temperature difference between the heating valve and the cooling valve, and the heating temperature can be controlled more precisely. In addition, when the film thickness increases to the preset value, the opening degree of the cooling valve will be adjusted, so that the opening degree of the cooling valve will be dynamically adjusted according to the increase of the film thickness, thus enabling more reliable control.

[0015] Furthermore, in step S3 , Is the actual temperature, Is the ambient temperature, k loss Is the heat dissipation coefficient, and then calculate the opening degree of the heating valve , at this time, the cooling valve is closed and the heating valve is relied on to maintain the temperature.

[0016] With the above settings, the opening degree of the heating valve is determined by the heat dissipation power to ensure that the opening degree of the heating valve can be adjusted in real time according to the heat dissipation situation at steady state.

[0017] Furthermore, step S4 also includes: when the temperature rises back to the preset first high temperature value, the cooling valve is at The rate is turned on to 5%; when the temperature is lower than the second height value, the heating valve is adjusted at a rate.

[0018] With the above settings, when the temperature is too high, the cooling valve is adjusted, and when the temperature is lower than the second high temperature value, the heating valve is adjusted at the same rate to ensure the reliability of the adjustment.

[0019] Further, the heating device includes a first heating pipe and a heating mechanism, and the heating mechanism is sleeved outside the first heating pipe; the cooling device includes a first cooling pipe, and one or more second cooling pipes are arranged inside the first cooling pipe, and a liquid is arranged between the first cooling pipe and the second cooling pipe.

[0020] With the above settings, the cooling valve in the cooling pipe controls the gas in the main air pipe to enter the second cooling pipe. Since water is injected between the first cooling pipe and the second cooling pipe, when the gas passes through the second cooling pipe, the heat of the gas can be absorbed by the water in the first cooling pipe to complete the cooling of the gas. The cooled gas continues to flow downward into the main air pipe and then enters the bottom diffusion plate from the main air pipe, so as to ensure the cooling and heating effects.

[0021] Further, a first flow pipe is arranged on the lower side of the first cooling pipe, and a second flow pipe is arranged on the upper side of the first cooling pipe. Both the first flow pipe and the second flow pipe are communicated with the first cooling pipe.

[0022] With the above settings, by connecting the first flow pipe to a water pipe and the second flow pipe to another water pipe, water can enter the first cooling pipe from the first flow pipe, and then the water is discharged through the second flow pipe, so as to take away the heat of the gas in the second cooling pipe through the flowing water.

[0023] Further, a gas collecting hood is arranged between the upper end of the box body and the main air pipe, a suction fan is arranged between the main air pipe and the gas collecting hood, and a grille and a sponge column are arranged between the heating pipe and the cooling pipe where the main air pipe is located.

[0024] With the above settings, the gas collecting hood is used to centrally introduce the high-temperature gas in the box body into the main air pipe. A suction fan is arranged between the main air pipe and the gas collecting hood, and the gas in the first cavity can be sucked into the main air pipe through the suction fan. Due to the arrangement of the grille and the sponge column, the air flow will encounter resistance in the main air pipe. If the valve device of the cooling pipe or the heating pipe is opened, the gas will preferentially pass through the cooling pipe or the heating pipe, and the installation positions of the grille and the sponge column are between the heating pipe and the cooling pipe.

[0025] Further, the bottom diffusion disk includes an outer diffusion disk and an inner diffusion disk. The inside of the outer diffusion disk is hollowed out. The outer diffusion disk is further provided with a second cavity and a first connection hole. The first connection hole is connected to the main air pipe. One or more second connection holes are provided on each side wall of the second cavity. The inner diffusion disk is connected to the outer diffusion disk through the second cavity. The inside of the inner diffusion disk is hollowed out. The inner diffusion disk is provided with an annular groove. The side close to the outer diffusion disk of the annular groove is the air inlet end, and the side far from the outer diffusion disk of the annular groove is the air outlet end. A third connection hole is provided on the outer side wall of the air inlet end of the inner diffusion disk, and the third connection hole is arranged corresponding to the second connection hole. The inner diffusion disk is provided with a third cavity, and a first through hole is uniformly arranged on the side wall of the third cavity.

[0026] With the above settings, the first connection hole is connected to the main air pipe. Since the inside of the outer diffusion disk is hollowed out, the gas can flow from the inside of the outer diffusion disk to the second connection hole. The inner diffusion disk is connected to the outer diffusion disk through the second cavity, and a third connection hole is provided on the outer side wall of the air inlet end of the inner diffusion disk. The third connection hole is connected to the second connection hole, so that the gas in the outer diffusion disk can flow to the inner diffusion disk. And the annular groove can be used to place the box body. When the box body is placed in the annular groove, the sealing performance between the inner diffusion disk and the box body can be ensured. A first through hole is uniformly arranged on the side wall of the third cavity. When the gas in the outer diffusion disk enters the inner diffusion disk through the second connection hole, the gas in the inner diffusion disk can uniformly transport the gas to the first cavity through the first through hole, preventing local overheating or overcooling of the temperature inside the box body and ensuring the uniformity of the temperature inside the box body.

[0027] Further, the heating pipe further includes a second heating pipeline, and a heating valve is arranged on the second heating pipeline. The heating valve includes a driving motor and a ball valve. The output shaft of the driving motor is connected to the ball valve, and the ball valve is arranged in a matching manner with the second heating pipeline. The cooling pipe further includes a third cooling pipeline, and a cooling valve is arranged on the third cooling pipeline. The cooling valve includes a driving motor and a ball valve. The output shaft of the driving motor is connected to the ball valve, and the ball valve is arranged in a matching manner with the third cooling pipeline.

[0028] With the above settings, when the gas needs to be heated, the driving motor drives the ball valve to rotate, so that the gas in the main air pipe can enter the first heating pipeline. When the heating temperature reaches the set temperature, the driving motor drives the ball valve to rotate, so that the gas in the main air pipe cannot enter the first heating pipeline. When the gas needs to be cooled, the driving motor drives the ball valve to rotate, so that the gas in the main air pipe can enter the second cooling pipeline. When the cooling temperature reaches the set temperature, the driving motor on the cooling pipe drives the ball valve to rotate, so that the gas in the main air pipe cannot enter the second cooling pipeline. Description of the Drawings

[0029] Figure 1 This is the front view of the present invention.

[0030] Figure 2 This is the sectional view of the heating device in the present invention.

[0031] Figure 3 This is the front view of the valve device in the present invention.

[0032] Figure 4 This is the front view of the cooling device in the present invention.

[0033] Figure 5 This is the exploded view of the bottom diffusion plate in the present invention.

[0034] Figure 6 is Figure 5 the sectional view at A-A in

[0035] Figure 7 is Figure 6 the enlarged view at B in

[0036] Figure 8 This is the product after printing of the present invention Figure 1 .

[0037] Figure 9 This is the product after printing of the present invention Figure 2 .

[0038] Explanation of the reference numerals in the drawings: 1 - box body; 2 - heating tube; 21 - first heating pipeline; 22 - heating plate; 23 - second heating pipeline; 3 - cooling tube; 31 - first cooling pipeline; 311 - first flow pipe; 312 - second flow pipe; 32 - second cooling pipeline; 33 - third cooling pipeline; 4 - bottom diffusion plate; 41 - outer diffusion plate; 411 - first connection hole; 412 - second connection hole; 413 - second cavity; 42 - inner diffusion plate; 421 - third connection hole; 422 - first through hole; 423 - annular groove; 424 - third cavity; 5 - cooling valve; 51 - driving motor; 52 - ball valve; 06 - heating valve; 6 - main air pipe; 61 - installation position of the exhaust fan; 62 - installation position of the grille and the sponge column; 63 - first temperature sensor installation position; 64 - second temperature sensor installation position; 7 - air collecting hood. Detailed implementation manners

[0039] Embodiment 1.

[0040] As Figure 1-9As shown, an industrial additive manufacturing constant temperature control method is controlled by an industrial additive manufacturing temperature control device. The industrial additive manufacturing temperature control device includes a box body 1. A first cavity is arranged inside the box body 1. A printing nozzle (not shown in the figure) is arranged inside the first cavity. One end of the main air pipe 6 is connected and arranged with the upper end of the box body 1. The main air pipe 6 is communicated with the first cavity. The other end of the main air pipe 6 is connected and arranged with the bottom diffusion plate 4. The bottom diffusion plate is communicated with the first cavity. A heating pipe 2 and a cooling pipe 3 are arranged along the main air pipe 6 in communication. The heating pipe 2 is provided with a heating device. The heating device includes a first heating pipe 21 and a heating mechanism. The first heating pipe 21 is sleeved with a heating mechanism; A control module is also arranged outside the industrial additive manufacturing temperature control device. The control module is any one of a PLC module, a single-chip microcomputer and a computer. The control module is the main control device for the operation of the industrial additive manufacturing temperature control device.

[0041] The cold air pipe is provided with a cooling device; the cooling device includes a first cooling pipe 31. One or more second cooling pipes 32 are arranged inside the first cooling pipe 31. A liquid is arranged between the first cooling pipe 31 and the second cooling pipes 32.

[0042] As Figure 1-2 shown, a gas collecting hood 7 is arranged between the upper end of the box body 1 and the main air pipe 6. A suction fan (not shown in the figure) is arranged between the main air pipe 6 and the gas collecting hood 7. The gas collecting hood 7 is used to place the consumables on the 3D printing device. And a suction fan (not shown in the figure) is arranged between the main air pipe 6 and the gas collecting hood 7. The gas in the first cavity can be sucked into the main air pipe 6 through the suction fan (not shown in the figure). The installation position 61 of the suction fan is located between the main air pipe 6 and the gas collecting hood 7.

[0043] A temperature sensor (not shown in the figure) is arranged inside the main air pipe 6. A temperature sensor is arranged at one end of the main air pipe 6 close to the gas collecting hood 7, which can detect the gas temperature when entering the main air pipe 6. A temperature sensor (not shown in the figure) is arranged at one end of the main air pipe 6 close to the bottom diffusion plate 4, which can detect the gas temperature when exiting the main air pipe 6. The specific positions of the temperature sensors are the temperature sensor installation position one 63 and the temperature sensor installation position two 64.

[0044] A first flow pipe 311 is arranged on the lower side of the first cooling pipe 31. A second flow pipe 312 is arranged on the upper side of the first cooling pipe 31. Both the first flow pipe 311 and the second flow pipe 312 are communicated with the first cooling pipe 31. The first flow pipe 311 is connected to a water pipe, and the second flow pipe 312 is connected to another water pipe. It can make water enter the first cooling pipe 31 from the first flow pipe 311, and then the water is discharged through the second flow pipe 312, thereby taking away the heat of the gas in the second cooling pipe 32 through the flowing water.

[0045] The main air pipe 6 is provided with a grille (not shown in the figure) and a sponge column (not shown in the figure) between the heating pipe 2 and the cooling pipe 3. Due to the arrangement of the grille (not shown in the figure) and the sponge column (not shown in the figure), the air flow will encounter resistance in the main air pipe 6. If the valve device 5 of the cooling pipe 3 or the heating pipe 2 is opened, the gas will preferentially pass through the cooling pipe 3 or the heating pipe 2. The installation positions 62 of the grille and the sponge column are located between the heating pipe 2 and the cooling pipe 3.

[0046] Both ends of the first heating pipe 21 gradually narrow towards the middle to form an arc-shaped part. A heating disc 22 is sleeved outside the arc-shaped part. Both ends of the first heating pipe 21 gradually narrow towards the middle to form an arc-shaped part, and the resistance disc is sleeved outside the arc-shaped part. The heating disc 22 heats the position of the arc-shaped part. When the gas passes through the first heating pipe 21, since the cross-sectional area in the middle of the first heating pipe 21 is smaller than that at both ends, the gas flow velocity increases at the position of the arc-shaped part, enabling the gas to quickly carry away the heat. The heating disc 22 is separated from the first heating pipe 21 to prevent dust and impurities from accumulating on the heating disc 22.

[0047] The heating pipe 2 further includes a second heating pipe 23. A heating valve 06 is arranged on the second heating pipe 23. The heating valve 06 includes a driving motor 51 and a ball valve 52. The output shaft of the driving motor 51 is connected to the ball valve 52, and the ball valve 52 is arranged in a matching manner with the second heating pipe 23. The cooling pipe 3 further includes a third cooling pipe 33. A cooling valve 5 is arranged on the third cooling pipe 33. The cooling valve 5 includes a driving motor 51 and a ball valve 52. The output shaft of the driving motor 51 is connected to the ball valve 52, and the ball valve 52 is arranged in a matching manner with the third cooling pipe 33.

[0048] With the above arrangement, when the gas needs to be heated, the driving motor 51 drives the ball valve 52 to rotate, enabling the gas in the main air pipe to enter the first heating pipe. When the heating temperature reaches the set temperature, the driving motor 51 drives the ball valve 52 to rotate, preventing the gas in the main air pipe from entering the first heating pipe. When the gas needs to be cooled, the driving motor 51 drives the ball valve 52 to rotate, enabling the gas in the main air pipe to enter the second cooling pipe 32. When the cooling temperature reaches the set temperature, the driving motor 51 on the cooling pipe drives the ball valve 52 to rotate, preventing the gas in the main air pipe from entering the second cooling pipe 32.

[0049] As Figure 5-7 shown, the bottom diffusion disc 4 includes an outer diffusion disc 41. The inside of the outer diffusion disc 41 is hollow. The outer diffusion disc 41 is further provided with a second cavity 413 and a first connection hole 411. The first connection hole 411 is connected to the main air pipe 6. One or more second connection holes 412 are arranged on each side wall of the second cavity 413. The first connection hole 411 is connected to the main air pipe 6. Since the inside of the outer diffusion disc 41 is hollow, the gas can flow from the inside of the outer diffusion disc 41 to the second connection holes 412. The bottom diffusion disk 4 further includes an inner diffusion disk 42. The inner diffusion disk is connected to the outer diffusion disk 41 through a second cavity 413. The inner diffusion disk 42 is hollow inside. The inner diffusion disk 42 is provided with an annular groove 423. The side close to the outer diffusion disk 41 of the annular groove 423 is the air inlet end, and the side far from the outer diffusion disk 41 of the annular groove 423 is the air outlet end. A third connection hole 421 is provided on the outer side wall of the air inlet end of the inner diffusion disk 42. The third connection hole 421 is arranged corresponding to the second connection hole 412. The inner diffusion disk is connected to the outer diffusion disk 41 through the second cavity 413, and a third connection hole 421 is provided on the outer side wall of the air inlet end of the inner diffusion disk 42. The third connection hole 421 is connected to the second connection hole 412, so that the gas in the outer diffusion disk 41 flows to the inner diffusion disk 42, and the annular groove 423 can be used to place the box body 1. When the box body 1 is placed in the annular groove 423, the sealing performance between the inner diffusion disk 42 and the box body 1 can be ensured.

[0050] The inner diffusion disk 42 is provided with a third cavity 424. The side wall of the third cavity 424 is uniformly provided with first through holes 422. The side wall of the third cavity 424 is uniformly provided with first through holes 422. When the gas in the outer diffusion disk 41 enters the inner diffusion disk 42 through the second connection hole 412, the gas in the inner diffusion disk can uniformly transport the gas to the first cavity through the first through holes 422, preventing local overheating or overcooling of the temperature inside the box body 1 and ensuring the uniformity of the temperature inside the box body 1.

[0051] When using this industrial additive manufacturing temperature control device, when the box body 1 is placed in the annular groove 423, it can effectively isolate the interference of the external environment, ensure the uniformity and stability of the temperature inside the cavity, and reduce the uneven shrinkage of the material caused by local temperature differences.

[0052] Embodiment Two.

[0053] An industrial additive manufacturing temperature control method, the specific steps include: Due to the heat balance equation , P heat is the heating heat, P print is the heat generated during printing, is the heat dissipated to the environment, is the heat provided by the heating valve, is the heat dissipated by the cooling valve, In this embodiment, taking the set time as 300 seconds, the target temperature as 450 °C, the normal temperature as 25 °C, the heat storage capacity of the box body as 500, and the heat generated under the standard film thickness of the printed product as 500 w, and the heat generated when the film thickness is increased as 200 w as an example for illustration.

[0054] In the S1 heating-up stage, the temperature inside the box is heated to the target temperature, and the feedforward heating requirement is calculated , where C is the heat storage capacity of the box, T set is the target temperature, T0 is the normal temperature, Δt is the set time, and then the opening degree of the heating valve is calculated ; , where is the maximum heating power provided by the heating device, and the opening degree of the cooling valve is calculated ; , where is the maximum heat dissipation power of the cooling device, and P print is the heat generation power during printing; The opening degree of the heating valve is adjusted from the preset opening degree to the opening degree of the heating valve at a preset rate ; The opening degree of the cooling valve is adjusted from the closed state to the opening degree of the cooling valve according to the preset valve opening degree rate; In this embodiment, the opening degree of the heating valve: from 20% (i.e., the preset opening degree) → 75%, and the rate limit is Δuh / Δt ≤ 0.5% / s; The opening degree of the cooling valve: from 0% → 5%, with the same rate Δuc / Δt ≤ 0.5% / s.

[0055] The opening degree adjustment is preset to be performed every 10 seconds.

[0056] In the S2 steady-state control stage during printing, the opening degree of the heating valve is determined according to the heat generated by the printing nozzle, the current opening degree of the cooling valve, the maximum heat generated by cooling, and the maximum heat generated by heating ; , where u c is the opening degree of the cooling valve, and then through PID feedback regulation, for the case where the printing nozzle generates 500w power, the initial PID parameters are: Then on this basis, the opening degrees of the heating valve and the cooling valve are adjusted according to the PID algorithm. The specific PID algorithm is as follows: ; where is the output, is the input such as the current opening degree of the heating valve or the cooling valve.

[0057] If the film thickness exceeds the preset value (it can be detected by the film thickness detection device or determined that the film thickness has exceeded the preset value when the preset film thickness is reached within the preset time period), the opening degree of the cooling valve is adjusted, and the opening degree of the cooling valve ; The heat that the printing nozzle needs to generate to increase the film thickness, that is, after reaching the preset film thickness, the initial opening of the cooling valve is adjusted from 5% to 13.3%, so that the opening of the cooling valve increases, thereby improving the cooling effect of the cooling valve, and thus enabling rapid cooling when generating a large amount of heat.

[0058] In the maintenance control stage after S3 printing ends, calculate the heat dissipation power , where T actual is the actual temperature, T ambient is the ambient temperature, and these two temperatures can be measured by means of a temperature sensor. k loss is the preset heat dissipation coefficient, and then calculate the opening of the heating valve . At this time, close the cooling valve and rely on the heating valve to maintain the temperature.

[0059] In the non-printing state maintenance stage, the heating valve is completely closed. When the temperature rises to the first high temperature value such as 460 °C, the cooling valve opens to 5% at a rate of Δ uc ≤0.5% / s . When the temperature is lower than the second high temperature value such as 440 °C, the heating valve is fine-tuned at a rate of Δ uh ≤0.5% / s .

[0060] As Figure 8-9 shown, for the product produced by adjusting through the above temperature control method, it can be seen from the figure that the texture is clear and there is no large-area depression, so that the overall forming effect is good and the temperature control effect is good.

[0061] The working principle of the present invention: A first cavity is provided in the box body 1, and the first cavity can be used to place a 3D printing device. A heating pipe 2 is connected and provided on one side of the main air pipe 6. When the temperature in the first cavity is lower than the set temperature, the valve device 5 in the heating pipe 2 controls the gas in the main air pipe 6 to enter the first heating pipe 21, and the heating device heats the gas in the first heating pipe 21 to complete the heating of the gas. The heated gas continues to flow downward into the main air pipe 6 and then enters the bottom diffusion plate 4 from the main air pipe 6; The cooling pipe 3 is provided with a first cooling pipe 31, and a plurality of second cooling pipes 32 are provided in the first cooling pipe 31. When the temperature in the first cavity is higher than the set temperature, the valve device 5 in the cooling pipe 3 controls the gas in the main air pipe 6 to enter the second cooling pipe 32. Since water is injected between the first cooling pipe 31 and the second cooling pipe 32, when the gas passes through the second cooling pipe 32, the heat of the gas can be absorbed by the water in the first cooling pipe 31 to complete the cooling of the gas. The cooled gas continues to flow downward into the main air pipe 6 and then enters the bottom diffusion plate 4 from the main air pipe 6; The heated or cooled gas flows through the main air pipe 6 to the bottom diffusion plate 4, and the gas flows from the bottom diffusion plate 4 into the first cavity to complete the temperature regulation of the box body 1; when the temperature does not need to be regulated, the drive motor 51 controls the ball valve 52 so that the gas does not enter the heating pipe 2 or the cooling pipe 3.

[0062] During the temperature control process, in the heating-up stage, the feed-forward heating demand is first determined by the difference between the target temperature and the actual temperature, the opening degree of the heating valve is determined according to the feed-forward heating demand, and the opening degree of the cooling valve is determined according to the heat generated by the print head and the maximum cooling temperature. Then, the heating valve is adjusted from the starting opening degree to the opening degree of the heating valve at a preset rate, and the cooling valve is adjusted from the closed state to the opening degree of the cooling valve at a preset speed. This can ensure that the heating valve and the cooling valve are adjusted at a certain rate, and the feed-forward heating demand can be met after the heating valve is opened, so that the situation of linear heating-up will not occur, and the temperature control in the heating-up stage is good. When in the printing steady state, the opening degree of the feed-forward heating valve is determined by the heat generated by the heating valve and the cooling temperature generated by the cooling valve at the current opening degree and the maximum heating temperature, and the opening degree of the heating valve is initially determined. Then, the dynamic opening degrees of the heating valve and the cooling valve are adjusted by the PID algorithm, so as to realize reliable and stable maintenance at the preset temperature in the steady state. In addition, after the forming printing process is completed, the cooling valve is closed, and the opening degree of the heating valve is determined according to the heat dissipation power to maintain a certain temperature of the box body, preventing direct cooling from causing the formed part to change from a hot state to a cold state, resulting in depressions in some positions and affecting the forming effect. In addition, when maintaining in the non-printing state, the heating valve is directly closed, reducing energy consumption and ensuring the cooling effect of the formed product at the same time. The temperature control effect is good and the forming effect is good through the temperature control methods at different stages and different temperatures.

[0063] When using this control method to print PEEK materials, forced cooling can be avoided, and the heating and cooling rates can be controlled. Therefore, forced cooling can be avoided, and the crystallinity of PEEK materials can be effectively improved, making the hardness and strength of PEEK materials significantly improved.

[0064] And controlling the heating and cooling rates can avoid stress concentration in the box body, and can also better maintain the stability of the printed product, reduce warping and cracking of the printed product, and meet the strict requirements for printing quality in high-end application fields.

Claims

1. A temperature control method for industrial additive manufacturing, implemented by a temperature control device, the temperature control device comprising a box, wherein a first cavity is provided in the box, characterized in that: The upper end of the box is connected to one end of the main air pipe, the main air pipe is connected to the first cavity, the other end of the main air pipe is connected to the bottom diffusion plate, the bottom diffusion plate is connected to the first cavity, a heating pipe and a cooling pipe are connected along the main air pipe, the heating pipe is provided with a heating device and a heating valve; the cold air pipe is provided with a cooling device and a cooling valve; a 3D printing nozzle is provided in the box; the specific steps include: S1 heating stage, according to the preset target temperature and the actual temperature difference, the box body heat storage capacity coefficient and the set time, the feedforward heating demand is calculated ; Then calculate the heating valve opening according to the feedforward heating demand and the maximum heating capacity ; Adjust the heating valve opening from the preset opening size to the heating valve opening size according to the preset rate ; Determine the cooling valve opening degree according to the heat generated by the print head, the maximum heat dissipation power of the cooling device, and the minimum value of the set opening degree; adjust the cooling valve opening degree from the closed state to the cooling valve opening degree according to the preset valve opening rate; S2 is the steady-state control stage during printing. The heating valve opening is determined based on the heat generated by the print head, the current opening of the cooling valve, the maximum heat generated by cooling, and the maximum heat generated by heating. ; Then through PID feedback regulation, the cooling valve opening is adjusted according to the increased heat generated by printing; S3: Maintenance control phase after printing is completed, calculate the heat dissipation power ; and determine the opening of the heating valve according to the heat dissipation power and the maximum heat generated by the heating valve and keep the cooling valve in a closed state; S4 non-printing state maintenance stage, the heating valve is closed at a preset rate.

2. The industrial additive manufacturing temperature control method according to claim 1, characterized in that: In step S1: Feedforward heating demand , C is the preset box's heat storage capacity, T set is the target temperature, T0 is the normal temperature, △t is the set time; Heating valve opening ; The maximum heating power provided by the heating device, the cooling valve opening ; is the maximum heat dissipation power of the cooling device, P print The power for printing heat.

3. The industrial additive manufacturing temperature control method according to claim 1, characterized in that: In step S2, the heating valve opening ; Step S2 also includes adjusting the opening of the cooling valve when the film thickness exceeds a preset value. ; The heat required to generate by the print head to increase the film thickness.

4. The industrial additive manufacturing temperature control method according to claim 1, characterized in that: In step S3 , T actual is the actual temperature, T ambient is the ambient temperature, k loss is the heat dissipation coefficient, and then calculate the heating valve opening At this time, close the cooling valve and rely on the heating valve to maintain the temperature.

5. The industrial additive manufacturing temperature control method according to claim 1, characterized in that: Step S4 also includes: when the temperature rises to the preset first high temperature value, the cooling valve is turned on at Δ uc ≤0.5% / s When the temperature is lower than the second height value, the heating valve opens at a rate of Δ uh ≤0.5% / s The rate is adjusted.

6. The industrial additive manufacturing temperature control method according to claim 1, characterized in that: The heating device comprises a first heating pipe and a heating mechanism, wherein the first heating pipe is provided with a heating mechanism; the cooling device comprises a first cooling pipe, wherein one or more second cooling pipes are provided in the first cooling pipe, and liquid is provided between the first cooling pipe and the second cooling pipe.

7. The industrial additive manufacturing temperature control method according to claim 1, characterized in that: A first flow pipe is disposed at the lower side of the first cooling pipe, and a second flow pipe is disposed at the upper side of the first cooling pipe. Both the first flow pipe and the second flow pipe are connected to the first cooling pipe.

8. The industrial additive manufacturing temperature control method according to claim 1, characterized in that: An air collecting hood is arranged between the upper end of the box body and the main air pipe, an exhaust fan is arranged between the main air pipe and the air collecting hood, and a grid and a sponge column are arranged on the main air pipe between the heating pipe and the cooling pipe.

9. The industrial additive manufacturing temperature control method according to claim 1, characterized in that: The bottom diffuser plate includes an outer diffuser plate and an inner diffuser plate, the outer diffuser plate is hollowed out, the outer diffuser plate is also provided with a second cavity and a first connecting hole, the first connecting hole is connected to the main air pipe, and each side wall of the second cavity is provided with more than one second connecting hole; the inner diffuser plate is connected to the outer diffuser plate through the second cavity, the inner diffuser plate is hollowed out, the inner diffuser plate is provided with an annular groove, the side of the annular groove close to the outer diffuser plate is the air inlet end, and the side of the annular groove away from the outer diffuser plate is the air outlet end, the outer side wall of the air inlet end of the inner diffuser plate is provided with a third connecting hole, and the third connecting hole is provided corresponding to the second connecting hole; the inner diffuser plate is provided with a third cavity, and the side wall of the third cavity is evenly provided with first perforations.

10. The industrial additive manufacturing temperature control method according to claim 1, characterized in that: The heating pipe also includes a second heating pipe, on which a heating valve is arranged, and the heating valve includes a driving motor and a ball valve, the output shaft of the driving motor is connected to the ball valve, and the ball valve is matched with the second heating pipe. The cooling pipe also includes a third cooling pipe, on which a cooling valve is arranged, and the cooling valve includes a driving motor and a ball valve, the output shaft of the driving motor is connected to the ball valve, and the ball valve is matched with the third cooling pipe.

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