CN107244066B

CN107244066B - Multi-material deposition head for deposition system

Info

Publication number: CN107244066B
Application number: CN201710602350.9A
Authority: CN
Inventors: 金国庆; 胡兵兵; 陈涛; 杨湛; 孙立宁
Original assignee: Suzhou University
Current assignee: Suzhou University
Priority date: 2017-07-21
Filing date: 2017-07-21
Publication date: 2023-05-23
Anticipated expiration: 2037-07-21
Also published as: CN107244066A

Abstract

The invention discloses a multi-material deposition head for a deposition system, which comprises a plurality of nozzles, a material deposition pipeline connected with the nozzles and a material feeding pipeline connected with the material deposition pipeline, wherein the material deposition pipeline comprises a top cover component positioned at the top of the material deposition pipeline, a pressing plate component positioned at the middle position of the material deposition pipeline and a deposition control component positioned below the material deposition pipeline, and the material deposition pipeline is divided into a sealing pressure chamber and a material storage chamber by the top cover component, the pressing plate component and the deposition control component. The invention can rapidly and stably realize the feeding of external materials and can realize the accurate control and deposition of the materials.

Description

Multi-material deposition head for deposition system

Technical Field

The invention relates to the technical field of 3D printing, in particular to a multi-material deposition head for a deposition system.

Background

Currently, 3D printing technology has been accepted by most people and many designs and studies have been developed. Most RP & M systems so far have been fabricated using only a single build material, and accuracy, repeatability and reliability issues have been difficult to guarantee exactly.

Research gap analysis and current ongoing research in the commercial market clearly indicate that a multi-material RP & M system is needed. While there is no viable solution available in the commercial market for RP & M for multi-material fabrication, research currently being conducted in this area focuses on developing multi-material deposition apparatus that can be used to deposit two materials or to deposit FGM materials. At present, there have been some progress in the field of multi-material fabrication of objects of two build materials at home and abroad, however, there is no multi-material deposition head designed for depositing more than two build materials at present, due to the need to rapidly and stably achieve feeding of external materials, and precise control and deposition of materials.

Accordingly, in view of the above-described problems, it is desirable to provide a multi-material deposition head for a deposition system.

Disclosure of Invention

In view of the above, it is an object of the present invention to provide a multi-material deposition head for a deposition system, which can rapidly and stably achieve feeding of an external material and can achieve precise control and deposition of the material.

In order to achieve the above object, the technical solution provided by the embodiments of the present invention is as follows:

a multi-material deposition head for a deposition system, the multi-material deposition head comprising a plurality of nozzles, a material deposition conduit connected to the nozzles, and a material feed conduit connected to the material deposition conduit, the material deposition conduit comprising a top cap assembly positioned on top of the material deposition conduit, a platen assembly positioned intermediate the material deposition conduit, and a deposition control assembly positioned below the material deposition conduit, the material deposition conduit being divided into a sealed pressure chamber and a material storage chamber by the top cap assembly, the platen assembly, and the deposition control assembly.

As a further improvement of the invention, the top cover assembly comprises a top cover body, a rubber pad positioned below the top cover body, and a material pipeline and an air pressure pipeline positioned below the top cover body and the rubber pad, wherein the top cover body and the rubber pad are provided with a first through hole and a second through hole which are respectively used for communicating the material pipeline and the air pressure pipeline.

As a further improvement of the present invention, each component in the cap assembly is a rubber member.

As a further improvement of the invention, the pressure plate assembly comprises a pressure plate main body, a rubber pressure plate embedded in the pressure plate main body, and a hanging door assembly positioned below the rubber pressure plate and embedded in the pressure plate main body.

As a further improvement of the present invention, the hanger assembly may include a hanger housing and a hanger, the hanger being closable in accordance with a pressure exerted by the material in the sealed pressure chamber and a reverse pressure of the material storage chamber.

As a further improvement of the present invention, the platen assembly further includes a material access door that opens during feeding and closes when pressure is applied to the platen assembly.

As a further improvement of the invention, the deposition control assembly is characterized by comprising a housing cover, a body, an electromagnet mounted on the side of the body, and a deposition trigger and a spring mounted in the body below the housing cover.

As a further improvement of the invention, the invention is characterized in that the housing cover, the body and the deposition trigger are provided with a plurality of corresponding material inlets, the material inlets on the housing cover and the body are always in an aligned state, and the material deposition is controlled by controlling the state of the material inlets of the deposition trigger.

As a further improvement of the present invention, the deposition control assembly includes:

a first state in which the spring pushes the deposition trigger away from the material inlet of the body when the electromagnet is not activated;

in a second state, when the electromagnet is activated, the deposition trigger moves toward the electromagnet, and during the movement, the material inlet holes on the deposition trigger align with the material inlet holes on the housing cover and the body for material deposition.

As a further improvement of the present invention, the material deposited by the multi-material deposition head is a photopolymer resin.

The beneficial effects of the invention are as follows:

the invention is provided with the unique pressing plate component, so that the feeding of external materials can be realized rapidly and stably;

the present invention provides a deposition control assembly consisting of an electromagnet system that, when activated, can deposit material continuously or in droplet formation, enabling precise control and deposition of the material.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present invention, and other drawings may be obtained according to the drawings without inventive effort to those skilled in the art.

FIG. 1 is a schematic perspective view of a multi-material nozzle deposition system according to an embodiment of the present invention;

FIG. 2 is a schematic side view of a material deposition conduit according to an embodiment of the present invention;

FIGS. 3a and 3b are schematic perspective views and schematic exploded views, respectively, of a top cap assembly according to an embodiment of the present invention;

FIG. 3c is a schematic perspective view of a pressure plate assembly according to an embodiment of the present invention;

FIG. 3d is a schematic perspective view of a deposition control assembly according to an embodiment of the present invention;

FIGS. 4a and 4b are schematic views illustrating the closing and opening of a swing door according to an embodiment of the present invention;

FIG. 4c is a schematic diagram of a door control without pressure applied by material in accordance with one embodiment of the present invention;

FIGS. 5a and 5b are schematic views of curing using a first UV light source and a second UV light source, respectively, in accordance with the present invention;

FIG. 6a is a schematic illustration of deposition of more than two materials in the same layer in an embodiment of the present invention;

fig. 6b and 6c are schematic diagrams of curing the deposited layer of fig. 6a using a first UV light source and a second UV light source, respectively.

Detailed Description

In order to make the technical solution of the present invention better understood by those skilled in the art, the technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.

Referring to fig. 1, in one embodiment of the present invention, a multi-material nozzle deposition system is disclosed, which includes a multi-material deposition head 10 integrated with a plurality of nozzles, a nozzle rotation device 20 connected to the multi-material deposition head and used to drive the nozzles to rotate, and a UV light source for curing the material.

The multi-material deposition head 10 comprises a plurality of nozzles 11, material deposition pipelines 12 connected with the nozzles 11 and material feeding pipelines 13 connected with the material deposition pipelines 12, wherein the nozzles 11 are positioned above a deposition platform 15, a rotary platform 16 is arranged right above the deposition platform 15, a plurality of mounting holes (not numbered) are formed in the rotary platform 16 to fixedly mount each material deposition pipeline 12, and the material feeding pipelines 13 are connected with the material deposition pipelines 12 in a communicating manner so as to feed deposited materials to the material deposition pipelines 12. Preferably, the nozzles 11, the material deposition pipes 12, and the material feed pipes 13 in the present invention are installed in a one-to-one correspondence to form respective passages for material deposition.

In the preferred embodiment of the present invention, 7 nozzles 11, 7 material deposition pipes 12 and 7 material feeding pipes 13 are taken as examples, the 7 nozzles 11 are uniformly distributed above the deposition platform 15 at equal intervals in circumference, and 7 mounting holes are formed in the rotation platform 16 at equal intervals in circumference for correspondingly mounting the 7 material deposition pipes 12. Two or more multi-material parts can be printed by 7 nozzles. Preferably, the material deposited by the multi-material nozzle deposition system is a photopolymer resin, although other UV capable materials may be used in other embodiments.

It should be understood that in other embodiments, the number of nozzles, material deposition conduits, and material feed conduits may be set to 2 or more, and other numbers of nozzles, material deposition conduits, and material feed conduits may be similarly arranged in a one-to-one correspondence, i.e., two or more multi-material components may be printed. The arrangement of the nozzles above the deposition platform and the arrangement of the mounting holes on the rotary platform may also be other uniform or non-uniform arrangements, and are not limited to the uniform distribution of the circumference in the present embodiment, and will not be illustrated here.

As shown in connection with fig. 2 and 3a to 3d, the material deposition tube 12 in this embodiment includes a top cap assembly 121 positioned at the top of the material deposition tube, a platen assembly 122 positioned at a middle position of the material deposition tube, and a deposition control assembly 123 positioned under the material deposition tube.

Specifically, the material deposition tube 12 is divided into a sealed pressure chamber 1201 and a material storage chamber 1202 by the above-described components. The upper end of the sealing pressure chamber 1201 is composed of three rubber sealing elements to form a buckle combined top cover assembly 121 with material and air pressure pipelines, a multipurpose pressing plate assembly 122 is arranged between the sealing pressure chamber 1201 and a material storage chamber 1202, and a deposition control assembly 123 is arranged at the lower end of the material storage chamber 1202 close to a nozzle.

Referring to fig. 2 in combination with fig. 3a and 3b, the cap assembly 121 includes a cap body 1211, a rubber mat 1212 positioned below the cap body 1211, and a material pipe 1213 and a pneumatic pipe 1214 positioned below the cap body 1211 and the rubber mat 1212, wherein the cap body 1211 and the rubber mat 1212 are provided with a first through hole 1215 and a second through hole 1216 for communicating the material pipe 1213 and the pneumatic pipe 1214, respectively. Each component of the cap assembly 121 is a rubber member, and air tightness above the seal pressure chamber 1201 can be ensured.

Referring to fig. 2 in combination with fig. 3c and 4a to 4c, the material deposition tube 12 may be divided into a sealed pressure chamber 1201 and a material storage chamber 1202 by a platen assembly 122, and the platen assembly 122 may include a platen body 1221, a rubber platen 1222 embedded in the platen body 1221, and a door assembly located below the rubber platen 1222 and embedded in the platen body 1221, and the door assembly may include a door housing (not shown) and a door 1223, and the door 1223 may be closed according to a pressure applied by a material in the sealed pressure chamber 1201 and a reverse pressure of the material storage chamber 1202.

Referring to fig. 4a, when the pressure exerted by the material does not reach the pressure threshold at which the door 1223 opens, the door 1223 is in a closed state; referring to fig. 4b, when the pressure exerted by the material reaches a pressure threshold at which the door 1223 opens, the door 1223 is in an open state. Referring to fig. 4c, when there is no pressure applied by the material, the state of the hanging door 1223 is determined by the air pressure in the sealed pressure chamber 1201 and the reverse pressure of the material storage chamber 1202, and when the reverse pressure of the material storage chamber 1202 is greater than the air pressure in the sealed pressure chamber 1201, the hanging door 1223 is in a closed state, whereas the hanging door 1223 is in an open state.

Further, the platen assembly 122 also includes a material access door that is opened during the feeding process and that closes when pressure is applied to the platen assembly.

Referring to fig. 2 in combination with fig. 3d, the deposition control assembly 123 in this embodiment is comprised of an electromagnet system that, when activated, can deposit material continuously or in droplet formation. Specifically, the deposition control assembly 123 includes a housing cover 1231, a body 1232, an electromagnet 1233 mounted to a side of the body 1232, and a deposition trigger (not shown) and a spring (not shown) mounted within the body 1232 below the housing cover 1231. The housing cover 1231, the body 1232 and the deposition trigger are provided with a plurality of corresponding material inlets, the material inlets on the housing cover 1231 and the body 1232 are always in an aligned state, and the material deposition is controlled by controlling the state of the material inlets of the deposition trigger.

The deposition control assembly 123 operates on the principle:

when the electromagnet 1233 is not activated, the spring pushes the deposition trigger away from the material inlet of the body 1232; when the electromagnet 1233 is activated, the deposition trigger moves toward the electromagnet 1233, during which the material inlet holes on the deposition trigger align with the material inlet holes on the housing cover 1231 and the body 1232 for material deposition.

It should be understood that the multi-material deposition head in this embodiment is described by way of example as applied to a multi-material nozzle deposition system, and of course, in other embodiments, the multi-material deposition head may be applied to other nozzle deposition systems as well, and will not be described in detail herein by way of example.

Referring to fig. 1, the nozzle rotating device 20 in this embodiment includes a servo motor 21 and a rotating belt 22, the servo motor 21 is connected to the side of the rotating platform 16 integrated with a plurality of nozzles through the rotating belt 22, the servo motor 21 can rotate the rotating platform 16 and the nozzles clockwise or anticlockwise, the maximum rotation angle is 180 degrees to control the positions of the nozzles, and a matching algorithm is designed to control the operation of the servo motor to realize the ordered printing task of the multi-material component.

Referring to fig. 1 in combination with fig. 5a and 5b, the UV light source in this embodiment includes a first UV light source 31 connected to the outside of the deposition control assembly 123 and a second UV light source 32 integrated on the deposition control assembly 123. The first UV light source 31 is a main UV light source, and is used for immediately solidifying a large amount of material volume, so that the solidification rate of the material can be increased, and the printing speed can be increased; the second UV light source 32 is a UV point light source provided by a UV lamp integrated in the deposition control assembly 123 for precisely curing the small volume deposition to accelerate the curing process by aiming the curing source at a specific material volume.

The deposition system is a multi-material nozzle deposition system based on SLA, which is provided with a matched deposition control method, and specifically comprises the following steps:

firstly, adopting a direct slicing algorithm technology, and combining all parts of a shear layer together by calculating a starting point and an ending point of each slice;

after finding the sequence of segments, generating a closed NURBS curve representing the profile of the cut layer based on the Open CASCADEs basis;

and then controlling the position of the multi-material deposition head through a nozzle rotating device according to the outline of each cutting layer, and carrying out multi-material deposition and UV curing.

The specific steps of the multi-material nozzle deposition system for material deposition in this embodiment are as follows:

1. the feed device is turned on to begin delivering material from the feed chute pump to the material storage chamber via the material feed conduit. Each material feed conduit is dedicated to a particular material and has one end connected to a material source tank and the other end connected to a platen assembly. The feeding device pumps material by means of a crankshaft connected to a dedicated pump, and is closed when the material storage chamber is full.

2. After the material storage chamber of each nozzle is filled with the desired materials and support materials, the deposition apparatus starts the deposition process. The air compressor is turned on and a constant pressure on the platen assembly is maintained. The pressure required for each nozzle needs to be controlled and can be calculated using the following formula derived from Poiseulle's law:

where P is the nozzle pressure, V is the deposition flow rate, η is the efficiency, l is the nozzle length, t is the unit time, and r is the nozzle diameter. The deposition flow rate is controlled by the pressure applied to the pressure assembly, and the pressure of each nozzle is dependent on the material properties and geometry of the nozzle tip. Thus, the pressure of each nozzle is adjusted according to the desired flow rate.

3. The first deposition is performed by moving the Z-axis close to the nozzle deposition system. The motion of the Z axis is controlled by a servo motor that can move the Z axis up or down.

4. For a first deposition conditioning nozzle arrangement, the desired material nozzle is first selected, seven nozzles are mounted on a rotating disk connected to a servo motor that can rotate the nozzle 180 ° clockwise and counterclockwise.

5. After adjusting the Z-axis, deposition control is performed and the nozzle is selected for a first deposition of material for continuous deposition or sedimentation deposition. When a material tool path is defined during the pre-treatment, deposition control actuation is predefined. Deposition control allows for precise control of the amount of material deposited, it is important to know that the flow is controlled by the pressure applied by the pressure plate, whereas the deposition pattern (continuous or falling) is controlled by the deposition control assembly. For quality and precision, both the pressure mechanism and deposition control need to be perfectly coordinated.

6. The material deposition process is followed by a curing process that is completed layer by layer. However, when multiple layers of materials are deposited, each material in the layers needs to be cured. The material curing process may be accomplished by using a primary UV light source or UV point light source, depending on the amount, geometry, and area of material to be cured. When multiple materials are deposited in small amounts and more frequently, different materials will require different UV light intensities depending on the material properties and photoinitiator intensities, so it is not possible to cure using a primary UV light source, and thus a UV point light source is used. UV point source processing is slower than the primary UV source, but more accurate and easy to control.

Referring to fig. 6a, when more than two materials are deposited in the same layer, it is not possible to cure using the first UV light source 31 in fig. 6b as the (primary UV light source) since different materials will require different UV light intensities to cure. In this case, the primary UV light source curing may cause the material to overcure while curing another material under the same layer, which would create geometric defects to the cured layer. To address this problem, as shown in fig. 6c, a second UV light source 32 (UV point light source) may be used, which may be an integrated UV spotlight, which may increase the time of the curing process, but may provide better control and accuracy when curing multiple materials in the same layer. As the first layer cures, the Z-axis moves downward, allowing the next layer to begin deposition and repeating the cycle until all of the object's deposition cure is complete.

The technical scheme shows that the invention has the following beneficial effects:

1. the invention can deposit more than two construction materials and print parts of more than two materials;

2. the servo motor is arranged to drive the nozzle to rotate, so that the accurate printing of the multi-material parts can be realized;

3. the invention is provided with the unique pressing plate component, so that the feeding of external materials can be realized rapidly and stably;

4. the invention provides a deposition control assembly consisting of an electromagnet system that, when activated, can deposit material continuously or in droplet formation, enabling precise control and deposition of the material;

5. the first UV light source is arranged on the outer side of the printing nozzle, so that the large-volume solidification of materials can be realized, and the printing speed is improved; a second UV light source is integrated on the deposition control assembly to form a UV spot for precision curing of small volume deposition to accelerate the curing process by aiming the curing source at a specific material volume to improve print quality.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in detail below, and that the embodiments described in the examples may be combined as appropriate to form other embodiments that will be apparent to those skilled in the art.

Claims

1. A multi-material deposition head for a deposition system, the multi-material deposition head comprising a plurality of nozzles, a material deposition tube connected to the nozzles, and a material feed tube connected to the material deposition tube, the material deposition tube comprising a top cap assembly positioned on top of the material deposition tube, a platen assembly positioned in a middle position of the material deposition tube, and a deposition control assembly positioned below the material deposition tube, the material deposition tube being divided into a sealed pressure chamber and a material storage chamber by the top cap assembly, the platen assembly, and the deposition control assembly;

the upper end of the sealing pressure chamber is formed by three rubber sealing pieces to form a buckle combined top cover assembly with a material and an air pressure pipeline, a multipurpose pressing plate assembly is arranged between the sealing pressure chamber and the material storage chamber, and a deposition control assembly is arranged at the lower end of the material storage chamber close to the nozzle;

the top cover assembly comprises a top cover body, a rubber pad positioned below the top cover body, and a material pipeline and an air pressure pipeline positioned below the top cover body and the rubber pad, wherein the top cover body and the rubber pad are provided with a first through hole and a second through hole which are respectively used for communicating the material pipeline and the air pressure pipeline;

the pressing plate assembly comprises a pressing plate main body, a rubber pressing plate embedded in the pressing plate main body and a hanging door assembly positioned below the rubber pressing plate and embedded in the pressing plate main body;

the door assembly comprises a door shell and a door, wherein the door is closed according to the pressure exerted by the materials in the sealed pressure chamber and the reverse pressure of the material storage chamber.

2. The multi-material deposition head for a deposition system of claim 1, wherein each component of the top cap assembly is a rubber piece.

3. The multi-material deposition head for a deposition system of claim 1, wherein the platen assembly further comprises a material access door that is opened during feeding and that closes when pressure is applied to the platen assembly.

4. The multi-material deposition head for a deposition system of claim 1, wherein the deposition control assembly comprises a housing cover, a body, an electromagnet mounted to a side of the body, and a deposition trigger and spring mounted within the body below the housing cover.

5. The multi-material deposition head for a deposition system of claim 4, wherein the housing cover, the body, and the deposition trigger are provided with a plurality of corresponding material inlets, the material inlets on the housing cover and the body being always in a state thereof, and the material deposition being controlled by controlling the state of the material inlets of the deposition trigger.

6. The multi-material deposition head for a deposition system of claim 5, wherein the deposition control assembly comprises:

7. The multi-material deposition head for a deposition system of claim 1, wherein the material deposited by the multi-material deposition head is a photopolymer resin.