WO2016106607A1

WO2016106607A1 - Laser melting and laser milling composite 3d printing apparatus

Info

Publication number: WO2016106607A1
Application number: PCT/CN2014/095673
Authority: WO
Inventors: 徐毅; 李军旗; 聂炎
Original assignee: 深圳市圆梦精密技术研究院
Priority date: 2014-12-30
Filing date: 2014-12-30
Publication date: 2016-07-07

Abstract

A laser melting and laser milling composite 3D printing apparatus (1) comprises a base (100) having a machining platform (109); a powder spreading structure (104) is arranged on the base; a laser emitting structure (101) and a laser milling head (114) are arranged above the machining platform; the laser emitting structure emits a laser beam to melt a metal powder layer on the machining platform so as to form a single-layer or multi-layer approximate body; the laser milling head emits a laser beam to perform milling on the single-layer or multi-layer approximate body. The apparatus integrates the milling-based removal type precision machining and the laser beam melting 3D printing-based incremental laminating manufacturing process as a whole, and therefore, machined parts do not require secondary machining, and the problems of difficult clamping, large machining error, part deformation during machining and difficult machining are avoided.

Description

Laser melting and laser milling composite 3D printing equipment

Technical field

The present invention relates to the technical field of 3D printing devices, and more particularly to laser melting and laser milling composite 3D printing devices.

Background technique

Metal fused 3D printing technology (Selective Laser Melting, SLM) is a high-brightness laser that directly melts the metal powder material without the need for a binder. The 3D model directly forms an arbitrarily complex structural part equivalent to that of the casting.

Although the metal-melting 3D printing technology can form parts that reach the casting strength level, the shape of the formed parts is large and the surface finish is not high. Thus, the formed parts need to be processed twice by conventional machining methods. Processing can get the shape and surface accuracy required by the aerospace manufacturing industry. Most parts of the aerospace industry, such as engine nozzles, blades, honeycomb combustion chambers, etc., are generally complex thin-wall or lattice sandwich structures, or larger-sized shapes, or free-form surfaces, etc. When the parts processed by the metal-melting 3D printing technology are placed in the machine for secondary processing, the following problems exist:

1), the clamping is difficult, or after clamping, due to the coordinate transformation can not accurately locate the part reference point, resulting in large processing error;

2) For parts with thin-walled structures, the stress of the parts is deformed due to the surface of the unsupported parts during processing;

3) Some parts have complicated internal structure, and the tool cannot penetrate into the inside, which makes it difficult to process.

Due to the above problems, the current metal melting 3D printing technology has been applied to the manufacture of aircraft parts, but the application surface is narrow, and it is only applied to some parts that are not required for precision and strength, or the shape is simple and easy. There is still a big gap in the processing of secondary machined parts.

technical problem

The object of the present invention is to provide a laser melting and laser milling composite 3D printing device, which aims to solve the prior art, using metal melting 3D The parts processed by the printing technology are subjected to secondary processing on the machine tool, and there are problems of difficulty in clamping, large processing error, variability of parts, and difficulty in processing.

Technical solution

The present invention is achieved by a laser melting and laser milling composite 3D printing apparatus comprising a base, the base being provided with a processing platform moving vertically; the base being provided with a metal powder for laying The processing platform forms a powder-laying structure of a metal powder layer, the powder-laying structure is located at a front end of the processing platform; a laser emitting structure and a laser milling head movable in a three-dimensional space are respectively disposed above the processing platform; The laser emitting structure emits a laser beam to melt-process a metal powder layer on the processing platform to form a single layer or a plurality of layers; the laser milling head emits a laser beam to a single layer formed on the processing platform or Multi-layer approximation of the shape for milling.

Further, the base is provided with two guide rails arranged side by side, the processing platform is located between the two guide rails; the powder laying structure comprises a scraper and a powder storage box, and the two ends of the scraper respectively Actively connected to the two guide rails, a gap between the lower end of the scraper and the processing platform; the powder storage tank has a powder storage chamber with an upper end opening and used for installing metal powder, and the base is provided with a through hole in which an upper end of the powder storage chamber is aligned; a powder moving chamber of the powder storage tank is provided with a vertical movement and a powder conveying table for transporting metal powder to the base, the powder conveying powder The stages are respectively arranged in alignment with the upper end opening and the through hole of the powder storage chamber.

Further, two sides of the processing platform are respectively provided with sensors for detecting the thickness of the metal powder layer laid on the processing platform.

Further, the laser emitting structure includes a laser generator that emits a laser beam and a plurality of polarizers that are arranged in rotation and used to reflect the laser beam, and the plurality of the polarizers are spaced apart on a transmission path of the laser beam.

Further, the laser emitting structure includes a receiving box, a plurality of the polarizers are disposed in the receiving box, and a lower end of the receiving box has an exit port, and the laser beam reflected by the polarizer It is emitted from the exit port.

Further, a collimating beam expanding mirror is disposed between the laser generator and the accommodating case, and the laser beam emitted by the laser generator is expanded by the collimating beam expanding mirror to enter the accommodating In the box.

Further, the two guide rails are movably connected with a gantry, the gantry includes two spaced apart connecting arms and a cross beam, and the lower ends of the two connecting arms are movably connected to the two rails respectively. The two ends of the beam are respectively connected to the upper ends of the two connecting arms; the beam is movably connected with a moving terminal of the beam moving, and the moving terminal is movably connected with a connecting plate that moves up and down with respect to the moving terminal. The laser milling head is coupled to the connecting plate.

Further, a cooling pipeline for circulating cooling water is disposed in the laser milling head.

Further, the laser melting and laser milling composite 3D printing apparatus further includes a recovery tank having a recovery chamber for recovering metal powder on the susceptor, the recovery tank being located at the susceptor Below, a recovery port communicating with the recovery chamber is disposed in the base.

Further, the recovery port is located at a rear end of the processing platform along a moving direction when the blade is laid.

Beneficial effect

Compared with the prior art, the present invention provides a laser melting and laser milling composite 3D printing device processing part, and uses a laser beam emitted from a laser emitting structure to melt the metal powder layer layer by layer, and then laser-mills the laser beam to the single layer. Or multi-layer approximation of the shape for milling, repeating the cycle until the part is finished. The 3D printing device integrates the traditional milling-based demolition precision machining with the laser beam fusion 3D printing-based incremental lamination process. The integration can not only overcome the defects of the traditional 3D printing technology in terms of size and shape accuracy, but also overcome the constraints of the machining process on the complexity of the components, so that it is not necessary to perform secondary processing on the processed parts to avoid The difficulty of fashion clips, large processing errors, deformation of parts during processing and difficult processing, opening up a broader application space for 3D printing technology, providing new methods and means for the manufacture of core precision parts in the aerospace industry; Using a laser beam to mill a single or multiple layers of approximate shape, which is non-contact The milling process avoids the defects of the traditional tool directly contacting the single or multiple layers of the approximate body, greatly improving the precision of the milling process.

DRAWINGS

1 is a perspective view of a laser melting and laser milling composite 3D printing apparatus according to an embodiment of the present invention;

2 is a perspective view of a laser milling head according to an embodiment of the present invention.

Embodiments of the invention

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The implementation of the present invention will be described in detail below with reference to specific embodiments.

1 to 2, a preferred embodiment of the present invention is provided.

The 3D printing apparatus 1 provided by the present invention combines laser milling processing and laser melting, and can be used for molding various parts, such as parts required for the aerospace manufacturing industry.

The laser melting and laser milling composite 3D printing apparatus 1 includes a susceptor 100, a powder laying structure, a laser emitting structure 101, and a laser milling head 114, wherein the susceptor 100 serves as a foundation for the entire 3D printing apparatus 1, and functions as a carrier. The processing platform 109 is disposed on the 100 in the vertical direction, and the metal powder is laid on the processing platform 109; the powder laying structure is disposed on the base 100, which is located at the front end of the processing platform 109, and the powder laying structure is used for metal The powder or the like is conveyed onto the processing platform 109, and the metal powder forms a metal powder layer on the processing platform 109; the laser emitting structure 101 is located above the processing platform 109, which emits a laser beam that can move in a horizontal plane, and the laser beam is used for The metal powder layer formed on the processing platform 109 is melt processed to form a single layer or a plurality of layers of approximate shapes; the laser milling head 114 is located above the processing platform 109, which can move stereoscopically in space, and the laser milling head 114 can emit laser light. The bundle is subjected to milling of a melt-molded single or multiple layer approximation on the processing platform 109.

Referring to FIG. 1, the XY plane parallel to the processing platform 109 is set to a horizontal plane, the Z direction is a vertical direction, and the plane perpendicular to the horizontal plane is a vertical plane, so that the processing platform 109 can move up and down in the Z direction. The laser beam emitted by the laser emitting structure 101 moves in the XY plane, and the laser milling head 114 can move in the X, Y, and Z directions.

In the laser melting and laser milling composite 3D printing apparatus 1 described above, the laser emitting structure 101 is used to emit a laser beam molten metal powder layer for 3D printing, and the laser beam emitted from the laser milling head 114 is used to process the laser emitting structure 101 each time. Layer or multi-layer approximation of the body for milling, combined with 3D printing technology and milling.

In the actual processing, the specific operation process is as follows:

1), the powder-laying structure transports the metal powder onto the processing platform 109, and is laid on the processing platform 109 to form a metal powder layer; according to the 3D printing technology, the laser emitting structure 101 laser-melts the metal powder layer on the processing platform 109. , layer by layer to form a single layer or a plurality of layers of approximate bodies;

2) milling a single-layer or multi-layered approximate body member formed on the processing platform 109 by using a laser beam emitted from the laser milling head 114 to achieve the required size and surface precision of the member;

3) Repeat the above steps 1) and 2) until the shape of the final part is processed.

Each time the above steps 1) and 2) are completed, the processing platform 109 is moved downward by a certain distance to ensure the distance between the metal powder layer relocated on the processing platform 109 and the focus of the laser beam emitted by the laser emitting structure 101. constant. In step 1), the laser beam emitted by the laser emitting structure 101 is moved in a horizontal plane, and a single layer or a plurality of layers are formed in the metal powder layer on the processing platform 109; in the step 2), the laser milling head 114 is used to emit The laser beam moves in a three-dimensional space and can be milled in all directions for all types of single or multi-layer approximations.

The laser melting and laser milling composite 3D printing apparatus 1 is used to process the parts, and the metal powder layer is melted layer by layer by the laser beam, and then the single or multi-layer approximate body is milled by the laser beam emitted by the laser milling head 114. The cycle repeats until the part is finished. The 3D printing device integrates the traditional laser-milling-based removal precision machining with the laser beam fusion 3D printing-based incremental laminate manufacturing process, which can overcome the traditional 3D. The defects of the printing technology in terms of size and shape accuracy can also overcome the constraints of the machining process on the complexity of the parts. Therefore, it is not necessary to perform secondary processing on the processed parts to avoid the current clamping difficulties and machining errors. Large and complicated parts are deformed and difficult to process, which opens up a wider application space for 3D printing technology and provides new methods and means for the manufacture of core precision parts in the aerospace industry.

In addition, the laser beam emitted by the laser milling head 114 is used to mill a single layer or a plurality of layers, which is a non-contact milling process, which avoids the defects of the traditional tool directly contacting the single or multiple layers of the approximate body. Greatly improve the precision of milling.

In this embodiment, two rows of guide rails 105 arranged in parallel are arranged on the base 100, and the two rails 105 are arranged on both sides of the processing platform 109; the powder spreading structure comprises a scraper 104 and a powder storage box 103, and the scraper 104 The two ends are respectively movably connected to the two guide rails 105, so that the scraper 104 can be moved along the guide rail 105 in a horizontal plane, and the lower end surface of the scraper 104 has a gap with the processing platform 109; the powder storage box 103 has an upper end opening. The powder storage chamber of the powder storage tank 103 is used for storing metal powder. The powder storage tank 103 is located below the base 100, and in the base 100, there is a passage connecting the upper end of the powder storage box 103. The hole, that is, the through hole is aligned with the upper end opening of the powder tank 103, of course, the through hole is also located between the two guide rails 105.

The powder storage box 103 is further provided with a powder conveying table which can be moved up and down, and the powder conveying table is arranged in alignment with the upper end opening of the powder storage box 103 and the through hole in the base 100, so that when the scraper 104 needs to be in the processing platform When the metal powder layer is laid on the 109, the powder powder bed carries the metal powder and moves upwards, respectively passing through the upper end opening of the powder storage box 103 and the through hole of the base 100 until the metal powder is exposed on the base 100, so that The metal powder can be scraped onto the processing platform 109 by the doctor blade 104 to form a metal powder layer. Of course, the thickness of the metal powder layer formed on the processing platform 109 each time coincides with the gap between the lower end of the doctor blade 104 and the processing platform 109.

Thus, depending on the actual processing needs, the thickness of the metal powder layer laid on the processing platform 109 each time can be selected, and only the blade 104 needs to be adjusted to adjust the gap between the lower end of the blade 104 and the processing platform 109.

In order to detect the thickness of the metal powder layer laid on the processing platform 109, in the embodiment, sensors 107 are respectively disposed on both sides of the processing platform 109, and the sensor 107 is used for the metal powder laid on the processing platform 109. The thickness of the layer is detected, and the information detected by the sensor 107 is fed back to the control center, and the gap between the processing platform 109 and the doctor blade 104 is adjusted by the control center.

Specifically, in order to more accurately detect the thickness of the metal powder layer, in the embodiment, a plurality of the above-mentioned sensors 107 are respectively disposed on both sides of the processing platform 109 along the sides of the processing platform 109.

The laser emitting structure 101 includes a laser generator 1011, a collimating beam expander 1013, and a plurality of rotationally arranged polarizers 1012, wherein the laser generator 1011 is used to generate a laser beam, and the laser beam emitted by the laser generator 1011 is collimated. The beam expander 1013 expands the beam, and the expanded laser beam passes through the plurality of polarizers 1012, and by adjusting the rotation of the plurality of polarizers 1012, the transmission path of the laser beam can be changed to realize the movement of the laser beam in the horizontal plane. The shape requirements of the approximate body member are processed as needed, and the rotation angles of the plurality of polarizers 1012 are adjusted correspondingly.

The polarizers 1012 are spaced apart from each other on the transmission path of the laser beam for reflecting the laser beam to achieve the purpose of changing the direction in which the laser beam is transmitted, so that the laser beam is vertically incident on the processing platform 109. In this embodiment, a plurality of polarizers 1012 are disposed in the accommodating case 1014, and the laser beam passing through the collimating beam expander 1013 enters the accommodating case 1014, and is reflected by the plurality of polarizers 1012 to the processing platform 109. On the metal powder layer.

The lower end of the accommodating case 1014 is provided with an exit port, and the laser beam reflected by the polarizer 1012 in the accommodating case 1014 is emitted through the exit port of the accommodating case 1014; a focusing mirror is disposed in the exit port of the accommodating case 1014. The focus beam is used to focus the laser beam. Thus, the collimating beam expander 1013 is located between the laser generator 1011 and the receiving box 1014, and the laser beam expanded by the collimating beam expander 1013 enters the receiving box. In 1014, the plurality of polarizers 1012 perform reflection processing, and are further emitted through the exit port of the housing case 1014.

In this embodiment, in order to realize automatic control of the plurality of polarizers 1012, the laser emitting structure 101 further includes a polarization controller for controlling the rotation adjustment of the plurality of polarizers 1012. Of course, according to the needs of the processing, The embedded control program or the like, according to different processing, the polarization controller performs different rotation adjustments on the plurality of polarizers 1012.

In order to realize the up-and-down movement of the processing platform 109, a lifting motor 111 is connected below the processing platform 109, and the driving of the processing platform 109 is driven by the power of the lifting motor 111, and the paving structure is laid on the processing platform 109 each time. After a layer of metal powder, the lifting platform controls the processing platform 109 to descend a fixed distance, thereby ensuring that the distance of the laser beam focus on the metal powder layer is constant.

In this embodiment, a gantry 106 is disposed on the two guide rails 105. The gantry 106 includes two connecting arms 1062 and a cross member 1061. The lower ends of the two connecting arms 1062 are movably connected to the two guide rails 105, respectively. It is movable along the guide rail 105, and the beam 1061 is connected to the upper ends of the two connecting arms 1062 such that the beam 1061 is arranged across the rails 105 in a span. A moving terminal 112 is movably coupled to the beam 1061, and the moving terminal 112 is movable along the beam 1061.

A connecting plate 113 is also movably connected to the moving terminal, and the connecting plate 113 is movable up and down with respect to the moving terminal, that is, moving in the vertical direction and moving in the Z direction. The laser milling head 114 is attached to the web 113 such that when the web 113 is moved vertically, the laser milling head 114 is also moved vertically.

In the above structure, the beam 1061 can be moved along the two guide rails 105, that is, in the Y direction, and the moving terminal 112 can be moved along the beam 1061, that is, moved in the X direction, and the connecting plate 113 is opposed to the connecting plate. The 113 moves up and down, that is, moves in the Z direction, so that the laser milling head 114 can move in the three-dimensional space.

In addition, the laser milling head 114 is provided with a cooling pipe 115. The cooling pipe 115 is connected to the cooling water. Thus, by circulating the cooling water in the cooling pipe 115, the flow of the cooling water can be utilized to take away the laser milling. The heat generated during the working process of the components in the head 114 serves to dissipate heat, ensuring better working efficiency and performance of the laser milling head 114.

In this embodiment, the laser melting and laser milling composite 3D printing apparatus 1 further includes a metal powder recovery structure for recovering the remaining metal powder processed on the susceptor 100, thereby facilitating the metal powder. Recycling.

Specifically, the metal powder recovery structure includes a recovery tank 110, and the recovery tank 110 is provided with a recovery chamber for accommodating the recovered metal powder. The recovery tank 110 is located below the base 100, and a recovery port is disposed in the base 100. The recovery port communicates with the recovery chamber of the recovery tank 110, so that the remaining metal powder processed on the susceptor 100 can enter the recovery chamber of the recovery tank 110 through the recovery port, recover the metal powder in the chamber, and filter the residue. Re-cycle.

In the present embodiment, the recovery port is disposed on the side of the processing platform 109. Of course, along the moving direction when the blade 104 is laid, the recovery port is disposed at the rear end of the processing platform 109. Alternatively, as other embodiments, the recovery ports may be arranged on both sides of the processing platform 109.

In order to make the laser melting and laser milling composite 3D printing device 1 during the processing, the metal powder is not oxidized, so that the performance of the molded part is better. In this embodiment, the laser melting and laser milling composite 3D printing device 1 The utility model also includes a processing chamber having a processing space, and the processing space is in a vacuum state, or the processing space is filled with an inert gas, and the above-mentioned susceptor 100 is disposed in the processing space of the processing chamber, so that the environment can be reduced The influence of metal melting or solidification improves the mechanical and physical properties of the metal, opening up a broader application space for laser melting 3D printing technology, and providing new methods and means for the production of high melting point metals.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Claims

A laser melting and laser milling composite 3D printing apparatus, comprising: a base, the base is provided with a processing platform moving vertically; the base is provided with a metal powder for laying on the processing platform Forming a powder coating structure of a metal powder layer, the powder laying structure is located at a front end of the processing platform; a laser emitting structure and a laser milling head movable in a three-dimensional space are respectively disposed above the processing platform; the laser emitting structure Ejecting a laser beam to melt process a metal powder layer on the processing platform to form a single layer or a plurality of layers; the laser milling head emits a laser beam pair to form a single layer or multiple layers on the processing platform The body is milled.
A laser melting and laser milling composite 3D printing apparatus according to claim 1, wherein said base is provided with two guide rails arranged side by side, said processing platform being located between said two guide rails; The powder laying structure comprises a scraper and a powder storage box, wherein two ends of the scraper are respectively movably connected to the two guide rails, and a gap between the lower end of the scraper and the processing platform is provided; the powder storage tank has an upper end opening and a powder storage chamber for installing metal powder, wherein the base is provided with a through hole aligned with an upper end opening of the powder storage chamber; a vertical movement of the powder storage chamber of the storage container is provided for The metal powder is transported to the powder conveying table on the base, and the powder conveying table is respectively arranged in alignment with the upper end opening and the through hole of the powder storage chamber.
The laser melting and laser milling composite 3D printing apparatus according to claim 1, wherein both sides of the processing platform are respectively provided with sensors for detecting the thickness of the metal powder layer laid on the processing platform.
The laser melting and laser milling composite 3D printing apparatus according to any one of claims 1 to 3, wherein the laser emitting structure comprises a laser generator that emits a laser beam and a plurality of rotating arrangements and for the pair of laser beams A polarizing mirror that performs reflection, a plurality of the polarizers are spaced apart on a transmission path of the laser beam.
The laser melting and laser milling composite 3D printing apparatus according to claim 4, wherein the laser emitting structure comprises a receiving box, a plurality of the polarizers are placed in the receiving box, and the capacity The lower end of the box has an exit port through which a laser beam reflected by the polarizer is emitted.
A laser melting and laser milling composite 3D printing apparatus according to claim 5, wherein a collimating beam expanding mirror is disposed between said laser generator and said housing, and said laser beam is emitted from said laser generator After the bundle is expanded by the collimating beam expanding mirror, it enters the accommodating box.
The laser melting and laser milling composite 3D printing apparatus according to any one of claims 1 to 3, characterized in that the two rails are movably connected with a gantry, the gantry comprising two spaced apart connections An arm and a beam, the lower ends of the two connecting arms are respectively movably connected to the two rails, and two ends of the beam are respectively connected to the upper ends of the two connecting arms; the beam is movably connected with a beam moving The mobile terminal is movably connected to a connecting plate that moves up and down with respect to the moving terminal, and the laser milling head is connected to the connecting plate.
The laser melting and laser milling composite 3D printing apparatus according to any one of claims 1 to 3, characterized in that the laser milling head is provided with a cooling line for circulating cooling water.
The laser melting and laser milling composite 3D printing apparatus according to any one of claims 1 to 3, wherein the laser melting and laser milling composite 3D printing apparatus further comprises a recycling box, the recycling box having The device recovers a recovery chamber of the metal powder on the susceptor, the recovery tank is located below the susceptor, and the susceptor is provided with a recovery port communicating with the recovery chamber.
A laser melting and laser milling composite 3D printing apparatus according to claim 9, wherein said recovery port is located at a rear end of said processing platform along a moving direction of said doctor when the powder is laid.