Metal hot melting modeling deposition printing head and method

Abstract

The invention relates to the technical field of metal additive manufacturing, in particular to a metal hot melting modeling deposition printing head and method.The printing head comprises a storage bin, a modeling assembly, an upper baffle and a side baffle, and the storage bin, the modeling assembly, the upper baffle and a printed additive (or the side baffle) are used for forming a shaping chamber for shaping and curing a molten metal printing material; and the outer contour surface of the printed finished product is restrained through the surface shape of the modeling assembly, the inclination angle of the outer contour surface can be adjusted by rotating the modeling assembly, and the outer contour surface of the printed additive is further adjusted. The printing head is used for intermittently printing molten metal, the shape of a printing additive is restrained through the shaping chamber, subsequent printing is carried out after cooling, the smoothness of the outer surface of a printed finished product is greatly improved through intermittent printing, and the problems that a step effect exists, the porosity is high, and the mechanical strength is poor in the traditional process are solved; and the printing efficiency is high, the printing cost is low, and the large-scale generation requirement can be met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of metal additive manufacturing, and particularly relates to a metal hot-melting modeling deposition print head and a method. BACKGROUND

[0002] At present, the printing raw material of the additive manufacturing technology for printing a three-dimensional structure is mainly thermoplastic plastic. The additive manufacturing process of thermoplastic plastic is relatively mature, the processing speed is fast, and the yield is high. However, the process flow of metal additive manufacturing with metal as the printing raw material is not mature, and many problems need to be solved. Compared with the additive manufacturing process with thermoplastic plastic as the raw material, metal has the characteristics of high melting point, strong metal liquid flowability and easy oxidation, which leads to poor stability of the printed local structure in the additive manufacturing process, and problems such as deformation are prone to occur. Although the current metal additive manufacturing technology can manufacture very complex and very small detail structures, the production speed is slow, the energy consumption is high, and the average cost is too high. Therefore, it is not suitable for large-scale industrialization and mass production The metal additive manufacturing technology is currently mainly divided into material extrusion process (ME), powder bed fusion process (PBF), direct energy deposition process (DED) and material / binder jetting process (MJ / BJ). According to statistics, in 2020, the market share of the four additive processes in the field of metal additive manufacturing was: ME 10%, PBF 54%, DED 16% and MJ / BJ 16%. These four processes have their own advantages and disadvantages. The advantages of the material extrusion process (ME) are low equipment cost, but the precision and surface quality of the processed product are poor, the product performance has directionality, the printing process needs a support structure, and the material extrusion deposits a metal and filler bonding material mixture by extruding a filament containing metal powder. Then the metal and filler bonding material mixture is deposited and modeled at a fixed point. Finally, the metal powder blank is sintered and connected into a shape.

[0003] The advantages of the powder bed fusion process (PBF) are that high-complexity small structures can be printed, the printing process is simple, and the final contour can be printed in one step, but the physical properties of the parts have directionality, there is obvious step effect, the surface quality is low, the energy consumption is high, and residual stress is left in the parts.

[0004] The advantages of the direct energy deposition process (DED) are fast production speed and simple process, which can be used for rapid repair of large parts, but the resolution is low, the surface is rough and needs subsequent processing, there is obvious step effect, the complexity of the manufactured parts is limited, and the printing process needs a support structure.

[0005] The material / adhesive jetting process (MJ / BJ) has the advantages of being able to print composite parts of multiple materials, and being suitable for multiple materials, but the types of mature adhesives are less, and there are problems of easy clogging, low strength, and the like, and subsequent processing is required to remove the adhesive and sinter the metal powder, which will cause the part to shrink and affect the size, and the finished product has problems of high porosity, weak mechanical strength, and the like.

[0006] The above four processes, except for the material extrusion process (ME), all use raw materials that are not metal powder raw materials, and the ME process still uses wire with metal powder, which is still strictly speaking using metal powder as raw material. Using metal powder as raw material generally has problems of high product porosity and weak mechanical strength. As shown in Figure 1 , since the printed finished product is formed by stacking "thin lines" formed by melting metal powder, there is a significant step effect problem. The material extrusion process (ME) is a droplet dropping method, which has too high uncontrollability and a low good product rate.

[0007] Although additive manufacturing has unique advantages in lightweight, complex structure, customization, and the like that cannot be replaced, due to the limitations of existing technologies, additive manufacturing is more applied to thermoplastic raw materials, and metal additive manufacturing still cannot be called the mainstream technology of metals, and traditional manufacturing methods (such as metal casting or pressure casting processes) are still the mainstream of metal manufacturing. Therefore, it is urgent to propose a metal printing technology using metal melt as raw material to make up for the shortcomings of existing metal printing technologies and broaden the use scenarios and range of metal additive manufacturing. SUMMARY

[0008] Therefore, the present application creates a metal hot melting modeling deposition print head and method, which provides a print head that can provide metal material shaping and cooling, controls the shape of the printed additive single element using a shaping chamber to meet the requirements of the outer contour surface of the printed finished product, and realizes high stability shaping of the printing material in an intermittent printing manner, solving the problems of rough finished product surface and obvious step effect existing in the conventional process using metal powder as the printing material.

[0009] To achieve the above object, the technical scheme of the present application is as follows: The present application creates a metal hot melting modeling deposition print head for printing materials in a molten state, comprising: a storage cabin, a modeling assembly, an upper baffle, and a side baffle; The storage cabin is provided with an inlet and an outlet. The upper baffle is arranged above the discharge port, the molding assembly is rotationally connected with the storage cabin through a rotating shaft perpendicular to the cross section of the discharge port, the side of the molding assembly and the upper baffle away from the storage cabin is coplanar, and the side baffle is slidingly connected to the side of the upper baffle away from the storage cabin; the side baffle can slide along the side of the molding assembly and the upper baffle away from the storage cabin. When there is printed additive, the storage cabin, the molding assembly, the upper baffle and the printed additive form a shaping chamber of the printing material. When there is no printed additive, the storage cabin, the molding assembly, the upper baffle and the side baffle form a shaping chamber of the printing material.

[0010] Preferably, the width of the molding assembly in the direction perpendicular to the cross section of the discharge port is the length of the single-printed additive.

[0011] Preferably, the surface of the molding assembly for constituting the inner wall of the shaping chamber is a plane or a curved surface.

[0012] Preferably, a cooling liquid channel is arranged in the molding assembly, and an outlet and an inlet of the cooling liquid channel are arranged on the surface of the molding assembly not for constituting the inner wall of the shaping chamber; the cooling liquid is circulated through the outlet and the inlet of the cooling liquid channel to cool and shape the printing material flowing into the shaping chamber through the discharge port.

[0013] Preferably, the molding assembly rotates around the rotating shaft to change the internal space of the shaping chamber, so as to realize additive printing of different geometric shapes.

[0014] Preferably, the surface shape of the molding assembly for constituting the inner wall of the shaping chamber is changed to change the internal space of the shaping chamber, so as to realize additive printing of different geometric shapes.

[0015] Preferably, at least one supplementary feeding port which can be controlled to be opened and closed is arranged on the upper baffle, and the supplementary feeding port is used to add the printing material into the shaping chamber.

[0016] Preferably, a transmission device of metal wires or alloy wires is arranged in the storage cabin, the metal wires or alloy wires are transmitted to the discharge port through the transmission device, and a heater is arranged on the inner side of the discharge port, which is used to melt the metal wires or alloy wires into molten metal.

[0017] Another aspect of the present application provides a metal hot melting molding deposition method, which comprises the following steps: S1: moving the metal hot melting molding deposition print head to a position to be printed; S2: when there is no printed additive, sliding the side baffle to close the opening of the shaping chamber, and forming the shaping chamber of the printing material by the storage cabin, the molding assembly, the upper baffle and the side baffle; when there is printed additive, sliding the side baffle to open the opening of the shaping chamber, and forming the shaping chamber of the printing material by the storage cabin, the molding assembly, the upper baffle and the printed additive; The molten metal enters the shaping chamber through the outlet, and the temperature of the molten metal is higher than the melting point of the metal; S3: After the molten metal in the shaping chamber solidifies, the metal hot melting modeling deposition printing head is moved to the next printing position.

[0018] Preferably, the metal hot melting modeling deposition is carried out in a vacuum environment, and when the molten metal in the shaping chamber is in a full state, the molten metal in the shaping chamber is continuously pressurized.

[0019] Compared with the prior art, the application can achieve the following beneficial effects: The printing head provided by the application can flexibly adjust the outer contour surface and the size of the shaping chamber by rotating, translating or replacing the modeling component, so as to adapt to the printing of products with different outer contour surfaces. This flexible adjustment enables the metal additive printing using the printing head to meet the needs of customized production, and by reasonably adjusting the size of the shaping chamber, the production speed can be improved to realize rapid large-scale production.

[0020] Compared with the traditional processing technology using metal powder as the printing material, the printing material of the application is molten metal, and the printing additive is constrained by the shaping chamber, which avoids the problems of rough printing surface and obvious step effect existing in the traditional metal powder bed melting and direct energy deposition process. The step effect refers to the fact that in the process of metal powder bed melting or direct energy deposition printing, the printing additive is in the form of "thin lines", and the printed product is composed of "thin lines", so there are serious layering and protrusion problems on the outer contour surface, which presents a stepped outer surface. Since the printed product obtained by the printing method of the application does not have the step effect, subsequent polishing is not required, the processing efficiency is effectively improved, the printing cost is saved, and large-scale production requirements can be met. In addition, the traditional processing technology using metal powder as the printing material has the problem of incomplete melting of the metal powder during the melting process, which may cause small pores due to incomplete melting of the powder, resulting in poor mechanical strength of the printed product.

[0021] Since the metal material printing process requires melting of the metal, compared with thermoplastic plastic, the metal liquid has strong fluidity and is not easy to form, and after printing, the metal liquid is prone to overflow and spread, resulting in a large deviation between the printed surface and the preset surface. Especially in the printing of complex structures, the traditional method needs a support structure to prevent the part from collapsing and to avoid deformation of the printed product. However, the application uses intermittent printing, and the printing material at each position is well constrained by the shaping chamber, which can effectively avoid problems such as deformation and even collapse of the printing material. In addition, in order to realize rapid shaping, a cooling circulation loop is arranged in the modeling component, which can significantly improve the solidification speed of the molten metal and improve the printing efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the stepped effect of the printed product described in the background art; Figure 2 This is a schematic diagram of the structure of a metal hot melt molding deposition printhead provided according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the feed inlet provided according to an embodiment of the present invention; Figure 4 This is a side view of a metal hot melt molding deposition printhead provided according to an embodiment of the present invention; Figure 5 AA is a cross-sectional view of a metal hot melt molding deposition printhead provided according to an embodiment of the present invention; Figure 6 This is a schematic diagram of additive printing provided according to an embodiment of the present invention; Figure 7 This is an optional internal structure diagram of a storage compartment provided according to an embodiment of the present invention.

[0023] The reference numerals in the figures include: 1. Storage chamber, 11. Inlet, 12. Outlet, 13. Conveying device, 14. Heater, 15. Metal wire or alloy wire, 2. Shaping component, 21. Surface used to form the inner wall of the shaping chamber, 22. Coolant channel, 23. Rotating shaft, 3. Upper baffle, 4. Side baffle, 5. Rolling wheel, 6. Shaping chamber. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and do not constitute a limitation thereof. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the invention. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the invention are not shown or described in the specification. This is to avoid obscuring the core parts of the invention with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0025] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other to form various embodiments without conflict. Meanwhile, each step or action in the method description can be sequentially changed or adjusted in a manner obvious to those skilled in the art. Therefore, the various sequences in the description and the drawings are only for clear description of a certain embodiment, and do not mean a necessary sequence, unless otherwise stated that a certain sequence must be followed.

[0026] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" and the like can explicitly or implicitly include one or more features. In the description of the present application, unless otherwise stated, "a plurality of" means two or more.

[0027] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood through specific circumstances.

[0028] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0029] Please refer to Figure 2 , Figure 3 , Figure 4 and Figure 5 In an embodiment of the present application, a metal hot melting molding deposition print head is provided, which is mainly aimed at the scene where the printing material is molten metal, and is also applicable to the scene where the printing material is thermoplastic plastic and the like according to the application needs. The print head comprises: a storage cabin, a molding assembly, an upper baffle and a side baffle; The storage cabin 1 is provided with an inlet 11 and an outlet 12. The upper baffle 3 is arranged above the outlet 12, the molding assembly 2 is rotationally connected with the storage cabin 1 through a rotation shaft 23 perpendicular to the cross section of the outlet 12, the side surface of the molding assembly 2 and the upper baffle 3 away from the storage cabin 1 is coplanar, and the side baffle 4 is slidingly connected to the side surface of the upper baffle 3 away from the storage cabin 1; the side baffle 4 can slide along the side surface of the molding assembly 2 and the upper baffle 3 away from the storage cabin 1. When there is printed additive, the storage cabin 1, the molding assembly 2, the upper baffle 3 and the printed additive form a shaping chamber 6 of the printing material. When there is no printed additive, the storage cabin 1, the molding assembly 2, the upper baffle 3 and the side baffle 4 form the shaping chamber 6 of the printing material.

[0030] Specifically, the storage cabin 1 is used for storing and transporting the molten metal printing material, the upper end of the storage cabin 1 is provided with an inlet 11, the inlet 11 is usually connected with a device for providing molten metal, and the printing material can be injected into the storage cabin 1 through the inlet 11. The side surface of the lower end position of the storage cabin 1 is provided with an outlet 12, the left side of the outlet 12 communicates with the storage cabin 1, and the right side communicates with the shaping chamber 6, the molten metal in the storage cabin 1 flows into the shaping chamber 6 through the outlet 12.

[0031] Regarding the composition of the shaping chamber 6, the embodiment of the present application is provided with an upper baffle 3 above the outlet 12 of the storage cabin 1, the upper baffle 3 is in a horizontal state, and the width in the direction perpendicular to the cross section of the outlet 12 can be adjusted according to the printing requirements. In the vicinity of the upper baffle 3, a rotation shaft 23 with an axis perpendicular to the cross section direction of the outlet 12 is arranged, that is, the rotation shaft 23 is perpendicular to the side surface of the storage cabin 1 provided with the outlet 12. The molding assembly 2 is rotationally connected with the storage cabin 1 through the rotation shaft 23, and the molding assembly 2 is tightly attached to the side surface of the storage cabin 1 provided with the outlet 12, and the molding assembly 2 can rotate around the rotation shaft 23 to change the space angle between the surface 21 of the molding assembly 2 used for constituting the inner wall of the shaping chamber and the horizontal direction. In the direction perpendicular to the cross section of the outlet 12, the width of the molding assembly 2 is equal to the width of the upper baffle 3, that is, the side surface of the molding assembly 2 and the upper baffle 3 away from the storage cabin 1 is coplanar.

[0032] Thus, the molding assembly 2, the upper baffle 3 and the side of the storage cabin 1 below the upper baffle 3 form a non-fully sealed space, which is the shaping chamber 6. During the printing process, the lower surface of the shaping chamber 6 abuts against the bottom surface of the printed additive or the printing platform, the front surface of the shaping chamber 6, i.e. the surface opposite to the surface 21 of the molding assembly 2 for constituting the inner wall of the shaping chamber, abuts against the side surface of the molding assembly 2 or the printing platform, and the left side of the shaping chamber 6 opposite to the side of the storage cabin 1 provided with the discharge port 12 is in an open state. During the printing process, the left side of the shaping chamber 6 abuts against the side surface of the printed additive, and at this time, the shaping chamber 6 is fully sealed. When there is the printed additive, the storage cabin 1, the molding assembly 2, the upper baffle 3 and the printed additive form the closed shaping chamber 6, the molten metal in the storage cabin 1 flows into the shaping chamber 6 from the discharge port 12, and the shaping chamber 6 can constrain the shape of the additive, so as to avoid the molten metal overflowing and spreading, thereby causing a large difference between the outer surface of the printed additive block and the surface to be printed. The additive block is the structural block after the molten metal in the shaping chamber 6 solidifies, and when the printing head of the embodiment of the present application is used for printing, the outer contour surface of the finished product is composed of the additive blocks.

[0033] However, when the additive is printed for the first time, i.e. when the first additive block is printed, there is no printed additive on the left side of the printing head, and at this time, the left side opening of the shaping chamber 6 cannot be shielded by the printed additive. Therefore, the embodiment of the present application is provided with a side baffle 4 on the side of the upper baffle 3 away from the storage cabin 1, a sliding groove is formed in the side baffle 4, a rolling wheel 5 is slidably connected in the sliding groove, and the shaft of the rolling wheel 5 is fixed on the side of the upper baffle 3 away from the storage cabin 1. Under the cooperation of the sliding groove and the rolling wheel 5, the side baffle 4 can slide along the side of the molding assembly 2 and the upper baffle 3 away from the storage cabin 1, so that the side baffle 4 can block the left side opening of the shaping chamber 6 or completely not shield the left side opening of the shaping chamber 6.

[0034] During the printing process of the additive other than the first additive block (when there is the printed additive), the left side opening of the shaping chamber 6 is located at the position of the printed additive block, so that the shaping chamber 6 can be sealed, and the newly printed additive block needs to be fused with the printed additive block. Therefore, at this time, the left side opening of the shaping chamber 6 should be in an open state, so that the molten metal in the shaping chamber 6 can contact the printed additive block to realize solidification and fusion. In this case, the side baffle 4 is slid so that the side baffle 4 completely does not shield the left side opening of the shaping chamber 6. The storage cabin 1, the molding assembly 2, the upper baffle 3 and the printed additive (the printed additive block) form the shaping chamber 6 capable of constraining the shape of the printed material.

[0035] In the printing process of the first additive block (without the printed additive), since the left opening of the shaping chamber 6 is not the printed additive block, the left side of the shaping chamber 6 needs to be sealed, otherwise the molten metal in the shaping chamber 6 will flow to the left side, causing the shaping chamber 6 to fail to constrain the shape of the additive block. In this case, the sliding side baffle 4 is used to completely block the left opening of the shaping chamber 6. The storage cabin 1, the molding assembly 2, the upper baffle 3 and the side baffle 4 form the shaping chamber 6 which can constrain the shape of the printing material.

[0036] According to the actual printing needs, the width of the molding assembly 2 and the upper baffle 3 in the direction perpendicular to the discharge port 12 section can be adjusted, and the width is the length of the single printing additive, that is, the length of each additive block. In the printing process, the temperature of the liquid printing material (molten metal) in the printing head should be higher than the melting point of the metal material, so that when the molten metal in the shaping chamber 6 contacts the printed additive, the two parts can be fused together for solidification.

[0037] In order to improve the solidification efficiency of the molten metal in the shaping chamber 6, the embodiment of the present application also innovatively designs the molding assembly 2, at least one cooling liquid channel 22 is arranged in the molding assembly 2, and the outlet and inlet of the cooling liquid channel 21 are opened on any surface of the molding assembly 2 except the surface 21 used to constitute the inner wall of the shaping chamber. The cooling liquid is filled through the inlet of the cooling liquid channel 21, and the cooling liquid is discharged through the outlet of the cooling liquid channel 21. The cooling liquid is circulated through the outlet and inlet of the cooling liquid channel 21, and the printing material flowing into the shaping chamber 6 from the discharge port 12 is shaped and cooled.

[0038] Since the outer surface of the finished product is different when printing the product, the contour line has different curvature, and the angle with the horizontal direction is also different, therefore, the embodiment of the present application designs the molding assembly 2 to be rotatably connected with the storage cabin 1 through the rotating shaft 23, and the surface space angle of the additive block is changed by rotating the molding assembly 2 (actually to realize the rotation of the surface 21 used to constitute the inner wall of the shaping chamber), that is, the angle between the surface of the additive block corresponding to the surface 21 used to constitute the inner wall of the shaping chamber and the horizontal plane is changed, and the internal space of the shaping chamber 6 is changed, and the additive blocks of different geometrical shapes are printed. When the outer surface precision requirement is not high, the molding assembly 2 with the surface 21 used to constitute the inner wall of the shaping chamber as a plane can be directly used for printing, and the step effect when printing curved surface is effectively inhibited by tilting the plane and reducing the layer distance interface. Or the product can be slightly polished after printing, that is, the finished product with no step effect and high smoothness of the outer surface can be obtained. When the smoothness of the outer surface of the printed finished product is required to be high, in order to avoid subsequent polishing treatment, the molding assembly 2 with the surface 21 used to constitute the inner wall of the shaping chamber as a curved surface can be used for printing, the curvature of the surface 21 used to constitute the inner wall of the shaping chamber matches the preset curvature of the outer surface of the finished product, and the outer surface of the additive block is constrained by using the molding assembly 2.

[0039] As an optional embodiment, since the metal hot melting molding deposition print head provided by the application is in a molten state, in addition to the direct injection of molten metal through the feed port 11 of the storage cabin 1, the molten metal can also be provided in a molten state by melting the metal, such as Figure 7 As shown in the figure, a set of conveying devices 13 are arranged in the interior of the storage cabin 1, the conveying devices 13 can adopt a feeding roller, and the metal wire or alloy wire 15 is conveyed into the storage cabin 1 through the feed port 11 of the storage cabin 1, and the metal wire or alloy wire 15 is conveyed along the conveying device 13 to the discharge port 12, and a heater 14 is arranged on the inner side of the discharge port 12, and the heater 14 heats the metal wire or alloy wire 15 by arc, laser, resistance heating or the like, so that the metal wire or alloy wire 15 is melted to form molten metal, and the molten metal flows into the shaping chamber 6 through the discharge port 12 to solidify and print.

[0040] As an optional embodiment, the print head is also provided with an operating cover connected with a vacuum pump to realize additive printing in a vacuum environment to prevent the molten metal from being oxidized by air.

[0041] As an optional embodiment, a pressurizing device can be arranged at the position of the feed port 11 of the storage cabin 1, after the molten metal is quantitatively injected through the feed port 11 of the storage cabin 1, when the molten metal in the shaping chamber 6 is in a full state, the pressurizing device is used to continue to pressurize the molten metal in the shaping chamber 6 to realize compaction of the molten metal in the shaping chamber 6 and reduce the porosity. Common pressurizing methods can be selected as follows: a small amount of molten metal is continuously injected into the shaping chamber 6 when the molten metal in the shaping chamber 6 is in a full state, and the pressure mode can adopt air pressure, hydraulic pressure or other optional modes.

[0042] As an optional embodiment, at least one supplementary feed port which can be controlled to be opened or closed is arranged on the upper baffle 3, and the supplementary feed port is used to add printing material into the shaping chamber 6. Specifically, when printing a large device, the size of a single additive block is large, and there may be uneven distribution of printing material in the shaping chamber 6 or the printing material flows too long in the shaping chamber 6, which causes solidification in the flowing process. To solve this problem, a plurality of supplementary feed ports can be opened on the upper baffle 3, and the opening and closing of each supplementary feed port can be controlled individually, and each supplementary feed port can be connected with the storage cabin 1 through a pipeline structure, and the printing material in the storage cabin 1 flows into the shaping chamber 6 through the pipeline and the supplementary feed port, thereby improving the uniformity of feeding. In addition, an additional printing material storage device can also be configured for each supplementary feed port.

[0043] Based on the above print head, the application also provides a metal hot melting molding deposition method, which comprises the following steps: S1: as shown in the figure, Figure 6As shown, taking printing a semi-cylinder as an example, first, according to the curvature of the outer surface of the product to be printed (the semi-cylinder), a molding assembly 2 with a surface 21 that matches the curvature of the outer surface of the product to be printed is selected to constitute the inner wall of the forming chamber.

[0044] In the printing process, the interior of the semi-cylinder does not need to be specially constrained to the outer surface, and can be printed according to the conventional "thin line" printing method, or directly printed into a rectangular column as shown in Figure 6 , only the outermost contour of the semi-cylinder is printed by the printing head of the present application, and the interior can be printed by the conventional printing method or by the printing head of the present application. The outermost contour of the semi-cylinder needs to be printed by the printing head of the present application to solve the problem of the step effect that occurs during printing.

[0045] For any printing layer, the metal hot-melt molding deposition printing head is moved to the position to be printed and is precisely positioned so that the front opening of the forming chamber 6 abuts against the printed interior "thin line".

[0046] S2: When printing the first additive block of each "thin line", since there is no printed additive on the side, the side baffle 4 needs to be slid to close the left opening of the forming chamber 6, and a closed forming chamber 6 is formed by the storage cabin 1, the molding assembly 2, the upper baffle 3 and the side baffle 4.

[0047] For the non-first additive block of each "thin line", since there is a printed additive on the side, the left opening of the forming chamber 6 abuts against the side of the printed additive, so the left opening of the forming chamber 6 does not need to be closed, and at this time the side baffle 4 is slid to open the left opening of the forming chamber 6, and a closed forming chamber 6 is formed by the storage cabin 1, the molding assembly 2, the upper baffle 3 and the printed additive.

[0048] After the forming chamber 6 is formed, the molten metal is quantitatively injected through the feeding port 11 of the storage cabin 1, the amount of molten metal injected is related to the volume of the formed forming chamber 6, and the amount injected is slightly higher than the volume of the forming chamber 6 to compensate for the volume shrinkage during the solidification of the metal. The temperature of the molten metal injected into the printing head needs to be higher than the melting point of the metal, which not only ensures that the molten metal does not block the discharge port 12, but also facilitates the contact between the printed additive and the molten metal when the molten metal contacts the printed additive, so that the surface of the printed additive that contacts the molten metal undergoes slight melting, and the additive blocks printed in different times are fused and solidified together to form a smooth outer surface.

[0049] S3: After the molten metal in the forming chamber 6 solidifies, the metal hot-melt molding deposition printing head is moved to the next printing position to print the next additive block, and the above process is repeated until the semi-cylinder is printed.

[0050] During the printing process, a suitable shaping component 2 can be selected for printing based on the required smoothness of the printed product's outer surface. If the requirement for smoothness of the printed product's outer surface is low, a shaping component 2 with a flat surface 21 used to form the inner wall of the molding chamber can be used. This reduces the difficulty of control during the printing process, and the resulting "fine lines" are more refined. Figure 6 As shown in Figure B. If a high degree of smoothness is required for the outer surface of the printed product, a modeling component 2 with a curved surface 21 forming the inner wall of the molding chamber is used. Furthermore, the curvature of the surface 21 forming the inner wall of the molding chamber matches the curvature of the outer surface of the semi-cylinder. In this case, the smoothness of the printed outer surface is higher, the printed product closely matches the design drawings, and no secondary polishing is required. The "fine lines" obtained at this time are as follows: Figure 6 As shown in C.

[0051] The printing process can be carried out in a vacuum environment to avoid metal oxidation.

[0052] In summary, the above description is merely a preferred embodiment of this specification and is not intended to limit the scope of protection of this specification. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this specification should be included within the scope of protection of this specification.

[0053] The systems, apparatuses, modules, or units described in one or more of the above embodiments may be implemented by a computer chip or entity, or by a product having a certain function. A typical implementation device is a computer. Specifically, a computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or any combination of these devices.

[0054] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0055] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

Claims

1. A metal hot melt modeling deposition print head for printing a material that is a molten metal, characterized in that, The application relates to a metal hot-melt molding deposition printing head. The application comprises a storage cabin, a molding assembly, an upper baffle and a side baffle. The storage cabin is provided with an inlet and an outlet. The upper baffle is arranged above the outlet, the molding assembly is rotationally connected with the storage cabin through a rotating shaft perpendicular to the cross section of the outlet, the side of the molding assembly and the upper baffle away from the storage cabin is coplanar, and the side baffle is slidingly connected to the side of the upper baffle away from the storage cabin. When there is printed additive, the storage cabin, the molding assembly, the upper baffle and the printed additive form a shaping chamber of the printing material. When there is no printed additive, the storage cabin, the molding assembly, the upper baffle and the side baffle form a shaping chamber of the printing material.

2. The metal hot-melt molding deposition printing head according to claim 1, characterized in that, The width of the molding assembly in the direction perpendicular to the cross section of the outlet is the length of the additive in single printing.

3. The metal hot-melt molding deposition printing head of claim 1, wherein, The surface of the molding assembly for constituting the inner wall of the shaping chamber is a plane or a curved surface.

4. The metal hot-melt molding deposition printing head of claim 1, wherein, The molding assembly is internally provided with a cooling liquid channel, and the cooling liquid channel is provided with an outlet and an inlet on the surface of the molding assembly which is not used for constituting the inner wall of the shaping chamber; cooling liquid circulation is carried out through the outlet and the inlet of the cooling liquid channel, and the printing material flowing into the shaping chamber from the outlet is shaped and cooled.

5. The metal hot-melt molding deposition printing head of claim 1, wherein, The molding assembly rotates around the rotating shaft, and is used for changing the internal space of the shaping chamber and realizing additive printing of different geometric shapes.

6. The metal hot-melt molding deposition printing head of claim 1, wherein, The surface shape of the molding assembly for constituting the inner wall of the shaping chamber is changed, the internal space of the shaping chamber is changed, and additive printing of different geometric shapes is realized.

7. The metal hot-melt molding deposition printing head of claim 1, wherein, At least one supplementary inlet which can be controlled to be opened or closed is arranged on the upper baffle, and the supplementary inlet is used for adding printing material into the shaping chamber.

8. The metal hot-melt molding deposition printing head of claim 1, wherein, A transmission device of metal wires or alloy wires is arranged in the storage cabin, the metal wires or alloy wires are transmitted to the outlet through the transmission device, a heater is arranged on the inner side of the outlet, and the heater is used for hot melting the metal wires or alloy wires into molten metal.

9. A method of metal hot-melt modeling deposition, characterized by, The application further discloses a method for using the metal hot-melt molding deposition printing head. S1: moving the metal hot-melt molding deposition printing head to a position to be printed; S2: when there is no printed additive, sliding the side baffle to close the opening of the shaping chamber, and forming the shaping chamber of the printing material by the storage cabin, the molding assembly, the upper baffle and the side baffle; when there is printed additive, sliding the side baffle to open the opening of the shaping chamber, and forming the shaping chamber of the printing material by the storage cabin, the molding assembly, the upper baffle and the printed additive; The molten metal enters the shaping chamber through the outlet, and the temperature of the molten metal is higher than the melting point of the metal; S3: after the molten metal in the shaping chamber solidifies, moving the metal hot-melt molding deposition printing head to a next printing position.

10. The method of metal hot-melt forming deposition according to claim 9, characterized in that, The metal hot-melt molding deposition is carried out in a vacuum environment, and when the molten metal in the shaping chamber is in a full state, the molten metal in the shaping chamber is continuously pressurized.

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