3D printing robots and 3D printing equipment

Abstract

The present application discloses a 3D printing robot and a 3D printing device, wherein the 3D printing robot comprises: a robot body having an axis joint and a first mechanical arm, the first mechanical arm having a first stiffness; a feeding system arranged on the first mechanical arm, comprising a storage device for caching granular materials and a melt extrusion device for melting the granular materials into fluid materials and outputting them under pressure; a print head arranged at the end of the first mechanical arm of the robot body, comprising a nozzle for extruding the fluid material; a feeding pipeline arranged between the end of the melt barrel of the melt extrusion device and the print head, one end of which is connected to the melt extrusion device and the other end is connected to the print head, comprising a pipeline body having a second stiffness and a temperature control device arranged on the pipeline body; wherein the second stiffness is less than the first stiffness. The 3D printing robot and the 3D printing device provided by the present application can take into account the robot's degree of freedom while also realizing a continuous and smooth supply of molten fluid materials.

Description

Technical Field

[0001] The present application relates to the technical field of robots, and in particular to a 3D printing robot and a 3D printing device. Background Art

[0002] At present, 3D printing technology is mainly divided into fused deposition modeling (FDM), liquid photosensitive resin photocuring (SLA or DLP), selective laser sintering (SLS), selective laser melting (SLM) and other technologies. Among them, fused deposition modeling technology is a commonly used technology in 3D printing technology. By controlling the print head, it extrudes molten filamentary materials such as thermoplastics, wax or metal filaments on the printing platform according to the contour and filling trajectory of each preset thickness slice layer of the 3D object, so that the molten material is deposited and solidified, and then the required 3D object is generated layer by layer.

[0003] Generally, the molten material needs to be heated and melted after being granulated before being transported to the print head and extruded by the nozzle located on the print head. During the printing process, the continuous and uniform supply of the molten material needs to be ensured to ensure the smooth progress of the printing operation and the quality of the 3D object. However, the traditional fused deposition modeling 3D printing process can only print smaller 3D objects. If the printing length, width and height are several meters or more, such as large-scale anime shapes, company reception desks, outdoor art sculptures, etc., it is not suitable. In particular, its traditional 3D printing wire with a wire diameter of millimeters and its wire melting system cannot meet the above printing requirements.

[0004] To this end, the industry has proposed using industrial robots as the executive components of melt extrusion 3D printing to achieve large-scale 3D object printing. However, when using 3D printing robots for 3D printing, the overall size of the 3D printing robot is often large, especially the extension distance of its robotic arm is long, which leads to a long channel path for extrusion of the material after it is melted, which is not conducive to temperature control and makes it difficult to achieve a continuous and uniform supply of molten material. In addition, since the moving parts of the industrial robot include multiple articulated arms / robotic arms connected by multiple axes, during the movement process, the multiple robotic arms have different movement trajectories due to different movement angles and torques, which will affect the extrusion conveying path of the material after it is melted to a certain extent. For example, if the path is set too short, it will limit the freedom of the robot's articulated arm / robotic arm and affect the printing path. If the path is set too long, it will be not conducive to the temperature consistency of the molten fluid material, resulting in poor extrusion and affecting the printing efficiency.

[0005] Furthermore, ordinary screw extruders require a length-to-diameter ratio of more than ten times to complete the plasticization of the material, while the 3D printing robot's melt extrusion device moves with the robot's mechanical arm during the printing process, so it is impossible to design a longer length. For example, it is usually only 3-5 times the length-to-diameter ratio. With such a length, it only takes a few seconds from granular material to extruded fluid material. The granular material has no time to plasticize, and poorly plasticized materials are microscopically uneven. After printing is completed, the printed 3D object product will continue to release stress during subsequent use, thereby causing deformation of the 3D object. This is a major problem in using industrial robots as melt extrusion 3D printing, which urgently needs to be overcome by technical personnel in this field.

[0006] Therefore, how to design a 3D printing robot including a melt extrusion system so as to achieve a continuous and smooth supply of molten fluid material while taking into account the robot's freedom is a technical problem that needs to be urgently solved by technicians in this field. Summary of the invention

[0007] In view of the shortcomings of the related technologies mentioned above, the purpose of the present application is to provide a 3D printing robot and a 3D printing device, which are used to solve technical problems such as the limited freedom of movement of the 3D printing robot due to its large size and the difficulty in achieving a continuous and smooth supply of molten material.

[0008] To achieve the above-mentioned purpose and other related purposes, the first aspect of the present application provides a 3D printing robot, comprising: a robot body, comprising a plurality of axial joints and a first robotic arm axially connected to each of the axial joints, the first robotic arm having a first stiffness; a feeding system, arranged on the first robotic arm between the third axial joint and the fourth axial joint of the robot body, comprising a storage device for caching granular material and a melt extrusion device for melting the granular material into a fluid material and outputting it under pressure; a print head, arranged at the end of the first robotic arm of the robot body, comprising a nozzle for extruding the fluid material; a feeding pipeline, arranged between the fourth axial joint of the robot body and the print head, one end of which is connected to the melt extrusion device and the other end is connected to the print head, comprising a pipeline body with a second stiffness and a temperature control device arranged on the pipeline body; wherein the second stiffness is less than the first stiffness.

[0009] The second aspect of the present application provides a 3D printing device, including: a molding chamber, used to provide a closed molding space for 3D printing operations; a printing platform, rotatably arranged in the molding chamber for carrying a molded 3D printed object; a 3D printing robot as described in any embodiment of the first aspect of the present application, arranged on a first side of the printing platform, used to melt powder or granular material and deposit it on the printing platform according to a first printing path to form the 3D object layer by layer; a subtractive robot, arranged on a second side of the printing platform and at a first preset angle to the 3D printing robot, including a second robotic arm that moves on the upper side of the printing platform according to a second motion path, and a cutting component arranged on the second robotic arm for performing subtractive processing on the 3D object deposited on the printing platform according to the subtractive path.

[0010] In summary, the 3D printing robot and 3D printing equipment provided by the present application realize the caching of granular materials and the melting of granular materials by arranging a feeding system with a material storage device and a melt extrusion device on the mechanical arm of the 3D printing robot, thereby shortening the conveying path of the molten fluid to a certain extent; furthermore, the present application realizes the short-path supply of the fluid material from the melt extrusion device to the nozzle of the print head by arranging a feeding pipeline for connecting the melt extrusion device and the print head between the mechanical arm and the print head, and the present application designs a feeding pipeline with a stiffness smaller than that of the mechanical arm and connects the feeding pipeline to the mechanical arm. It is arranged between the fourth axis joint of the robot body and the print head, which not only ensures the flexibility of the movement of each robot arm during the printing process, but also can reduce the instantaneous pressure changes caused by the fluid material, thereby ensuring the uniform supply of the fluid material; and the present application arranges a temperature control device on the pipeline body of the feeding pipeline, which can avoid the increase in viscosity of the fluid material due to heat loss or even cooling and solidification during long-distance transportation, thereby avoiding clogging of the fluid material in the pipeline body and the print head, ensuring the continuous supply of the fluid material, and thus improving the 3D printing efficiency and the printing quality of the object. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The specific features of the present application are shown in the attached claims. The features and advantages of the invention involved in the present application can be better understood by referring to the exemplary embodiments and drawings described in detail below. The drawings are briefly described as follows:

[0012] Figure 1 and Figure 2 They are respectively shown as schematic diagrams of the structures of 3D printing devices in different embodiments of the present application.

[0013] Figure 3 It is a schematic diagram of the structure of a molding chamber in one embodiment of the present application.

[0014] Figure 4Shown is a schematic diagram of zoned temperature control of a printing platform in one embodiment of the present application.

[0015] Figure 5 Shown is a schematic diagram of the structure of a 3D printing robot in one embodiment of the present application.

[0016] Figure 6 Shown is a schematic structural diagram of a melt extrusion device in one embodiment of the present application.

[0017] Figure 7 Shown is a schematic diagram of the structure of a print head in one embodiment of the present application.

[0018] Figure 8 Shown is a schematic diagram of the structure of a print head configured with an access device in one embodiment of the present application.

[0019] Fig. 9 and Fig.10 They are respectively schematic diagrams of the structure of the valve core at different viewing angles in one embodiment of the present application.

[0020] Fig.11 Shown is a cross-sectional view of a valve core in one embodiment of the present application.

[0021] Fig.12 It is a schematic diagram showing that the valve core is in a closed state in one embodiment of the present application.

[0022] Fig.13 It is a schematic diagram showing the cooperation between the valve core and the actuator in one embodiment of the present application.

[0023] Fig.14 It is a cross-sectional schematic diagram showing a valve core in an open state in a valve cavity in one embodiment of the present application.

[0024] Fig.15 It is a cross-sectional schematic diagram showing a valve core in a closed state in a valve cavity in one embodiment of the present application.

[0025] Fig.16 Shown is a cross-sectional view of a valve core in another embodiment of the present application.

[0026] Fig.17 It is a schematic diagram showing the working area of ​​the molding surface on the printing platform occupied by the second motion path in one embodiment of the present application.

[0027] Fig.18 It is a schematic diagram showing that the first motion path and the second motion path occupy the printing area and the working area of ​​the printing platform respectively in one embodiment of the present application. DETAILED DESCRIPTION

[0028] The following is an explanation of the implementation of the present application by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification.

[0029] In the following description, reference is sometimes made to the accompanying drawings, which describe several embodiments of the present application. It should be understood that other embodiments may also be used, and that changes in module or unit composition, electrical, and operation may be made without departing from the spirit and scope of the present application. The following detailed description should not be considered restrictive, and the scope of the embodiments of the present application is limited only by the claims that are published. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0030] It will be understood that, although the terms first, second, etc. may be used in some instances to describe various elements or parameters in this article, these elements or parameters should not be limited by these terms. These terms are only used to distinguish one element or parameter from another element or parameter. For example, the first mechanical arm may be referred to as the second mechanical arm, and similarly, the second mechanical arm may be referred to as the first mechanical arm without departing from the scope of the various described embodiments. The first mechanical arm and the second mechanical arm are both describing a mechanical arm, but unless the context clearly indicates otherwise, they are not the same mechanical arm. The terms "or" and "and / or" used in this article are interpreted as inclusive, or mean any one or any combination. Therefore, "A, B or C" or "A, B and / or C" means any of the following: A; B; C; A and B; A and C; B and C; A, B and C. Only when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way, will there be an exception to this definition.

[0031] It will be understood that when a part or element is referred to as being "on" or extending "onto" another element, the element may be directly on or directly extending onto the other element, or intervening elements may also be present. Conversely, when an element is referred to as being "directly on" or "extending directly onto" another element, there are no intervening elements. It will also be understood that when an element is referred to as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intervening elements. Conversely, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements.

[0032] Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe the relationship of one element, layer or region to another element, layer or region as illustrated in the figure. It will be understood that these terms are intended to cover different device orientations other than the orientation depicted in the figure. In this application, the "vertical", "horizontal" and "parallel" are defined as: including the situation of ±10% based on the standard definition. For example, vertical usually refers to an angle of 90° relative to a reference line, but in this application, vertical refers to a situation within 80° to 100°.

[0033] The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application. When used herein, the singular forms "a", "an", and "the" are intended to also include the plural forms unless the context clearly indicates otherwise. It will also be understood that when used herein, the terms "comprise", "include", "include" and / or "comprising" specify the presence of stated features, integers, steps, operations, elements and / or parts, but do not exclude the presence or increase of one or more other features, integers, steps, operations, elements, parts and / or combinations thereof.

[0034] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It will also be understood that the terms used herein should be interpreted as having the meaning consistent with their meaning in the context of this specification and the relevant field, and should not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0035] Unless otherwise expressly stated, comparative quantitative terms (such as "above" and "below") are intended to encompass the concept of equality. As an example, "above" may not only mean "greater than" in a mathematical sense, but may also mean "equal to".

[0036] In view of the technical problems mentioned in the background technology, the present application discloses a 3D printing robot and a 3D printing device. By arranging a feeding system with a material storage device and a melt extrusion device on the mechanical arm of the 3D printing robot, the granular material is cached and the granular material is melted, and the conveying path of the molten fluid is shortened to a certain extent; furthermore, the present application arranges a feeding pipeline for connecting the melt extrusion device and the print head between the mechanical arm and the print head, thereby realizing a short-path supply of the fluid material from the melt extrusion device to the nozzle of the print head, and the present application designs a feeding pipeline with a stiffness smaller than that of the mechanical arm, The feeding pipeline is arranged between the fourth axis joint of the robot body and the print head, which not only ensures the flexibility of the movement of each robot arm during the printing process, but also can reduce the instantaneous pressure changes caused by the fluid material, thereby ensuring the uniform supply of the fluid material; and the present application can avoid the increase in viscosity or even stagnation of the fluid material due to cooling caused by heat loss during long-distance transportation by arranging a temperature control device on the pipeline body of the feeding pipeline, thereby avoiding clogging of the fluid material in the pipeline body and the print head, ensuring the continuous supply of the fluid material, and thus improving the 3D printing efficiency and the printing quality of the object.

[0037] In any embodiment provided in the present application, the 3D object may be a 3D model obtained by stacking 3D printing materials layer by layer using 3D printing technology, which may be, for example, a sculpture of an animation or animal, a building for a company's front desk, or an outdoor art model. The 3D printing technology may be, for example, a fused deposition modeling technology based on fusible granular materials. In this example, the 3D printing material for constructing the 3D object may be, for example, a thermoplastic material. The thermoplastic material may be, for example, a polymer composite printing material containing nylon, paraffin, casting wax, artificial rubber, metal, ceramic, etc., which may be heated to a flowing or semi-fluid state in the form of powder or granular material, and then stacked and cooled layer by layer to form a 3D object.

[0038] In some embodiments, the present application provides a 3D printing device. Figure 1 and Figure 2 , respectively showing the structural schematic diagrams of the 3D printing device in different embodiments of the present application. As shown in the figure, the 3D printing device includes a molding chamber 1, a printing platform 2, a 3D printing robot 3, and a subtractive robot 4.

[0039] The following is a detailed description of the 3D printing device of the present application.

[0040] The molding chamber 1 is used to provide a closed molding space for 3D printing operations. It should be understood that the fused deposition modeling printing technology is relatively sensitive to temperature. When the 3D printing material needs to be melted and extruded, it needs to be heated to the melting point to form a semi-fluid state. When the molten 3D printing material is extruded onto the printing platform, it needs to be cooled to a temperature below the melting point so that the printed layer is solidified and formed. Therefore, the molding chamber 1 needs to be set in a closed form to construct a closed internal environment to reduce the impact of the airflow outside the molding chamber on the 3D printing operation, and to make the temperature of the internal environment constant to facilitate temperature control.

[0041] In order to construct a constant temperature environment in the molding chamber, in one embodiment, the molding chamber 1 can be configured as a composite structure with multiple layers of materials. For example, the outer layer in contact with the external environment can be configured as metal or high-strength plastic to provide rigid support for the molding chamber. The inner layer in contact with the internal environment of the 3D printing operation can be configured as a heat-insulating material, such as polyurethane foam, polycarbonate board, aluminum silicate fiber or mineral wool, etc., to reduce heat loss in the internal environment.

[0042] In one embodiment, see Figure 3 Combined with Figure 1 and Figure 2 ,in, Figure 3 Shown is a schematic diagram of the structure of the molding chamber in one embodiment of the present application. As shown in the figure, the cross-section of the molding chamber 1 in the horizontal direction is a symmetrical hexagonal structure with four obtuse angles and two right angles. Specifically, the six angles located in the hexagonal structure are angle a, angle b, angle c, angle d, angle e, and angle f in the clockwise direction. Among them, the four obtuse angles are angle b, angle c, angle d, and angle e. For the convenience of distinction, angle b, angle c, angle d, and angle e can also be described as the first obtuse angle b, the second obtuse angle c, the third obtuse angle d, and the fourth obtuse angle e, respectively. The two right angles are angle a and angle f. For the convenience of distinction, angle a and angle f are also described as the first right angle a and the second right angle f, respectively. In Figure 3 In the example shown, the six corners are all sharp corners. In other examples, in order to avoid bumping into the operator, the six corners may be configured as rounded corners.

[0043] In one embodiment, if Figure 3As shown, an entrance and exit 13 of the molding chamber 1 is provided on one side of the molding chamber 1, and the width of the entrance and exit 13 is greater than the rotation diameter of the printing platform 2. The rotation diameter can be referred to the description in the subsequent embodiments, which will not be repeated here. The entrance and exit 13 can be used for the entry and exit of operators, and the loading and unloading of various devices, structures, components, and 3D objects in the 3D printing equipment. In order to ensure that the molding chamber 1 can provide a closed internal environment during the 3D printing process, in one implementation, the entrance and exit 13 can be configured as a revolving door, and the revolving door is connected to the molding chamber 1 by a hinge, so that the revolving door can realize the opening and closing of the molding chamber 1 through a rotational motion. Of course, in some other implementations, it can also be configured as a sliding door, an automatic door, etc.

[0044] In one embodiment, if Figure 2 As shown, the 3D printing robot 3 is arranged between the first right angle a and the first obtuse angle b in the molding chamber 1, and the subtractive robot 4 is arranged between the second right angle f and the fourth obtuse angle e in the molding chamber 1. In another embodiment, as Figure 1 As shown, the 3D printing robot 3 is arranged between the first right angle a and the first obtuse angle b in the molding chamber 1, and the subtractive robot 4 is arranged between the second obtuse angle c and the third obtuse angle d in the molding chamber 1. However, this is not limited to the above. The 3D printing robot 3 and the subtractive robot 4 can also be arranged at other positions in the molding chamber 1, which can be determined according to actual production needs. It should be noted that the molding chamber 1 is configured as follows: Figures 1 to 3 The hexagonal structure shown is only a schematic representation. In this example, in order to minimize the area of ​​the molding chamber 1 and reduce the heating range, thereby increasing the speed of heat transfer, which is beneficial to controlling the temperature in the molding chamber, the side length of the hexagonal structure is set according to the width of the 3D printing robot 3 and the subtractive robot 4. In certain other examples, the molding chamber 1 can also be set to other shapes besides rectangles and hexagons, such as pentagons, circles, etc., which are determined according to actual production needs and are not limited in this application.

[0045] In one embodiment, if Figure 3As shown, a first auxiliary equipment configuration area 11 is provided outside the edge formed between the first obtuse angle b and the second obtuse angle c in the molding chamber 1, and a second auxiliary equipment configuration area 12 is provided outside the edge formed between the third obtuse angle d and the fourth obtuse angle e in the molding chamber 1. The outer edge refers to the external area of ​​the molding chamber corresponding to a certain edge of the hexagonal structure formed by the molding chamber 1. For example, the outer edge formed between the first obtuse angle b and the second obtuse angle c refers to the area outside the molding chamber 1 corresponding to the edge m shared by the first obtuse angle b and the second obtuse angle c. The first auxiliary equipment configuration area 11 is used to configure the first auxiliary equipment, and the second auxiliary equipment configuration area 12 is used to configure the second auxiliary equipment. It should be noted that the first auxiliary equipment configuration area 11 or the second auxiliary equipment configuration area 12 can be configured separately or together. Of course, the first auxiliary equipment configuration area 11 or the second auxiliary equipment configuration area 12 may not be provided. It is determined according to the actual needs of configuring the first auxiliary equipment and the second auxiliary equipment, and this application does not impose any restrictions on this.

[0046] In one embodiment, the first auxiliary device or the second auxiliary device can be configured as a power supply device, such as a generator, to provide a stable power supply for the 3D printing device. In another embodiment, it can also be configured as an imaging device for real-time observation of the 3D printing process outside the molding room to ensure the normal operation of the 3D printing robot and the subtractive robot, but it is not limited to this, and its specific configuration is determined according to actual production needs.

[0047] In some embodiments, the 3D object is difficult to maintain constant internal temperature and external atmosphere temperature between stacked layers due to its large size, which causes different thermal stresses on the stacked layers, leading to stress accumulation inside the 3D object, and then uneven shrinkage, causing the 3D object to warp, deform, and other problems. In view of this, the molding chamber 1 is equipped with an atmosphere temperature control system, and the temperature control system can be configured to include a hot and cold air circulation convection device, which is used to keep the temperature of the stacked layers of the 3D object constant, thereby avoiding problems such as warping and deformation of the 3D object.

[0048] Of course, in some other embodiments, the molding chamber 1 may be equipped with an air conditioner and a fan to control the temperature of the internal environment of the molding chamber within a suitable range. A dehumidifier and other equipment may also be configured to adjust the humidity of the internal environment to ensure that the various devices, structures, and components in the 3D printing device can work normally, and at the same time ensure that the 3D printing materials can be in an ideal state, thereby ensuring that the 3D printing operation can proceed smoothly. In addition, an air purification system may be configured in the molding chamber 1 to promptly remove the gas and particles generated during the printing process, thereby ensuring the cleanliness of the internal environment. Those skilled in the art may select a specific configuration based on the actual design under the guidance of this application.

[0049] In one embodiment, the printing platform 2 is rotatably disposed in the molding chamber 1 for supporting the molded 3D object. Figure 3 In the example shown, the printing platform 2 is configured as a circular platform, and the diameter of the circular platform ranges from 2800mm to 3600mm, for example, approximately 2800mm, 2900mm, 3000mm, 3100mm, 3200mm, 3300mm, 3400mm, 3500mm, or 3600mm. In some other examples, the printing platform 2 can also be configured as a shape other than a circle, such as a rectangle or a hexagon. In this case, the printing platform 2 has a rotation diameter and a rotation center. The rotation diameter refers to the diameter of the circular range occupied by the printing platform 2 when it rotates, and the rotation center refers to the center of the circular range occupied by the printing platform 2 when it rotates. It should be understood that when the printing platform is configured as a circular platform, the rotation diameter and the rotation center are the diameter and center of the printing platform, and the rotation diameter and the rotation center are not repeated in the subsequent embodiments.

[0050] In one embodiment, in order to realize the rotation of the printing platform 2, a rotating shaft (not shown) is provided on the printing platform 2, and a grating encoder and a servo motor are provided on the rotating shaft. The grating encoder is used to provide measurement and feedback of the rotation angle of the printing platform 2. The servo motor is used to provide rotational power for the rotating shaft. In some examples, the servo motor can drive the rotating shaft to rotate clockwise and counterclockwise. In some embodiments, the servo motor can also be replaced by a hydraulic motor.

[0051] In one embodiment, the grating encoder includes a grating encoder housing, a grating encoder disk and a reading head. The grating encoder housing is arranged around the rotating shaft and accommodates the grating encoder disk and the reading head. The grating encoder disk has grating strips. When the rotating shaft rotates, the grating strips on the grating encoder disk will be blocked and generate corresponding optical signals. The reading head may include an optical measuring device such as a camera, and obtains the rotation information of the rotating shaft by interpreting the generated optical signal, and feeds the information back to a control device, thereby realizing real-time control of the rotation of the printing platform.

[0052] In one embodiment, a brake locator is provided on the printing platform 2, and the brake locator is used to stop the rotational movement of the printing platform 2. At the same time, it can also prevent the printing platform 2 from rotating due to external forces when the movement stops, thereby further ensuring the printing accuracy. In one implementation, the brake locator can be configured to include a brake driver and a locking pin, and the brake driver controls the movement of the locking pin to lock the locking pin on the printing platform, thereby stopping the rotational movement of the printing platform. The brake driver can be, for example, a motor.

[0053] In one embodiment, a temperature control component for controlling the temperature of the molding surface is provided on the printing platform 2. The molding surface refers to the surface where the printing platform contacts the printing layer of the 3D object. In one example, the temperature control component includes a temperature sensor, a temperature controller, a heating element, and a cooling element. The temperature sensor is used to monitor the temperature of the molding surface in real time. The heating element is used to provide heat energy to increase the temperature of the molding surface. It can be, for example, a resistance heater, a heating winding, and a heating cable. The cooling element is used to provide a cooling effect to reduce the temperature of the molding surface. It can be, for example, a fan, a cooling water circulation system, and a refrigerant circulation system. Specifically, when the temperature sensor detects that the temperature of the molding surface is lower than a threshold, the temperature controller controls the heating element to operate until the temperature of the molding surface reaches the threshold. When the temperature sensor detects that the temperature of the molding surface is higher than the threshold, the temperature controller controls the cooling element to operate until the temperature of the molding surface reaches the threshold. The threshold is a temperature value or temperature range pre-set by the operator that is lower than the melting point of the 3D printing material, so that the printing layer can be solidified when deposited on the molding surface.

[0054] In one embodiment, the printing platform 2 can perform zone temperature control on the molding surface. For details, please refer to Figure 4 , which is a schematic diagram showing the temperature control of the printing platform in a zone in one embodiment of the present application. Figure 4 As shown, the printing platform 2 can be divided into eight temperature zones. Figure 4 One of the temperature zones is indicated by the letter t, and each temperature zone has an independent temperature control component to achieve independent temperature control of each temperature zone. Furthermore, a heat insulation layer or heat insulation material may be provided between each temperature zone to reduce heat transfer between temperature zones, thereby improving the temperature control accuracy. Of course, any number of temperature zones may be provided on the printing platform 2, and those skilled in the art may select a suitable number of temperature zones according to the actual design under the guidance of this application. It should be noted here that the temperature control component on the printing platform 2 may work in conjunction with the atmosphere temperature control system in the molding chamber 1 described in the aforementioned embodiment, so as to ensure that the 3D printing material for constructing the 3D object has a temperature that is conducive to molding when in contact with the printing platform 2, and to avoid warping or deformation of the 3D object due to temperature difference.

[0055] See also Figure 5 Combined with Figure 1 ,in, Figure 5 The diagram is a schematic diagram of the structure of a 3D printing robot in one embodiment of the present application. Figure 1 and Figure 5As shown, the 3D printing robot 3 is arranged on the first side of the printing platform 2, and is used to melt the powder or granular material and deposit it on the printing platform 2 according to the first printing path to form the 3D object layer by layer, including a robot body 30, a feeding system 32, a print head 33, and a feeding pipeline 34.

[0056] Wherein, the first side of the printing platform 2 is as follows Figure 1 The position of the 3D printing robot 3 shown, that is, as described in the above embodiment, the 3D printing robot 3 is arranged between the first right angle and the first obtuse angle in the molding chamber 1. In one implementation, the 3D printing robot 3 can be fixedly arranged on the first side of the printing platform 2. In order to achieve the fixation of the 3D printing robot 3, it can further include a first base 35. The first base 35 is used as a basic component of the 3D printing robot 3 to carry the robot body 30. In one example, the weight of the first base 35 is large to provide a firm stability of the whole machine, thereby reducing mechanical vibration and ensuring that the 3D printing robot maintains balance. The material of the first base 35 includes but is not limited to cast iron, alloy, and carbon structural steel, so that the first base 35 has sufficient rigidity and strength, thereby giving the first base 35 sufficient durability and bearing capacity. It should be understood that the first base 35 can be used as the base of the robot body 30 in the 3D printing robot 3, and its specific structure can be changed based on different functional requirements or structural requirements.

[0057] The robot body 30 includes a first mechanical arm 31 and a plurality of axial joints. A print head 33 is configured at the end of the first mechanical arm 31 to provide the print head 33 with the freedom to move in space, thereby improving the accuracy of the print head 33. In this embodiment, the first mechanical arm 31 is axially connected to the axial joint, and the axial joint enables the print head 33 to generate a rotational rotation centered along the axis of the first mechanical arm 31 or a hinged rotation perpendicular to the axis of the first mechanical arm 31. For example, the 3D printing robot 3 can be configured as a six-axis industrial robot, which is provided with six axial joints to provide six-axis rotation, and the six axial joints can be configured on the print head 33 and the first mechanical arm 31 separately or in combination.

[0058] In one embodiment, if Figure 5As shown, the first mechanical arm 31 has a relative proximal end and a distal end, the proximal end of which is connected to the first base 35, and the distal end of which is provided with a print head 33. It should be noted here that in the subsequent embodiments, in order to clearly illustrate the relative positions of various components, structures, assemblies, mechanisms, components, or devices in the 3D printing robot, the proximal end and the distal end of the first mechanical arm are used as a reference for distinction, and the side of each component, structure, assembly, mechanism, component, or device that is relatively close to the proximal end of the first mechanical arm is called the proximal end (also called the proximal side), and the side that is relatively close to the distal end of the first mechanical arm is called the distal end (also called the distal side).

[0059] It should be understood that the first robotic arm 31 in the present application refers to a robot robotic arm including multiple robotic articulated arms. For example, in an embodiment where the 3D printing robot is a six-axis industrial robot, the first robotic arm 31 includes a first robotic articulated arm 310 and a second robotic articulated arm 311 .

[0060] Figure 5 The six axis joints are the first axis joint 312, the second axis joint 313, the third axis joint 314, the fourth axis joint 315, the fifth axis joint 316, and the sixth axis joint 317. The first axis joint 312 is connected to the first base 35, and provides a rotational rotation centered around the axis of the first base 35. The second axis joint 313 is connected to the proximal end of the first mechanical joint arm 310 and close to the first axis joint 312. The second axis joint 313 provides a hinge-type rotation around an axis perpendicular to the first mechanical joint arm 310 (which may correspond to the axis of the second axis joint 313). The third axis joint 314 is connected to the proximal end of the second mechanical joint arm 311, and provides a hinge-type rotation around an axis perpendicular to the second mechanical joint arm 311 (which may correspond to the axis of the third axis joint 314). The fourth axis joint 315 is connected to the distal end of the second mechanical joint arm 311, and provides a rotational rotation centered on the axis of the second mechanical joint arm 311. The fifth axis joint 316 and the sixth axis joint 317 can be arranged on the print head 33 in cooperation with each other to provide hinged rotation and rotational rotation of the print head 33 respectively.

[0061] In some other examples, the 3D printing robot can also be configured as a five-axis industrial robot, which is provided with five axis joints to provide five-axis rotation. It should be noted that the axis joints can be configured to any number to meet actual production needs, and this application does not impose any restrictions on this. For the sake of ease of description and explanation, the following embodiments are described by taking the 3D printing robot 3 configured as a six-axis industrial robot as an example, which should not be understood as a limitation on this application.

[0062] In one embodiment, the first robotic arm 31 may be configured as a slender or thick approximately cylindrical shape, and may be made of a suitable rigid material, for example, a lightweight and high-strength metal alloy such as an aluminum alloy, a magnesium alloy, or a carbon composite material.

[0063] In one embodiment, each axis joint includes an angle encoder, which can provide relative rotation information of the first robot arm 31. The information provided by the encoders of all axis joints can determine the position where the print head accumulates 3D printing materials. Furthermore, a control device can control the 3D printing operation based on the rotation information provided by each encoder.

[0064] In the embodiment where the 3D printing robot is configured as a six-axis industrial robot, the control device is used to control the six axis joints to rotate, thereby controlling the first mechanical arm 31 to move along the first motion path, and then controlling the print head 33 to move along the first printing path, so as to achieve layer-by-layer deposition of 3D printing materials. The first motion path refers to the movement path of the first mechanical arm 31 during the entire printing process, and the movement path reflected in each mechanical joint arm in space is not the same. The first printing path refers to the movement path of the print head 33 when the 3D printing material is deposited during the movement of the first mechanical arm 31 along the first motion path. Further, the first printing path can be the movement path of the print head. In order to distinguish it from the second control device included in the subtractive robot in the subsequent embodiments, the control device included in the 3D printing robot is referred to as the first control device, and the first control device and the second control device are not repeated later.

[0065] In one embodiment, the first control device includes a processing unit, a storage unit and a plurality of interface units. Each of the interface units is respectively connected to the first mechanical arm and the print head and other devices or components or mechanisms that are independently packaged and transmit data through the interface in the 3D printing robot. The first control device also includes at least one of the following: a prompt device, a human-computer interaction device, etc. The interface unit determines its interface type according to the connected device, component or mechanism, which includes but is not limited to: a universal serial interface, a video interface, an industrial control interface, a wireless communication port, etc. The storage unit is used to store the printing program, and the processing unit is connected to the storage unit, and is used to control the various components or components or structures in the 3D printing robot 3 to coordinate and realize the 3D printing operation of the print head 33 when executing the printing program.

[0066] like Figure 5As shown, the feeding system 32 is arranged on the first mechanical arm between the third axis joint 314 and the fourth axis joint 315 of the robot body 30, that is, arranged on the second mechanical joint arm 311. Specifically, in order to maximize the reduction of the burden on the second mechanical joint arm 311 and avoid interfering with the flexibility of the second mechanical joint arm 311 when moving, the feeding system 32 can be configured at a position close to the third axis joint 314. Of course, in certain other embodiments, the feeding system 32 can also be arranged on the first mechanical joint arm 310 and the second mechanical joint arm 311 at the same time, and is carried by the first mechanical joint arm 310 and the second mechanical joint arm 311 at the same time. The material of the feeding system 32 includes but is not limited to metal, and the connection method with the mechanical arm includes but is not limited to welding and one-piece molding connection. The specific configuration method and configuration position are determined according to actual production needs, and this application does not limit this.

[0067] In one embodiment, if Figure 5 As shown, the feeding system 32 includes a hopper 321 and a melt extrusion device 322, wherein the hopper 321 is used to buffer 3D printing materials such as powder or granular materials, and the melt extrusion device 322 is used to melt the 3D printing materials into fluid materials and output them under pressure.

[0068] In one embodiment, the accumulator 321 is connected to an external silo through an air pipeline, and a portion of the air pipeline is arranged in the first mechanical arm between the second axis joint 313 and the third axis joint 314 of the robot body 30. That is, the air pipeline is arranged in the first mechanical joint arm 310. In this embodiment, the external silo is used for long-term and large-scale storage of granular materials to ensure sufficient supply of raw materials. The granular materials are transported to the accumulator 321 through the air pipeline. The accumulator 321 is used for temporary storage of granular materials and can adjust the flow rate of granular materials to ensure that the subsequent transportation of granular materials can be carried out smoothly. In one example, a negative pressure airflow can be generated in the air pipeline by an air source device such as a blower or a compressor to promote the transportation of granular materials in the airflow pipeline.

[0069] In one embodiment, the pellets buffered in the accumulator 321 are conveyed to the melt extrusion device 322 by a feeding screw disposed at the bottom of the accumulator 321. In one example, the feeding screw can uniformly and continuously convey the pellets from the accumulator 321 to the melt extrusion device 322 by rotational motion. The feeding screw can be configured to include a screw body, a spiral blade, a spiral thread, and a spiral drive device. The material of the screw body can be configured to be metal, and its surface is smooth, so that the pellets can be smoothly conveyed. The spiral blades and the spiral threads are arranged in a spiral shape along the axis of the screw body to push the pellets to move during the rotation process. The pitch between the spiral blades and the spiral threads can be determined according to the properties of the pellets, and this application is not limited. The spiral drive device can be configured as a drive motor, which is used to provide power for the rotation of the screw body.

[0070] In one embodiment, see Figure 6 Combined with Figure 5 ,in, Figure 6 The structure diagram of the melt extrusion device in one embodiment of the present application is shown as follows: Figure 5 and Figure 6 As shown, the melt extrusion device 322 includes a melt barrel 3221, a plurality of heaters, and a screw mechanism (not shown). The melt barrel 3221 is connected to the accumulator 321. The plurality of heaters are sleeved on the circumference of the melt barrel 3221. The screw mechanism is arranged inside the melt barrel 3221 and along the axial direction of the melt barrel 3221, and is used to drive the molten fluid material to be pressurized and extruded toward the outlet direction of the melt barrel 3221 when rotating. Figure 5 and Figure 6 In the illustrated embodiment, the melt barrel 3221 is used to receive granular material delivered by a feeding screw arranged at the bottom of the storage container 321, and the multiple heaters are used to heat and melt the granular material into a fluid material. The screw mechanism can rotate to stir and mix the unmelted granular material and the molten fluid material to achieve sufficient melting of the granular material, and the molten fluid material is pressurized and extruded toward the outlet direction of the melt barrel 3221.

[0071] In order to provide power for the rotational movement of the screw mechanism, in one embodiment, the melt extrusion device 322 includes a drive motor 3225 disposed at the proximal end of the melt barrel 3221 and linked to the screw mechanism. In one example, the drive motor 3225 may also include a speed regulator, which can control the rotation speed of the drive motor, thereby controlling the rotation speed of the screw mechanism, thereby controlling the speed at which the fluid material is extruded. In an embodiment, the drive motor 3225 is, for example, a servo motor, and the speed regulator is, for example, a reducer linked to the servo motor; of course, in other embodiments, the speed regulator is also, for example, a control circuit of the servo motor to control the rotation speed of the servo motor.

[0072] In certain other embodiments, the screw mechanism may further include a screw body and spiral blades in addition to the drive motor 3225. The specific structure and function of the screw body and the spiral blades can be found in the description of the aforementioned embodiments and will not be repeated here.

[0073] Considering that the melt barrel, the main component of the 3D printing robot's melt extrusion device, moves with the robot's mechanical arm during the printing process and cannot be designed to be longer, that is, the melt barrel, which is the main body of the melt extrusion device, cannot be simultaneously straddled on two mechanical joint arms (otherwise it will affect the freedom of movement of the mechanical arms). Therefore, the melt barrel can only be set on one of the mechanical joint arms, that is, the aforementioned second mechanical joint arm. In order to avoid shortening the heating path from the granular material to the extruded fluid material and affecting the uniformity of the plasticization of the granular material, the present application designs a spiral microchannel and multi-stage heating on the melt barrel, and then heats the feeding pipeline with greater freedom of movement to extend the heating path of the fluid material, so that the granular material can be fully plasticized and present as shown in the following figure. Figure 5 and Figure 6 Embodiment described.

[0074] In this embodiment, if Figure 5 and Figure 6 As shown, the heater includes a preheater 3222 and a main heater, wherein the preheater 3222 is sleeved in the middle area of ​​the melting barrel 3221, and the main heater is sleeved at the distal end of the melting barrel 3221. It should be understood that the preheater 3222 is used to preliminarily heat the granular material entering the melting barrel 3221 within a temperature range, so that the temperature of the granular material is increased to a near-molten state, and the main heater is used to further increase the temperature of the material within a certain temperature range to fully melt the material. The preheater 3222 cooperates with the main heater to gradually increase the temperature of the material, thereby reducing thermal shock and temperature fluctuations to ensure that the material is heated evenly.

[0075] In one example, the heating temperature range of the preheater 3222 is 80℃-120℃, for example, it can be approximately 80℃, 81℃, 82℃, 83℃, 84℃, 85℃, 86℃, 87℃, 88℃, 89℃, 90℃, 91℃, 92℃, 93℃, 94℃, 95℃, 96℃, 97℃, 98℃, 99℃, 100℃, 101℃, 102℃, 103℃, 104℃, 105℃, 106℃, 107℃, 108℃, 109℃, 110℃, 111℃, 112℃, 113℃, 114℃, 115℃, 116℃, 117℃, 118℃, 119℃, or 120℃, etc.

[0076] In one embodiment, if Figure 6 As shown, the main heater includes a first main heater 3223 and a second main heater 3224, wherein the first main heater 3223 is sleeved at the distal end of the melt barrel 3221, and the second main heater 3224 is located between the preheater 3222 and the first main heater 3223. Specifically, the second main heater 3224 is used to further heat the material heated by the preheater 3222 so that it is completely melted into a fluid material. In one example, the heating temperature range of the second main heater 3224 is 120°C-220°C, for example, it can be approximately 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 195°C, 200°C, 205°C, 210°C, 215°C, or 220°C.

[0077] The first main heater 3223 is used to maintain the material heated by the second main heater 3224 in a molten fluid state, so that the temperature of the fluid material is constant. In one example, the heating temperature range of the first main heater 3223 is 220°C-240°C, for example, it can be approximately 220°C, 221°C, 222°C, 223°C, 224°C, 225°C, 226°C, 227°C, 228°C, 290°C, 230°C, 231°C, 232°C, 2330°C, 234°C, 235°C, 236°C, 237°C, 238°C, 239°C, or 240°C. It should be noted that the preheater 3222, the second main heater 3224, and the first main heater 3223 can be adjusted according to the properties of the granular material that actually needs to be melted under the technical enlightenment of this application.

[0078] In order to maintain the heating temperature of the preheater 3222 and the main heater within their respective heating temperature ranges, in one embodiment, the melt extrusion device 322 is provided with one or more temperature sensors corresponding to the heating areas of the preheater 3222 and the main heater, respectively. The temperature sensors are used to monitor the material temperature in the respective heating areas of the preheater 3222 and the main heater in real time, respectively. Matchingly, the melt extrusion device 322 can also be further configured with a temperature controller and a cooling device, the cooling device is used to provide cooling for the melt barrel section between the preheater 3222 and the accumulator 321 to prevent the granular material at the feed port from softening and getting stuck in the throat when it encounters heat, and it can be, for example, a cooling water circulation device and a refrigerant circulation device. Specifically, when the temperature sensor detects that the material temperature in each heating area is lower than the corresponding heating temperature range, the temperature controller controls the preheater 3222 and the main heater to operate until the material temperature in each heating area is within the corresponding heating temperature range, and maintains the set temperature in a thermal compensation manner. When the temperature sensor detects that the material temperature is higher than the corresponding heating temperature range, the temperature controller controls the heater to stop working or the auxiliary cooling device to operate until the material temperature in each heating area is back within the corresponding heating temperature range.

[0079] In some embodiments, the one or more temperature sensors are connected to a computer system of a 3D printing robot that controls one or more heaters based on the temperature reported by the one or more temperature sensors. For example, the computer system can control one or more heaters to adjust the temperature of the material in each of the heaters, feed lines and / or nozzles. In some embodiments, the system operates as a closed-loop feedback system to maintain an approximately constant temperature of the device or device component (i.e., a barrel, nozzle or feed line). The temperature of the material in different parts of the device can be the same or different. In some embodiments, the feedback system is controlled using a proportional integral derivative (PID) controller, a Bang-Bang controller, a predictive controller, a fuzzy control system, or any other suitable algorithm.

[0080] In one embodiment, the feeding system 32 includes a pressure sensor for detecting the pressure of the fluid material in the extrusion channel of the print head 33. The structure and function of the extrusion channel can be referred to the description in the subsequent embodiments. The types of the pressure sensor include but are not limited to piezoelectric sensors, strain gauge sensors, and capacitive sensors. According to the real-time monitoring of the pressure fluctuations in the entire feeding process by the pressure sensor, the speed of the extruded molten fluid material can be controlled, and then the speed of the material deposited on the printing platform can be controlled. In this embodiment, the pressure sensor is also configured with a computer feedback system, and the computer feedback system can use a proportional integral differential (PID) controller, a Bang-Bang controller, a predictive controller, a fuzzy control system, an expert system controller or any other suitable control algorithm. In some embodiments, the sampling rate of the pressure sensor is about 20ms or faster, such as about 10ms or faster, about 5ms or faster, or about 2ms or faster. In some embodiments, the pressure of the fluid material in the extrusion channel is controlled within a preset target pressure.

[0081] As mentioned above, the granular material is transported from the external material bin to the accumulator 321 through the gas pipeline, and then transported to the melt extrusion device 322 through the feeding screw configured at the bottom of the accumulator 321. The melt extrusion device 322 heats and melts the granular material into a fluid material through the preheater 3222 and the main heater, and the screw mechanism located inside the melt extrusion device 322 pressurizes and extrude the fluid material. Subsequently, the fluid material is output to the print head 33 through the feeding pipeline 34.

[0082] like Figure 5 As shown in FIG. 1 , the feed pipe 34 is disposed between the end of the melt barrel 3221 and the print head 33, and except for the two ends of the feed pipe 34 being physically connected to the melt barrel 3221 and the print head 33, the pipe between the two ends of the feed pipe 34 is not physically connected to other parts of the robot body 30, so that the feed pipe 34 will not limit the freedom of the robot joint arm / mechanical arm. In this embodiment, the axis of the starting end of the feed pipe 34 is almost perpendicular to the axis of the melt barrel 3221 and extends horizontally, as shown in FIG. Figure 6 In the state shown, the feeding pipeline 34 extends in a direction away from the second mechanical joint arm so as not to affect the movement trajectory or movement route of the second mechanical joint arm 311, the fourth axis joint 315 and the print head 33.

[0083] In this embodiment, the length of the feeding pipeline 34 is greater than the maximum movement distance between the fourth axis joint 315 of the robot body 30 and the print head 33. It should be understood that in the example where the 3D printing robot is configured as a six-axis industrial robot, the print head 33 located at the end of the first robot arm has multiple degrees of freedom in space by means of the movement of multiple joints and articulated arms. In this embodiment, the length of the feeding pipeline 34 is greater than the maximum distance between the fourth axis joint 315 and the print head 33, which can avoid limiting the movement of the print head 33 in space, ensure that the print head 33 does not generate additional resistance during the printing process, and thus ensure the printing accuracy.

[0084] In one embodiment, the feeding pipeline 34 includes a pipeline body and a temperature control device. The pipeline body has a second stiffness, and correspondingly, the first mechanical arm 31 has a first stiffness. Among them, the stiffness refers to the ability of the first mechanical arm 31 or the pipeline body to resist elastic deformation when subjected to force, which is used to characterize the ease with which the first mechanical arm 31 or the pipeline body is deformed. The stiffness is determined by the material and structure of the rigid body. The greater the stiffness, the stronger the ability of the rigid body to resist deformation. Conversely, the smaller the stiffness, the weaker the ability of the rigid body to resist deformation. In one example, the second stiffness is less than the first stiffness. It should be understood that the second stiffness of the pipeline body is less than the first stiffness of the first mechanical arm 31, which means that when the pipeline body is deformed, the force applied to the first mechanical arm 31 cannot cause the first mechanical arm 31 to deform. This is to say that the pipeline body can be configured as a hose structure. It should be noted that when connecting the melt extrusion device 322 and the print head 33, the direction of the pipeline body needs to be adjusted, and the smaller rigidity makes the pipeline body easy to install; in addition, the smaller rigidity can reduce the instantaneous pressure changes caused by the internal molten fluid material, thereby ensuring the smooth flow of the fluid material, and then ensuring that the fluid material can be evenly extruded by the print head; furthermore, since the second rigidity is smaller than the first rigidity, the pipeline body with smaller rigidity makes it possible for the feeding pipeline 34 to not generate reaction force or traction force to resist the above movement and limit the freedom of the robot joint arm / mechanical arm when the four-axis joint 315 of the first robot arm 31 and the joint arm between the print head 33 are rotating, extending and contracting.

[0085] In one embodiment, the body of the feeding pipeline 34 is a high temperature resistant rubber tube, plastic tube or metal corrugated tube.

[0086] In another embodiment, the feed pipe 34 has a threaded support structure and is a high temperature resistant hose. When the threaded support structure is a continuous support body of a preset length, the hose body is a threaded tube, or a certain section of the high temperature resistant hose body is a threaded tube; when the threaded support structure is an interval support body of a preset length, at least two sections of the hose body are threaded tubes. Here, the threaded tube is made of rubber or metal, and the threaded tube can be easily bent under the action of external force but will not collapse under the negative pressure generated in the hose body, or collapse at the bend during large bending, thereby ensuring the fluidity of the fluid material during the process of conveying the molten fluid material.

[0087] In some embodiments, in order to better ensure the support of the threaded tube, the threaded tube can be further a steel wire threaded tube, and the steel wire threaded tube is a three-layer structure. The inner and outer layers of the three-layer structure are made of plastic materials, such as PTFE (Polytetrafluoroethylene), etc.; the middle layer is a steel wire reinforcement structure, such as a spiral steel wire, etc. Therefore, the steel wire reinforcement structure can ensure to a greater extent that the threaded tube will not collapse under the action of negative pressure, enhance the support force, and ensure the fluidity of the fluid.

[0088] In one embodiment, the temperature control device is disposed on the pipeline body. It should be understood that the distance between the melt extrusion device and the print head is relatively far, and the fluid material may generate heat loss during the long-distance transportation process, causing the fluid material to gradually cool and stagnate or increase the viscosity of the fluid material due to heat loss, thereby causing the material to be blocked in the pipeline body. Therefore, in order to ensure that the fluid material can be stably transported to the print head, the temperature control device is disposed on the pipeline body of the present application.

[0089] In one implementation, the temperature control device is configured as a computer system or a thermostat, a temperature sensor embedded in the pipeline body, and a heating wire wrapped around the pipeline body. Furthermore, an auxiliary cooling element may be configured to quickly reduce the excessive temperature of the fluid material. Of course, the temperature control device may also be configured in other forms, as long as it can heat and maintain a constant temperature of the fluid material in the pipeline body. In certain other implementations, the temperature control device may be further configured with a cooling element on the basis of configuring the heating wire to prevent the fluid material from being heated to too high a temperature.

[0090] In order to control the fluid material in the pipeline body at a suitable temperature, in one embodiment, a temperature control sensor is provided at the far end of the feeding pipeline 34. The temperature control sensor can cooperate with the temperature control device. Specifically, when the temperature control sensor detects that the material temperature in the pipeline body is lower than a threshold, the temperature controller controls the heating wire to operate until the material temperature reaches the threshold. When the temperature sensor detects that the material temperature is higher than the threshold, the temperature controller controls the heating wire to stop operating until the material temperature reaches the threshold again. The threshold is a temperature value or temperature range pre-set by the operator that can make the material in a molten state.

[0091] Generally, when it is necessary to stop delivering molten material to the print head, the print head is usually controlled to deliver or stop delivering molten material by controlling the opening and closing of the valve mechanism of the print head. However, it is difficult for the valve mechanism of the ordinary print head nozzle to achieve complete closure of the print head, which will cause leakage of molten material and thus affect printing accuracy; and if the valve mechanism is completely closed, the fluid material inside the valve mechanism will generate pressure due to thermal expansion, which will press the closed valve mechanism to the inner wall of the valve cavity, and produce direct mechanical contact with the print head, which will not only make it impossible to reopen the valve mechanism the next time it is used, or require greater force to force the switch, which will cause mechanical wear of the valve mechanism. After repeated use, the valve mechanism is likely to loosen and affect its service life. Long-term use will also cause damage to the print head, thereby affecting the smooth progress of 3D printing operations.

[0092] Therefore, this application is in the following Figures 7 to 16 The print head proposed in each of the illustrated embodiments is used to solve the technical problems that the valve mechanism is difficult to completely close the print head, causing leakage of molten material and resulting in low printing accuracy, and forced closing of the valve mechanism may cause damage to the print head.

[0093] In one embodiment, see Figure 7 , which is a schematic diagram of the structure of a print head in one embodiment of the present application, wherein the dotted line in the figure only schematically represents the internal structure of the print head 33, such as Figure 7 As shown, the print head 33 includes a print head body 331, a valve chamber 332 located in the print head body 331, a valve core 333 arranged in the valve chamber 332, an extrusion channel 334 connected to the feeding pipeline 34, and a nozzle 335 connected to the extrusion channel 334, and the nozzle 335 includes a tapered extrusion port 3351 for printing fluid material.

[0094] In this embodiment, the valve core 333 can rotate at a certain angle in the valve cavity 332 to switch the channel between the extrusion channel 334 and the nozzle 335 between the open state and the closed state. In other words, after the granular 3D printing material is heated to a molten fluid material by the heater of the feeding system 32, the fluid material is output to the print head 33 through the feeding pipeline 34, specifically, the feeding pipeline 34 connected to the print head body 331 is output to the extrusion channel 334, and then output to the valve core 333. When the valve core 333 is in the open state, the fluid material can be output to the nozzle 335 through the extrusion channel 334, and finally extruded through the tapered extrusion port 3351 and deposited on the printing platform. When the valve core 333 is in the closed state, the fluid material is only output to the valve core 333 and stops flowing to the subsequent structure.

[0095] In one embodiment, an access device 324 is disposed on the upper side of the print head 33. Figure 8 Combined with Figure 7 ,in, Figure 8 The structure diagram of the print head configured with the access device in one embodiment of the present application is shown. Figure 8 As shown, the access device 324 is arranged along the first direction, and is used to connect the feeding pipeline 34 and the extrusion channel 334. Figure 7 and Figure 8 In the illustrated embodiment, the access device 324 is connected to the feed pipe 34 in a transverse configuration so as to conform to the bending trend of the feed pipe 34, that is, the feed pipe 34 is connected transversely from a direction away from the print head 33, so as to avoid causing the end of the feed pipe 34 to have a large curvature to affect the smoothness of its internal channel. The access device 324 is connected to the extrusion channel 334 in a vertical configuration, that is, the access device 324 is connected to the feed pipe 34 and is spatially perpendicular to the extrusion channel 334.

[0096] In order to clarify the definition of direction and the operation mode between different structures, a three-dimensional space defined by a first direction, a second direction, and a third direction is defined in the embodiments disclosed in the present application. The first direction, the second direction, and the third direction are all straight lines and are perpendicular to each other. For example, the length extension direction of the access device is defined as the first direction or the horizontal direction (for example Figure 7 The direction in which the length of the valve core extends is defined as the second direction (for example, Figure 7 The vertical direction is also called the vertical direction, the vertical line direction, or the up-down direction, and is defined as the third direction or vertical (for example Figure 7 The first direction, the second direction, and the third direction will not be described in detail in the subsequent embodiments.

[0097] In one embodiment, both ends of the access device 324 are provided with compensation heaters for heating the fluid material passing through the access device 324, and the types of the compensation heaters include but are not limited to resistance heaters, heating windings, and heating cables. It should be understood that when the 3D printing material, such as powder or granular material, is heated to a molten fluid material by the heater of the feeding system, the fluid material needs to be output from the feeding system 32 to the print head 33 through the feeding pipeline 34. In this process, in order to avoid the heat loss of the fluid material, in order to ensure that the fluid material reaches the viscosity requirement for smooth extrusion, in particular, the channel of the access device 324 and the extrusion channel 334 are perpendicular to each other in space, in order to avoid the fluid from being blocked in a large turn, before the fluid material is output to the extrusion channel 334, it is necessary to perform compensation heating on the fluid material, and further control the viscosity of the fluid material to maintain a relatively low state, so as to ensure that it is in a fluid state that meets the extrusion requirements.

[0098] In one embodiment, if Figure 8 As shown, the two sides of the print head 33 are symmetrically provided with terminal heaters 336 for heating the fluid material in the print head 33. It should be understood that when the valve core 333 rotates in the valve cavity 332 to switch between the open state and the closed state, the fluid material should be ensured to be in the best flow state so that the friction force on the valve core 333 when rotating in the valve cavity 332 is minimized. Therefore, it is necessary to set the terminal heater 336 at the position corresponding to the valve core 333 on the print head 33 to avoid the increase of the viscosity of the fluid material, so as to minimize the obstruction when the valve core 333 rotates.

[0099] In one embodiment, in order to avoid the increase of viscosity of the fluid material due to insufficient temperature and carbonization due to excessive heating, thereby avoiding hindering the switching of the valve core 333 in the valve chamber 332, a terminal temperature sensor for detecting the temperature of the fluid material in the print head 33 is provided on the print head 33, and the terminal temperature sensor can monitor the temperature of the fluid material at the valve core 333 in real time. Matching, a temperature controller and a cooling device can also be configured to achieve control of the temperature of the fluid material. The specific functions of the temperature controller and the cooling device can refer to the description in the above embodiment, and will not be repeated here.

[0100] In one embodiment, before the valve core 333 switches from the closed state to the open state, such as before starting a new printing task or before the 3D printing robot is started, the material left in the valve cavity 332 in the previous printing task solidifies into a solid state due to long-term cooling and is embedded in the valve cavity 332. Therefore, the terminal heater 336 preheats the material reserved in the print head 33 and melts it into a fluid material. It should be noted that when the 3D printing job is completed, the valve core 333 will switch from the open state to the closed state, and the fluid material will be reserved in the valve core 333 and the valve cavity 332. As the temperature cools, the reserved fluid material will solidify again and lock the valve core 333 in the valve cavity 332. At this time, if the valve core 333 needs to be switched to the open state, the solidified material reserved in the valve core 333 and the valve cavity 332 needs to be melted into a fluid material again to unlock the valve core 333.

[0101] As mentioned above, the terminal heater 336 heats and melts the material reserved in the print head 33 into a fluid material, and the valve core 333 switches from a closed state to an open state. At the same time, the feeding system 32 outputs the fluid material to the print head through the feeding pipeline 34. Thereafter, the fluid material reserved in the print head 33 and the fluid material output by the feeding system 32 are output to the nozzle 335 through the opened valve core 333, and finally extruded through the aforementioned conical extrusion port 3351.

[0102] Furthermore, before starting a new printing task or before the 3D printing robot is started, it takes some time for the melted fluid material of the granular material newly entering the melt barrel 3221 to output the fluid material to the print head through the feeding pipe 34. If the 3D printing robot is already moving to execute the printing instruction at this time, and the material left in the valve chamber 332 in the previous printing task is melted into fluid material, it will be delivered to the nozzle in time to avoid empty coating of the nozzle of the print head. In other words, the groove formed on the shaft body of the print head of the present application also has the function of pre-storing part of the printing material to achieve seamless connection with the newly flowing in fluid material.

[0103] In one embodiment, in order to smoothly guide the fluid material to the tapered extrusion port 3351, reduce the resistance and turbulence of the fluid material when it flows, ensure that the flow of the fluid material inside the nozzle 335 is more stable, and the sensor detects the real temperature inside the nozzle more accurately, the nozzle 335 includes a tapered inner cavity surrounded by a tapered inner surface. It should be understood that with the cooperation of the tapered inner cavity and the tapered extrusion port 3351, the cross-sectional area of ​​the fluid material gradually decreases when passing through the nozzle 335, so that the fluid material can be extruded and deposited on the printing platform at a higher flow rate and more evenly.

[0104] In one embodiment, see Figures 9 to 11 ,in, Fig. 9 and Fig.10 They are schematic diagrams showing the structure of the valve core in different viewing angles in one embodiment of the present application. Fig.11 The cross-sectional view of the valve core in one embodiment of the present application is shown. Figures 9 to 11 As shown, the valve core 333 includes a shaft body 3331, a flow channel 3332 radially penetrating the shaft body 3331, and a sink groove 3333 partially surrounding the shaft body 3331. The partially surrounding means that the area where the sink groove 3333 surrounds the shaft body 3331 is an open arc structure.

[0105] In one embodiment, the flow channel 3332 has an inlet hole 33321 and an outlet hole 33322. Fig.10 As shown, the inlet holes 33321 of the flow channel 3332 are all located in the sink 3333, so that the fluid material from the extrusion channel 334 can be filled into the sink 3333, and the valve core 333 is in Fig.10 In the open state shown, the flow channel 3332 connects the extrusion channel 334 and the tapered extrusion port 3351 to allow the fluid material to flow through the nozzle 335 .

[0106] In one embodiment, if Fig. 9 As shown, the outlet hole 33322 of the flow channel 3332 is partially located in the sink 3333. That is, in the embodiment where the sink 3333 is configured as an open arc-shaped structure, a portion of the outlet hole 33322 is located in the arc-shaped structure, and another portion is located outside the arc-shaped structure. Fig.12 , which is a schematic diagram showing a valve core in a closed state in one embodiment of the present application. Fig.12 As shown, when the valve core 333 is in a closed state, the outlet hole 33322 of the flow channel 3332 is misaligned with the tapered extrusion port 3351 to prevent the fluid material from flowing through the nozzle 335 and keep the fluid material filled in the sink 3333 between the valve core 333 and the valve cavity 332 .

[0107] In one embodiment, please combine Figures 7 to 10 The shaft body 3331 is disposed in the valve cavity 332 along the second direction. In order to realize the rotational movement of the valve core 333 in the valve cavity 332, the valve core 333 is axially connected to the valve cavity 332, such as Fig. 9 As shown, the shaft body 3331 includes a rotating shaft section 33311 and a suspended section 33312. The rotating shaft section 33311 is axially connected to both sides of the valve chamber 332, and the suspended section 33312 is located between the rotating shaft sections 33311 on both sides. In this example, the flow channel 3332 and the sink 3333 corresponding to the extrusion channel 334 are formed in the suspended section 33312.

[0108] In one embodiment, to further realize the rotation of the valve core in the valve cavity, the valve core 333 can be matched with an actuator. Fig.13 Combined with Figure 7 ,in, Fig.13 The schematic diagram of the valve core and the actuator in one embodiment of the present application is shown as follows: Figure 7 and Fig.13 As shown, the first end of the shaft body 3331 is connected to the actuator 337, and the actuator 337 is used to drive the valve core 333 to rotate, thereby realizing the valve core 333 Fig.10 The open state shown is the same as Fig.12 It should be understood that the first end corresponds to the right side of the shaft body 3331, and the second end described in the subsequent embodiments is the side away from the first end, that is, the left side of the shaft body 3331. The first end and the second end will not be repeated in the following. Figure 7 and Fig.13 In the example shown, the actuator 337 is disposed in the print head 33 in a first direction perpendicular to the second direction, and is movably connected to the first end of the shaft body 3331. In other words, the shaft body 3331 and the actuator 337 are perpendicular to each other in space, and the actuator 337 is movably connected to the first end of the shaft body 3331.

[0109] In one embodiment, the actuator 337 is configured as a pneumatic actuator. In this embodiment, the actuator 337 can be configured as a cylinder, including a slider 3371 and a first piston 3372 and a second piston 3373 fixed at both ends of the slider 3371. The body of the slider 3371 is movably connected to the first end of the shaft body 3331. The first piston 3372 and the second piston 3373 are respectively configured to move linearly in the slider 3371 when driven by the air pressure generated by the cylinder 3371 to drive the shaft body 3331 to rotate.

[0110] In one implementation, the shaft body 3331 is movably connected to the body of the slider 3371 via a spline 338 surrounding the first end. Specifically, a rack is provided at the position where the slider 3371 contacts the spline 338, and the rack can mesh with the spline 338, thereby driving the shaft body 3331 to rotate. For example, Fig.13In the example shown, the valve core 333 is in the open state. At this time, the first piston 3372 is driven by the air pressure in the first air pressure tube 339, and moves linearly in the slider 3371 along the direction of the arrow indicated by the dotted line in the figure, which will drive the shaft body 3331 to rotate counterclockwise, so that the outlet hole of the flow channel is misaligned with the tapered extrusion port, thereby switching the valve core 333 to the closed state. If the valve core 333 needs to be switched to the open state again, it is only necessary to drive the second piston 3373 with the gas in the second air pressure tube 340, so that the second piston 3373 moves linearly in the slider 3371 in the direction opposite to the arrow, thereby driving the shaft body 3331 to rotate clockwise until the outlet hole of the flow channel is connected with the tapered extrusion port.

[0111] In this embodiment, the choice of the two-choice air circuit consisting of the first air pressure tube 339 and the second air pressure tube 340 can be configured such that the computer control system drives the end electromagnetic air valve according to the instructions of the printing program, and the action time can be 0.1s-0.5s, for example, approximately 0.1s, 0.2s, 0.3s, 0.4s or 0.5s, etc., depending on the actual situation.

[0112] In one embodiment, the actuator 337 is configured as a mechanical actuator. In this embodiment, the first piston 3372 and the second piston 3373 can be configured to be driven by a mechanical force such as a motor, such as a driving source such as a servo motor. The specific driving process can be referred to the above description and will not be repeated here.

[0113] In one embodiment, in order to switch the valve core 333 between the open state and the closed state, the rotation angle of the shaft body 3331 is 15-45°, preferably, the rotation angle is 20°. For example, the rotation angle can be configured as 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°, 30°, 31°, 32°, 33°, 34°, 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°, 44°, or 45°, etc. It should be understood that the rotation angle can be adjusted accordingly according to the setting position of the inlet and outlet of the flow channel.

[0114] See also Fig.14 and Fig.15 , Fig.14 It is a cross-sectional schematic diagram showing a valve core in an open state in a valve cavity in one embodiment of the present application; Fig.15 The figure shows a cross-sectional schematic diagram of a valve core in a closed state in a valve cavity in one embodiment of the present application; Fig.14The valve core 333 is shown in an open state in the valve cavity 332. In this state, the extrusion channel 334 and the inlet hole 33321, flow channel 3332, outlet hole 33322 of the valve core 333 and the flow channel of the nozzle are in a connected state. When the feeding system 322 outputs the fluid material to the print head 321 through the extrusion channel 334 of the access device 324 via the feeding pipeline 34, the fluid material is output to the valve core 333 through the extrusion channel 334 perpendicular to the feeding pipeline 34, and while being filled in the sink 3333, it is output to the nozzle through its flow channel 3332 through the outlet hole 33322 to achieve subsequent printing operations. When it needs to be closed, as shown in FIG. Fig.15 The valve core 333 is shown in a closed state in the valve cavity 332. In the closed state, the valve core 333 rotates in the valve cavity 332 by a preset angle, such as the above-mentioned 20°.

[0115] like Fig.15 As shown, when in the closed state, the outlet hole 33322 of the flow channel 3332 of the valve core 333 is misaligned with the tapered extrusion port 3351, so that the outlet hole 33322 of the flow channel 3332 is blocked by the inner wall of the valve cavity 332 to prevent the fluid material in the flow channel 3332 from flowing through the nozzle 335. In this state, the fluid material from the extrusion channel 334 will fill the fluid material in the sink 3333 between the valve core 333 and the valve cavity 332, so that the valve core 333 is wrapped by the fluid material and is in a similar "suspended" state, and is maintained between the valve core 333 and the valve cavity 332, so that The valve core 333 is almost wrapped by the fluid material, thereby avoiding direct mechanical contact between the valve core and the print head. Before the valve core 333 needs to be switched to the open state next time, it is necessary to preheat the material reserved in the sink 3333 by the preset end heater 336 and melt it into fluid material. The re-melted fluid material acts as a lubricant to a certain extent, so that when the valve core 333 is rotated again, the valve core 333 will be smoothly adjusted to the extrusion channel 334 and the inlet hole 33321, flow channel 3332, outlet hole 33322 of the valve core 333 and the tapered extrusion port of the nozzle are in a connected state.

[0116] In order to facilitate the instructions to the operator, in one embodiment, the second end of the shaft body 3331 is provided with an identification structure to indicate the open state and the closed state of the valve core 333. The identification structure can be configured as at least one of a structural identification, a text identification, and a symbol identification, and the manner of being configured at the second end of the shaft body 3331 includes but is not limited to pasting, engraving, labeling, laser engraving, and a digital display screen. For example, the identification structure can be configured as "□", when the valve core 333 is in an open state, the identification structure indicates an upright "□", and when the valve core 333 is in a closed state, the identification structure indicates an inclined "◇". In this way, the operator can judge whether the valve core 333 is in an open state or a closed state only according to the direction of the identification structure, so as to proceed to the next step. It should be noted here that the above example is only an exemplary description and should not be understood as a limitation of the present application. The identification structure can be configured in any form as long as it can provide instructions to the operator.

[0117] As mentioned above, the sink 3333 corresponds to the extrusion channel 334 formed in the suspension section 33312 of the shaft body 3331. Fig.10 As shown, the width d1 of the sink 3333 is greater than or equal to the aperture d2 of the extrusion channel 334. Fig.10 In the illustrated embodiment, the aperture d2 of the extrusion channel 334 is equal to the aperture d2 of the flow channel 3332, so that the molten fluid material can be quickly output from the extrusion channel 334 to the flow channel 3332, and then flow from the conical inner cavity of the nozzle 335 to the conical extrusion port 3351. Since the inlet hole 33321 of the flow channel 3332 is all located in the groove 3333, the width d1 of the groove 3333 needs to be greater than or equal to the aperture d2 of the extrusion channel 334.

[0118] In one embodiment, the length of the top edge of the side wall of the sink 3333 is less than the surface perimeter of the shaft body 3331. The top edge of the side wall refers to the upper edge of the side wall where the sink 3333 and the shaft body 3331 meet. Fig. 9 As shown, the top edge of the side wall of the groove 3333 partially overlaps with the surface of the shaft body 3331. As mentioned above, the groove 3333 only partially surrounds the shaft body 3331, so the length of the top edge of the side wall of the groove 3333 is less than the surface circumference of the shaft body 3331.

[0119] In one embodiment, if Fig.11 As shown, the angle β corresponding to the arc line of the top edge of the side wall of the trough 3333 is between 270° and 330°, for example, it can be approximately 270°, 280°, 290°, 300°, 310°, 320°, or 330°, etc., which is determined according to actual production needs and is not limited in this application.

[0120] In one embodiment, the inlet hole 33321 of the flow channel 3332 is located in the area with the largest groove depth of the sink 3333. When the molten fluid material is output from the extrusion channel 334 to the flow channel 3332, the fluid material is filled into the sink 3333 from the junction between the extrusion channel 334 and the inlet hole 33321. Specifically, the fluid material is first deposited at the inlet hole 33321, and then gradually diffused to other areas of the sink 3333. Therefore, when the inlet hole 33321 is located in the area with the largest groove depth of the sink 3333, the fluid material can be evenly diffused to the entire sink.

[0121] In one embodiment, the maximum groove depth d3 of the sink 3333 is less than or equal to the diameter d4 of the flow channel 3332. In one embodiment, the volume of the sink 3333 is greater than or equal to the volume of the flow channel 3332, so that the fluid material filled in the sink 3333 is greater than or equal to the fluid material filled in the flow channel 3332.

[0122] In one embodiment, if Fig.11 As shown, the depth of the trough 3333 increases from one end of the outlet hole 33322 of the flow channel 3332 toward one end of the inlet hole 33321 of the flow channel 3332, and decreases after passing through the inlet hole 33321 of the flow channel 3332. That is to say, when the fluid material diffuses from the inlet hole 33321 of the flow channel 3332 from both sides to the entire trough 3333, the cross-sectional area of ​​the trough 3333 gradually decreases, and the fluid material can be filled in the trough 3333 at a faster speed.

[0123] In another embodiment, see Fig.16 , which is a cross-sectional view of a valve core in another embodiment of the present application, such as Fig.16 As shown, the sink 3333 has a trend of increasing depth from one end of the outlet 33322 of the flow channel 3332 toward the other end. Of course, the sink 3333 can also be set to other shapes, which are determined according to actual production needs, and this application does not impose any restrictions on this.

[0124] In one embodiment, the length of the intersection of the sink 3333 and the flow channel 3332 is less than 1 / 2 of the aperture of the outlet hole 33322. Fig.16 For example, the aperture of the outlet hole 33322 is equal to the diameter d4 of the flow channel 3332, and the length of the intersection of the sink 3333 and the flow channel 3332 is expressed as d5. Fig.16 As shown, d5 is less than 1 / 2 of d4.

[0125] The following combination Figures 5 to 16 The working process of the 3D printing robot described in this application is described in detail.

[0126] First, the end heaters 336 disposed on both sides of the print head 33 preheat the reserved material in the print head 33, so that it melts into a fluid material, so that the valve core 333 is wrapped by the fluid material and is in a similar "suspended" state. According to the instructions of the printing program, the computer control system turns on the power source to act on the actuator 337, so that the first piston 3372 of the actuator 337 moves linearly, driving the shaft body 3331 to rotate a certain angle, and making the flow channel 3332 connect the extrusion channel 334 and the tapered extrusion port 3351, and present Fig.10 or Fig.14 The open state shown. In this process, the granular material is transported from the external silo to the accumulator 321 through the gas pipeline, and then transported to the melt extrusion device 322 through the feeding screw arranged at the bottom of the accumulator 321. The melt extrusion device 322 heats and melts the granular material into a fluid material through the preheater 3222, the second main heater 3224, and the first main heater 3223, respectively. The screw mechanism located inside the melt extrusion device 322 pressurizes and extrude the fluid material. Subsequently, the fluid material is output to the print head 33 through the feeding pipeline 34. Then, the fluid material is output to the valve core 333 through the extrusion channel 334 perpendicular to the feeding pipeline 34, and while filling the sink 3333, it is output to the nozzle 335 through the flow channel 3332 to realize the subsequent printing operation.

[0127] When it is necessary to stop conveying the fluid material, the computer control system will shut down the power source and act on the actuator according to the instructions of the printing program, so that the second piston 3373 of the actuator 337 moves linearly in the opposite direction, driving the shaft body 3331 to rotate in the opposite direction by a certain angle, so that the outlet hole 33322 of the flow channel 3332 is misaligned with the tapered extrusion port 3351, and presents Fig.12 or Fig.15 In the closed state shown, the fluid material is prevented from flowing through the nozzle 335.

[0128] In one embodiment, the 3D object constructed by the 3D printing robot needs to be further processed, such as cutting it to obtain a smooth surface, or grinding, lapping, carving, drilling and other processing operations to meet user needs. In another embodiment, the support connected to the 3D object needs to be removed. In view of this, the subtractive robot 4 included in the 3D printing device of the present application is used to further finely process and high-quality surface treatment the 3D object.

[0129] Please continue reading Figure 1 ,like Figure 1As shown, the subtractive robot 4 is arranged on the second side of the printing platform 2 and is at a first preset angle with the 3D printing robot 3, including a second robotic arm 41 and a cutting assembly 42. The second robotic arm 41 can move on the upper side of the printing platform 2 according to a second motion path. The cutting assembly 42 is arranged on the second robotic arm 41, and is used to perform subtractive processing on the 3D object deposited on the printing platform 2 according to the subtractive path.

[0130] The cutting component 42 is used to perform subtractive processing on a 3D object. For example, it can be configured as a milling cutter or a grinding wheel.

[0131] The second mechanical arm 41 and the first mechanical arm 31 may have the same configuration, which will not be described in detail here. In one example, the subtractive robot 4 is configured as a six-axis industrial robot. The following embodiments are described by taking the subtractive robot 4 as a six-axis industrial robot as an example, which should not be construed as a limitation of the present application. It should be understood that the second mechanical arm 41 in the present application refers to a robot mechanical arm including multiple mechanical joint arms.

[0132] In one embodiment, the subtractive robot 4 further includes a second control device, which is used to control the six axis joints in the subtractive robot 4 to rotate, thereby controlling the subtractive robot 4 to move along the second motion path, and then controlling the cutting assembly to move along the subtractive path to achieve subtractive processing of the 3D object. The second motion path refers to the movement path of the second robot 41 during the entire printing process, and the subtractive path refers to the movement path of the cutting assembly when performing subtractive processing on the 3D object during the movement of the second robot 41 along the second motion path. The second control device has the same configuration as the first control device, and will not be repeated here.

[0133] In one embodiment, the second mechanical arm 41 of the subtractive robot 4 has a third stiffness, and the third stiffness is greater than the first stiffness of the first mechanical arm 31 of the 3D printing robot 3. The stiffness refers to the ability of the first mechanical arm 31 or the second mechanical arm 41 to resist elastic deformation when subjected to force, and is used to characterize the ease with which the first mechanical arm 31 is deformed. It should be understood that the third stiffness of the second mechanical arm 41 is greater than the first stiffness of the first mechanical arm 31, which means that when the first mechanical arm 31 is deformed, the force applied to the second mechanical arm 41 cannot cause the second mechanical arm 41 to deform. It should be noted that in the process of subtractive processing of 3D objects, a large cutting force will be generated, which will cause a large impact and vibration to the second mechanical arm 41. At this time, if the stiffness of the second mechanical arm 41 is insufficient, the second mechanical arm 41 will be deformed or the movement path of the second mechanical arm 41 will produce errors, thereby affecting the processing accuracy and surface quality of the 3D object. Relatively speaking, in the process of depositing the molten 3D printing material layer by layer, the first mechanical arm 31 is subjected to a relatively small force of molten extrusion, and the rigidity requirement for the first mechanical arm 31 is relatively low. Therefore, in this embodiment, the third rigidity of the second mechanical arm 41 needs to be greater than the first rigidity of the first mechanical arm 31.

[0134] In one embodiment, the second side of the printing platform 2 is as follows Figure 1 The position of the subtractive robot 4 shown, that is, as described in the aforementioned embodiment, the subtractive robot 4 is arranged between the second obtuse angle and the third obtuse angle in the molding chamber 1. In order to realize the arrangement of the subtractive robot 4 on the second side of the printing platform 2, the subtractive robot 4 may further include a second base 43, and the second base 43 may be configured in the same manner as the first base 35, which will not be described in detail here. In this embodiment, the 3D printing robot 3 and the subtractive robot 4 have a first preset angle, and the first preset angle is the angle α between the connecting lines formed by the 3D printing robot 3, the center of rotation of the printing platform 2, and the subtractive robot 4, Figure 1 In the example shown, the first preset angle α is 90°.

[0135] In another embodiment, the second side of the printing platform 2 is as follows Figure 2 The position of the subtractive robot 4 shown in FIG. 1 is that, as described in the above embodiment, the subtractive robot 4 is arranged between the second right angle and the fourth obtuse angle in the molding chamber 1 . Figure 2 In the example shown, the first preset angle α is 180°.

[0136] In one embodiment, the working area of ​​the second mechanical arm 41 of the subtractive robot 4 performing subtractive processing on the upper side of the printing platform 2 according to the second motion path occupies 75%-100% of the area of ​​the molding surface on the printing platform 2, wherein the molding surface refers to the area on the printing platform 2 for depositing 3D printing materials for building 3D objects, and its range may be less than or equal to the range of the printing platform 2. For example, the working area of ​​the second motion path on the upper side of the printing platform 2 may occupy approximately 75%, 80%, 85%, 90%, 95%, or 100% of the molding surface area.

[0137] In one embodiment, in an example where the working area of ​​the second motion path occupies 75% of the area of ​​the forming surface, see Fig.17 , which is a schematic diagram showing the working area occupied by the second motion path on the molding surface of the printing platform in one embodiment of the present application, Fig.17 The subtractive robot 4 is indicated by a small circle, the printing platform 2 is indicated by a large circle, and the shaded part indicates the range of the working area on the forming surface 21 occupied by the subtractive robot 4. In this example, the length of the second robot arm 41 is set within a suitable range to ensure that the working area of ​​the second motion path can occupy at least 75% of the area of ​​the forming surface 21, so that the subtractive robot 4 can achieve the cutting operation of the entire 3D object without changing its position through the rotation of its six axes and the rotation of the printing platform 2.

[0138] It should be noted here that Fig.17 The working area occupied by the subtractive robot 4 on the molding surface 21 when the subtractive robot 4 is arranged between the second obtuse angle and the third obtuse angle in the molding chamber 1 is only schematically represented, and should not be understood as a limitation of the present application. For example, in another example, the subtractive robot 4 is arranged between the second right angle and the fourth obtuse angle. At this time, the working area of ​​the second motion path on the upper side of the printing platform 2 can still occupy 75%-100% of the molding surface area.

[0139] In one embodiment, see Fig.18 , which is a schematic diagram showing that the first motion path and the second motion path occupy the printing area and the working area of ​​the printing platform respectively in one embodiment of the present application, Fig.18In the figure, two small circles respectively indicate the 3D printing robot 3 and the subtractive robot 4, a large circle indicates the printing platform 2, and the shadow areas corresponding to the 3D printing robot 3 and the subtractive robot 4 respectively indicate the first motion path and the second motion path. As shown in the figure, the first mechanical arm 31 of the 3D printing robot 3 in the printing area on the upper side of the printing platform 2 according to the first motion path and the second mechanical arm 41 of the subtractive robot 4 in the subtractive processing operation area on the upper side of the printing platform 2 according to the second motion path are connected at the rotation center of the printing platform 2. In this way, the 3D printing robot 3 and the subtractive robot 4 can print and cut the 3D object at the same time. While maximizing the printing area and the operation area, the printing operation and the cutting operation do not interfere with each other, thereby improving the manufacturing efficiency of the 3D object, and can also achieve 100% coverage of the entire platform molding area by time-sharing operation with the help of the rotation of the printing platform.

[0140] In another embodiment, the printing area of ​​the first mechanical arm of the 3D printing robot on the upper side of the printing platform according to the first motion path and the subtractive processing operation area of ​​the second mechanical arm of the subtractive robot on the upper side of the printing platform according to the second motion path respectively occupy 75%-100% of the area of ​​the molding surface on the printing platform, expanding the single area area of ​​the printing area and the operation area. For details, please refer to Fig.17 The description of any embodiment in the above will not be repeated here. For example, the printing area and the operation area may occupy approximately 75%, 80%, 85%, 90%, 95%, or 100% of the molding surface area, respectively. Of course, the second mechanical arm of the subtractive robot may also be configured to print 3D objects, which may be determined according to actual production requirements.

[0141] In summary, in order to overcome the technical problems existing in the related art that the 3D printing robot has limited freedom of movement due to its large size and it is difficult to achieve continuous and smooth supply of molten materials, the 3D printing robot and 3D printing equipment provided by the present application realize the caching and melting of granular materials by arranging a feeding system with a material storage device and a melt extrusion device on the mechanical arm of the 3D printing robot, thereby shortening the conveying path of the molten fluid to a certain extent; furthermore, the present application realizes the short-path supply of fluid material from the melt extrusion device to the nozzle of the print head by arranging a feeding pipeline for connecting the melt extrusion device and the print head between the mechanical arm and the print head. In addition, the present application designs a feeding pipeline with a stiffness lower than that of the robotic arm, and sets the feeding pipeline between the fourth-axis joint of the robot body and the print head. This not only ensures the flexibility of the movement of each robotic arm of the robot during the printing process, but also can reduce the instantaneous pressure changes caused by the fluid material, thereby ensuring the uniform supply of the fluid material; and the present application sets a temperature control device on the pipeline body of the feeding pipeline, which can avoid the increase in viscosity of the fluid material due to heat loss or even cooling and solidification during long-distance transportation, thereby avoiding clogging of the fluid material in the pipeline body and the print head, ensuring the continuous supply of the fluid material, and thereby improving the 3D printing efficiency and the printing quality of the object.

[0142] In addition, by providing a valve cavity for accommodating the valve core in the print head, and providing a flow channel in the valve core that radially penetrates the shaft body of the valve core and docks with the extrusion channel, the flow channel can realize the open state of the valve core when the extrusion channel and the tapered extrusion port are connected, and the valve core can be closed when the outlet hole of the flow channel is misaligned with the tapered extrusion port on the print head nozzle, so as to control whether the fluid material can flow through the nozzle on the print head, thereby realizing the normal opening and complete closing of the print head, avoiding leakage of the fluid material, and thus ensuring the printing accuracy. By providing a partially surrounding sink groove on the shaft body of the valve core, the valve core can fill the fluid material in the sink groove when it is in the closed state and keep it between the valve core and the valve cavity, so that the valve core is wrapped by the fluid material, and then the valve core is in a similar "suspended" state, which can prevent the valve core from being pressed on the inner wall of the valve cavity due to the thermal expansion of the fluid material when it is closed, and avoid direct mechanical contact between the valve core and the print head, so as to avoid damage to the print head, thereby ensuring the smooth progress of the printing operation.

[0143] Furthermore, by arranging a 3D printing robot for printing 3D objects and a subtractive robot for performing subtractive processing on 3D objects in the molding chamber, the integration of printing operations and subtractive processing is achieved, thereby avoiding the need to re-clamp and reposition the 3D objects and improving the processing efficiency. By arranging the 3D printing robot and the subtractive robot on the first side and the second side of the rotatable printing platform, while achieving a reasonable layout of the 3D printing robot and the subtractive robot in the molding chamber, the 3D printing robot and the subtractive robot can respectively perform printing and subtractive processing on 3D objects without changing position, thereby further improving the processing efficiency.

[0144] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A 3D printing robot, characterized in that: include: The robot body comprises a plurality of axial joints and a first mechanical arm axially connected to each of the axial joints, wherein the first mechanical arm has a first stiffness; A feeding system is arranged on the first robot arm between the third axis joint and the fourth axis joint of the robot body, and includes a hopper for caching granular materials and a melt extrusion device for melting the granular materials into fluid materials and outputting them under pressure; the melt extrusion device includes a melt barrel connected to the hopper, a screw mechanism arranged in the melt barrel for pressurizing and extruding the molten fluid material, and a plurality of heaters sleeved on the periphery of the melt barrel; A print head, arranged at the end of the first mechanical arm of the robot body, comprising a valve cavity located in the print head body, a valve core arranged in the valve cavity, an extrusion channel connected to the feeding system, and a nozzle connected to the extrusion channel; wherein the valve core comprises a shaft body, radially penetrating the shaft body for connecting to a flow channel of the extrusion channel, and a sink groove partially surrounding the shaft body; wherein when the valve core is in an open state, the flow channel connects the extrusion channel and the nozzle to allow fluid material to flow through; and when the valve core is in a closed state, the outlet of the flow channel is misaligned with the nozzle to prevent the fluid material from flowing through, and the fluid material filled in the sink groove is kept between the valve core and the valve cavity; A feeding pipeline is arranged between the end of the melt barrel of the melt extrusion device and the print head, and is used to transport the fluid material output by the melt barrel to the print head. One end of the feeding pipeline is connected to the melt extrusion device, and the other end is connected to the print head. The feeding pipeline includes a pipeline body with a second stiffness and a temperature control device arranged on the pipeline body for maintaining the temperature of the fluid material; wherein the second stiffness is less than the first stiffness.

2. The 3D printing robot according to claim 1, characterized in that: The material storage device is connected to an external material bin through an air pipeline, and a part of the air pipeline is passed through the first robot arm between the second axis joint and the third axis joint of the robot body.

3. The 3D printing robot according to claim 1, characterized in that: The granular material buffered in the accumulator is transported to the melt extrusion device through a feeding screw arranged at the bottom of the accumulator.

4. The 3D printing robot according to claim 3, characterized in that: The melt extrusion device comprises a driving motor which is arranged at the proximal end of the melt barrel and is linked to a screw mechanism.

5. The 3D printing robot according to claim 3, characterized in that: The heater comprises a pre-heater sleeved on the middle area of ​​the melting barrel and a main heater sleeved on the far end of the melting barrel.

6. The 3D printing robot according to claim 5, characterized in that: The main heater comprises a first main heater sleeved on the distal end of the melt barrel and a second main heater located between the pre-heater and the first main heater.

7. The 3D printing robot according to claim 6, characterized in that: The heating temperature range of the preheater is 80°C-120°C; the heating temperature range of the second main heater is 120°C-220°C; the heating temperature range of the first main heater is 220°C-240°C.

8. The 3D printing robot according to claim 6, characterized in that: The melt extrusion device is provided with temperature sensors corresponding to the heating areas of the pre-heater and the main heater respectively.

9. The 3D printing robot according to claim 1, characterized in that: The material feeding system comprises a pressure sensor for detecting the pressure of the material in the extrusion channel.

10. The 3D printing robot according to claim 1, characterized in that: The length of the feeding pipeline is greater than the maximum distance between the fourth axis joint of the robot body and the print head.

11. The 3D printing robot according to claim 1, characterized in that: The temperature control device is configured as a computer system, a temperature sensor embedded in the pipeline body, and a heating wire wound around the pipeline body.

12. The 3D printing robot according to claim 1, characterized in that: A temperature control sensor is arranged at the far end of the feeding pipeline.

13. The 3D printing robot according to claim 9, characterized in that: An access device is arranged on the upper side of the print head and is arranged along the first direction and connected to the feeding pipeline and the extrusion channel.

14. The 3D printing robot according to claim 13, characterized in that: Compensation heaters for heating the fluid material passing through the access device are arranged at both ends of the access device.

15. The 3D printing robot according to claim 1, characterized in that: Terminal heaters for heating the fluid material in the print head are symmetrically arranged on both sides of the print head.

16. The 3D printing robot according to claim 1, characterized in that: The print head is provided with a terminal temperature sensor for detecting the temperature of the fluid material in the print head.

17. A 3D printing device, characterized in that: include: A molding chamber, used to provide a closed molding space for 3D printing operations; A printing platform, rotatably disposed in the molding chamber for carrying a molded 3D object; The 3D printing robot according to any one of claims 1 to 16, arranged on the first side of the printing platform, for melting powder or granular material and depositing it onto the printing platform according to a first printing path to form the 3D object layer by layer; The subtractive robot is arranged on the second side of the printing platform and at a first preset angle with the 3D printing robot, comprising a second robotic arm that moves on the upper side of the printing platform according to a second motion path, and a cutting component arranged on the second robotic arm for performing subtractive processing on the 3D object deposited on the printing platform according to the subtractive path.

Images