CN110340366B

CN110340366B - Sand mold support combined type double-gantry additive manufacturing equipment and printing method

Info

Publication number: CN110340366B
Application number: CN201910618960.7A
Authority: CN
Inventors: 邢飞; 孙中刚; 夏振宇; 唱丽丽; 徐国建
Original assignee: Nanjing Zhongke Raycham Laser Technology Co Ltd
Current assignee: Nanjing Zhongke Raycham Laser Technology Co Ltd
Priority date: 2019-07-10
Filing date: 2019-07-10
Publication date: 2020-10-23
Anticipated expiration: 2039-07-10
Also published as: CN110340366A

Abstract

The invention provides sand mold support combined type double-gantry additive manufacturing equipment and a printing method, which comprise a metal 3D printing system, a sand mold 3D printing system, a double-gantry machine tool, a workbench and a control system, wherein the metal 3D printing system is a powder feeding type metal 3D printing system or an arc fuse wire 3D printing system; the metal 3D printing system is provided with a working head for performing metal 3D printing on the substrate; the sand mold 3D printing system is provided with a printing nozzle for performing sand mold 3D printing, and the printing nozzle and the working head are fixed on the first connecting plate; and the control system controls the printing spray head and the working head to alternately perform layer-by-layer metal part printing and sand mold supporting operation on the substrate, wherein compaction operation is performed through a pressure plate on the second connecting plate after each layer of sand mold support is printed. The invention can solve the problems that the common electric arc additive manufacturing equipment can not print and support and can not manufacture complex metal parts with the characteristics of large inclination angle, partial hollowing and the like.

Description

Sand mold support combined type double-gantry additive manufacturing equipment and printing method

Technical Field

The invention relates to the technical field of metal 3D printing, in particular to sand mold supporting combined type double-gantry additive manufacturing equipment and a printing method.

Background

The additive manufacturing (3D printing) technology for large-scale metal material complex structural members is derived from Rapid Prototyping (RP) technology, and has been widely regarded and developed domestically in recent decades. The core process of the technology is to carry out layer-by-layer fused deposition on a metal material in the form of spherical powder or wire material through high-energy beam current (including laser, plasma beam or electron beam and the like) with the aid of numerical control equipment to form a large structural member. Different from the traditional 'removal' type cutting processing mode, the technology carries out layer-by-layer deposition according to the 'growth' type concept, and the utilization rate of raw materials is greatly improved; meanwhile, the design and the processing process of a large number of dies are avoided, so that the preparation period of the component is greatly shortened. As a beneficial supplement to the traditional forming method of metal materials, the 3D printing technology solves the problem that a plurality of thermal deformation preparation technologies cannot overcome, is continuously developed and mature, is widely applied to the fields of new product design, medical instruments, aerospace and the like, is a perfect combination of the traditional manufacturing technology and the new material manufacturing technology, and can be called as a major technical revolution in the manufacturing field.

The arc fuse 3D printing technology (also known as arc additive manufacturing technology, WAAM for short) adopts a layer-by-layer surfacing mode to manufacture a metal solid component, is developed mainly based on TIG, MIG/MAG, PLASMA and other welding technologies, a forming part is composed of arc fuses, has uniform chemical components and high density, an open forming environment theoretically has no limit to the size of a formed part, and the forming speed can reach 4-8 kg/h. With the development of aerospace technology in China, a solid rocket engine as a booster of a carrier rocket becomes a feasible technical scheme. The key components of the solid booster are large-size special-shaped structures of binding connection rings connected with the core level, the traditional turning and milling composite processing is adopted, the material waste is huge, the processing period is long, the cost is high, and the key technical bottleneck for restricting the development of the solid booster is formed. The high realisability of arc additive manufacturing in large sized profiled components provides an important breakthrough for solving the above-mentioned bottlenecks.

However, the arc fuse 3D printing technology is limited by its own process flow and technical characteristics, is not generally suitable for all metal material structural members, and has its application range and limitations. The arc fuse 3D printing technology is line forming, is suitable for solid piece printing and forming, but is not suitable for intermittent printing, so that metal support is difficult to print, and complex parts with the characteristics of large inclined angle, partial hollowing and the like cannot be printed; in addition, after printing is completed, the separation difficulty of the substrate and the part is large, and time and labor are wasted.

Disclosure of Invention

The invention aims to provide sand mold support combined type double-gantry additive manufacturing equipment and a printing method, and aims to solve the problems that common electric arc additive manufacturing equipment cannot print supports and manufacture complex metal parts with characteristics of large inclination angles, partial hollowing and the like, and the printed parts are time-consuming and labor-consuming when separated from a substrate.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

two longmen additive manufacturing of sand mould support combined type are equipped, include: including metal 3D printing system, sand mould 3D printing system, two longmen lathe, workstation and control system, wherein:

the double gantry machine tool is provided with a pair of bases, two groups of upright columns are respectively arranged on the opposite bases and respectively comprise a first upright column group and a second upright column group, and the first upright column group and the second upright column group are both arranged to slide relative to the bases and limit the sliding direction to be the X direction;

the first vertical column group is provided with a first cross beam which is mounted on two vertical columns of the first vertical column group in a crossing mode, the first cross beam is arranged to move along the vertical direction defined by the vertical columns and defines the moving direction as the Z direction; the first cross beam is provided with a first connecting plate which is arranged to move along the direction defined by the first cross beam and defines the moving direction as Y1 direction;

the second vertical column group is provided with a second cross beam which is mounted on two vertical columns of the second vertical column group in a crossing mode, the second cross beam is arranged to move along the vertical direction defined by the vertical columns and defines the moving direction as the Z direction; the second beam is provided with a second connecting plate which is arranged to move along the direction defined by the second beam and defines the moving direction as Y2 direction;

the workbench is arranged between two bases of the double-gantry machine tool, forms a working area for additive manufacturing and is used for fixing a substrate for additive manufacturing printing;

the metal 3D printing system is provided with a working head for performing metal 3D printing on the substrate; the sand mold 3D printing system is provided with a printing nozzle, sand mold powder is sprayed out through the printing nozzle to perform sand mold 3D printing on the substrate, and the printing nozzle and the working head are fixed to the first connecting plate side by side at intervals;

a platen is fixed to the second connecting plate, and the platen is provided with a plane pressing down towards the substrate for compacting the printing sand powder;

the control system set to with metal 3D printing system, sand mould 3D printing system and two dragon door machine beds respectively electrical connection for control its operation, include: by controlling the movement of the two stand columns, the two cross beams, the first connecting plate and the second connecting plate, the printing operation that a printing nozzle of a sand mold 3D printing system on the first connecting plate prints a sand mold support on a substrate and a working head of a metal 3D printing system prints metal parts and metal supports layer by layer on the substrate is performed alternately, and after each layer of sand mold support is printed, compaction operation is performed through a pressure plate on the second connecting plate.

Further, the metal 3D printing system is an arc fuse 3D printing system and comprises a welding gun, a wire feeder, a wire disc and a welding machine power supply, wherein the welding gun is used as the working head; the metal welding wire is placed in the wire reel, the wire feeder is arranged to transmit the metal welding wire to the front end of the welding gun, the welding machine power supply is arranged to convert electric energy into heat energy at the front end of the welding gun after the welding machine power supply is started, so that the metal welding wire is melted to be in a molten state, and metal 3D printing is carried out on the substrate.

Further, the welding gun of the arc fuse 3D printing system is as high as the working point of the printing nozzle.

Further, the metal 3D printing system is a powder feeding type metal 3D printing system and comprises a powder feeding type laser processing head, an optical fiber, a laser and a powder feeder; the powder feeding type laser processing head is used as the working head; the powder feeder is used for storing metal powder and conveying the metal powder to the front end of the powder feeding type laser processing head through the powder feeder; the laser is used for emitting a set laser beam with high energy density, the laser beam is transmitted to the powder feeding type laser processing head through the optical fiber, metal powder is melted after the laser beam is collimated and focused by an optical module in the powder feeding type laser processing head, and powder feeding type metal 3D printing is carried out.

Furthermore, the working points of the powder feeding type laser processing head and the printing spray head are equal in height.

Further, the control system controls the metal 3D printing system and the sand mold 3D printing system to perform 3D printing, and the first layer is printed by 3D printing of the molding sand powder performed by the sand mold 3D printing system.

Further, sand mould 3D printing system is including printing shower nozzle, fortune sand pipeline, extrusion mechanism and feed bin, and the storage has the sand mould powder that fine sand powder and adhesive mix formed in the feed bin, and extrusion mechanism is set to be used for carrying the sand mould powder to printing the shower nozzle through fortune sand pipeline, and carry out sand mould 3D on the base plate and print.

Furthermore, the movements in the X direction, the Y1 direction, the Y2 direction and the Z direction are all provided with movement guide mechanisms.

According to the improvement of the invention, the additive manufacturing printing method of the sand mold support combined type double-gantry additive manufacturing equipment is further provided, and comprises the following steps:

step 1, controlling a printing nozzle of the sand mold 3D printing system to print a first layer of sand support and a layer height H1 on the substrate, and then controlling a first column group and a first beam of a double-gantry machine tool to leave a working area;

step 2, controlling a second column group and a second beam of the double-gantry machine tool to move, enabling a pressure plate on a second connecting plate to compact the printed sand support, changing the layer height of the sand support into k x H1, and then controlling the second column group and the second beam to leave a working area;

step 3, controlling the first column group and the first beam of the double-gantry machine tool to move, so that the working head on the first connecting plate prints the metal parts and the first layer of the metal support layer by layer on the substrate, wherein the layer height H2 is k H1; then controlling the first vertical column group and the first cross beam to leave the working area;

and 4, judging whether the additive manufacturing printing part is finished or not, if not, repeating the steps 1-3, alternately printing the part layer by using the two 3D printing systems, and compacting by using a pressing disc after the molding sand of each layer supports and prints until the printing operation is finished.

Further, the method further comprises a separation process after printing is completed, and the method comprises the following steps:

after the printing of the part is finished, the part is separated from the substrate in a sawing or linear cutting mode, then the sand mold support is dissolved by using a dissolving agent, and the residual metal support is removed, so that the final metal part is obtained.

According to the technical scheme, the printing principle of the sand mold supporting combined type double-gantry additive manufacturing system is as follows: the device is provided with an arc fuse or laser cladding metal 3D printing system and a sand mold 3D printing system at the same time, the running tracks of the two 3D printing systems are planned in advance, and a motion executing mechanism is controlled to operate the two 3D printing systems to print parts alternately layer by layer; the metal part structure is printed by a metal 3D printing system, and the physical support structure is printed by a sand mold 3D printing system; after the printing of the part is finished, the part is separated from the substrate in a sawing or linear cutting mode, then the sand mold support is dissolved by using a dissolving agent, and the residual metal support is removed, so that the final metal part is obtained. The invention can solve the problems that the common electric arc additive manufacturing equipment can not print and support, can not manufacture complex metal parts with the characteristics of large inclination angle, partial hollow and the like, and simultaneously wastes time and labor when the printed parts are separated from the substrate.

Meanwhile, the double gantry bed mechanism foundation is adopted, and compared with 3D printing based on a multi-axis robot, the double gantry bed mechanism foundation has the advantages in safety; meanwhile, the invention can print large-size metal parts and overcomes the limitation that the printing size of the multi-axis robot structure is limited by the arm extension.

It should be understood that all combinations of the foregoing concepts and additional concepts described in greater detail below can be considered as part of the inventive subject matter of this disclosure unless such concepts are mutually inconsistent. In addition, all combinations of claimed subject matter are considered a part of the presently disclosed subject matter.

The foregoing and other aspects, embodiments and features of the present teachings can be more fully understood from the following description taken in conjunction with the accompanying drawings. Additional aspects of the present invention, such as features and/or advantages of exemplary embodiments, will be apparent from the description which follows, or may be learned by practice of specific embodiments in accordance with the teachings of the present invention.

Drawings

The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. Embodiments of various aspects of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

fig. 1 is a schematic diagram of a sand-supported composite dual gantry additive manufacturing apparatus in which the metal 3D printing system is an arc fuse 3D printing system, according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a sand mold supporting composite double gantry additive manufacturing equipment according to another embodiment of the present invention, wherein the metal 3D printing system is a powder feeding type 3D printing system.

FIG. 3 is a top view of a printed part of an exemplary embodiment of the present invention.

FIG. 4 is a cross-sectional view of a printed part of an exemplary embodiment of the present invention.

Detailed Description

In order to better understand the technical content of the present invention, specific embodiments are described below with reference to the accompanying drawings.

In this disclosure, aspects of the present invention are described with reference to the accompanying drawings, in which a number of illustrative embodiments are shown. Embodiments of the present disclosure are not necessarily intended to include all aspects of the invention. It should be appreciated that the various concepts and embodiments described above, as well as those described in greater detail below, may be implemented in any of numerous ways, and that the concepts and embodiments disclosed herein are not limited to any embodiment. In addition, some aspects of the present disclosure may be used alone, or in any suitable combination with other aspects of the present disclosure.

With reference to the examples shown in fig. 1 and 2, the invention generally provides a sand mold support composite type double-gantry additive manufacturing equipment, which is provided with an arc fuse or laser cladding metal 3D printing system and a sand mold 3D printing system at the same time, and parts are printed alternately layer by layer and sand mold support is carried out through the two 3D printing systems; the metal part structure is printed by a metal 3D printing system, and the physical support structure is printed by a sand mold 3D printing system; after the printing of the part is finished, the part is separated from the substrate in a sawing or linear cutting mode, then the sand mold support is dissolved by using a dissolving agent, and the residual metal support is removed, so that the final metal part is obtained. The invention can solve the problems that the common electric arc additive manufacturing equipment can not print and support, can not manufacture complex metal parts with the characteristics of large inclination angle, partial hollow and the like, and simultaneously wastes time and labor when the printed parts are separated from the substrate.

Fig. 1 shows an exemplary embodiment of a sand-supported composite dual gantry additive manufacturing apparatus of the present invention, wherein the metal 3D printing system is an arc fuse 3D printing system for printing metal parts.

Referring to fig. 1, the sand mold supporting composite type double-gantry additive manufacturing equipment comprises: the device comprises an arc fuse 3D printing system, a sand mold 3D printing system, a double-gantry machine tool, a workbench and a control system. The control system is arranged to be electrically connected with the metal 3D printing system, the sand mold 3D printing system and the double gantry machine bed respectively and used for controlling the operation of the metal 3D printing system, the sand mold 3D printing system and the double gantry machine bed.

In the embodiment shown in fig. 1, the control system is configured as a control cabinet 4, and power circuits, control loops, communication lines, etc. are disposed inside the control cabinet for controlling the assembly of the two printing systems (sand mold 3D printing and arc fuse 3D printing), such as the integration of hardware and/or software, so as to control the printing process.

Referring to fig. 1, the double gantry machine has a pair of bases 31 as bed members of the machine, oppositely mounted on the ground. Two groups of upright columns are respectively arranged on the opposite bases and are respectively a first upright column group and a second upright column group. The first set of uprights has two left uprights 321 and two right uprights 322. The two left columns 321 are oppositely disposed at corresponding positions on the opposite bases 31, respectively, and are located on the left side in the figure. The two right posts 322 are oppositely disposed at corresponding positions on the opposite bases 31, respectively, and are located at the right side in the figure.

Referring to fig. 1, each of the first and second sets of posts is configured to slidably move relative to the base 31 and defines a sliding direction as the X direction. The movement mechanism is preferably a linear motor or a rotary motor in combination with a belt/chain drive.

As shown in fig. 1, a first cross member 331 is disposed on the first column set. Specifically, a first beam 331 is mounted transversely to the two uprights 321 of the first set of uprights, the first beam 331 being arranged to move along a vertical direction defined by the uprights 321 and defining a movement direction as Z-direction. That is, the first beam 331 is vertically movable along the upright 321 in the direction shown in fig. 1. The movement mechanism is preferably a rotating motor in combination with a worm drive.

As shown in fig. 1, the first beam 331 is provided with a first connecting plate 351, which is disposed to be movable along a direction defined by the first beam and defines a moving direction as Y1 direction. I.e., in the orientation shown in fig. 1, the first linkage plate 351 is movable along the first beam 331, preferably by a linear motor, or a rotary motor in combination with a belt/chain drive.

As shown in fig. 1, a second cross member 332 is disposed on the second column set. Specifically, second beam 332 is mounted transversely to two uprights 322 of the second set of uprights, second beam 332 being arranged to move along a vertical direction defined by uprights 322 and defining a movement direction as the Z-direction. That is, first beam 331 is vertically movable along upright 322 in the orientation shown in FIG. 1. The movement mechanism is preferably a rotating motor in combination with a worm drive.

The second beam 332 is provided with a second connecting plate 352, which is configured to move along a direction defined by the second beam 332 and defines a moving direction as Y2. I.e., in the orientation shown in fig. 1, the second link plate 352 is movable along the second beam 332, preferably by a linear motor, or a rotary motor in combination with a belt/chain drive.

As shown in fig. 1, the table 34 is disposed between two bases 31 of the double gantry machine, constitutes a working area for additive manufacturing, and is used for fixing a substrate 54 for additive manufacturing printing.

As in fig. 1, reference numeral 5 denotes a printed metal part.

Referring to fig. 1, the arc fuse 3D printing system constituting the metal 3D printing system has a working head 11 for performing metal 3D printing on a substrate 54. As shown in fig. 1, the arc fuse 3D printing system further comprises a wire feeder 12, a wire reel 13-1 and a welder power supply 14, wherein the welding gun 11 is used as the working head for performing 3D printing, a metal welding wire is placed in the wire reel 12, the wire feeder 13-1 is configured to convey the metal welding wire to the front end of the welding gun 11, and the welder power supply 14 is configured to convert electric energy into heat energy at the front end of the welding gun after the welder power supply is started, so as to melt the metal welding wire to a molten state, and perform 3D printing on metal on a substrate 54.

Sand mould 3D printing system is including printing shower nozzle 21, fortune sand pipeline 22, extrusion mechanism 23 and feed bin 24, and the storage has the sand mould powder that fine sand powder and binder mix to form in the feed bin 24, and extrusion mechanism 23 is set to be used for carrying the sand mould powder to printing shower nozzle 21 through fortune sand pipeline 22, and printing shower nozzle 21 is used for spouting the sand mould powder in order to carry out sand mould 3D on base plate 54 and print.

As shown in fig. 1, the print head 21 is secured to a first linkage plate 351 in spaced apart relation alongside the weld gun 11.

Preferably, the working point of the welding gun 11 of the arc fuse 3D printing system is as high as the working point of the printing nozzle 21, so as to ensure that the welding gun or the printing nozzle can effectively avoid interference and collision with the printed parts when printing a complex model in the alternate printing process.

Referring to fig. 1, a platen 36 is fixed to the second connecting plate 352, and the platen 36 is provided with a flat surface pressed downward toward the base plate for compacting the printing sand powder.

With reference to fig. 1 and the foregoing gantry type machine tool structure, during the printing process, the control cabinet 4 controls the two columns (321, 322), the two beams (331, 332), and the first connecting plate 351 and the second connecting plate 352 to move, so that the printing operation of printing the sand mold support on the substrate by the printing nozzle 21 of the sand mold 3D printing system on the first connecting plate and the printing operation of printing the metal part and the metal support by the working head (welding gun 11) of the metal 3D printing system layer by layer are performed alternately, wherein the compacting operation is performed by the platen 36 on the second connecting plate 352 after each layer of sand mold support is printed.

Specifically, after each layer of sand mold support is printed, the movement of the double gantry machine is controlled, so that the second connecting plate 352 moves to drive the platen to move so as to compact the printed sand mold support.

As shown in fig. 1, the X-direction, Y1-direction, Y2-direction and Z-direction movements are all preferably provided with a movement guide mechanism, such as a slide rail type guide mechanism.

Fig. 2 is a schematic diagram of a sand mold support composite type double-gantry additive manufacturing equipment according to another embodiment of the present invention, wherein the double-gantry machine tools are of the same structure, and the base, the upright column, the cross beam and the connecting plate are all of the same structure and connection manner, and the same reference numerals are used for the sake of convenience of description.

In the embodiment illustrated in fig. 1, the sand mold 3D printing system adopts the same structure and connection relationship as those in fig. 1, and details are not repeated here.

As shown in fig. 2, what is different from the embodiment in fig. 1 is that the metal 3D printing system in this embodiment is a powder feeding type metal 3D printing system, that is, a cladding type 3D printing system, and includes a powder feeding type laser processing head 15, an optical fiber 16, a laser 17, and a powder feeder 18. In this embodiment, the powder feeding type laser processing head is used as the working head for performing 3D printing on metal.

The powder feeder 18 is provided for storing metal powder, which is conveyed to the front end of the powder feed type laser processing head 15 by the powder feeder 18; the laser 17 is used for emitting a set laser beam with high energy density, transmitting the laser beam to the powder feeding type laser processing head 15 through the optical fiber 16, and melting metal powder after being collimated and focused by an optical module in the powder feeding type laser processing head so as to perform powder feeding type metal 3D printing.

Likewise, the print head 21 is fixed to the first connecting plate 351 side by side and spaced apart from the powder feed type laser processing head 15.

Preferably, the working point of the powder feeding type laser processing head 15 is equal to the working point of the printing nozzle 21 in height, so that interference and collision between a welding gun or the printing nozzle and a printed part during printing of a complex model can be effectively avoided in the alternate printing process.

The platen 36 of the second connecting plate 352 likewise has a flat surface pressed down toward the base plate 54 to compact the printed sand powder.

In the example of fig. 2, the movements in the X direction, the Y1 direction, the Y2 direction, and the Z direction are all provided with movement guide mechanisms.

With reference to fig. 2 and the aforementioned gantry machine tool structure, during the printing process, the control cabinet 4 controls the two columns (321, 322), the two beams (331, 332), and the first connecting plate 351 and the second connecting plate 352 to move, so that the printing operation of the printing nozzle 21 of the sand mold 3D printing system on the first connecting plate for printing the sand mold support on the substrate and the printing operation of the working head (powder feeding laser processing head 15) of the metal 3D printing system for printing the metal part and the metal support layer by layer on the substrate are performed alternately, wherein each layer of sand mold support is compacted by the platen 36 on the second connecting plate 352 after being printed.

In the process of controlling the metal 3D printing system and the sand mold 3D printing system to perform 3D printing by the control system (e.g., the control cabinet 4) in combination with the two exemplary embodiments of fig. 1 and 2, the printing of the first layer is 3D printing of molding sand powder by the sand mold 3D printing system.

As shown in fig. 3 and 4, the combined type double gantry additive manufacturing equipment of the present invention has a powder feeding type metal 3D printing system and a sand mold 3D printing system at the same time, the running track and speed of the double gantry machine tool are planned in advance, and after the control cabinet 4 reads and identifies the running track and speed, the movement of the double gantry machine tool is controlled, the printing nozzle 21 is operated to print the first layer of the sand mold support 52 on the substrate 54, the layer height H1 is controlled, and the upright column 321 and the cross beam 331 are controlled to leave the working area; and then controlling the double gantry machine to move and operating the press disc 36 to compact the sand mold support 52, wherein the height of the first layer of the sand mold support 52 is changed to k H1, and k is the compaction ratio. Controlling right upright 322 and cross-beam 332 away from the work area; and controlling the left upright post 321, the cross member 331 and the first connecting plate 35-1 to move, controlling the working head to print the metal part 51 and the first layer of the metal support 53 on the base plate 54, ensuring that the layer height H2 is k H1, and controlling the left upright post member 321 and the left beam member 331 to leave the working area. The parts 5 are thus printed layer by layer using two 3D printing systems in alternation, wherein the height of each layer of the metal part and sand mould support is made according to the settings of the first layer described above.

With reference to fig. 1 and 2, according to the disclosure of the present invention, there is also provided an additive manufacturing printing method for sand mold supporting composite dual gantry additive manufacturing equipment, comprising:

and 4, judging whether the additive manufacturing printing part is finished or not, if not, repeating the steps 1-3, alternately using two 3D printing systems to print the part layer by layer, and using a pressing disc to perform compaction operation after the molding sand support of each layer is printed, wherein the height of each layer of the metal part and the molding sand support is set according to the first layer until the printing operation is finished.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims

1. The utility model provides a two longmen vibration material disk equipment of sand mould support combined type which characterized in that, includes metal 3D printing system, sand mould 3D printing system, two longmen lathe, workstation and control system, wherein:

2. The sand mold supporting combined type double gantry additive manufacturing equipment according to claim 1, wherein the metal 3D printing system is an arc fuse wire 3D printing system and comprises a welding gun, a wire feeder, a wire reel and a welding machine power supply, and the welding gun is used as the working head; the metal welding wire is placed in the wire reel, the wire feeder is arranged to transmit the metal welding wire to the front end of the welding gun, the welding machine power supply is arranged to convert electric energy into heat energy at the front end of the welding gun after the welding machine power supply is started, so that the metal welding wire is melted to be in a molten state, and metal 3D printing is carried out on the substrate.

3. A sand supporting composite double gantry additive manufacturing equipment according to claim 2, wherein a welding gun of the arc fuse 3D printing system is as high as a working point of a printing nozzle.

4. A sand supported composite double gantry additive manufacturing apparatus according to claim 1, wherein said metal 3D printing system is a powder fed metal 3D printing system comprising a powder fed laser machining head, an optical fiber, a laser, and a powder feeder; the powder feeding type laser processing head is used as the working head; the powder feeder is used for storing metal powder and conveying the metal powder to the front end of the powder feeding type laser processing head through the powder feeder; the laser is used for emitting a set laser beam with high energy density, the laser beam is transmitted to the powder feeding type laser processing head through the optical fiber, metal powder is melted after the laser beam is collimated and focused by an optical module in the powder feeding type laser processing head, and powder feeding type metal 3D printing is carried out.

5. A sand supporting composite double gantry additive manufacturing apparatus according to claim 4, wherein the powder feeding type laser processing head is at the same height as the working point of the printing nozzle.

6. The sand mold support composite double gantry additive manufacturing equipment according to claim 1, wherein in the 3D printing process of the metal 3D printing system and the sand mold 3D printing system controlled by the control system, the first layer printing is 3D printing of molding sand powder by the sand mold 3D printing system.

7. A sand mold supporting composite double gantry additive manufacturing apparatus according to claim 1, wherein the sand mold 3D printing system comprises a printing nozzle, a sand transporting pipe, an extruding mechanism, and a bin, wherein sand mold powder formed by mixing fine sand powder and a binder is stored in the bin, and the extruding mechanism is configured to convey the sand mold powder to the printing nozzle through the sand transporting pipe and perform sand mold 3D printing on the substrate.

8. A sand supporting composite double gantry additive manufacturing equipment according to claim 1, wherein the movements in the X direction, the Y1 direction, the Y2 direction and the Z direction are all provided with movement guide mechanisms.

9. An additive manufacturing printing method of sand mold supporting composite double gantry additive manufacturing equipment according to any one of claims 1 to 8, comprising:

step 3, controlling the first column group and the first beam of the double-gantry machine tool to move, so that the working head on the first connecting plate prints a first layer of metal parts and metal supports layer by layer on the substrate, wherein the layer height H2= k H1; then controlling the first vertical column group and the first cross beam to leave the working area;

10. The additive manufacturing printing method of claim 9, further comprising a separation process after printing is completed, comprising the steps of: