CN114393823B

CN114393823B - Multi-material 3D printing equipment and method

Info

Publication number: CN114393823B
Application number: CN202210066551.2A
Authority: CN
Inventors: 刘晓冬; 王功; 张晓日; 刘学攀
Original assignee: Technology and Engineering Center for Space Utilization of CAS
Current assignee: Technology and Engineering Center for Space Utilization of CAS
Priority date: 2022-01-20
Filing date: 2022-01-20
Publication date: 2024-04-09
Anticipated expiration: 2042-01-20
Also published as: CN114393823A

Abstract

The invention provides a multi-material 3D printing device and a method, wherein the multi-material 3D printing device comprises: the device comprises a base, a printing platform unit, an ultraviolet light unit, a feeding, spreading and scraping integrated unit, a rotary switching type material box unit and a cleaning and air drying unit; the feeding, spreading and scraping integrated unit comprises: the device comprises a scraping rotary disc, a scraping rotary bearing, a scraping motor, a spreading scraping piece and n groups of feeding units. The multi-material 3D printing device and method provided by the invention have the following advantages: through the comprehensive design to printing platform unit, feed shop material scrape material integration unit, rotatory switching formula magazine unit and washing air-dry unit, from the printing precision is guaranteed comprehensively in each angle, is fit for the 3D printing field that different layers or same layer adopted multiple printing material.

Description

Multi-material 3D printing equipment and method

Technical Field

The invention belongs to the technical field of multi-material 3D printing, and particularly relates to multi-material 3D printing equipment and a method.

Background

3D printing is a technology for constructing objects by using a bondable material such as powdered metal or plastic based on digital model files in a layer-by-layer printing manner.

Traditional 3D printing techniques print for a single material, whereby only parts of a single material can be printed. With the increasing demands of people on the functions and performances of products, the use requirement of parts made of single materials is difficult to meet, and the research on the manufacture of multi-material parts becomes a hot spot of the current research.

The multi-material 3D printing mode is a high and new technology for preparing new materials and controllable materials. The principle is that three-dimensional molding is realized by overlapping layers, so that the printing gradient of multiple materials is increased, and the combination of different materials is realized.

The existing multi-material 3D printing mainly has the following problems: the precision of the multi-material 3D printing equipment is not high, the mechanical structure design integration level and the degree of automation are not high, and the industrial use requirements are hardly met. In addition, only the combination of layers and different materials between layers can be realized, and the splicing and forming of the same layer and different materials cannot be realized.

Disclosure of Invention

Aiming at the defects existing in the prior art, the invention provides multi-material 3D printing equipment and a method, which can effectively solve the problems.

The technical scheme adopted by the invention is as follows:

the present invention provides a multi-material 3D printing apparatus comprising: the device comprises a base (100), a printing platform unit (200), an ultraviolet light unit (300), a feeding, spreading and scraping integrated unit (400), a rotary switching type material box unit (500) and a cleaning and air drying unit (600);

the printing platform unit (200) is fixedly arranged above the base (100); the ultraviolet light unit (300) is fixedly arranged below the base (100); wherein the printing platform unit (200) comprises a platform lifting mechanism (201) and a printing platform (202); the printing platform (202) is driven by the platform lifting mechanism (201) to perform lifting movement; the printing surface of the printing platform (202) and the light emergent direction of the ultraviolet optical unit (300) are coaxially arranged up and down;

the rotary switching type cartridge unit (500) comprises a cartridge switching driving mechanism and n cartridges (505); -mounting n of said cartridges (505) and one of said washing and air drying units (600) along a ring; the cartridge switching driving mechanism drives the n cartridges (505) and one cleaning and air drying unit (600) to integrally rotate, and when one of the cartridges (505) rotates to a printing station, the cartridges (505), the printing platform (202) and the ultraviolet optical unit (300) which are positioned at the printing station are positioned on the same vertical line up and down; when the cleaning and air drying unit (600) rotates to a printing station, the cleaning and air drying unit is used for cleaning and air drying the printing surface of the printing platform (202), so that the rotation switching of each material box (505) and the cleaning and air drying unit (600) is realized;

the feeding, spreading and scraping integrated unit (400) comprises: a scraping driving mechanism, a spreading scraping piece (404) and n groups of feeding units (405);

the number of the spreading scraping pieces (404) is the same as that of the material boxes (505), and each spreading scraping piece (404) is positioned above a corresponding material box (505); each group of feeding units (405) corresponds to one of the spreading scrapers (404) and is used for independently feeding the spreading scrapers (404);

the scraping driving mechanism is fixedly arranged above the material box switching driving mechanism and is used for driving the spreading scraping piece (404) and the feeding unit (405) to integrally rotate, so that spreading and scraping are realized.

Preferably, the platform lifting mechanism (201) is a ball screw lifting mechanism, comprising: a lifting motor (2011), a screw rod (2012), a sliding block (2013), an upper limit switch (2014) and a lower limit switch (2015);

the screw rod (2012) is vertically arranged; the sliding block (2013) is sleeved on the screw rod (2012); the outside of the sliding block (2013) is fixedly provided with the horizontally arranged printing platform (202); the lifting motor (2011) is used for driving the screw rod (2012) to rotate; and at the upper limit position and the lower limit position of the sliding block (2013) in sliding, the upper limit switch (2014) and the lower limit switch (2015) are respectively arranged.

Preferably, an output shaft of the scraping motor (403) is sleeved with an installation angle limiting sheet (406), and the angle limiting sheet (406) is of a fan-shaped structure; a contact switch (407) is fixedly arranged on the rotating path of the angle limiting sheet (406); and the forward and reverse rotation angles of the scraping motor (403) are controlled through the cooperation of the angle limiting sheet (406) and the contact switch (407).

Preferably, the washing and air drying unit (600) integrates a washing unit and an air drying unit.

The invention also provides a printing method of the multi-material 3D printing device, which comprises the following steps:

step 1, configuring n groups of feeding units (405) by the multi-material 3D printing equipment, wherein each group of feeding units (405) corresponds to one printing material;

the printing material M (F) required for the current print layer is determined so that a particular feed unit is selected among the n groups of feed units (405), denoted as: a specific feeding unit T (F); the specific feeding unit T (F) corresponds to the specific material box H (F) and the specific material spreading scraping piece G (F);

step 2, controlling the cartridge switching driving mechanism to move so that the specific cartridge H (F), the specific feeding unit T (F) and the specific spreading scraper G (F) are rotated to a printing station;

meanwhile, on one hand, the specific feeding unit T (F) is controlled to inject the printing material M (F) into the scraper cavity (4041A) of the specific spreading scraper G (F); on one hand, the scraping driving mechanism is controlled to move so as to drive the specific spreading scraping piece G (F) to reciprocate in the specific material box H (F), and in the moving process of the specific spreading scraping piece G (F), the injected printing material M (F) is paved, and the thickness is one printing layer thickness, so that feeding and spreading integrated operation is realized;

step 3, after the specific material box H (F) rotates to a printing station and the material spreading in the specific material box H (F) is completed, controlling the printing platform (202) to move downwards until the bottommost surface of the printing platform (202) is a printing layer thickness from the bottom of the specific material box H (F); wherein the bottom of the specific material box H (F) is optical glass;

controlling an ultraviolet optical unit (300) to penetrate through optical glass at the bottom of a specific material box H (F) from bottom to top, and performing projection curing on a printing material M (F) in the specific material box H (F) according to a set shape so as to cure the printing material M (F) with a single layer thickness to the bottommost surface of a printing platform (202) according to the set shape;

step 4, controlling the printing platform (202) to ascend;

controlling the material box switching driving mechanism to move so as to enable the cleaning and air drying unit (600) to rotate to a printing station;

step 5, controlling the printing platform (202) to descend, enabling the solidified material on the bottom surface of the printing platform (202) to sink into the cleaning unit, and carrying out ultrasonic cleaning on the solidified material on the bottom surface of the printing platform (202) through the cleaning unit;

after the cleaning is finished, the printing platform (202) is controlled to rise to a certain height, so that the solidified material on the bottom surface of the printing platform (202) is positioned above the air drying unit, and the solidified material on the bottom surface of the printing platform (202) is air-dried through the air drying unit;

and 6, returning to the step 1, determining the printing material M (F) needed to be used for the same layer or the next printing layer, and performing cyclic printing to obtain parts made of different layers or the same layer by adopting a plurality of printing materials.

The multi-material 3D printing device and method provided by the invention have the following advantages:

through the comprehensive design to printing platform unit, feed shop material scrape material integration unit, rotatory switching formula magazine unit and washing air-dry unit, from the printing precision is guaranteed comprehensively in each angle, is fit for the 3D printing field that different layers or same layer adopted multiple printing material.

Drawings

Fig. 1 is a schematic diagram of the overall structure of a multi-material 3D printing device according to the present invention;

fig. 2 is a schematic diagram of an internal structure of the multi-material 3D printing device provided by the invention after a base is hidden;

FIG. 3 is a block diagram of the feed-spreading-scraping integrated unit and the rotary switching type cartridge unit provided by the invention under an angle;

FIG. 4 is a block diagram of the feed-spreading and scraping integrated unit and the rotary switching cartridge unit provided by the invention at another angle;

FIG. 5 is a block diagram of the feed-and-spread-material-scraping integrated unit provided by the invention;

FIG. 6 is a diagram of the positional relationship between a paver scraper and a magazine provided by the invention;

FIG. 7 is a block diagram of a paver scraper provided by the present invention;

FIG. 8 is a block diagram of a doctor blade holder provided by the present invention;

FIG. 9 is a block diagram of a doctor blade provided by the invention;

fig. 10 is a block diagram of a cleaning and air drying unit and a printing platform provided by the invention;

FIG. 11 is a block diagram of a cleaning unit according to the present invention;

FIG. 12 is a block diagram of a bubble generator provided by the present invention;

FIG. 13 is a block diagram of an air outlet plate according to the present invention.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects solved by the invention more clear, the invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

The invention provides a multi-material 3D printing device, which mainly comprises: the printing device comprises a base 100, a printing platform unit 200, an ultraviolet light unit 300, a feeding, spreading and scraping integrated unit 400, a rotary switching type material box unit 500 and a cleaning and air drying unit 600. The invention relates to a printing platform unit 200, which is fixed in position, and is characterized in that a material box or a cleaning and air drying unit 600 for different printing materials is rotationally switched to a printing station under the printing platform unit 200 through a rotary switching material box unit 500, 3D printing is realized, or the solidified middleware on the bottom surface of the printing platform is cleaned and air-dried, and multi-material 3D printing is realized through the cross matching of 3D printing and cleaning.

The precision of multi-material 3D printing is effectively improved through the fine design of the printing platform unit 200, the ultraviolet light unit 300, the feeding, spreading and scraping integrated unit 400, the rotary switching type material box unit 500 and the cleaning and air drying unit 600.

The following details of the structural components of the present invention:

(one) a printing platform unit 200:

the printing platform unit 200 is fixedly installed above the base 100. During the 3D printing, the position of the printing platform unit 200 is fixed.

Referring to fig. 10, the printing platform unit 200 includes a platform lifting mechanism 201 and a printing platform 202; the printing platform 202 is driven by the platform lifting mechanism 201 to perform lifting movement;

specifically, the platform lifting mechanism 201 is a ball screw lifting mechanism, including: a lifting motor 2011, a screw 2012, a sliding block 2013, an upper limit switch 2014 and a lower limit switch 2015;

the screw 2012 is vertically arranged; a mounting slide block 2013 is sleeved on the screw rod 2012; the outside of the slide block 2013 is fixedly provided with a horizontally arranged printing platform 202; the lifting motor 2011 is used for driving the screw 2012 to rotate; at the upper limit and the lower limit positions where the slider 2013 slides, an upper limit switch 2014 and a lower limit switch 2015 are installed, respectively, so as to limit the position limit of the printing platform 202.

(II) ultraviolet optical unit 300:

referring to fig. 2, an ultraviolet light unit 300 is fixedly installed under the base 100; the printing surface of the printing platform 202 and the light emitting direction of the ultraviolet light unit 300 are coaxially arranged up and down.

Specifically, the ultraviolet optical unit 300 is fixed under the printing platform 202 by using a high-precision ultraviolet DLP optical system, and the material box between the ultraviolet optical unit 300 and the printing platform 202 is a material box of a printing station, so that the material boxes of the printing platform 202, the ultraviolet optical unit 300 and the printing station are arranged in a longitudinal straight line.

The ultraviolet optical unit 300 passes through the optical glass at the bottom of the material box from bottom to top, and performs projection curing on the printing material in the material box, so that the single layer thick printing material is cured to the bottom printing surface of the printing platform 202 according to the set shape.

(III) rotating the switching cartridge unit 500:

the multi-material 3D printing device provided by the invention is a device for realizing multi-material 3D printing by switching the material boxes of different printing materials to the printing stations under the printing platform 202 through rotating and switching the material boxes with the fixed positions of the printing platform 202. In order to ensure printing precision, realize the stability and levelness of the rotary switching of the material box and prevent the uneven thickness of the printing material in the material box during the rotary switching, the invention provides a rotary switching material box unit with fine design, wherein a main body adopts an axisymmetric structure and is assisted by adopting a slewing bearing, so that the rotary switching precision of the material box is ensured. It should be emphasized that the rotary switching type cartridge unit described below is only one specific implementation, and in practical applications, the rotary switching type cartridge unit 500 of other structural forms may be adopted, as long as the rotation of the cartridge 505 can be achieved, and the specific structural form of the rotary switching type cartridge unit is not limited in the present invention.

Referring to fig. 3 and 4, the rotary switching cartridge unit 500 includes a cartridge switching drive mechanism and n cartridges 505;

the cartridge switching driving mechanism drives the n cartridges 505 and the one washing and air drying unit 600 to integrally rotate.

As a specific implementation, the cartridge switching drive mechanism includes a rotary disc 501, a rotary bearing 502, a rotary motor 503, and a connection bracket 504;

the rotary disc 501 is horizontally arranged, a connecting bracket 504 is fixedly arranged on the lower coaxial center of the rotary disc 501, a rotating motor 503 is fixedly arranged on the lower coaxial center of the connecting bracket 504, and the rotary disc 501 is driven to horizontally rotate through the rotating motor 503;

a rotary bearing 502 is coaxially arranged at the bottom of the rotary disc 501; the slewing bearing 502 adopts an inner ring slewing bearing and an outer ring slewing bearing, and the outer ring bearing is fixed with the surface of the base 100; the inner ring bearing is fixed with the bottom surface of the rotary disc 501, and the rotary disc 501 stably rotates under the supporting action of the rotary bearing 502;

n cartridges 505 and one cleaning and air drying unit 600 are fixedly installed along the ring shape on the surface of the rotary disc 501; for example, 5 cartridges 505 and one purge air dryer unit 600 may be installed. When the rotary disc 501 rotates, the material boxes 505 and the cleaning and air drying unit 600 are driven to synchronously rotate, and when one material box 505 rotates to a printing station, the material box 505, the printing platform 202 and the ultraviolet optical unit 300 which are positioned at the printing station are positioned on the same vertical line up and down; when the cleaning and air drying unit 600 rotates to the printing station, the cleaning and air drying unit is used for cleaning and air drying the printing surface of the printing platform 202; by the rotation of the rotary plate 501, the rotation switching of each cartridge 505 and the cleaning and air drying unit 600 is realized.

The rotary switching cartridge unit 500 has the following features:

(1) And the main body of the rotary switching type material box unit adopts an axisymmetric structure and is assisted by adopting a slewing bearing, so that the rotary switching precision of the material box is ensured.

(2) The surface of the rotary tray 501 is integrated with the cartridge 505 and the cleaning and air drying unit 600, so that the cartridge 505 and the cleaning and air drying unit 600 can be switched. That is, the cartridge 505 and the cleaning and air drying unit 600 share the same set of rotary switching mechanism, and no special rotary switching mechanism design is required for the cleaning and air drying unit, so that the complexity of the equipment structure is simplified, and the equipment integration level is high.

(IV) a feeding, spreading and scraping integrated unit 400:

the feeding, spreading and scraping integrated unit 400 is used for independently feeding, spreading and scraping each cartridge 505 in the rotary switching cartridge unit 500. It should be emphasized that the feeding, spreading and scraping integrated unit 400 described below is only a specific implementation manner, and in practical applications, the feeding, spreading and scraping integrated unit 400 with other structural forms may also be adopted, as long as scraping can be implemented, and the specific structural form of the feeding, spreading and scraping integrated unit 400 is not limited in the present invention.

Referring to fig. 3, 4 and 5, the feeding, spreading and scraping integrated unit 400 includes: a scraping drive mechanism, a spreading scraper 404 and n groups of feeding units 405.

The scraping driving mechanism is fixedly arranged above the material box switching driving mechanism and is used for driving the spreading scraping piece 404 and the feeding unit 405 to integrally rotate, so that spreading and scraping are realized.

As a specific implementation, the scraping driving mechanism includes a scraping rotating disc 401, a scraping rotating bearing 402, and a scraping motor 403.

Wherein, the number of the spreading scraping pieces 404, the number of the feeding units 405 and the number of the material boxes 505 are the same, one spreading scraping piece 404, one feeding unit 405 and one material box 505 are in one-to-one correspondence, in the multi-material 3D printing process, the feeding unit 405 feeds the corresponding spreading scraping piece 404, and the spreading scraping piece 404 reciprocates in the material box 505, so as to spread and scrape the material boxes 505. N spreading scraping pieces 404 are fixedly arranged on the outer periphery of the scraping rotary disk 401 in an outward extending manner; each paver scraper 404 is located above a corresponding one of the cartridges 505; each group of feeding units 405 corresponds to one of the paving scraping pieces 404 and is used for independently feeding the paving scraping pieces 404;

the scraping rotary disc 401 is positioned above the rotary disc 501, and a scraping rotary bearing 402 is coaxially arranged between the scraping rotary disc 401 and the rotary disc 501; the scraping rotary bearing 402 adopts an inner ring rotary bearing and an outer ring rotary bearing, the outer ring bearing is fixed with the rotary disc 501, and the inner ring bearing is fixed with the scraping rotary disc 401 and the feeding unit 405; the scraping rotary disk 401 stably rotates during scraping by the supporting effect of the scraping rotary bearing 402, and the scraping rotary disk 401, the spreading scraping piece 404 and the feeding unit 405 synchronously move during scraping, so that the relative positions of the spreading scraping piece 404 and the corresponding feeding unit 405 are unchanged;

a scraping motor 403 is fixedly arranged on the lower coaxial center of the scraping rotary disk 401, and the scraping rotary disk 401 is driven to rotate through the scraping motor 403;

when the scraping rotary disc 401 rotates, the spreading scraping piece 404 and the feeding unit 405 are driven to synchronously rotate to realize scraping; the scraping motor 403 is fixed on the connecting bracket 504 of the rotary switching type material box unit 500, and when the rotary switching type material box unit 500 performs rotary motion, the scraping motor 403, the scraping rotary disk 401, the spreading scraping member 404 and the feeding unit 405 are driven to form integral synchronous motion.

The feeding, spreading and scraping integrated unit 400 provided by the invention also has the following innovative design:

(4.1) Angle limiting sheet 406 and contact switch 407

In the invention, an output shaft of a scraping motor 403 is sleeved with an angle limiting sheet 406, and the angle limiting sheet 406 is of a fan-shaped structure; a contact switch 407 is fixedly installed on the rotation path of the angle limiting piece 406; the forward and reverse rotation angles of the scraping motor 403 are controlled by the cooperation of the angle limiting sheet 406 and the contact switch 407.

Specifically, the angle limiting piece 406 has a fan-shaped structure, and two endpoints of the fan are P1 and P2, respectively. When P1 contacts the contact switch 407, the spreading scraper 404 is located at the left side C1 of the magazine 505; then, the scraping motor 403 rotates and drives the spreading scraping piece 404 and the angle limiting piece 406 to synchronously rotate, and at this time, when the angle limiting piece 406 rotates, the sector arc line of the angle limiting piece 406 continuously contacts with the contact switch 407; the spreading scraper 404 rotates from the left side C1 position to the right side C2 position of the magazine 505;

when P2 of the angle limiting piece 406 contacts the contact switch 407, the paver scraper 404 rotates exactly to the right side C2 position of the magazine 505; then, the scraping motor 403 is triggered to reversely rotate, so that the spreading scraping member 404 rotates from the right side C2 position to the left side C1 position of the magazine 505, and at the same time, the angle limiting piece 406 rotates, so that the P1 end point is continuously close to the contact switch 407, and when the P1 end point contacts the contact switch 407, the spreading scraping member 404 just rotates to the left side C1 position of the magazine 505. This is continuously cycled to effect a reciprocating oscillating motion of the pavement scraper 404 in the magazine 505.

(4.2) the feeding unit 405

Each set of feed units 405 is for feeding a corresponding cartridge 505.

Referring to fig. 5, each set of feed units 405 includes a cartridge 405A, a feed conduit 405B, and a solenoid valve 405C.

The cartridges 405A contain a printing material, and correspond to a cartridge 505, and the cartridges 405A are powered by an external air compressor, and are controlled by a solenoid valve 405C to provide individual feeding of each cartridge 405A, and to deliver the printing material to a doctor blade holder 4041 in the cartridge 505 via a delivery tube 405B.

(4.3) spreading scraper 404

Referring to fig. 6-9, the paver scraper 404 includes: a blade holder 4041, a left blade 4042, and a right blade 4043;

the scraper frame 4041 comprises a scraper cavity 4041A and a scraper arm 4041B which is fixedly integrated with the inner side of the scraper cavity 4041A;

wherein the scraper arm 4041B is used for being fixed with the periphery of the scraping rotary disk 401; in the present invention, as shown in fig. 7, the scraper arm 4041B is formed by three orthogonal planes, and is matched with the mounting groove of the scraping rotary disk 401, and the scraper arm 4041B is placed in the mounting groove and locked and fixed. Therefore, the fixed end of the scraper arm 4041B is composed of three orthogonal planes, and is matched with the mounting groove composed of the three orthogonal planes, so that high repeated positioning accuracy can be realized, the three orthogonal planes are fixed by a single loose screw, complete locking with six degrees of freedom can be realized, and high stability can be realized no matter the scraper for feeding and spreading is used for rotary scraping or linear reciprocating scraping. And the thickness precision of the printing layer is not affected by the cantilever structure formed by single-side fixation.

The scraper cavity 4041A is located in the material box 505, the scraper cavity 4041A is provided with a through type hollow structure cavity, and the length and radian of the scraper cavity 4041A are matched with the inner cavity of the material box 505 and are used for reciprocating rotation along the inner cavity of the material box 505 so as to realize efficient scraping. In addition, the scraper cavity 4041A adopts an optimized open type inclined plane design, so that printing materials can be conveniently supplemented in real time by means of natural gravity in the 3D printing process.

The left side and the right side of the scraper cavity 4041A are respectively provided with a left scraper 4042 and a right scraper 4043 with adjustable heights; the left blade 4042 and the right blade 4043 are spaced from the bottom surface of the blade cavity 4041A by one print layer thickness. Wherein, the lateral wall of both sides scraper and scraper cavity 4041A, the finish machining leans on the face cooperation, has long waist hole to design on the scraper, can realize the fine setting of high accuracy and fix the locking through two screws with the clearance gauge to the realization is scraped the material layer thickness and is different.

The spreading scraping piece provided by the invention has the following advantages:

1) The integrated feeding and spreading integrated scraper is a spreading and scraping piece with double scrapers and scraper cavities for accommodating printing materials, and the traditional feeding and spreading are integrated into spreading and feeding at the same time, so that the spreading and feeding efficiency is improved;

2) The height of the scraper is adjustable, so that scraping materials with different layer thicknesses are realized, and various use requirements are met.

3) The spreading scraping piece and the scraping rotating disc are installed in a matched mode through three orthogonal plane structures, and high stability of the spreading integrated scraper in the process of rotating scraping or linearly reciprocating scraping is guaranteed.

Therefore, the spreading scraping piece provided by the invention is a spreading feeding integrated scraper, can simplify the traditional 3D printing work flow of feeding before spreading into feeding and spreading at the same time, and has a simpler structure.

The design of orthogonal plane cooperation leaning surface makes the installation of supplying and laying integration scraper dismantlement realize high repeated positioning accuracy to guarantee each layer thickness uniformity in the 3D printing process, finally directly guarantee 3D and print finished product precision and structural performance.

The invention can effectively solve the problems of efficiency and printing precision commonly existing in the 3D printing industry at the present stage. The integrated scraper for spreading materials can be fixed by adopting a single loosening-preventing screw, so that high stability and high precision can be realized, and the scraper and the material box after the photo-curing 3D printing is finished can be cleaned conveniently.

(V) cleaning and air drying unit 600:

and (3) whether the cleaning of printing residual materials is complete or not in the 3D printing process of the photo-curing various materials directly influences the quality of a printed product. Especially when the photocuring molding additive is manufactured, most of printing raw materials are in a liquid or paste state. In order to achieve multi-gradient printing of multiple materials, it is necessary to ensure that different printing materials do not contaminate each other during execution of a print job. Each time a material is printed, the printing surface can not have other remnants, so that printing of different materials can be realized at each layer or even at a single pixel level. Traditional cleaning methods can physically damage the surface quality of printed products to some extent or can not thoroughly clean the printed products.

Therefore, the invention designs a cleaning and air-drying unit which is used for multi-material 3D printing, and adopts the modes of ultrasonic cleaning, a tonoplast generator and an air outlet plate to ensure that printing materials cannot be polluted mutually in the execution process of a printing task, thereby ensuring the quality of a printing product.

The cleaning and air drying unit 600 includes: a cleaning unit and an air drying unit;

(5.1) cleaning Unit

Referring to fig. 10, 11 and 12, the cleaning unit includes a cleaning cartridge 601, an ultrasonic generator 602, a bubble generator 603, a self-leveling liquid outlet 604 and a self-leveling liquid return 605;

the outer shape of the cleaning cartridge 601 is the same as that of the cartridge 505, and therefore, switching to the cleaning cartridge 601 is achieved in the same manner as that of the rotational switching of the cartridge 505.

The bottom of the cleaning box 601 is provided with an ultrasonic generator 602;

two sides of the cleaning box 601 are respectively provided with a self-leveling liquid outlet 604 and a self-leveling liquid return port 605; between the self-leveling liquid outlet 604 and the self-leveling liquid return 605, a liquid bubble generator 603 is installed.

The principle is as follows:

the cleaning box 601 is made of a 3D printing nonmetallic material, so that a complex mechanism can be realized, and vibration transmission is reduced.

The self-leveling liquid outlet 604 and the self-leveling liquid return outlet 605 are respectively connected with a peristaltic pump to realize the circulation of cleaning liquid. The circulation mode is as follows: the cleaning fluid is positioned in the liquid container, enters the cleaning box through the self-leveling liquid return port 605 by the peristaltic pump, is pumped out from the self-leveling liquid outlet 604 by the peristaltic pump and is filtered, and finally, the filtered cleaning fluid is returned into the liquid container. Since the self-leveling liquid outlet 604 and the self-leveling liquid return port 605 are designed to be plane self-leveling, the cleaning liquid can flow in and out stably.

The bottom of the cleaning box 601 is provided with an ultrasonic generator 602 which can generate cavitation effect to clean the surface of the printing piece.

Ultrasonic power is not excessive because ultrasonic generator 602 power would cause damage to the printed part structure. Thus, the power of the ultrasonic generator 602 does not uniformly distribute the particle deposition on the liquid surface, and thus, particles in the solution cannot be discharged from the cleaning tank 601 through the self-leveling liquid outlet 604. The invention particularly designs the liquid bubble generator 603 in order to ensure that the residual material particles in the cleaning box 601 can be effectively discharged from the horizontal liquid outlet 604 and filtered, and the cleaning liquid in the cleaning box 601 is clean.

Referring to fig. 12, the tonoplast generator 603 includes a tonoplast generator body 6031, the tonoplast generator body 6031 has a cavity structure, and a surface of the tonoplast generator body 6031 is provided with a plurality of vent holes 6032 communicated with the cavity structure; the back of the liquid bubble generator body 6031 is provided with an air inlet hole 6033 communicated with the cavity structure; the air inlet hole 6033 is connected with an air source.

Through connecting the gas circuit, make gas produce great bubble along the round hole in vacuole generator 603 surface, make the deposit granule evenly distributed in the cleaning box liquid in the liquid surface to get into from the horizontal liquid outlet 604 filtration along with the liquid circulation, thereby guarantee that the washing liquid in the cleaning box keeps good cleaning performance, can work for a long time under the condition of not changing the washing liquid.

In addition, in the invention, a plurality of round holes are designed around the cleaning box and are the overflow tanks 607, so that overflow liquid can be stored, and cleaning liquid is prevented from splashing to other places of the device. The cleaning box is also provided with an overflow hole 608, the overflow hole 608 is slightly higher than the surface of the overflow groove 607 and lower than the upper surface of the outer wall of the cleaning box, when excessive cleaning liquid is caused by some abnormal reasons in the cleaning box, the liquid can enter the overflow hole 608 to trigger the overflow sensor 609, so that the cleaning system is suspended, and the damage or pollution to printing equipment caused by excessive overflow or outflow is avoided.

(5.2) air drying Unit

Referring to fig. 13, the air drying unit includes an air outlet plate 606; referring to fig. 13, the air outlet plate 606 adopts a porous integrated surface air outlet structure, the air outlet plate 606 is horizontally arranged above the cleaning unit, one end of the air outlet plate 606 is an air inlet 606A, and the air inlet 606A is connected with an air source through an air circuit electromagnetic valve; the upper surface of the air outlet plate 606 is provided with a plurality of air outlets 606B; one end of the air outlet plate 606 is fixed with the periphery of the scraping rotary disk 401, and the swing of the air outlet plate 606 is realized under the drive of the scraping rotary disk 401.

The air outlet plate 606 directly blows to the bottom of the printing platform through the air outlet 606B, and drives to swing through the scraping rotary disc 401 in the air outlet process, so that the function of air-drying the printing surface at the bottom of the printing platform is realized.

The air outlet plate is designed to be a porous integrated type surface air outlet structure, so that the problem that the printed piece is physically damaged due to air outlet of a traditional air nozzle is greatly reduced; in addition, the porous inherited surface of the invention has the advantages of air outlet, large air-drying area, and effectively improved air-drying efficiency and effect.

Referring to fig. 10, the cleaning and air drying unit 600 operates according to the following principle:

the surface of the rotary disc 501 is divided into 6 stations, wherein five stations are the material box and one station is the cleaning and air drying unit 600. Each cartridge corresponds to a printing material.

The rotary disc 501 rotates to rotate the corresponding material box of the printing material needed at present to the printing station below the printing platform;

the printing platform descends into a material box, and the printing material with a single layer thickness is solidified to the bottommost surface of the printing platform 202 according to a set shape through the cooperation with the ultraviolet optical unit 300, so that the printing is finished;

the printing platform is lifted and triggers the photoelectric switch to enter a cleaning link:

the rotary disc 501 rotates to move the cleaning box to a printing station below the printing platform;

the printing platform descends into the cleaning box, and the ultrasonic wave and the cleaning liquid in the cleaning box clean the printing residual materials on the bottom surface of the printing platform.

After cleaning, the printing platform is lifted to a certain height above the air outlet plate, the scraping rotary disc 401 drives the air outlet plate 606 to swing, and the air outlet plate 606 reciprocates to air-dry the printing cleaning surface at the bottom of the printing platform.

In the cleaning process, if the program crash movement of the printing platform is uncontrolled, if the program crash movement is in touch with the upper limit and the lower limit, the power-off emergency stop is carried out.

Therefore, the cleaning and air drying unit provided by the invention has the following characteristics:

1) The ultrasonic generator and the vacuole generator are matched to generate low-frequency bubbles, so that particles are uniformly distributed on the surface of the liquid, and then the particles in the solution are discharged from the cleaning box through the self-leveling structure, thereby ensuring the cleaning of the cleaning liquid in the cleaning box and avoiding the cleaning liquid from being polluted;

2) The air outlet plate is designed to be a porous integrated type surface air outlet structure, so that the problem that the printed piece is physically damaged due to air outlet of a traditional air nozzle is greatly reduced; in addition, the porous inherited surface of the invention has the advantages of air outlet, large air-drying area, and effectively improved air-drying efficiency and effect.

The device is reasonable in structural design, high in integration level, convenient to operate and high in practicality. The ultrasonic cleaning, the liquid bubble method generator and the air outlet plate are adopted, so that the liquid bubble generator can ensure that cleaning sediment is not precipitated in the ultrasonic cleaning tank while the cleaning liquid is recycled, and the quality of each cleaning liquid is ensured.

And the air-out of the air-drying plate air-dries the cleaning surface, so that no liquid or residual materials are ensured on the printed piece.

The cleaning device realizes that multiple cleaning modes are integrated at the same position and different heights, reduces the time of the whole cleaning process while realizing superposition of multiple cleaning modes, and improves the working efficiency.

step 1, configuring n groups of feeding units 405 by the multi-material 3D printing equipment, wherein each group of feeding units 405 corresponds to one printing material;

the printing material M (F) required for the current print layer is determined so that a specific feeding unit is selected among the n groups of feeding units 405, expressed as: a specific feeding unit T (F); the specific feeding unit T (F) corresponds to the specific material box H (F) and the specific material spreading scraping piece G (F);

step 2, controlling the rotating motor 503 to drive the rotary disc 501 to rotate, so that the specific material box H (F), the specific material feeding unit T (F) and the specific material spreading scraping piece G (F) are all rotated to a printing station;

meanwhile, on the one hand, the specific feeding unit T (F) is controlled to inject the printing material M (F) into the doctor blade cavity 4041A of the specific blanket-scraping member G (F); on the one hand, the scraping motor 403 is controlled to drive the scraping rotary disc 401 to rotate, so that the specific spreading scraping piece G (F) is driven to reciprocate in the specific material box H (F), the injected printing material M (F) is paved in the movement process of the specific spreading scraping piece G (F), and the thickness is one printing layer thickness, so that feeding and spreading integrated operation is realized;

step 3, after the specific material box H (F) rotates to the printing station and the material spreading in the specific material box H (F) is completed, controlling the printing platform 202 to move downwards until the bottommost surface of the printing platform 202 is a printing layer thickness from the bottom of the specific material box H (F); wherein the bottom of the specific material box H (F) is optical glass;

controlling the ultraviolet optical unit 300 to pass through the optical glass at the bottom of the specific material box H (F) from bottom to top, performing projection curing on the printing material M (F) in the specific material box H (F) according to a set shape, and curing the printing material M (F) with a single layer thickness to the bottommost surface of the printing platform 202 according to the set shape;

step 4, controlling the printing platform 202 to ascend;

the rotary motor 503 is controlled to drive the rotary disc 501 to rotate, so that the cleaning and air drying unit 600 rotates to a printing station;

step 5, controlling the printing platform 202 to descend, so that the solidified material on the bottom surface of the printing platform 202 sinks into the cleaning unit, and performing ultrasonic cleaning on the solidified material on the bottom surface of the printing platform 202 through the cleaning unit;

after the cleaning is finished, the printing platform 202 is controlled to rise to a certain height, so that the solidified material on the bottom surface of the printing platform 202 is positioned above the air drying unit, and the solidified material on the bottom surface of the printing platform 202 is air-dried through the air drying unit;

The structure design is reasonable, the 3D printing process is effectively optimized, the 3D printing automation is realized, the labor cost is greatly reduced, and the labor time is reduced. And the photo-curing 3D printing has strong adaptability and universality in terms of practical use angle of the printing material. The printing product can be applied to related front-edge industries such as aerospace biomedical treatment and the like.

The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which is also intended to be covered by the present invention.

Claims

1. A multi-material 3D printing apparatus, comprising: the device comprises a base (100), a printing platform unit (200), an ultraviolet light unit (300), a feeding, spreading and scraping integrated unit (400), a rotary switching type material box unit (500) and a cleaning and air drying unit (600);

the printing platform unit (200) is fixedly arranged above the base (100); the ultraviolet light unit (300) is fixedly arranged below the base (100); wherein the printing platform unit (200) comprises a platform lifting mechanism (201) and a printing platform (202); the printing platform (202) is driven by the platform lifting mechanism (201) to perform lifting movement; the printing surface of the printing platform (202) and the light emergent direction of the ultraviolet optical unit (300) are coaxially arranged up and down; wherein, platform elevating system (201) is ball screw elevating system, includes: a lifting motor (2011), a screw rod (2012), a sliding block (2013), an upper limit switch (2014) and a lower limit switch (2015);

the screw rod (2012) is vertically arranged; the sliding block (2013) is sleeved on the screw rod (2012); the outside of the sliding block (2013) is fixedly provided with the horizontally arranged printing platform (202); the lifting motor (2011) is used for driving the screw rod (2012) to rotate; the upper limit switch (2014) and the lower limit switch (2015) are respectively arranged at the upper limit position and the lower limit position of the sliding block (2013) in a sliding way;

the number of the spreading scraping pieces (404) is the same as the number of the material boxes (505),

-each of said spreading scrapers (404) is located above a corresponding one of said cartridges (505); each group of feeding units (405) corresponds to one of the spreading scrapers (404) and is used for independently feeding the spreading scrapers (404);

the scraping driving mechanism is fixedly arranged above the material box switching driving mechanism and is used for driving the spreading scraping piece (404) and the feeding unit (405) to integrally rotate, so that spreading and scraping are realized;

the scraping driving mechanism comprises a scraping rotating disc (401), a scraping rotating bearing (402) and a scraping motor (403); an output shaft of the scraping motor (403) is sleeved with an angle limiting sheet (406), and the angle limiting sheet (406) is of a fan-shaped structure; a contact switch (407) is fixedly arranged on the rotating path of the angle limiting sheet (406); and the forward and reverse rotation angles of the scraping motor (403) are controlled through the cooperation of the angle limiting sheet (406) and the contact switch (407).

2. The multi-material 3D printing apparatus according to claim 1, wherein the purge air drying unit (600) integrates a purge unit and an air drying unit.

3. A printing method of a multi-material 3D printing device according to any one of claims 1-2, comprising the steps of:

the printing material required for the current print layer is determined such that a particular feed unit is selected among the n groups of feed units (405), denoted as: a specific feed unit; the specific feeding unit corresponds to the specific material box and the specific spreading scraping piece;

step 2, controlling the material box switching driving mechanism to move so that the specific material box, the specific material feeding unit and the specific material spreading scraping piece all rotate to the printing station;

meanwhile, on one hand, controlling the specific feeding unit to inject printing materials into the scraper cavity (4041A) of the specific spreading scraper; on one hand, the scraping driving mechanism is controlled to move so as to drive the specific spreading scraping piece to reciprocate in the specific material box, and in the moving process of the specific spreading scraping piece, the injected printing material is paved, and the thickness is one printing layer thickness, so that feeding and spreading integrated operation is realized;

step 3, after the specific material box rotates to a printing station and the material spreading in the specific material box is completed, controlling the printing platform (202) to move downwards until the bottommost surface of the printing platform (202) is a printing layer thickness from the bottom of the specific material box; wherein the bottom of the specific material box is optical glass;

controlling an ultraviolet optical unit (300) to penetrate through optical glass at the bottom of a specific material box from bottom to top, and carrying out projection curing on printing materials in the specific material box according to a set shape, so that the printing materials with single layer thickness are cured to the bottommost surface of a printing platform (202) according to the set shape;

step 4, controlling the printing platform (202) to ascend;

and 6, returning to the step 1, determining the printing materials needed to be used for the same layer or the next printing layer, and performing cyclic printing to obtain parts which are made of different layers or the same layer and are made of a plurality of printing materials.