CN113665105A

CN113665105A - High-quality three-dimensional powder bonding 3D printing method

Info

Publication number: CN113665105A
Application number: CN202111097908.5A
Authority: CN
Inventors: 鄢然; 李欣飞; 夏磊
Original assignee: Chongqing University of Technology
Current assignee: Chongqing University of Technology
Priority date: 2021-09-18
Filing date: 2021-09-18
Publication date: 2021-11-19
Anticipated expiration: 2041-09-18
Also published as: CN116901435A; CN113665105B

Abstract

The invention discloses a high-quality three-dimensional powder bonding 3D printing method, which comprises the steps of decomposing a product into a plurality of horizontal printing layers in a computer along the vertical direction, spreading powder layer by layer in a printing device according to the thickness of each printing layer, adopting a printing nozzle to condense powder in the product outline range of each layer by spraying a binder after each layer of powder is spread, printing layer by layer upwards, and finally obtaining a product; the method is characterized in that a printing spray head is adopted to print twice along the product outline range of each layer in the powder laying process of each layer. The device has the advantages of improving the printing efficiency and the quality precision, conveniently realizing printing different materials in one product, along with simple structure and flexible and convenient control.

Description

High-quality three-dimensional powder bonding 3D printing method

Technical Field

The invention relates to the field of rapid forming of product manufacturing, in particular to a high-quality three-dimensional powder bonding 3D printing method.

Background

3D Printing belongs to one of rapid prototyping technologies, also called additive manufacturing; the method is a technology for constructing an object by stacking, bonding and molding materials such as plastic, metal, ceramic powder and the like layer by using a laser, a hot melting nozzle and the like on the basis of a digital model. In recent years, 3D printing technology has been widely used in many fields such as industrial design, jewelry, automobiles, aerospace, dental and medical industries, education, and the like.

Currently, common 3D printers include a plurality of types, such as selective laser melting SLM, selective laser sintering SLS, three-dimensional powder bonding, fused deposition modeling FDM (fused deposition modeling), and the like. Wherein three-dimensional powder bonding printing is the 3DP process technology. The 3DP process is similar to the SLS process and uses powder materials for forming, such as ceramic powders, metal powders. Except that the material powders are not joined by sintering, but rather the cross-section of the part is "printed" on top of the material powders by means of a binder (e.g. silicone) through a spray head. Parts bonded with adhesives have low strength and require post-processing. The specific process comprises the following steps: after the last layer is bonded, the forming cylinder descends by a printing layer thickness distance, which is usually 0.013-0.1 mm, the powder supply cylinder pushes out a plurality of powders, and the powders are pushed into the forming cylinder by the powder paving roller to be paved. The spray heads selectively spray adhesive build faces according to the formation data for a next build section under computer control. And feeding, spreading and spraying the binder in cycles to finally finish the binding printing of the three-dimensional powder. The part which is not sprayed with the adhesive is dry powder which plays a supporting role in the forming process and is removed after the forming is finished.

As manufacturing advances, many products are made with different materials in different parts to achieve different properties. However, the mainstream 3D printers in the market can only adopt a single material to print objects basically, so that the 3D printers have great limitations and cannot print parts made of two or more materials at one time. The same is true for the 3DP process.

CN105196549B discloses a parallel multi-station 3D printer, which provides a novel parallel multi-station 3D printer suitable for rapid prototyping technology, comprising a computer, a support, a 3D printer set, and a conveyor belt system. The 3D printing unit is a 3D printer with a plurality of stations arranged side by side according to needs, and printing tasks are regulated and controlled by a computer, so that parallel pipeline printing is realized.

The printer of the above-mentioned prior patent has the following inconveniences. 1 although the printing of various materials can be realized in one product, the fixed printing assembly line guide rail is adopted for guiding, and the defects of complex assembly line guide rail structure, inconvenient control and scheduling and poor flexibility exist. 2 when spreading powder before printing on each layer, adopt conventional shop's powder roller device and powder jar cooperation to accomplish and spread the powder, there are the structure complicacy, slow, spread powder back surface and exist the ripple easily, the roughness is low grade defect. 3, the specific printing process adopts a classical printing mode, namely, a printing head is adopted to print once along the outline of the layer of product when one layer of powder is laid, and the product is obtained by printing layer by layer, so that the thickness of each layer of powder cannot be too thick due to the action limitation of a printing binder, and the printing head is adopted to print once when one layer of powder is laid, so that the printing efficiency is lower; if the thickness of each layer of powder is increased to improve the printing efficiency, the printing quality and precision are reduced, so that the printing efficiency and the quality precision cannot be both satisfied.

Disclosure of Invention

Aiming at the defects of the prior art, the technical problems to be solved by the invention are as follows: how to provide one kind can improve shop's powder precision and convenience, can improve the high quality three-dimensional powder bonding 3D printing method of printing efficiency and quality precision to further make it conveniently realize printing different materials in a product, and have simple structure, control nimble convenient characteristics.

In order to solve the technical problems, the invention adopts the following technical scheme:

A3D printing method for bonding high-quality three-dimensional powder comprises the steps of decomposing a product into a plurality of horizontal printing layers in a computer along the vertical direction, spreading powder layer by layer in a printing device according to the thickness of each printing layer, adopting a printing nozzle to condense the powder in the product outline range of each layer by spraying a binder after each layer of powder is spread, printing upwards layer by layer and finally obtaining the product; the method is characterized in that a printing spray head is adopted to print twice along the product outline range of each layer in the powder laying process of each layer.

Therefore, the method can better facilitate the adhesive to enable the powder to be adhered, fixed and formed by spraying the adhesive twice after one-time powder spreading, printing and spraying, and greatly improves the product quality.

Furthermore, the high-quality 3D printer is realized by adopting the following high-quality 3D printer, wherein the high-quality 3D printer comprises a printing platform which is horizontally arranged, a plurality of printing stations are arranged on the printing platform, each printing station is fixedly provided with a set of printing device, the high-quality 3D printer further comprises a forming cylinder device and a guide system, and the guide system is used for guiding the butt joint of the forming cylinder device and the printing devices; the printing device comprises Y-axis guide rails which are arranged on a support arm at the upper end of an installation support of a printing station along the length direction of the support arm, an X-axis guide rail is vertically erected between the two Y-axis guide rails along the horizontal direction, two ends of the X-axis guide rail are slidably matched on the Y-axis guide rails, a Y-axis motion control mechanism for controlling the X-axis guide rail to slide on the Y-axis guide rails is further arranged, a printing head support is slidably matched and arranged on the X-axis guide rail and provided with an X-axis motion control mechanism for controlling the printing head support to slide on the X-axis guide rails, and a printing nozzle is arranged on the printing head support; the printing device also comprises a powder supply mechanism arranged above the rear end of the mounting bracket and a powder paving mechanism.

Thus, the X-direction and Y-direction movement control of the printing nozzle is convenient to control.

Furthermore, the Y-axis motion control mechanism is a Y-axis electric sliding table, a guide rail of the Y-axis electric sliding table forms a Y-axis guide rail on one side, the sliding table of the Y-axis electric sliding table is fixed with one end of the X-axis guide rail, the Y-axis guide rail on the other side is a linear guide rail, and the other end of the X-axis guide rail is slidably clamped and matched on the linear guide rail.

Therefore, the device has the advantages of simple structure, convenience in control and reliable control precision.

Furthermore, the X-axis motion control mechanism is an X-axis electric sliding table, the guide rail of the X-axis electric sliding table forms an X-axis guide rail, and a printing head support is arranged on the sliding table of the X-axis electric sliding table.

Further, the powder supply mechanism comprises a powder box, a discharge port is arranged on the lower portion of the powder box, a quantitative discharge mechanism is arranged at the discharge port, a discharge shuttle groove extending towards the front lower side is connected to the lower portion of the quantitative discharge mechanism, and notches at the lower end of the discharge shuttle groove are horizontally arranged along the width direction between the two corresponding mounting brackets.

Therefore, the powder supply mechanism can quantitatively discharge and supply powder according to the required quantity of each spreading, and powder blanking can be conveniently carried out to enter the powder spreading mechanism.

Further, quantitative discharge mechanism includes that a level sets up the measurement sleeve in discharge gate department, it links to each other to link up the measurement sleeve from top to bottom to link up the discharge gate, the coaxial measurement that is provided with in measurement sleeve inside axle center department changes the roller, the measurement is changeed and is provided with along the rectangle blade of axial extension on the circumference surface of roller along circumference evenly distributed, rectangle blade length and the unanimous and outside surface of measurement sleeve inner chamber length and the setting of rotationally laminating of measurement sleeve inner chamber wall, the one end of measurement commentaries on classics roller is rotationally worn out the measurement sleeve tip and is linked to each other with a servo motor for the measurement.

Like this, can rely on for the measurement servo motor control measurement to change the roller and rotate, rotate fixed angle at every turn, can utilize the cavity between two blades to scrape the powder of fixed volume size and down the blanking, guarantee even ration and supply powder.

Furthermore, the two ends of the powder box are fixed on the side face of the powder box mounting plate which is vertically arranged, the lower end of the powder box mounting plate is fixed with the mounting bracket, and the servo motor for metering is fixed on the side face of the other side of the powder box mounting plate.

Thus, the powder supply mechanism is convenient to mount and fix.

Further, spread powder mechanism includes a powder holding tank of arranging along the width direction level between two corresponding installing supports, powder holding tank both ends are unsettled to be fixed near both ends position below at the X axle guide rail through ascending connecting plate, the powder holding tank link up from top to bottom and set up and the rear end (with the adjacent one end of powder case) side on have the scraper of setting downwards, the scraper lower extreme has the horizontally cutting edge that is located and prints the plane height, the powder holding tank once can hold the powder that at least one deck printed the required shop powder, when the X axle guide rail slides to Y axle guide rail rear end, powder holding tank upper end can dock with ejection of compact shuttle groove lower extreme notch.

Like this, the powder holding tank slides to Y axle guide rail rear end along the X axle guide rail during shop's powder, and the powder falls into the powder holding tank from quantitative discharge mechanism ration ejection of compact and through ejection of compact shuttle groove in, then slides along the Y axle guide rail along the X axle guide rail, relies on the scraper to strickle off the powder that falls in the powder holding tank forward, realizes the stone. Adopt scraper stone more convenient and powder surfacing like this, the equal integrated installation of stone mechanism and printing shower nozzle is on X axle guide rail moreover, and the printing shower nozzle can be followed stone mechanism and realized printing immediately at the stone motion in-process, can realize moreover that the reciprocal in-process of stone respectively prints once, improves printing quality and efficiency.

Furthermore, the front side of the printing head bracket is downwards provided with a forward L-shaped front side nozzle mounting plate, and a horizontal part at the lower end of the front side nozzle mounting plate is structurally provided with a first printing nozzle.

Therefore, when the powder spreading device moves forwards along with the X-axis guide rail for spreading materials, the printing spray head can be controlled to firstly spray the adhesive in front of the X-axis guide rail once according to the outline of the layer of products, so that one-time preprinting is realized, powder is paved on the adhesive and is combined with the adhesive and is scraped by the scraper, and then the printing spray head is controlled to normally print once in the resetting process of the X-axis guide rail. Therefore, the printing is carried out twice by paving materials once, the forming strength of the product can be improved, and the printing thickness of each layer can be increased to improve the printing efficiency. Meanwhile, the whole structure is simpler, and the material spreading is convenient, fast and reliable.

As a better option, a nozzle vertical motion control mechanism for controlling the front nozzle mounting plate to vertically slide is further arranged on the printing head support.

Therefore, the height of the first printing nozzle can be adjusted up and down, so that the position of the printing nozzle can be adjusted to be adhered to the upper surface of powder for printing in two times of printing in one material spreading process, and the printing precision is improved better. Specifically, when the first printing nozzle moves forwards along with the X-axis guide rail and prints before material spreading, the position of the first printing nozzle can be adjusted downwards, so that the first printing nozzle is positioned at a position lower than the height of powder on one layer of the scraper, adhesive spraying printing is completed by adhering to the upper surface of the powder on the upper layer, and the contour precision of a printed product is better ensured. Then after the printing is finished, when the first printing spray head moves backwards along with the X-axis guide rail and resets, the first printing spray head is adjusted upwards to return to the position horizontal to the scraper to realize normal printing; and after the X-axis guide rail moves backwards and resets to the starting end, the layer of printing is finished, the baseplate tray in the forming cylinder falls for a layer of powder distance, and the first printing nozzle is controlled to move downwards for the same distance to perform the next layer of printing, so that the process is circulated until the printing is finished. Therefore, the appearance quality of the whole product can be better improved, the structure is simpler, and the implementation is facilitated.

Further, the vertical movement control mechanism of the sprayer comprises a vertical guide rail which is vertically and fixedly arranged on one side of the printing head support, one side of the upper end of the front-side sprayer mounting plate can be matched with the vertical guide rail in a sliding mode, a sprayer vertical movement control motor is fixedly arranged at the upper end of the vertical guide rail, the vertical movement control mechanism of the sprayer further comprises a screw rod which is arranged in parallel with the vertical guide rail at intervals, the sprayer vertical movement control motor is in transmission connection with the screw rod and can drive the screw rod to rotate, a nut is screwed on the screw rod in a threaded fit mode, and the nut is relatively fixed to the upper end of the front-side sprayer mounting plate.

Thus, the spray head vertical motion control motor rotates to drive the screw rod to rotate, the nut is limited by the vertical guide rail through the front side spray head mounting plate, and the front side spray head mounting plate is driven to realize vertical sliding control through the screw rod and nut transmission pair formed by the screw rod and the nut. Therefore, the device has the characteristics of simple structure, reliable control, stable motion and high control precision.

Alternatively, the front nozzle mounting plate is fixed on the side surface of the front end of the printing head bracket; the side face of the rear end of the printing head support is also provided with a rear side nozzle mounting plate which is backwards L-shaped, the horizontal part of the lower end of the rear side nozzle mounting plate is structurally provided with a second printing nozzle, and the printing head support is also provided with a nozzle vertical motion control mechanism used for controlling the rear side nozzle mounting plate to vertically slide.

Therefore, when the X-axis guide rail moves back to the rear end of the Y-axis guide rail for feeding, the spray head vertical movement control mechanism can control the second printing spray head to rise upwards to exceed the height of the discharge shuttle groove so as to avoid interference. Then when normally printing, control the second and print the shower nozzle and drop back to the printing position downwards for two of relying on this structure print the shower nozzle and can realize twice at least printing in the in-process that the spreading mechanism moved the spreading forward along with X axle guide rail and come and go. For example, when normally printing, first printing shower nozzle and second print the shower nozzle and can set up the home position and be located and the scraper is the same high horizontal plane, when the stone device is the spreading forward, realize printing for the first time to this layer of powder by the second printing shower nozzle in rear, accomplish the in-process that returns and reseed to this layer of powder stone at the stone device, realize printing the second time to this layer of powder by the first printing shower nozzle in the place ahead, so twice printing of a stone can improve product quality and efficiency better, wherein the product profile of printing for the second time can also be taken the regional scope between the product profile of twice stone around twice, improve the appearance profile linking effect between twice stone better, improve the product precision better. Meanwhile, as different printing nozzles are adopted in the two times of printing, the binders adjusted in different proportions can be adopted, so that the performances of the binders are more targeted, for example, the binders with normal 3D printing effect are adopted in the first time of printing, and the binders capable of better improving the combination effect between the printed powder layer and the powder layer to be paved are adopted in the second time of printing, so that the final printing effect can be better improved, and the product quality is improved. In addition, for some special products, for example, for products with consistent width in the front-back direction, the device can even realize the special effect of printing four times in the process of spreading materials back and forth once, and the product quality and the production efficiency are better improved.

Further, the vertical movement control mechanism of the spray head comprises a vertical guide rail which is vertically and fixedly arranged on the support of the printing head, one side of the upper end of the rear spray head mounting plate is slidably matched on the vertical guide rail, a spray head vertical movement control motor is fixedly arranged at the upper end of the vertical guide rail, the vertical movement control mechanism of the spray head further comprises a screw rod which is arranged in parallel with the vertical guide rail at intervals, the spray head vertical movement control motor is in transmission connection with the screw rod and can drive the screw rod to rotate, a nut is screwed on the screw rod in a threaded fit mode, and the nut is relatively fixed at the upper end of the rear spray head mounting plate.

Thus, the spray head vertical motion control motor rotates to drive the screw rod to rotate, the nut is limited by the vertical guide rail through the front spray head mounting plate, and the rear spray head mounting plate is driven to realize vertical sliding control through the screw rod and nut transmission pair formed by the screw rod and the nut. Therefore, the device has the characteristics of simple structure, reliable control, stable movement and high control precision.

Further, the guide system is a guide system without a fixed guide rail, and the guide system without a fixed guide rail can generate a guide path as required.

Therefore, a fixed guide rail is omitted, and the guide rail is generated according to needs instead, so that the control is more flexible and convenient.

Furthermore, the guide system without fixed guide rails comprises a plurality of positioning points arranged on the surface of the printing platform, positioning guide members are arranged at the positions of the positioning points, and the positioning points are arranged in an array to form a two-dimensional guide point cloud array; the guiding system also comprises an automatic guiding vehicle, wherein a point cloud detection sensor capable of being inductively positioned with a positioning guiding component at each positioning point is arranged on the automatic guiding vehicle, a universal wheel system is also arranged below the automatic guiding vehicle and is connected with a driving motor, and the driving motor can drive the universal wheel system to steer and run; the forming cylinder device is arranged on the automatic guided vehicle.

Therefore, when the equipment is used, the positions of the positioning guide components on each positioning point can be detected by the point cloud detection sensor, the automatic guided vehicle is controlled to run and move forwards between different positioning points, and the running path is generated by the control and planning of the two-dimensional guide point cloud array, so that the forming cylinder device can travel on the printing platform along with the automatic guided vehicle and complete the butt joint between different printing devices, different materials can be printed at different positions in one product, and the performance difference requirements of different positions are met. Meanwhile, the method has the advantages of flexible and changeable control, better interference avoidance and realization of more printing sequence possibilities; the number of printing stations and automatic guided vehicles can be arranged according to actual production needs.

Further, the positioning guide member is an electromagnetic generator, and the point cloud detection sensor is a magnetic navigation sensor.

The electromagnetic generator can be controlled by a computer or other control device to open and close, and when in use, the electromagnetic generator passing by the path can be opened along a required traveling path, and the electromagnetic generators on the traveling path are connected in series to form the effect similar to the guiding magnetic strip. And simultaneously, other electromagnetic generators are closed, and the automatic guided vehicle is guided to run along the path by using the magnetic navigation sensor. Different driving paths can be generated better according to the requirements of the corresponding automatic guided vehicles, interference of other automatic guided vehicles can be avoided better, a plurality of printing stations can be arranged on the printing platform, a plurality of automatic guided vehicles are arranged, more automatic guided vehicles can work together on the same printing platform to participate in printing, and efficiency is greatly improved. Meanwhile, the running path shields the interference of other positioning points, and the reliability and the stability of the running path are greatly improved.

Further, the positioning guide member is buried under the upper surface of the printing platform.

Thus, the protection can be improved and the service life can be prolonged.

Furthermore, in each locating point, at least one wireless charging potential is further included, a wireless charging device is buried under the wireless charging potential, a wireless charging coil is correspondingly arranged in the middle of the lower surface of the automatic guided vehicle, the wireless charging coil is connected with a storage battery mounted on the automatic guided vehicle, and the storage battery is connected with the driving motor.

Therefore, automatic charging driving continuation of the automatic guided vehicle can be realized, and the moving sequence and the moving path of the automatic guided vehicle can be more conveniently controlled.

Further, at least part of the wireless charging position is positioned at a printing station on the printing platform.

Therefore, the automatic guided vehicle can be charged in the printing waiting time after driving into the printing station, and the charging process does not occupy the working time.

Furthermore, the automatic guided vehicle is also provided with a wireless communication control module, and the wireless communication control module is connected with the driving motor to realize control.

Therefore, the automatic guided vehicle is conveniently controlled to move forwards according to the planned path through wireless communication of a computer and other control devices at a remote place.

Furthermore, the automatic guided vehicle or the printing station is also provided with a positioning sensor, and the printing station or the automatic guided vehicle is also correspondingly provided with a positioning sensor detection component.

Therefore, when the automatic guided vehicle runs to a printing station, the automatic guided vehicle can be accurately positioned by means of the matching detection between the positioning sensor and the positioning sensor detection component, the forming cylinder device on the automatic guided vehicle and the printing device on the printing station can be accurately butted, and the printing quality is guaranteed.

Further, the positioning sensor preferably adopts a contact switch, and the positioning sensor detection member adopts a rigid member capable of being matched with the contact switch to realize contact detection.

Therefore, the device has the advantages of simple structure, convenience and quickness in implementation and reliability in use.

Furthermore, the two pairs of contact switches are respectively installed on contact switch installation frames arranged on two sides of the automatic guided vehicle upwards, and the positioning sensor detection component is a contact protrusion correspondingly formed on a pair of installation supports of the printing station.

Therefore, the automatic guided vehicle can be accurately positioned at the printing station.

Furthermore, the universal wheel system comprises four Mecanum wheels arranged at four corners below the automatic guided vehicle, and each Mecanum wheel is respectively connected with a corresponding driving motor.

Therefore, the driving motor drives the four Mecanum wheels to rotate at different rotating speeds, so that the automatic guided vehicle can move in different directions, and the steering running of the automatic guided vehicle can be better controlled.

Furthermore, the automatic guided vehicle comprises a horizontally arranged bottom plate, the Mecanum wheels and the corresponding driving motors are installed below the bottom plate, the forming cylinder device is installed above the middle part of the bottom plate, the point cloud detection sensor is installed below the bottom plate, the wireless charging coil is installed below the bottom plate, and the wireless communication control module is installed above the bottom plate.

In this way, the realization of the functions of the components is better facilitated.

Furthermore, the forming cylinder device comprises a forming cylinder which is fixedly arranged above the middle part of the automatic guided vehicle in an overhead mode, a circle of flanging which extends outwards horizontally is arranged at the upper end of the forming cylinder to form a printing plane, a bottom plate tray of the forming cylinder can be matched with the wall of an inner cavity of the forming cylinder in a vertically sliding mode, the forming cylinder device further comprises a lifting device which is arranged on the automatic guided vehicle below the forming cylinder, and a telescopic arm of the lifting device is upwards supported and connected to the lower surface of the bottom plate tray.

Therefore, after the lifting device upwards supports the bottom plate tray to the upper position of the inner cavity of the forming cylinder, powder spreading and printing are started, after each layer is printed, the lifting device retracts downwards for a distance of one layer, then powder spreading and printing are carried out in the inner cavity of the forming cylinder again, and the bottom plate tray descends layer by layer until printing is finished. Therefore, the device has the characteristics of simple structure, convenient control, stability and reliability.

Furthermore, four corners of the lower end of the forming cylinder are provided with downward supporting columns, and a supporting frame which is obliquely arranged outwards and downwards is further arranged below the peripheral flanging of the upper end of the forming cylinder.

In this way, the stability of the forming cylinder can be better ensured.

Furthermore, a waste accommodating groove is formed in the printing plane at the front end of the forming cylinder.

Therefore, waste materials generated in the process of paving can fall down, and paving is better assisted.

Further, the printing station is formed by installing a plurality of pairs of mounting brackets on one side of the printing platform at intervals in pairs, the mounting brackets are integrally in the shape of an inverted L-shaped support arm, the front end of the support arm horizontally extends forwards along the direction deviating from the edge of the printing platform, and the printing device is fixed on the mounting brackets.

Thus, the installation of the printing device is more convenient, and the butt joint of the forming cylinder device and the printing device is convenient.

In conclusion, the device has the advantages of being capable of improving printing efficiency and quality precision, conveniently realizing printing of different materials in one product, simple in structure and flexible and convenient to control.

Drawings

Fig. 1 is a schematic structural diagram of a high-quality 3D printer employed in a first embodiment of the present invention.

Fig. 2 is a schematic structural diagram of the single printing platform in fig. 1.

Fig. 3 is a schematic view of the structure of the individual printing apparatus of fig. 1.

Fig. 4 is a top view of fig. 3.

Fig. 5 is a schematic structural view of the separate powder supply mechanism in fig. 1.

Fig. 6 is a side sectional view of fig. 5.

Fig. 7 is a schematic structural diagram of the powder spreading mechanism in fig. 1.

Fig. 8 is a side sectional view of fig. 7.

Fig. 9 is a front view of the single acting guide carriage of fig. 1.

Fig. 10 is a schematic perspective view of fig. 9.

Fig. 11 is a schematic structural diagram of a printing apparatus of a high-quality 3D printer employed in the second embodiment.

Detailed Description

The present invention will be described in further detail with reference to specific embodiments.

The first embodiment: A3D printing method for bonding high-quality three-dimensional powder comprises the steps of decomposing a product into a plurality of horizontal printing layers in a computer along the vertical direction, spreading powder layer by layer in a printing device according to the thickness of each printing layer, adopting a printing nozzle to condense the powder in the product outline range of each layer by spraying a binder after each layer of powder is spread, printing upwards layer by layer and finally obtaining the product; the method is characterized in that a printing spray head is adopted to print twice along the product outline range of each layer in the powder laying process of each layer.

Specifically, the embodiment is implemented by using a high-quality 3D printer as shown in fig. 1 to 10, the printer includes a printing platform 1 horizontally disposed, a plurality of printing stations are disposed on the printing platform, each printing station is fixedly provided with a set of printing device, and the printer further includes a forming cylinder device and a guiding system, the guiding system is used for guiding the forming cylinder device and the printing device to be in butt joint; the guide system is characterized by being a guide system without a fixed guide rail, and the guide system without the fixed guide rail can generate a guide path as required.

The guide system without the fixed guide rail comprises a plurality of positioning points 2 arranged on the surface of a printing platform, positioning guide members are arranged at the positions of the positioning points 2, and the positioning points are arranged in an array to form a two-dimensional guide point cloud array; the guiding system also comprises an automatic guiding vehicle 3, a point cloud detection sensor 4 which can be inductively positioned with a positioning guiding component at each positioning point is arranged on the automatic guiding vehicle 3, a universal wheel system is also arranged below the automatic guiding vehicle 3 and is connected with a driving motor 5, and the driving motor 5 can drive the universal wheel system to steer and run; the forming cylinder device is mounted on a automated guided vehicle 3.

Wherein the positioning guide member is an electromagnetic generator, and the point cloud detection sensor 4 is a magnetic navigation sensor.

Wherein the positioning guide member is buried under the upper surface of the printing platform 1.

Thus, the protection can be improved and the service life can be prolonged.

The automatic guided vehicle is characterized by further comprising at least one wireless charging position 6 in each positioning point, a wireless charging device is buried below the wireless charging position 6, a wireless charging coil 7 is correspondingly arranged in the middle of the lower surface of the automatic guided vehicle, the wireless charging coil 7 is connected with a storage battery mounted on the automatic guided vehicle, and the storage battery is connected with the driving motor 5.

Wherein at least part of the wireless charging potential 6 is positioned at a printing station on the printing platform.

Wherein, still be provided with wireless communication control module 8 on the automated guided vehicle, wireless communication control module 8 and driving motor link to each other and realize control.

The automatic guided vehicle or the printing station is further provided with a positioning sensor 9, and the printing station or the automatic guided vehicle is further correspondingly provided with a positioning sensor detection component (not shown in the figure). In practice, the registration sensor detection member is mounted in the registration sensor detection member mounting hole 10 in the mounting bracket 20 of the print station.

Preferably, the positioning sensor 9 is a contact switch, and the positioning sensor detection member is a rigid member capable of being matched with the contact switch to realize contact detection.

The two pairs of contact switches are respectively installed on the contact switch installation frames 11 which are arranged on the two sides of the automatic guided vehicle upwards, and the positioning sensor detection components are protrusions for contact which are correspondingly formed on the pair of installation supports 20 of the printing station.

The universal wheel system comprises four Mecanum wheels 12 arranged at four corners below the automatic guided vehicle, and each Mecanum wheel 12 is connected with a corresponding driving motor 5.

Therefore, the driving motor drives the four Mecanum wheels to rotate at different rotating speeds, so that the automatic guided vehicle can move in different directions, and the steering running of the automatic guided vehicle can be better controlled. The mecanum wheel is a mature existing product, and the specific structure is not detailed here.

The automatic guided vehicle 3 comprises a horizontally arranged bottom plate, the mecanum wheels 12 and the corresponding driving motors 5 are installed below the bottom plate, the forming cylinder device is installed above the middle of the bottom plate, the point cloud detection sensor 4 is installed below the bottom plate, the wireless charging coils 7 are installed below the bottom plate, and the wireless communication control module 8 is installed above the bottom plate.

The forming cylinder device comprises a forming cylinder 13 which is fixedly arranged above the middle part of the automatic guided vehicle in an overhead mode, a circle of flanging which extends outwards horizontally is arranged at the upper end of the forming cylinder to form a printing plane 14, a bottom plate tray 15 of the forming cylinder can be matched with the inner cavity wall of the forming cylinder in a vertically sliding mode, the forming cylinder device further comprises a lifting device 16 which is arranged on the automatic guided vehicle below the forming cylinder, and a telescopic arm of the lifting device 16 is upwards supported and connected to the lower surface of the bottom plate tray.

Wherein, the four corners of the lower end of the forming cylinder are provided with downward supporting columns 17, and the lower position of the peripheral flanging of the upper end of the forming cylinder is also provided with a supporting frame 18 which is obliquely arranged outwards and downwards.

In this way, the stability of the forming cylinder can be better ensured.

Wherein, a waste material accommodating groove 19 is also arranged on the printing plane at the front end of the forming cylinder.

Wherein, the printing station is formed by installing a plurality of pairs of installing support 20 in printing platform one side at the interval in pairs, and installing support 20 wholly is the support arm form of falling L shape, and the support arm front end sets up along deviating from printing platform edge direction level forward extension, and printing device fixes on installing support 20.

The printing device comprises Y-axis guide rails 21 arranged on a support arm at the upper end of a mounting support along the length direction of the support arm, an X-axis guide rail 22 is vertically erected between the two Y-axis guide rails 21 along the horizontal direction, two ends of the X-axis guide rail 22 are slidably matched on the Y-axis guide rails 21, a Y-axis motion control mechanism used for controlling the X-axis guide rail to slide on the Y-axis guide rails is further arranged, a printing head support 23 is slidably matched and arranged on the X-axis guide rail and provided with an X-axis motion control mechanism used for controlling the printing head support 23 to slide on the X-axis guide rail, and a printing nozzle is arranged on the printing head support (only a printing nozzle mounting hole is shown in the figure); the printing device also comprises a powder supply mechanism arranged above the rear end of the mounting bracket and a powder paving mechanism.

The Y-axis motion control mechanism is a Y-axis electric sliding table, a guide rail 24 of the Y-axis electric sliding table forms a Y-axis guide rail on one side, a sliding table 25 of the Y-axis electric sliding table is fixed with one end of an X-axis guide rail 22, the Y-axis guide rail on the other side is a linear guide rail 26, and the other end of the X-axis guide rail 22 is slidably clamped and matched on the linear guide rail 26.

Wherein, X axle motion control mechanism is the electronic slip table of X axle, and the guide rail 27 of the electronic slip table of X axle forms the X axle guide rail, and the installation is beaten printer head support 23 on the slip table of the electronic slip table of X axle. The adopted electric sliding table is an existing product, comprises a motor, a guide rail, a sliding table and other components, and is driven by the motor to translate along the guide rail in a transmission mode of a screw nut pair, and the specific structure is not detailed here.

Wherein, supply powder mechanism to include a powder case 30, and powder case 30 lower part is provided with the discharge gate, and discharge gate department is provided with quantitative discharge mechanism, and quantitative discharge mechanism below is connected with a ejection of compact shuttle groove 31 that extends to the below, and ejection of compact shuttle groove 31 lower extreme notch is along two width direction horizontal arrangements that correspond between the installing support.

Wherein, quantitative discharge mechanism includes that a level sets up the measurement sleeve in discharge gate department, the discharge gate link to each other from top to bottom through the measurement sleeve 32, the coaxial measurement that is provided with in measurement sleeve inside axle center department changes roller 33, it is provided with along axial extension's rectangle blade to measure to change on the surface of roller 33's circumference evenly distributed along circumference, rectangle blade length and the unanimous and outside surface of measurement sleeve inner chamber length rotationally laminate the setting with measurement sleeve inner chamber wall, the one end of measuring commentaries on classics roller 33 rotationally wears out the measurement sleeve tip and links to each other with a servo motor 34 for the measurement.

Wherein, the both ends of powder case 30 are fixed on the powder case mounting panel 35 side of vertical setting, and powder case mounting panel 35 lower extreme and installing support are fixed, and servo motor 34 for the measurement is fixed on powder case mounting panel opposite side.

Thus, the powder supply mechanism is convenient to mount and fix.

Wherein, shop's powder mechanism includes one and follows the powder holding tank 36 that two width direction levels between the corresponding installing support arranged, powder holding tank 36 both ends are close to both ends position below through ascending connecting plate 37 unsettled the fixing in X axle guide rail, the powder holding tank link up from top to bottom and set up and have the scraper 38 of downward setting on the rear end (the one end adjacent with the powder case) side, scraper 38 lower extreme has the horizontally cutting edge that is located and prints the plane height, the powder holding tank once can hold the powder that at least one deck required shop powder was printed, when X axle guide rail slides to Y axle guide rail rear end, powder holding tank upper end can dock with ejection of compact shuttle groove lower extreme notch.

Wherein, the front side of the print head bracket is connected with a front side nozzle mounting plate 40 in a forward L shape in a downward mounting manner, and a horizontal part structure at the lower end of the front side nozzle mounting plate 40 is provided with a first print head (only the nozzle mounting hole is shown in the figure).

In this embodiment, the front nozzle mounting plate 40 is fixed to the front end side surface of the head support 23; a rear side nozzle mounting plate 41 in a backward L shape is further installed on the rear end side face of the printing head support 23, a second printing nozzle (only a printing nozzle mounting hole is shown in the figure) is structurally installed on the horizontal portion of the lower end of the rear side nozzle mounting plate 41, and a nozzle vertical movement control mechanism for controlling the rear side nozzle mounting plate to vertically slide is further arranged on the printing head support 23.

The nozzle vertical motion control mechanism comprises a vertical guide rail 42 which is vertically and fixedly arranged on a printing head support, one side of the upper end of a rear nozzle mounting plate 41 is slidably matched on the vertical guide rail 42, a nozzle vertical motion control motor 43 is fixedly arranged at the upper end of the vertical guide rail 42, the nozzle vertical motion control mechanism further comprises a screw 44 which is arranged in parallel with the vertical guide rail at intervals, the nozzle vertical motion control motor is in transmission connection with the screw and can drive the screw to rotate, a nut 45 is screwed on the screw 44 in threaded fit, and the nut is relatively fixed at the upper end of the rear nozzle mounting plate.

In addition, a computer-aided control system needs to be installed during implementation, and the control system divides slice data of each printing layer by horizontally slicing the imported three-dimensional CAD model and then sends the slice data to a 3D printer for printing, which is a mature prior art and therefore will not be described in detail here.

A second embodiment.

This embodiment is compared with the first embodiment. Only in the high-quality 3D printer that adopts printing device's beat printer head mounting structure to distinguish, do not set up the second on the rear side shower nozzle mounting panel and print the shower nozzle in this embodiment, but set up the front side shower nozzle mounting panel vertically slidable, the remaining part structure all is the same with first embodiment.

Specifically. Referring to fig. 11, in the present embodiment, a head vertical movement control mechanism for controlling the front side head mounting plate 40 to slide vertically is further provided on the head carriage 23.

The nozzle vertical motion control mechanism comprises a vertical guide rail 41 which is vertically and fixedly arranged on one side of the printing head support 23, one side of the upper end of the front nozzle mounting plate 40 is slidably matched on the vertical guide rail 41, a nozzle vertical motion control motor 42 is fixedly arranged on the upper end of the vertical guide rail 41, the nozzle vertical motion control mechanism further comprises a screw 43 which is arranged in parallel with the vertical guide rail at intervals, the nozzle vertical motion control motor 42 is in transmission connection with the screw 43 and can drive the screw to rotate, a nut 44 is screwed on the screw in a threaded fit mode, and the nut 44 is relatively fixed on the upper end of the front nozzle mounting plate 40.

The devices of the two embodiments can also realize the following production modes when in use.

The single-material part flow production mode comprises the following steps: this model is directed to mass production of parts of many kinds, few in number, composed of one material. During production, a part three-dimensional CAD model needing 3D printing is introduced into a computer system, the system distributes positions of the parts according to serial numbers, for example, the parts No. 1, 2 and 3 … are printed on the positions No. 1, 2 and 3 … respectively, and the automatic guided vehicle starts to print after driving into the printing positions. And automatically exiting after printing is finished, waiting for manual subsequent processing, and entering the next automatic guided vehicle for continuous printing.

Secondly, a multi-material part flow production mode is as follows: the mode breaks through the limitation that the existing printer based on the 3DP (three-dimensional powder bonding) process can only print a single material, meets the new printing requirement, and can be produced in batches. During production, the three-dimensional CAD model of the part is imported into a computer, and the computer distributes different material parts of the part to different stations for placing corresponding materials. When the parts are printed, the parts are from bottom to top, for example, an automatic guided vehicle prints the material A at the bottom at the No. 1 station, then goes to the No. 2 station under the computer scheduling to print the material B at the middle part, and then goes to the computer scheduling to go to the No. 3 station under the computer scheduling to print the material C at the top.

The computer scheduling flow during production can be as follows: printing station distribution is carried out on the part materials, if the part materials are single materials, one station is distributed, and if the part materials are multiple materials, the part materials are distributed according to the material types; planning a path for the automatic guided vehicle through the two-dimensional point cloud array, and driving the automatic guided vehicle into a corresponding printing station; slicing the part from bottom to top, and sending the data of the section of the slice to a printing station; layer by layer progressive; when the switching material is required to be printed, the path is planned again through the two-dimensional point cloud array, and the automatic guided vehicle drives into another station to continue printing.

The path planning process during production can be as follows: detecting the position of the existing automatic guided vehicle; avoiding the position of the existing guided vehicle; judging whether the target station is idle; planning a path; if the path is successfully planned, activating a two-dimensional point cloud array covered by the path; and if the path planning fails, the automatic guided vehicle is planned to leave the printing station, the automatic guided vehicle is driven into the overtaking buffer zone to wait, and the path planning is carried out again after the target station is idle.

Claims

1. A3D printing method for bonding high-quality three-dimensional powder comprises the steps of decomposing a product into a plurality of horizontal printing layers in a computer along the vertical direction, spreading powder layer by layer in a printing device according to the thickness of each printing layer, adopting a printing nozzle to condense the powder in the product outline range of each layer by spraying a binder after each layer of powder is spread, printing upwards layer by layer and finally obtaining the product; the method is characterized in that a printing spray head is adopted to print twice along the product outline range of each layer in the powder laying process of each layer.

2. The high-quality three-dimensional powder bonding 3D printing method according to claim 1, wherein the high-quality 3D printer is implemented by adopting a high-quality 3D printer, the high-quality 3D printer comprises a horizontally arranged printing platform, a plurality of printing stations are arranged on the printing platform, each printing station is fixedly provided with a set of printing device, and the high-quality 3D printer further comprises a forming cylinder device and a guide system, and the guide system is used for guiding the forming cylinder device to be in butt joint with the printing devices; the printing device comprises Y-axis guide rails which are arranged on a support arm at the upper end of an installation support of a printing station along the length direction of the support arm, an X-axis guide rail is vertically erected between the two Y-axis guide rails along the horizontal direction, two ends of the X-axis guide rail are slidably matched on the Y-axis guide rails, a Y-axis motion control mechanism for controlling the X-axis guide rail to slide on the Y-axis guide rails is further arranged, a printing head support is slidably matched and arranged on the X-axis guide rail and provided with an X-axis motion control mechanism for controlling the printing head support to slide on the X-axis guide rails, and a printing nozzle is arranged on the printing head support; the printing device also comprises a powder supply mechanism arranged above the rear end of the mounting bracket and a powder paving mechanism.

3. The high-quality three-dimensional powder bonding 3D printing method according to claim 2, wherein the Y-axis motion control mechanism is a Y-axis electric sliding table, a guide rail of the Y-axis electric sliding table forms a Y-axis guide rail on one side, the sliding table of the Y-axis electric sliding table is fixed with one end of the X-axis guide rail, the Y-axis guide rail on the other side is a linear guide rail, and the other end of the X-axis guide rail is slidably clamped and matched on the linear guide rail;

the X-axis motion control mechanism is an X-axis electric sliding table, a guide rail of the X-axis electric sliding table forms an X-axis guide rail, and a printing head support is installed on the sliding table of the X-axis electric sliding table.

4. The 3D printing method for high-quality three-dimensional powder bonding as defined in claim 2, wherein the powder supply mechanism comprises a powder box, a discharge port is arranged at the lower part of the powder box, a quantitative discharge mechanism is arranged at the discharge port, a discharge shuttle groove extending forwards and downwards is connected below the quantitative discharge mechanism, and a notch at the lower end of the discharge shuttle groove is horizontally arranged along the width direction between the two corresponding mounting brackets;

the quantitative discharging mechanism comprises a metering sleeve horizontally arranged at a discharging port, the discharging port is connected with the metering sleeve in a vertically penetrating manner, a metering rotating roller is coaxially arranged at the axis inside the metering sleeve, rectangular blades extending along the axial direction are uniformly distributed on the circumferential outer surface of the metering rotating roller along the circumferential direction, the length of each rectangular blade is consistent with that of an inner cavity of the metering sleeve, the outer side surface of each rectangular blade is rotatably attached to the inner cavity wall of the metering sleeve, and one end of each metering rotating roller rotatably penetrates through the end part of the metering sleeve and is connected with a metering servo motor;

the both ends of powder case are fixed on the powder case mounting panel side of vertical setting, and powder case mounting panel lower extreme and installing support are fixed, and servo motor for the measurement is fixed on powder case mounting panel opposite side.

5. The high-quality three-dimensional powder bonding 3D printing method according to claim 4, wherein the powder spreading mechanism comprises a powder holding tank horizontally arranged along the width direction between two corresponding mounting brackets, two ends of the powder holding tank are suspended and fixed below the positions, close to the two ends, of the X-axis guide rail through upward connecting plates, the powder holding tank is arranged in a vertically through mode, a scraper is arranged on the side face of the rear end of the powder holding tank, the lower end of the scraper is provided with a horizontal cutting edge located at the height of a printing plane, the powder holding tank can hold at least one layer of powder required to be spread during printing, and when the X-axis guide rail slides to the rear end of the Y-axis guide rail, the upper end of the powder holding tank can be in butt joint with a notch at the lower end of the discharging shuttle groove;

the front side of the printing head bracket is downwards provided with a forward L-shaped front side nozzle mounting plate, and a horizontal part structure at the lower end of the front side nozzle mounting plate is provided with a first printing nozzle.

6. The high-quality three-dimensional powder bonding 3D printing method according to claim 5, wherein a nozzle vertical movement control mechanism for controlling the front nozzle mounting plate to vertically slide is further arranged on the print head bracket;

the vertical motion control mechanism of shower nozzle includes that a vertical fixed setting is at the vertical guide rail of beating printer head support one side, and one side slidable ground cooperation of front side shower nozzle mounting panel upper end is on vertical guide rail, and the upper end of vertical guide rail is fixed and is provided with a shower nozzle vertical motion control motor, still includes a screw rod that sets up side by side with vertical guide rail interval, and shower nozzle vertical motion control motor is connected and can drive the screw rod rotatory with the screw rod transmission, and screw-thread fit has connect a nut soon on the screw rod, and the nut relatively fixed is in front side shower nozzle mounting panel upper end.

7. The high quality three dimensional powder bonding 3D printing method of claim 5 wherein the front side nozzle mounting plate is fixed to the side of the front end of the print head carriage; the side surface of the rear end of the printing head support is also provided with a rear side nozzle mounting plate which is backwards L-shaped, the horizontal part structure at the lower end of the rear side nozzle mounting plate is provided with a second printing nozzle, and the printing head support is also provided with a nozzle vertical motion control mechanism for controlling the rear side nozzle mounting plate to vertically slide;

the spray head vertical motion control mechanism comprises a vertical guide rail which is vertically and fixedly arranged on a print head support, one side of the upper end of a rear spray head mounting plate can be matched on the vertical guide rail in a sliding mode, a spray head vertical motion control motor is fixedly arranged at the upper end of the vertical guide rail, the spray head vertical motion control mechanism further comprises a screw rod which is arranged in parallel with the vertical guide rail at intervals, the spray head vertical motion control motor is in transmission connection with the screw rod and can drive the screw rod to rotate, a nut is screwed in threaded fit on the screw rod, and the nut is relatively fixed at the upper end of the rear spray head mounting plate.

8. The high quality three dimensional powder bonding 3D printing method according to claim 2 wherein the guide system is a guide system without fixed guides that can create guide paths as needed;

the guide system without the fixed guide rail comprises a plurality of positioning points arranged on the surface of the printing platform, positioning guide members are arranged at the positions of the positioning points, and the positioning points are arranged in an array to form a two-dimensional guide point cloud array; the guiding system also comprises an automatic guiding vehicle, wherein a point cloud detection sensor capable of being inductively positioned with a positioning guiding component at each positioning point is arranged on the automatic guiding vehicle, a universal wheel system is also arranged below the automatic guiding vehicle and is connected with a driving motor, and the driving motor can drive the universal wheel system to steer and run; the forming cylinder device is arranged on the automatic guided vehicle.

9. The method for high quality three dimensional powder bonding 3D printing as defined in claim 8 wherein the registration guide member is an electromagnetic generator and the point cloud detection sensor is a magnetic navigation sensor.

10. The high quality three dimensional powder bonding 3D printing method of claim 8 wherein the positioning guide member is embedded below the upper surface of the printing platform;

the positioning points also comprise at least one wireless charging position, a wireless charging device is embedded below the wireless charging position, a wireless charging coil is correspondingly arranged in the middle of the lower surface of the automatic guided vehicle, the wireless charging coil is connected with a storage battery arranged on the automatic guided vehicle, and the storage battery is connected with the driving motor;

at least part of the wireless charging position is positioned at a printing station on the printing platform;

the automatic guided vehicle is also provided with a wireless communication control module which is connected with the driving motor and realizes control;

the automatic guided vehicle or the printing station is also provided with a positioning sensor, and the printing station or the automatic guided vehicle is also correspondingly provided with a positioning sensor detection component;

the positioning sensor preferably adopts a contact switch, and the detection component of the positioning sensor adopts a rigid component which can be matched with the contact switch to realize contact detection;

the two pairs of contact switches are respectively arranged on contact switch mounting frames arranged upwards on two sides of the automatic guided vehicle, and the positioning sensor detection components are contact bulges correspondingly formed on a pair of mounting frames of the printing station;

the universal wheel system comprises four Mecanum wheels arranged at four corners below the automatic guided vehicle, and each Mecanum wheel is connected with a corresponding driving motor;

the automatic guided vehicle comprises a horizontally arranged bottom plate, the Mecanum wheels and the corresponding driving motors are arranged below the bottom plate, the forming cylinder device is arranged above the middle part of the bottom plate, the point cloud detection sensor is arranged below the bottom plate, the wireless charging coil is arranged below the bottom plate, and the wireless communication control module is arranged above the bottom plate;

the forming cylinder device comprises a forming cylinder which is fixedly arranged above the middle part of the automatic guided vehicle in an overhead mode, a circle of flanging which extends horizontally outwards to form a printing plane is arranged at the upper end of the forming cylinder, a bottom plate tray of the forming cylinder can be matched with the inner cavity wall of the forming cylinder in a vertically sliding mode, the forming cylinder device further comprises a lifting device which is arranged on the automatic guided vehicle below the forming cylinder, and a telescopic arm of the lifting device is upwards supported and connected to the lower surface of the bottom plate tray;

the printing station is formed by installing a plurality of pairs of mounting brackets on one side of the printing platform at intervals in pairs, the mounting brackets are integrally in the shape of an inverted L-shaped support arm, the front end of the support arm horizontally extends forwards along the direction deviating from the edge of the printing platform, and the printing device is fixed on the mounting brackets.