3D printing system based on zone temperature control and control method thereof

Abstract

The present application provides a 3D printing system and a control method thereof, the 3D printing system comprising: a material conveying system; a fixed print head connected to the material conveying system for extruding materials; a movable chamber having side walls, a forming platform being arranged in the space surrounded by the side walls; a middle partition located between the material conveying system and the chamber and arranged around the print head; a first heating component for heating the middle partition to form a heated first area; a control unit electrically connected to the print head and the first heating component for controlling the movement of the chamber relative to the print head during printing so that the material is deposited at different positions of the forming platform; and changing the first area as the chamber moves so that the first area corresponds to the area where the chamber is currently located. The 3D printing system can achieve zoned temperature control, thereby reducing energy consumption.

Description

[0001] This application claims priority to Chinese patent application No. 202110469563.5, filed on April 28, 2021, and entitled “3D printing system based on zoned temperature control and control method thereof”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention relates to the field of 3D printing, and more specifically, to a 3D printing system and a control method thereof. Background Art

[0003] 3D printing technologies based on material extrusion, such as fused deposition modeling (FDM), have been widely used in the field of 3D printing.

[0004] Material extrusion technology usually requires heating the material to a molten state, and then extruding the molten material onto a forming platform through a print head. The molten material is deposited layer by layer on the forming platform and solidified together to form a 3D printed part.

[0005] However, the solidification process of the molten material is greatly affected by the ambient temperature. If the ambient temperature is too high, the deposited molten material is not easy to solidify, resulting in collapse and wire drawing of the printed parts. If the ambient temperature is too low, the deposited molten material solidifies too quickly, resulting in loose interlayer bonding and a tendency for parts to crack. Therefore, how to accurately control the temperature of the extruded material has always been a research hotspot in this field. Summary of the invention

[0006] In a first aspect, a 3D printing system is provided, comprising: a material conveying system for conveying molten material; a fixed-position print head connected to the material conveying system and used to extrude the material; a movable chamber having side walls, a forming platform being provided in a space enclosed by the side walls, the forming platform being used to carry the material extruded by the print head; a middle partition plate located between the material conveying system and the chamber and arranged around the print head; a first heating component for heating the middle partition plate to form a heated first area; a control unit electrically connected to the print head and the first heating component, for controlling the movement of the chamber relative to the print head during printing so that the material is deposited at different positions of the forming platform; and changing the first area as the chamber moves so that the first area corresponds to the area where the chamber is currently located.

[0007] In a second aspect, a control method for a 3D printing system is provided, the 3D printing system comprising: a material conveying system for conveying molten material; a fixed-position print head connected to the material conveying system for extruding the material; a movable chamber having side walls, a forming platform being provided in a space enclosed by the side walls, the forming platform being used to carry the material extruded by the print head; a middle partition plate located between the material conveying system and the chamber and arranged around the print head; a first heating component for heating the middle partition plate to form a heated first area; the control method comprising: controlling the chamber to move relative to the print head so that the material is deposited at different positions of the forming platform; and controlling the first area to change as the chamber moves so that the first area corresponds to the area where the chamber is currently located.

[0008] The embodiment of the present application provides a zoned temperature control solution for a 3D printing system, which can accurately control the temperature of molten materials and reduce energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the structure of the 3D printing system provided in an embodiment of the present application.

[0010] Figure 2 yes Figure 1 Schematic diagram of the first heating component in the 3D printing system performing zone heating on the middle partition.

[0011] Figure 3 yes Figure 1 Another schematic diagram of the first heating component in the 3D printing system performing zoned heating on the middle partition.

[0012] Figure 4 is another structural schematic diagram of the 3D printing system provided in an embodiment of the present application.

[0013] Figure 5 It is a flowchart of a control method of a 3D printing system provided in an embodiment of the present application.

[0014] Figure 6 Detailed description of another flow chart of the control method of the 3D printing system provided in the embodiment of the present application. DETAILED DESCRIPTION

[0015] The 3D printing system usually sets the forming platform in the forming temperature control chamber. The position of the forming temperature control chamber of the existing 3D printing system is fixed. During the printing process, the forming platform will move within the space defined by the forming temperature control chamber, for example, the forming platform can move in the vertical direction and / or the plane direction relative to the print head within the space.

[0016] The above system design requires that the space of the forming temperature control room is large enough to meet the movement requirements of the forming platform. The overall temperature control of the forming temperature control room with a large space increases the difficulty of temperature control on the one hand, and also has the problem of high energy consumption on the other hand.

[0017] Specifically, when the object to be printed by the 3D printing system is large in volume, for example, when the 3D printing system uses an extruder that can support one-time surface forming (i.e., the length of the extruder can change with the change of the cross-sectional contour line of the part to be printed, for relevant descriptions, see WO2018 / 205149 A1, WO2020 / 087359 A1, etc.) to print super-large parts, the forming platform will inevitably need a larger moving space. In such scenarios, the above problems are particularly prominent.

[0018] The above-mentioned extrusion port capable of supporting one-time surface forming has a one-dimensional strip feature, that is, the length of the extrusion port in one dimension is much greater than its length in another dimension, and the extrusion port can change its length in the one-dimensional direction as the cross-sectional profile of the part to be printed changes, thereby forming an extrusion port of variable length, and then the material filling of the entire cross-section or a partially connected area in the cross-section can be completed through a unidirectional movement. The 3D printing method with this extrusion port feature can be called "Fused sheet deposition 3D printing" (FSD for short).

[0019] In order to solve the above problems, the present application provides a 3D printing system. Figure 1 As shown, the 3D printing system includes a material conveying system 1, a print head 2, a chamber 3, a forming platform 4, a middle partition 5, a first heating component 6 and a control unit 7.

[0020] The material conveying system 1 can be used to convey molten materials. For example, the material conveying system 1 can be a material conveying system formed by a single-stage or multi-stage screw feeding device, or the material conveying system 1 can be a pneumatic material conveying system or a piston material conveying system. The material conveying system 1 can heat solid materials to a molten state, or a flowable state, and transport the molten material (hereinafter referred to as molten material) to the print head 2.

[0021] The print head 2 is connected to the material delivery system 1 (fluid connection). The print head 2 can be a fixed position print head. For example, it can be fixed at Figure 1 The print head 2 is provided with a discharge port (not shown in the figure). The discharge port can also be called an extrusion port, and the print head 2 can extrude the molten material outward through the discharge port. Figure 1As shown, the print head 2 can extend downward from the middle partition 5 by a very small fixed distance, so that the discharge port of the print head 2 is placed above the forming platform 4 and as close to the forming platform 4 as possible.

[0022] The present application does not specifically limit the structural form of the discharge port of the print head 2. For example, the discharge port may be a discharge port with a variable length. As an example, the discharge port may change with the change of the cross-sectional contour of the area to be printed (or the cross section to be printed, which may be an irregular shape), so that the printing area can be printed or filled completely at one time. In other words, during the process of printing a certain area, the two ends of the discharge port in the length direction may always be aligned with the cross-sectional contour line of the area in the vertical direction. This printing method may be referred to as a printing method based on surface forming (as distinguished from the traditional line forming printing method in a successive pass).

[0023] The chamber 3 has a side wall 31. The side wall 31 encloses a second area 32, and the forming platform 4 is located in the second area 32. The side wall of the chamber 3 can be rectangular, cylindrical or cylindrical. The chamber 3 can be used to control the temperature of the material on the forming platform 4, so the chamber 3 can be called a temperature control cylinder.

[0024] The chamber 3 is movable. For example, the chamber 3 can drive the forming platform 4 to move in a plane (the plane refers to a plane parallel to the bottom surface of the middle partition). There are many ways to realize the movement of the chamber 3. For example, a movable platform can be set at the bottom of the chamber 3 to drive the movement of the chamber 3. The movable platform can be driven by a belt or a screw, which is not limited in the embodiments of the present application.

[0025] There may be a certain distance between the upper end of the chamber 3 and the middle partition 5. This distance can make the upper end of the chamber 3 lower than the bottom end of the print head 2 (the bottom of the discharge port) by a very small fixed distance. The setting of this distance is sufficient as long as it can avoid the print head 2 from colliding with the side wall 31. This distance setting method can not only ensure that the print head 2 does not collide with the side wall 31 of the chamber 3, but also can minimize the influence of the external environment (such as external temperature) on the forming process of the material inside the chamber 3. Of course, in other embodiments, the upper end of the chamber 3 and the middle partition can be connected together by some flexible components, so as to better control the temperature inside the chamber 3.

[0026] As mentioned above, the forming platform 4 can move in a plane following the chamber 3. In some embodiments, the forming platform 4 can also perform lifting and lowering motion and / or rotational motion relative to the chamber 3. For example, a lifting device 41 can be provided at the bottom of the forming platform 4, so as to drive the forming platform 4 to move up and down. In addition, the lifting device 41 can also be connected to the forming platform 4 through a rotating shaft, so as to drive the forming platform 4 to rotate.

[0027] It can be seen that the print head 2 in the embodiment of the present application is fixed and the forming platform 4 is movable. In the specific printing process, the movement of the forming platform 4 can be controlled so that the molten material extruded by the fixed print head 2 falls on the forming platform 4 layer by layer according to a preset trajectory, thereby printing a 3D printed part 20.

[0028] The middle partition 5 may be located between the material conveying system 1 and the chamber 3. The middle partition 5 may be arranged around the print head 2. For example, a mounting hole for the print head 2 may be provided in the center of the middle partition 5, and the print head 2 may be installed on the middle partition 5 through the mounting hole and pass through the middle partition to reach a position close to the forming platform 4. The provision of the middle partition 5 can prevent the temperature of the material conveying system 1 from affecting the material deposition process on the forming platform 4 to a certain extent.

[0029] Continue to see Figure 1 and Figure 2 , the first heating component 6 can be used to heat the middle partition 5. The first heating component 6 can be embedded in the middle partition 5, or it can be located on the outer wall of the middle partition 5. The first heating component 6 can be a heater formed by a resistance wire, etc., or it can be other types of heaters (such as infrared or electromagnetic heaters). The first heating component 6 can heat any area in the middle partition 5 to form multiple heating areas. For example, a heated first area 51 can be formed. The first area 51 corresponds to the area where the chamber 3 is currently located.

[0030] The control unit 7 can be electrically connected to the print head 2 and the first heating component 6. During the printing process, the control unit 7 can control the chamber 3 to move relative to the print head 2 so that the material is deposited at different positions on the forming platform 4. As the chamber 3 moves, the control unit 7 can also change the first area 51 so that the first area 51 corresponds to the area where the chamber 3 is currently located. For example, the first area 51 is controlled to always be located directly above the chamber 3. Figure 2 As shown, the middle partition 5 can be divided into many small temperature control units ( Figure 2 Each small square in the figure represents a temperature control unit). A heater can be set in each temperature control unit. The white square represents that the corresponding heater is in the off state; the gray square represents that the corresponding heater is in the on state. Figure 2 circled in the figure) to move to Figure 2 When in the position shown, the control unit 7 can control the heaters in the grids covered by the chamber 3 (which can refer to full coverage or partial coverage) to be in the on state, and the heaters in the uncovered grids to be in the off state.

[0031] In addition, in some embodiments, the control unit 7 can also control the length of the material outlet of the print head 2 to change as the cross-sectional contour line of the area to be printed changes, so as to fill the material into the area to be printed at one time.

[0032] The present application does not impose any specific restrictions on the composition of the control unit 7. For example, the control unit 7 may include multiple independent control units, which respectively control components such as the print head or the chamber; or the control unit 7 may also be an integrated master controller, through which various parts of the 3D printing system can be controlled.

[0033] The embodiment of the present application provides a zoned temperature control solution for a 3D printing system, which can change the temperature control position during the printing process, thereby reducing energy consumption.

[0034] Combination of the above Figure 1 and Figure 2 , describes in detail the control method of the first area that changes dynamically with the movement of the chamber 3. During the movement of the chamber 3, some areas can also be preheated, cooled down in advance, or stopped heating according to the movement trajectory of the chamber 3, making the zone temperature control more reasonable and accurate.

[0035] In some embodiments, the control unit 7 can also control the first heating component 6 to heat the area to which the chamber 3 is about to move in advance. Since the movement trajectory of the chamber 3 is known, the area to which the chamber 3 is about to move can also be predetermined. Figure 3 For example, assuming that chamber 3 is currently located directly below first region 51 (i.e., the region covered by the solid circle), and based on the print track of the print head, it can be determined that chamber 3 is about to move to region 52 (i.e., the region covered by the dotted circle), the heater in the small square covered by region 52 but not covered by first region 51 can be turned on in advance. The region to which chamber 3 is about to move can be determined based on actual conditions, for example, it can be determined by comprehensively considering factors such as the heating rate of the heater and the moving speed of chamber 3. For example, the region to which chamber 3 is about to move in the next millisecond, second, or seconds can be regarded as the "region to which chamber 3 is about to move".

[0036] The control unit 7 can also control the first heating component 6 to reduce the heating temperature of the area of ​​the chamber 3 that is about to be left, or stop heating the area in advance. Figure 3 For example, assuming that chamber 3 is currently located directly below the first area 51 (i.e., the area covered by the solid circle), and based on the printing trajectory of the print head, it can be determined that chamber 3 is about to move to area 52 (i.e., the area covered by the dotted circle), the heater in the small square covered by the first area 51 but not covered by area 52 can be turned off, or its heating temperature can be lowered.

[0037] The 3D printing system provided in the embodiment of the present application can preheat part of its temperature control area in advance, reduce the heating temperature in advance or stop heating, thereby avoiding the influence of the time lag of temperature change and making the heating efficiency of the entire system higher.

[0038] It is mentioned above that the forming platform 4 is located in the chamber 3. In some embodiments, the forming platform 4 can be at a significant distance from the side wall 31 of the chamber 3. In other embodiments, in order to improve the controllability of the temperature, the forming platform 4 and the side wall 31 can be designed to have a very small gap, or even close together. For example, assuming that the chamber 3 is cylindrical, the forming platform 4 can also be designed to be cylindrical, and the diameter of the forming platform 4 is basically consistent with the diameter of the inner wall of the chamber 3 (of course, the diameter of the forming platform 4 needs to be slightly smaller than the diameter of the side wall 31). In this way, see Figure 1 The middle partition plate 5, the side wall 31 of the chamber 3 and the forming platform 4 can together form a forming temperature control chamber 10 for the material. Temperature control of the forming temperature control chamber 10 can further reduce the volume of the temperature control area and improve the controllability of the temperature.

[0039] The position of the forming temperature control chamber 10 is variable, for example, the forming temperature control chamber 10 can move with the movement of the chamber 3. In addition, the size of the forming temperature control chamber 10 can be variable, for example, the forming temperature control chamber 10 can be increased as the forming platform 4 descends. Compared with the traditional solution of using a fixed forming temperature control chamber 10 for temperature control, the temperature control solution provided by the embodiment of the present invention is more flexible and reliable.

[0040] As a way to achieve this, Figure 4 As shown, a heat insulation layer 30 (such as Figure 4 That is, the heat insulation layer 30 may be located at least one of the forming platform 4, the side wall 31 of the chamber 3, or the middle partition 5. For example, Figure 4 In the embodiment, a heat insulating layer 30 is provided below the forming platform 4, on the outer wall of the side wall 31 of the chamber 3, and on the upper surface of the middle partition plate 5, that is, a heat insulating layer 30 is provided on the outer side of all the walls of the forming temperature control chamber 10. The heat insulating layer 30 can reduce the influence of the external environment on the forming temperature control chamber 10, and can also reduce the diffusion of the temperature in the forming temperature control chamber 10 to the outside.

[0041] As mentioned above, the bottom of the forming platform 4 may be provided with a lifting device 41, which can control the forming platform 4 to gradually descend as the material is deposited during the printing process. Since the distance between the middle partition 5 and the forming platform 4 will gradually increase as the forming platform 4 descends, the volume of the forming temperature control chamber 10 will gradually increase. If only the first heating component 6 is used to heat the forming temperature control chamber 10, the heat needs to be transferred from top to bottom, resulting in insufficient heating efficiency.

[0042] In order to solve the above problems, Figure 4 As shown, the 3D printing system provided in the embodiment of the present application may also be provided with a second heating component 8. The second heating component 8 may be a heater formed by a resistance wire or the like, or may be other types of heaters (such as infrared or electromagnetic heaters). The second heating component 8 may heat the side wall 31 of the chamber 3 to form a heated second area 32. The second heating component 8 may be installed on the inner side or outer side of the side wall 31 of the chamber 3, or may be embedded in the middle of the inner and outer sides of the side wall 31 of the chamber 3.

[0043] Furthermore, in some embodiments, the control unit 7 may also change the second area 32 as the forming platform 4 descends, so that the second area 32 corresponds to the area between the forming platform 4 and the middle partition plate 5. For example, the second area 32 may be an area on the side wall 31 of the chamber 3 between the forming platform 4 and the middle partition plate 5.

[0044] In the embodiment of the present application, the control unit 7 controls the second heating component 8 to heat the second area 32. The second area 32 can change as the forming platform 4 descends, so that the forming temperature control chamber 10 can obtain multi-directional heat energy, thereby improving the uniformity and efficiency of heating.

[0045] As a way to achieve this, Figure 4 As shown, the first heating component 6 can be a plurality of heaters evenly distributed in the middle partition 5. The second heating component 8 can be a plurality of heaters evenly distributed in the side wall 31 of the chamber 3. The control unit 7 can control the on and off of the plurality of heaters respectively, and control the heater corresponding to the current forming temperature control chamber 10 to be in a heating state, and the heater away from the forming temperature control chamber 10 to be in an off state. The heater corresponding to the current forming temperature control chamber 10 can be a heater located in the first area 51, and / or a heater located in the second area 32. Such a setting makes the control method of the zone temperature control simpler and the heating more uniform.

[0046] As a way to achieve this, Figure 4As shown, a third heating component 9 can also be provided for the 3D printing system. The third heating component 9 can be a heater formed by a resistance wire or the like, or can be other types of heaters (such as infrared or electromagnetic heaters). The third heating component 9 can heat the forming platform 4. The third heating component 9 can be provided inside or on the outer wall of the forming platform 4. For example, the third heating component 9 can be a plurality of heaters embedded inside the forming platform 4 and evenly distributed. It can be seen from the foregoing that the molten material can be deposited and formed on the forming platform 4 in the forming temperature control chamber 10. Therefore, by providing the third heating component 9, all directions of the forming temperature control chamber 10 can be heated, and the heating efficiency is higher.

[0047] The material in a molten state has its own heat, and the temperature and volume of the input material can be calculated in advance. Therefore, in some embodiments, in order to more accurately control the temperature of the forming temperature control chamber 10, the heat input of the material to the forming temperature control chamber 10 can be taken into account. In other words, the control unit 7 can control the temperature of the forming temperature control chamber 10 according to the heat input of the molten material. For example, a temperature control function can be set according to the heat input of the molten material to control at least one of the first heating component 6, the second heating component 8, and the third heating component 9, so that the temperature in the forming temperature control chamber 10 remains stable.

[0048] In some embodiments, the lifting device 41 may include a support rod 411 supporting the forming platform. The support rod 411 may be cylindrical. The support rod 411 may be provided with one or more ventilation holes 412. The one or more ventilation holes 412 may be used to cool the portion of the chamber 3 below the bottom surface of the forming platform 4 to prevent the temperature above the forming platform 4 from being conducted downward and affecting the performance of the mechanical components below the forming platform 4. For example, when the forming platform 4 is a rotatable forming platform, the support rod 411 may be supported on a turntable. Providing the one or more ventilation holes 412 may prevent the high temperature above the forming platform 4 from affecting the mechanical properties of the turntable below the forming platform 4.

[0049] In some embodiments, one or more ventilation holes (not shown in the figure) may also be provided on the middle partition 5. The one or more ventilation holes can be used to control the temperature inside the chamber 3. For example, air or refrigerant can be sucked in through the one or more ventilation holes to cool the chamber 3. The one or more ventilation holes can be in a normally open state, and can also be opened or closed according to actual needs. Take the example of a plurality of ventilation holes provided on the middle partition 5. The control unit 7 can perform on-off control on the plurality of ventilation holes according to actual needs. The on-off control strategy can refer to the control strategy of the first area mentioned above, that is, the state of the ventilation holes can be controlled to change with the change of the position of the chamber, so that the ventilation holes in the first area are in an open state. Of course, whether to enable the ventilation holes on the middle partition 5 can also be selected according to actual conditions. For example, when the temperature of chamber 3 generates a continuous heat input due to continuous material extrusion, at the same time, the insulation layer of chamber 3 makes the heat output less. This continuous heat accumulation causes the temperature of chamber 3 to exceed the temperature required for forming. In this case, after disconnecting the first heating component, the chamber temperature can only be cooled by natural cooling. At this time, the ventilation holes on the middle partition 5 can be opened to quickly reduce the chamber temperature, thereby realizing accurate and fast regulation of the chamber temperature.

[0050] Combination of the above Figure 1-Figure 4 , describes in detail the device embodiment of the present application. Figure 5-Figure 6 , describing a method embodiment of the present application. It should be understood that the method can be executed by the 3D printing system mentioned above, for example, can be executed by the control unit of the 3D printing system. Therefore, the parts not described in detail can be referred to above.

[0051] Specifically, the 3D printing system may include: a material conveying system for conveying molten materials; a fixed-position print head connected to the material conveying system for extruding materials; a movable chamber having side walls, a forming platform being arranged in the space enclosed by the side walls, the forming platform being used to carry the materials extruded by the print head; a middle partition plate located between the material conveying system and the chamber and arranged around the print head; and a first heating component for heating the middle partition plate.

[0052] Figure 5 The control method includes step S10 and step S20.

[0053] In step S10, the chamber is controlled to move relative to the print head so that the material is deposited at different positions of the forming platform.

[0054] In step S20, the first area is controlled to change with the movement of the chamber so that the first area corresponds to the area where the chamber is currently located, and the first heating component is controlled to heat the first area.

[0055] It should be understood that the embodiment of the present application does not specifically limit the order in which steps S10 and S20 are executed, and the two can be executed in parallel.

[0056] Alternatively, if Figure 6 As shown, step S20 may also include the following step S21, namely, controlling the third area to correspond to the area to which the chamber is about to move, and / or controlling the fourth area to correspond to the area that the chamber is about to leave, controlling the first heating component to preheat the third area; and / or controlling the first heating component to lower the temperature of the fourth area or stop heating the fourth area.

[0057] Optionally, the 3D printing system further includes a lifting device and a second heating component. The lifting device may be located at the bottom of the forming platform, and is used to control the forming platform to gradually descend as the material is deposited during the printing process; the second heating component may be used to heat the side wall of the chamber. Figure 6 As shown, the control method may further include step S30, i.e. controlling the second area to change as the forming platform descends so that the second area corresponds to the area between the forming platform and the middle partition, and controlling the second heating component to heat the second area.

[0058] Optionally, the middle partition, the side wall of the chamber and the forming platform of the 3D printing system can together form a forming temperature control chamber. Figure 6 As shown, the control method may further include step S40, namely controlling the temperature of the forming temperature control chamber according to the heat input of the material.

[0059] Optionally, the middle partition is further provided with ventilation holes for controlling the temperature inside the chamber; Figure 6 The control method may further include: controlling the ventilation holes on the middle partition plate located in the first heating area to open to ventilate the chamber.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A 3D printing system, characterized in that: include: Material conveying system, used to convey molten materials; A fixed-position print head connected to the material conveying system for extruding the material; A movable chamber having side walls, wherein a forming platform is arranged in the space enclosed by the side walls, and the forming platform is used to carry the material extruded by the print head; a middle partition, located between the material delivery system and the chamber and arranged around the print head; A first heating component is used to heat the middle partition to form a heated first area, and the first area is used to control the temperature of the forming temperature control chamber of the material formed around the middle partition, the side wall of the chamber and the forming platform; A control unit is electrically connected to the print head and the first heating component, and is used to control the movement of the chamber relative to the print head during printing so that the material is deposited at different positions on the forming platform; and to change the first area as the chamber moves so that the first area corresponds to the area where the chamber is currently located.

2. The 3D printing system according to claim 1, characterized in that: Also includes: A lifting device, located at the bottom of the forming platform, used to control the forming platform to gradually descend as the material is deposited during the printing process; a second heating component, used for heating the side wall of the chamber to form a heated second area; The control unit is further configured to change the second area as the forming platform descends, so that the second area corresponds to an area between the forming platform and the middle partition plate.

3. The 3D printing system according to claim 2, characterized in that: The lifting device comprises a support rod for supporting the forming platform, and a ventilation hole is arranged inside the support rod for cooling a portion of the chamber located below the bottom surface of the forming platform.

4. The 3D printing system according to claim 1, characterized in that: Also includes: The third heating component is used to heat the forming platform.

5. The 3D printing system according to claim 1, characterized in that: A heat insulation layer is arranged in at least one wall portion of the forming temperature control chamber.

6. The 3D printing system according to claim 1, characterized in that: The control unit is further used to control the first heating component to preheat a third area, wherein the third area is an area on the middle partition, and the third area corresponds to the area to which the chamber is about to move; and / or, The control unit is further used to control the first heating component to reduce the temperature of a fourth area or stop heating the fourth area, where the fourth area belongs to the first area and corresponds to an area that the chamber is about to leave.

7. The 3D printing system according to claim 2, characterized in that: The first heating component is a plurality of heaters evenly distributed in the middle partition; and / or the second heating component is a plurality of heaters evenly distributed in the side wall of the chamber.

8. The 3D printing system according to claim 1, characterized in that: The control unit is also used to control the temperature of the forming temperature control chamber according to the heat input of the material.

9. The 3D printing system according to any one of claims 1 to 8, characterized in that: The print head includes a discharge port with adjustable length; The control unit is further used to control the length of the material outlet to change as the cross-sectional contour line of the area to be printed changes, so as to fill the material into the area to be printed at one time.

10. The 3D printing system according to claim 1, characterized in that: The middle partition is also provided with ventilation holes for controlling the temperature inside the chamber; The control unit is further used to control the ventilation holes on the middle partition plate located in the first area to open, so as to ventilate the chamber.

11. A control method for a 3D printing system, characterized in that: The 3D printing system comprises: Material conveying system, used to convey molten materials; A fixed-position print head connected to the material conveying system for extruding the material; A movable chamber having side walls, wherein a forming platform is arranged in the space enclosed by the side walls, and the forming platform is used to carry the material extruded by the print head; a middle partition, located between the material delivery system and the chamber and arranged around the print head; A first heating component is used to heat the middle partition to form a heated first area, and the first area is used to control the temperature of the forming temperature control chamber of the material formed around the middle partition, the side wall of the chamber and the forming platform; The control method comprises: Control the movement of the chamber relative to the print head so that the material is deposited at different positions on the forming platform; control the first area to change as the chamber moves so that the first area corresponds to the area where the chamber is currently located; and control the temperature of the forming temperature control chamber according to the heat input of the material.

12. The control method according to claim 11, characterized in that: The 3D printing system further includes: a lifting device, located at the bottom of the forming platform, used to control the forming platform to gradually descend as the material is deposited during the printing process; a second heating component, used to heat the side wall of the chamber to form a heated second area; The control method further comprises: The second area is controlled to change as the forming platform descends, so that the second area corresponds to the area between the forming platform and the middle partition plate.

13. The control method according to claim 11, characterized in that: Also includes: controlling the first heating component to preheat a third area, the third area being an area on the middle partition, and the third area corresponding to an area to which the chamber is about to move; and / or, The first heating component is controlled to reduce the temperature of a fourth area or stop heating the fourth area, the fourth area belongs to the first area, and the fourth area corresponds to an area that the chamber is about to leave.

14. The control method according to any one of claims 11 to 13, characterized in that: The print head includes a discharge port with adjustable length; The control method further comprises: The length of the material outlet is controlled to change with the change of the cross-sectional contour line of the area to be printed, so that the material is filled into the area to be printed at one time.

15. The control method according to claim 11, characterized in that: The middle partition is also provided with ventilation holes for controlling the temperature inside the chamber; The control method further comprises: The ventilation holes on the middle partition plate located in the first area are controlled to open to ventilate the chamber.

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