CN107234808B - A multi-material nozzle deposition system and deposition method - Google Patents

Abstract

The invention discloses a multi-material nozzle deposition system. The system includes a multi-material deposition head integrated with a plurality of nozzles, a nozzle rotation device connected with the multi-material deposition head and used to drive the nozzles to rotate, and a UV lamp for curing materials. A light source, the multi-material deposition head includes several nozzles, material deposition pipelines connected to the nozzles, and material feeding pipelines connected to the material deposition pipelines, the nozzles, material deposition pipelines, and material feeding pipelines are installed in one-to-one correspondence, so that Channels for material deposition are respectively formed. The invention can deposit more than two building materials, and has high printing speed, high precision and good quality.

Description

A multi-material nozzle deposition system and deposition method

technical field

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

Background technique

At present, 3D printing technology has been accepted by most people, and a lot of design and research have been carried out. But so far, most RP&M systems can only be made with a single construction material, and the accuracy, repeatability and reliability are difficult to be guaranteed.

A research gap analysis of the commercial market and currently ongoing research clearly shows the need for multi-material RP&M systems. While there are no viable solutions in the commercial market for RP&M for multi-material manufacturing, current research in this area is focused on developing multi-material deposition equipment that can be used to deposit two materials or to deposit FGM materials. At present, some progress has been made in the field of multi-material manufacturing of objects with two construction materials at home and abroad, however, there is no deposition equipment designed to deposit more than two construction materials.

Therefore, in view of the above technical problems, it is necessary to provide a multi-material nozzle deposition system and deposition method.

Contents of the invention

In view of this, the purpose of the present invention is to provide a multi-material nozzle deposition system and deposition method, which can deposit more than two building materials, and has high printing speed, high precision and good quality.

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

A multi-material nozzle deposition system, the system includes a multi-material deposition head integrated with multiple nozzles, a nozzle rotation device connected to the multi-material deposition head and used to drive the nozzles to rotate, and a UV light source for curing materials, the The multi-material deposition head includes several nozzles, material deposition pipes connected to the nozzles, and material feed pipes connected to the material deposition pipes. The nozzles, material deposition pipes, and material feed pipes are installed in one-to-one correspondence to form each channels for material deposition.

As a further improvement of the present invention, the system also includes a deposition platform, and a rotating platform located above the deposition platform, the nozzle is located above the deposition platform, and several mounting holes are provided on the rotating platform for fixedly installing various material deposition pipelines.

As a further improvement of the present invention, the nozzles are evenly distributed above the deposition platform in a circular equidistant manner, and a number of equidistant circumferential mounting holes are provided on the rotating platform for correspondingly installing the material deposition pipelines.

As a further improvement of the present invention, the multi-material deposition head includes 7 nozzles, 7 material deposition pipes and 7 material feed pipes.

As a further improvement of the present invention, the nozzle rotating device includes a servo motor and a rotating belt, and the servo motor is connected to the side of the rotating platform integrated with several nozzles through the rotating belt.

As a further improvement of the present invention, the servo motor rotates the rotary platform clockwise or counterclockwise, and the maximum rotation angle of the rotary platform clockwise or counterclockwise is 180 degrees to control the position of the nozzle.

As a further improvement of the present invention, the UV light source includes a first UV light source connected to the outside of the material deposition pipeline and a second UV light source integrated on the material deposition pipeline.

As a further improvement of the present invention, the first UV light source is the main UV light source, which is used to immediately cure a large amount of material volume; the second UV light source 32 is a UV point light source, which is provided by the UV spotlight integrated in the deposition control assembly, for accurate Cures small volume deposits.

Correspondingly, a deposition method of a multi-material nozzle deposition system, the multi-material nozzle deposition system is an SLA-based multi-material nozzle deposition system, the deposition method specifically includes:

First use the direct slicing algorithm technique to combine all the parts of the clipped layer together by calculating the start and end points of each slice;

After finding the sequence of segments, generate a closed NURBS curve to represent the outline of the cutting layer based on the Open CASCADE foundation;

Then, according to the contour of each cutting layer, the position of the multi-material deposition head is controlled by the nozzle rotating device, and multi-material deposition and UV curing are performed.

As a further improvement of the present invention, the deposition method also includes:

控制每个喷嘴所需的压力，其中，P为喷嘴的压力，V为沉积流速，η为效率，l为喷嘴长度，t为单位时间，r为喷嘴直径。According to the formula

Control the pressure required for each nozzle, where P is the pressure of the nozzle, V is the deposition flow rate, η is the efficiency, l is the length of the nozzle, t is the unit time, and r is the diameter of the nozzle.

The beneficial effects of the present invention are:

The invention can deposit more than two build materials and can print parts with more than two materials;

The invention sets the servo motor to drive the nozzle to rotate, which can realize the accurate printing of multi-material parts;

In the present invention, a first UV light source is provided outside the printing nozzle, which can realize large-volume curing of materials and increase printing speed; a second UV light source is integrated on the deposition control component, which can form UV spots for precise curing of small-volume deposition. To speed up the curing process and improve print quality by targeting the curing source at a specific material volume.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments described in the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a three-dimensional structural schematic diagram of a multi-material nozzle deposition system in a specific embodiment of the present invention;

Fig. 2 is a side view structural schematic diagram of a material deposition pipeline in a specific embodiment of the present invention;

3a and 3b are respectively a three-dimensional structural schematic view and an explosive structural schematic view of the top cover assembly in a specific embodiment of the present invention;

Fig. 3c is a schematic diagram of the three-dimensional structure of the platen assembly in a specific embodiment of the present invention;

Fig. 3d is a three-dimensional structural schematic diagram of a deposition control component in a specific embodiment of the present invention;

Figures 4a and 4b are schematic diagrams of the closing and opening of the hanging door in a specific embodiment of the present invention, respectively;

Fig. 4c is a schematic diagram of the control principle of the hanging door when there is no pressure exerted by the material in a specific embodiment of the present invention;

Figures 5a and 5b are respectively the curing schematic diagrams using the first UV light source and the second UV light source in the present invention;

Figure 6a is a schematic diagram of the deposition of more than two materials deposited in the same layer in one embodiment of the present invention;

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

Detailed ways

In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described The embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

As shown in FIG. 1 , a specific embodiment of the present invention discloses a multi-material nozzle deposition system, which includes a multi-material deposition head 10 integrated with multiple nozzles, a nozzle connected to the multi-material deposition head and used to drive the nozzles to rotate A rotating device 20, and a UV light source for curing the material.

Multi-material deposition head 10 among the present invention comprises several nozzles 11, the material deposition pipeline 12 that is connected with nozzle 11 and the material feeding pipeline 13 that is connected with material deposition pipeline 12, and nozzle 11 is positioned at the top of deposition platform 15, and deposition platform 15 A rotating platform 16 is provided directly above, and a number of mounting holes (not labeled) are provided on the rotating platform 16 to fix and install each material deposition pipeline 12. Feed of deposition material. Preferably, the nozzle 11, the material deposition pipeline 12, and the material feeding pipeline 13 in the present invention are installed in a one-to-one correspondence, so as to respectively form channels for material deposition.

In the preferred embodiment of the present invention, 7 nozzles 11, 7 material deposition pipelines 12 and 7 material feeding pipelines 13 are taken as examples for illustration. The 7 nozzles 11 are evenly distributed above the deposition platform 15 in a circular equidistant manner, and the rotating platform The 16 is provided with 7 installation holes uniformly distributed in a circular equidistant manner for correspondingly installing the 7 material deposition pipelines 12 . With 7 nozzles, two or more multi-material parts can be printed. Preferably, the material deposited by the multi-material nozzle deposition system is photopolymer resin, of course, other materials capable of UV can also be used in other embodiments.

It should be understood that in other embodiments, the number of nozzles, material deposition pipes, and material feed pipes can be set to 2 or more than 2, and the number of nozzles, material deposition pipes, and material feed pipes is also one. With one corresponding setting, two or more multi-material parts can be printed. The arrangement of the nozzles above the deposition platform and the arrangement of the installation holes on the rotating platform can also adopt other uniform or non-uniform arrangements, not limited to the uniform distribution of the circumference in this embodiment, which will not be repeated here. Give examples one by one.

As shown in FIG. 2 and FIGS. 3a to 3d, the material deposition pipeline 12 in this embodiment includes a top cover assembly 121 located on the top of the material deposition pipeline, a platen assembly 122 located in the middle of the material deposition pipeline, and a cover assembly 122 located below the material deposition pipeline. Deposition Control Assembly 123 .

Specifically, the material deposition pipeline 12 is divided into a sealed pressure chamber 1201 and a material storage chamber 1202 by the above components. The upper end of the sealed pressure chamber 1201 is composed of three rubber seals to form a buckle combined top cover assembly 121 with materials and air pressure pipes. A multi-purpose pressure plate assembly 122 is arranged between the sealed pressure chamber 1201 and the material storage chamber 1202. The material A deposition control component 123 is provided at the lower end of the storage chamber 1202 near the nozzle.

Referring to FIG. 2 and shown in conjunction with 3a and 3b, the top cover assembly 121 includes a top cover body 1211, a rubber pad 1212 located under the top cover body 1211, and a material pipeline 1213 and an air pressure pipeline located under the top cover body 1211 and the rubber pad 1212. 1214 , the top cover body 1211 and the rubber pad 1212 are provided with a first through hole 1215 and a second through hole 1216 for communicating with the material pipeline 1213 and the air pressure pipeline 1214 respectively. All parts of the top cover assembly 121 are rubber parts, which can ensure the airtightness above the sealed pressure chamber 1201 .

Referring to Fig. 2 and shown in Fig. 3c and Figs. 4a-4c, the material deposition pipeline 12 can be divided into a sealed pressure chamber 1201 and a material storage chamber 1202 through the press plate assembly 122. The press plate assembly 122 includes a press plate main body 1221, embedded in the press plate main body The rubber pressing plate 1222 in 1221, the hanging door assembly located under the rubber pressing plate 1222 and embedded in the pressing plate main body 1221, the hanging door assembly can include the hanging door shell (not shown) and the hanging door 1223, the hanging door 1223 can be sealed according to the sealing pressure The pressure exerted by the material in the chamber 1201 and the counter pressure of the material storage chamber 1202 closes.

As shown in Figure 4a, when the pressure applied by the material does not reach the pressure threshold for opening the hanging door 1223, the hanging door 1223 is in a closed state; referring to Figure 4b, when the pressure applied by the material reaches the pressure threshold for opening the hanging door 1223, The hanging door 1223 is in an open state. As shown in Figure 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, when the reverse pressure of the material storage chamber 1202 is greater than the sealed When the air pressure in the pressure chamber 1201 is high, the hanging door 1223 is in a closed state, otherwise, the hanging door 1223 is in an open state.

Further, the platen assembly 122 also includes a material access door that is opened during feeding, and is closed when pressure is exerted on the platen assembly.

Referring to Figure 2 in conjunction with Figure 3d, the deposition control assembly 123 in this embodiment consists of an electromagnet system that, when activated, deposits material either continuously or in droplet formation. Specifically, the deposition control assembly 123 includes a housing cover 1231, a body 1232, an electromagnet 1233 installed on the side of the body 1232, and a deposition trigger (not shown) and a spring (not shown) installed in the body 1232 below the housing cover 1231 Show). The casing cover 1231, the body 1232 and the deposition trigger are provided with a number of corresponding material inlet holes. The material inlet holes on the casing cover 1231 and the body 1232 are always in alignment, and the material inlet holes are controlled by controlling the state of the deposition trigger material inlet holes. deposition.

The working principle of deposition control assembly 123 is:

When the electromagnet 1233 is not activated, the spring pushes the deposition trigger away from the material inlet hole of the body 1232; when the electromagnet 1233 is activated, the deposition trigger moves toward the electromagnet 1233, and during the movement, the deposition trigger The material inlet holes of the housing cover 1231 and the material inlet holes on the body 1232 are aligned for material deposition.

It should be understood that the multi-material deposition head in this embodiment is described as being applied to a multi-material nozzle deposition system as an example. Of course, in other embodiments, the multi-material deposition head can also be applied to other nozzle deposition systems. No more examples will be given in detail.

As shown in 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 several nozzles through the rotating belt 22, the servo motor 21 can be Rotate the rotating platform 16 and the nozzle clockwise or counterclockwise, the maximum rotation angle is 180 degrees to control the position of the nozzle, and a supporting algorithm is designed to control the operation of the servo motor to achieve the orderly printing task of multi-material parts.

Referring to FIG. 1 and shown in conjunction with FIGS. 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 . Among them, the first UV light source 31 is the main UV light source, which is used to immediately cure a large amount of material volume, which can accelerate the curing rate of the material and improve the printing speed; Spotlights are provided for precise curing of small volume deposits to speed up the curing process by targeting the curing source to specific material volumes.

The deposition system in the present invention is based on the SLA type multi-material nozzle deposition system, which is provided with a supporting deposition control method, specifically:

First use the direct slicing algorithm technique to combine all the parts of the clipped layer together by calculating the start and end points of each slice;

After finding the sequence of segments, generate a closed NURBS curve to represent the outline of the cutting layer based on the Open CASCADE foundation;

Then, according to the contour of each cutting layer, the position of the multi-material deposition head is controlled by the nozzle rotating device, and multi-material deposition and UV curing are performed.

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

1. The feeding device is turned on, and the material starts to be sent from the feeding tank pump to the material storage room through the material feeding pipeline. Each material feed line is dedicated to a specific material and is connected at one end to the material source tank and at the other end to the platen assembly. The feeder pumps the 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 required various materials and supporting materials, the deposition device starts the deposition process. Turn on the air compressor and maintain constant pressure on the platen assembly. The pressure required for each nozzle needs to be controlled and can be calculated using the following formula derived from Poiseulle's law:

Among them, P is the pressure of the nozzle, V is the deposition flow rate, η is the efficiency, l is the length of the nozzle, t is the unit time, and r is the diameter of the nozzle. The deposition flow rate is controlled by the pressure applied to the pressure assembly, and the pressure for each nozzle depends on the material properties and geometry of the nozzle tip. Therefore, the pressure of each nozzle is adjusted according to the required flow.

3. By approaching the nozzle deposition system, move the Z axis to perform the first deposition. The movement of the Z axis is controlled by a servo motor which can move the Z axis up or down.

4. To adjust the nozzle device for the first deposition, first select the required material nozzle, seven nozzles are installed on the rotating disk connected to the servo motor, the servo motor can rotate the nozzle 180° clockwise and counterclockwise.

5. After adjusting the Z axis, perform deposition control, and select the nozzle for the first material deposition for continuous deposition or sedimentation deposition. Predefined deposition controls are activated when material toolpaths are defined during preprocessing. Deposition control allows precise control of the amount of material deposited, it is important to understand that the flow rate is controlled by the pressure applied by the pressure plate, however the deposition mode (continuous or falling) is controlled by the deposition control assembly. For quality and precision, both the pressure mechanism and the deposition control need to be perfectly coordinated.

6. The material deposition process is followed by a layer-by-layer curing process. However, when multiple layers of material are deposited, each material in the layer needs to be cured. The material curing process can be done by using a main UV light source or a UV spot light source, depending on the quantity, geometry and area of the material to be cured. When multiple materials are deposited in a small amount and more frequently, different materials will require different UV light intensities according to the material properties and photoinitiator strength, so it is impossible to use the main UV light source for curing, so the UV point light source is used. UV point light source processing is slower than main UV light source, but more precise and easy to control.

Referring to Figure 6a, when more than two materials are deposited in the same layer, then it is not possible to use the first UV light source 31 (main UV light source) in Figure 6b to cure, because different materials will require different UV light intensity to cure. In this case, curing with the main UV light source may result in overcuring of the material while simultaneously curing another material under the same layer, which will create geometric defects in the cured layer. In order to solve this problem, as shown in Figure 6c, a second UV light source 32 (UV point light source) can be used, which can be an integrated UV spotlight, which may increase the time of the curing process, but when curing multiple materials in the same layer , provides better control and precision. As the first layer solidifies, the Z-axis moves down, allowing the deposition of the next layer to begin and the cycle repeats until the entire object has been deposited and solidified.

As can be seen from the above technical solutions, the present invention has the following beneficial effects:

1. The present invention can deposit more than two kinds of construction materials, and can print parts with more than two kinds of materials;

2. The invention sets the servo motor to drive the nozzle to rotate, which can realize the accurate printing of multi-material parts;

3. The present invention is equipped with a unique platen assembly, which can quickly and stably realize the feeding of external materials;

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

5. The present invention is equipped with a first UV light source outside the printing nozzle, which can realize large-volume curing of materials and improve printing speed; a second UV light source is integrated on the deposition control component, which can form UV spots for precise curing of small volumes Deposition to speed up the curing process and improve print quality by targeting the curing source to a specific material volume.

It will be apparent to those skilled in the art that the invention is not limited to the details of the above-described exemplary embodiments, but that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Accordingly, the embodiments should be regarded in all points of view as exemplary and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description, and it is therefore intended that the scope of the invention be defined by the appended claims rather than by the foregoing description. All changes within the meaning and range of equivalents of the elements are embraced in the present invention. Any reference sign in a claim should not be construed as limiting the claim concerned.

In addition, it should be understood that although this specification is described according to implementation modes, not each implementation mode only contains an independent technical solution, and this description in the specification is only for clarity, and those skilled in the art should take the specification as a whole , the technical solutions in the various embodiments can also be properly combined to form other implementations that can be understood by those skilled in the art.

Claims (10)

1. A multi-material nozzle deposition system is characterized by comprising a multi-material deposition head integrated with a plurality of nozzles, a nozzle rotating device connected with the multi-material deposition head and used for driving the nozzles to rotate, and a UV light source used for curing materials, wherein the multi-material deposition head comprises a plurality of nozzles, material deposition pipelines connected with the nozzles, and material feeding pipelines connected with the material deposition pipelines, and the nozzles, the material deposition pipelines and the material feeding pipelines are installed in a one-to-one correspondence manner to respectively form channels used for material deposition;

the material deposition pipeline comprises a top cover assembly positioned at the top of the material deposition pipeline, a pressure plate assembly positioned in the middle of the material deposition pipeline and a deposition control assembly positioned below the material deposition pipeline;

the material deposition pipeline is divided into a sealing pressure chamber and a material storage chamber, the upper end of the sealing pressure chamber is composed of three rubber sealing parts to form a buckle combined top cover component with a material and air pressure pipeline, a multipurpose pressing plate component is arranged between the sealing pressure chamber and the material storage chamber, and a deposition control component 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 which are positioned below the top cover body and the rubber pad, wherein a first through hole and a second through hole which are respectively used for communicating the material pipeline and the air pressure pipeline are formed in the top cover body and the rubber pad;

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 located below the rubber pressing plate and embedded in the pressing plate main body, wherein the hanging door assembly comprises a hanging door shell and a hanging door, and the hanging door is closed according to the pressure applied by the material in the sealed pressure chamber and the reverse pressure in the material storage chamber.

2. The multi-material nozzle deposition system of claim 1, further comprising a deposition platform, and a rotating platform above the deposition platform, wherein the nozzle is located above the deposition platform, and the rotating platform is provided with a plurality of mounting holes for fixedly mounting each material deposition conduit.

3. The multi-material nozzle deposition system of claim 2, wherein the nozzles are circumferentially and equally spaced above the deposition platform, and the rotating platform has a plurality of circumferentially and equally spaced mounting holes for correspondingly mounting the material deposition conduits.

4. A multi-material nozzle deposition system according to claim 1, wherein the multi-material deposition head comprises 7 nozzles, 7 material deposition conduits and 7 material feed conduits.

5. The multi-material nozzle deposition system of claim 1, wherein the nozzle rotating device comprises a servo motor and a rotating belt, and the servo motor is connected to a side of the rotating platform integrated with the plurality of nozzles through the rotating belt.

6. The multi-material nozzle deposition system of claim 5, wherein the servo motor rotates the rotary stage clockwise or counterclockwise with a maximum rotation angle of 180 degrees clockwise or counterclockwise to control the position of the nozzle.

7. The multi-material nozzle deposition system of claim 1, wherein the UV light source comprises a first UV light source attached to an outside of the material deposition conduit and a second UV light source integrated onto the material deposition conduit.

8. The multi-material nozzle deposition system of claim 7, wherein the first UV light source is a primary UV light source for immediately curing a large volume of material; the second UV light source 32 is a UV point source provided by a UV spot lamp integrated into the deposition control assembly for precise curing of small volume depositions.

9. A deposition method of a multi-material nozzle deposition system, wherein the multi-material nozzle deposition system is the multi-material nozzle deposition system of any one of claims 1 to 8, and the deposition method specifically comprises:

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

after finding the sequence of segments, generating a closed NURBS curve to represent the outline of the Open casade-based cut layer;

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

10. The deposition method of claim 9, further comprising:

according to the formula

Controlling the pressure required by each nozzle, wherein P is the pressure of the nozzle, 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.

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