CN110744819A

CN110744819A - 3D printing self-adaptive pressing feeding mechanism and printing method

Info

Publication number: CN110744819A
Application number: CN201911054874.4A
Authority: CN
Inventors: 汪馗; 赵安东; 张洪浩; 王琎; 谢训; 吴嘉唯
Original assignee: Central South University
Current assignee: Central South University
Priority date: 2019-10-31
Filing date: 2019-10-31
Publication date: 2020-02-04
Anticipated expiration: 2039-10-31
Also published as: CN110744819B

Abstract

The invention belongs to the technical field of printing equipment and discloses a 3D printing self-adaptive pressing feeding mechanism and a printing method, wherein a left feeding mechanism and a right feeding mechanism which are arranged on the 3D printing self-adaptive pressing feeding mechanism are identical in structure and are symmetrically arranged on the same horizontal plane; the left feeding mechanism is provided with a motor, a feeding gear mechanism, a V-shaped grooved wheel mechanism, a material guide pipe and a stop pin device, wherein the V-shaped grooved wheel mechanism is arranged on the same horizontal plane of the feeding gear mechanism, the material guide pipe is arranged below the feeding gear and the V-shaped grooved wheel mechanism, and the stop pin device is arranged above the V-shaped grooved wheel mechanism. The feeding device is suitable for simultaneous printing of different materials, and can effectively improve the printing efficiency; before each layer of printing and the alternate working of the spray heads, the working spray heads print a layer of detection sample in advance, so that the situation that materials are scraped to the surface of the sample in the printing process is avoided, and the printing defect caused by insufficient discharging in the initial stage of the double-spray-head exchange printing is prevented through printing the detection sample, so that the printing quality is improved.

Description

3D printing self-adaptive pressing feeding mechanism and printing method

Technical Field

The invention belongs to the technical field of printing equipment, and particularly relates to a 3D printing self-adaptive pressing feeding mechanism and a printing method.

Background

Currently, the closest prior art:

3D printing is used in various industries and is a technology for manufacturing products by a layer-by-layer printing method, of which fused deposition FDM (fused deposition modeling) technology is the most widely used, and is a process for constructing a three-dimensional entity by heating a bondable material such as thermoplastic to a temperature above the glass transition temperature, extruding and solidifying the material while a nozzle moves, based on a digital model. The stable feed extrusion mechanism and tight height control of the nozzles from the base plate are critical to successful printing of the product.

At present, most of 3D printers utilize a motor to drive a feeding gear and a bearing V-shaped groove wheel to match with a rolling feeding device for feeding, and the distance between the V-shaped groove wheel and the feeding gear cannot be adjusted, so that when materials with different hardness are printed, especially flexible materials are printed, wires are stressed and deformed between the feeding gear and the V-shaped groove wheel, and stable rolling pressure cannot be obtained. In addition, during the feeding process, the wire only obtains the unilateral friction force provided by the feeding gear, and the smoothness of material conveying is influenced.

At present, the height of most double-nozzle 3D printer nozzles can not be adjusted and are in the same horizontal position, and in the double-nozzle alternative printing process, due to installation errors, the surfaces of printed parts of products can be scratched by the nozzles which do not work along with the movement of a printing assembly, so that the quality and the performance of the products are affected. In addition, the non-working nozzles can generate fluid, and when the non-working nozzles start to work again, the fluid at the nozzle side can be wiped to the product side, so that the printing effect is seriously influenced.

In summary, the problems of the prior art are as follows:

(1) in the prior art, the printing wire obtains pressing force by designing the installation positions of the feeding gear and the V-shaped groove wheel, when the feeding gear rotates as a driving wheel, on one hand, friction force generated by the contact surface of the feeding gear and the printing wire drives the wire to move downwards, and on the other hand, friction force generated between the printing wire and the surface of the V-shaped groove wheel enables the V-shaped groove wheel to rotate synchronously. Therefore, the directions of the friction forces generated by the printing wire at the contact surface of the feeding gear and the contact surface of the V-shaped groove gear are opposite, and the unbalanced friction force on the two sides of the printing wire is small in feeding driving force, so that the problem of insufficient wire supply often occurs in the printing process. Moreover, due to the fact that the feeding gear and the V-shaped groove wheel are fixed in the installation position, the feeding mechanism cannot automatically adjust extrusion force according to the actual requirement of the printed wire, when insufficient feeding of the wire occurs, midway printing failure can be caused, and the wire can be printed again, and therefore working efficiency is low.

(2) In the prior art, when the feeding speed of materials is changed, particularly when the speed is increased, the stacking of soft materials in a triangular area formed by a feeding gear and a V-shaped grooved pulley cannot be avoided, the phenomenon of material gnawing occurs in hard materials, and the same feeding mechanism does not meet the requirement of printing materials with different hardness, so that the compatibility of the used materials is poor.

(3) In the prior art, in the process of printing by mixing different materials by using double nozzles, the heights of the double nozzles cannot be adjusted, and the non-working nozzles move along with the working nozzles in the printing process due to the existence of installation errors, so that the surfaces of printed products are scratched. Moreover, the existing printing mode can not avoid the problem that the flow material in the printing process influences the product and the like.

To solve the above problems, the patent publication No. CN 208841860U discloses a flexible feeding mechanism for a 3D printer, which proposes to add a circular elastic rubber sleeve on a feeding gear to increase the contact area between a power mechanism and a printing wire, thereby avoiding the phenomenon of gnawing the material. However, since the patent mentions that the distance between the feeding gears, i.e. the driving wheel and the bearing, remains unchanged, the rubber sleeve needs to be designed in different sizes to meet the printing requirements of different printing wires, which undoubtedly increases the production cost, and is inconvenient to assemble and disassemble and reduces the installation efficiency; in addition, different printing wires have different requirements on printing temperature, so that when the printing temperature is high, the ambient temperature around the feeding mechanism is correspondingly increased, and the rubber sleeve is deformed, so that the working requirement for stably and reliably supplying the wires cannot be guaranteed.

Publication number CN 204955439U patent discloses a feed mechanism for 3D printer, and this patent proposes that the initiative advances the silk wheel face and sets up sunken abrasive grain, has improved the frictional force that the wire rod fed to this patent is provided with adjustable hold-down mechanism, satisfies different diameter wire rod and prints the demand. However, the pressing mechanism in the patent cannot be automatically adjusted, the problem of feeding blockage in the printing process cannot be timely solved, and the printing progress is influenced; in addition, a large space is formed among the thread guide hole, the driving thread feeding wheel and the pressing mechanism, when flexible materials are printed, wires are easy to stack in the area, and normal feeding is affected.

The significance of solving the technical problems is as follows:

aiming at the analysis of the prior art, the automatic adjustment capability of the pressing force of the 3D printing feeding mechanism is improved, and the friction force of the driving feeding gear and the V-shaped grooved wheel to the printing wire is improved, so that the compatibility of the printing wire can be improved, and the stable and smooth supply of the wire is ensured; the method has the advantages that the printing mode is improved, the height of the nozzle is controlled to be adjustable, so that the influence of the flow on the sample is reduced, and the method plays an important role in improving the precision of the sample.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a 3D printing self-adaptive pressing feeding mechanism and a printing method. In particular to a printing method which is suitable for different 3D printing wire self-adaptive pressing feeding mechanisms and avoids the influence of the flow on the printed products.

The invention is realized in such a way that a 3D printing self-adaptive pressing feeding mechanism is provided with a double-nozzle 3D printer feeding mechanism; double-nozzle 3D printer feed mechanism includes left feed mechanism and right feed mechanism, left side feed mechanism is the same with right feed mechanism structure, same horizontal plane symmetrical arrangement.

The left feeding mechanism is provided with a motor and an end cover.

The end cover passes through the bolt fastening on the motor, includes on the end cover: drive gear, left pivot, right pivot and backstop round pin device, wherein drive gear, left pivot and right pivot all pass through bearing and end cover connection.

The driving gear is driven by the motor spindle to mesh with the left driven gear and drive the left rotating shaft to rotate, and the left driven gear is meshed with the right driven gear to drive the right rotating shaft to rotate.

The feeding gear is connected with the wedge surface of the left rotating shaft and rotates at the same speed, and the pressure sensor is arranged on the wedge surface of the feeding gear, which is in contact with the left rotating shaft, and is used for detecting the pressure between the left rotating shaft and the feeding gear.

The V-shaped grooved wheel and the compression spring are both arranged on the right rotating shaft and rotate at the same speed with the right rotating shaft.

The printing wire is conveyed to the material guide pipe to form the mechanism under the driving of double-side friction force provided by the feeding gear and the V-shaped groove wheel surface.

The guide pipe forming mechanism controls the guide pipe mechanism to move up and down under the cooperative coordination of the shifting fork mechanism and the height spring, so that the nozzle is controlled to move up and down.

The right feeding mechanism and the left feeding mechanism have the same structure.

Further, the V-shaped grooved wheel mechanism comprises an inner half side, an outer half side and a compression spring of the V-shaped grooved wheel, the inner half side and the outer half side of the V-shaped grooved wheel are respectively connected with the right rotating shaft through threads, and the inner half side and the outer half side of the V-shaped grooved wheel are automatically locked relative to the threads of the right rotating shaft under the action of the compression spring.

When the force value of a pressure sensor between the left rotating shaft and the feeding gear is further reduced, the speed of the motor is reduced, the stop pin popped out by the stop pin device is clamped into the groove in the outer ring of the V-shaped grooved wheel, the outer half side of the V-shaped grooved wheel rotates relative to the thread of the right rotating shaft, the distance between the inner half side and the outer half side of the V-shaped grooved wheel is reduced, the extrusion force of printing wires is increased, and the driving friction force of downward movement of the wires is improved.

Further, the nozzle height adjusting mechanism comprises a material guide pipe forming structure and a shifting fork mechanism. The shifting fork compresses a left spring upper stop block downwards to drive a left material guide pipe to move downwards, so that the height of the left nozzle from the printing bottom plate is reduced, and the proper extrusion height of the wire rod is controlled.

Further, when the left nozzle stops working, the stepping motor rotates clockwise, the left guide pipe assembly moves upwards under the action of the height spring, the height of the left nozzle structure of the nozzle height adjusting mechanism is increased from the printing bottom plate, the distance of the corresponding right nozzle from the printing bottom plate is correspondingly reduced, and printing work is prepared.

The invention also aims to provide a printing method of the 3D printing self-adaptive pressing feeding mechanism, in the printing method, the stepping motor in the shifting fork mechanism rotates anticlockwise to drive the cam on the outer side of the stepping motor to rotate anticlockwise, the shifting fork downwards compresses the upper stop of the left spring to drive the left material guide pipe assembly to move downwards, so that the height of the left nozzle from the printing bottom plate is reduced, and the proper extrusion height of the wire rod is controlled.

When the left nozzle of the real-time work stops working, the stepping motor rotates clockwise, the left guide pipe assembly moves upwards under the action of the height spring, the left nozzle structure of the nozzle height adjusting mechanism is increased in height from the printing bottom plate, and the distance between the corresponding right nozzle and the printing bottom plate is correspondingly reduced to prepare for printing.

Before each layer of sample is printed, a working left nozzle prints a detection sample in advance at a proper position away from the printing sample, so that the nozzle discharges normally during formal printing; meanwhile, the fluid at the working nozzle is completely adhered to the detection sample, and the phenomenon that the nozzle on the left side of the working is incompletely discharged at the beginning of printing is avoided.

The method specifically comprises the following steps:

① before each layer of sample is printed, the left nozzle is used to print the test sample in advance at a position away from the print sample, so as to ensure normal discharge of the nozzle during formal printing, and to make the fluid at the nozzle completely adhere to the test sample, thereby avoiding incomplete discharge of the left nozzle during printing.

② in the printing process or the feeding process, when the power value that is in between left gear axle and gyro wheel force sensor and detects reduces (or increases), the system judges according to the signal of feedback that the material extrudes pressure and reduces (or increases), thereby step motor counter-clockwise (or clockwise) rotation in the control shift fork mechanism, drive step motor outside cam counter-clockwise (or clockwise) and rotate, simultaneously, the shift fork is thereby down (or upwards) compress (or release) backstop on the high spring and drive left side passage constitution and move downwards (or upwards), make left side nozzle apart from printing bottom plate height reduce (or increase), the appropriate height of extruding of control wire rod, guarantee that the bonding that the material can be perfect is in one (or extruded smoothly).

③ when the left nozzle stops working, the stepping motor rotates clockwise, the left guide tube moves upwards under the action of the height spring, the left nozzle structure of the nozzle height adjusting mechanism increases the height from the printing bottom plate, the distance from the corresponding right nozzle to the printing bottom plate decreases correspondingly, and the printing operation is prepared.

The invention further aims to provide a double-nozzle 3D printer with the 3D printing self-adaptive pressing and feeding mechanism and the nozzle height adjustment function.

Another object of the present invention is to provide a terminal carrying a controller implementing the printing method.

Another object of the present invention is to provide a computer-readable storage medium including instructions which, when run on a computer, cause the computer to execute the printing method.

In summary, the advantages and positive effects of the invention are:

the 3D printing self-adaptive pressing feeding mechanism provided by the invention is provided with a double-nozzle 3D printing left feeding mechanism and a double-nozzle 3D printing right feeding mechanism, wherein the left feeding mechanism and the right feeding mechanism have the same structure and are symmetrically arranged on the same horizontal plane; the left feeding mechanism is provided with a motor, a feeding gear mechanism, a V-shaped grooved wheel mechanism, a material guide pipe and a stop pin device, wherein the V-shaped grooved wheel mechanism is arranged on the same horizontal plane of the feeding gear mechanism; the feeding gear mechanism and the V-shaped groove wheel mechanism respectively comprise gear shafts, the feeding gear mechanism and the V-shaped groove wheel mechanism are meshed through gears and both obtain wire feeding driving force, and the printing wire is subjected to bilateral driving friction force provided by the feeding gear and the V-shaped groove wheel, so that the feeding driving force is stronger and more balanced; a pressure sensor is arranged in the feeding gear mechanism and used for monitoring the extrusion force of the wires in real time; the stop pin device can limit the motion of the V-shaped groove wheel mechanism to adjust the pressing force obtained by printing the wire rod in real time, the feeding device is suitable for simultaneous printing of different materials, the material compatibility is better, and the printing efficiency can be effectively improved. When multi-material mixed printing is carried out, in order to avoid the influence of the flow on the printed product, the invention provides a flow-preventing 3D printing method which comprises the following steps: before each layer of printing and the alternate working of the spray heads, the working spray heads print a layer of detection sample in advance, so that the situation that materials are scraped to the surface of the sample in the printing process is avoided, and the printing defect caused by insufficient discharging in the initial stage of the double-spray-head exchange printing is prevented through printing the detection sample, so that the printing quality is improved.

Compared with the prior art, the invention has the advantages that:

the wire rod has higher double-side friction force between the feeding gear and the V-shaped groove wheel surface, so that the feeding driving force is stronger. The pressing mechanism can adjust pressing force according to real-time conditions, printing failure caused by feeding problems in the printing process is prevented, and therefore printing efficiency is improved.

The special design of the material guide pipe reduces the lower triangular space formed by the roller and the V-shaped grooved wheel, and avoids material stacking, so the material guide pipe is suitable for printing materials with different hardness, and has better material compatibility.

Different materials mix the printing process, and step motor drives shift fork automatic adjustment nozzle assembly apart from the height of bottom plate, avoids printing the process bleed and influences the product, reduces the product and prints the defect.

Drawings

Fig. 1 is a schematic view of a left feeding mechanism provided in an embodiment of the present invention.

Fig. 2 is a gear engagement diagram of the left feeding mechanism provided by the embodiment of the invention.

Fig. 3 is an isometric view of a dual nozzle feed mechanism according to an embodiment of the invention.

Fig. 4 is a schematic structural diagram of a feeding gear mechanism and a V-shaped groove wheel mechanism provided by the embodiment of the invention.

Fig. 5 is a schematic structural view of a material guide tube forming mechanism and a shifting fork mechanism in the nozzle height adjusting structure according to the embodiment of the present invention.

In the figure: 100. a feeding gear mechanism; 101. a left rotating shaft; 102. a right driven gear; 103. a left side bearing; 104. a feed gear; 105. a pressure sensor; 110. a motor; 120. an end cap; 130. printing a wire; 140. a drive gear; 150. a stop pin device; 200. a V-shaped grooved wheel mechanism; 201. a right rotating shaft; 202. a right driven gear; 203. a right side bearing; 204. the inner half side of the V-shaped grooved wheel; 205. the outer half edge of the V-shaped grooved wheel; 206. a compression spring; 300. a shifting fork mechanism; 301. a stepping motor; 302. a shifting fork; 400. the material guide pipes form a mechanism; 401. a material guide pipe; 402. a spring upper stop; 403. a height spring; 404. a throat pipe.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the prior art, the friction force of the two sides of the feeding gear and the V-shaped groove wheel surface is small, so that the friction force of the two sides of the printing wire is unbalanced, the feeding driving force is small, and the working efficiency is low. In the prior art, the feeding gear and the V-shaped groove wheel are arranged at a large triangular area, so that the situation that materials are stacked in the area cannot be avoided when soft materials are printed, the materials with different hardness cannot be printed, and the problem that the compatibility of the used materials is poor is caused. Among the prior art, the mixed printing in-process of different materials, step motor drives the shift fork can not automatic adjustment nozzle assembly apart from the height of printing the bottom plate, can not avoid printing the problem that the process seepage material influences the product and produces the printing defect because the material flows.

Aiming at the problems in the prior art, the invention provides a 3D printing self-adaptive pressing feeding mechanism and a printing method, and the invention is described in detail below with reference to the accompanying drawings.

As shown in fig. 1 to 4, the 3D printing adaptive pressing and feeding mechanism provided by the embodiment of the present invention is provided with a feeding mechanism of a dual-nozzle 3D printer; double-nozzle 3D printer feed mechanism includes left feed mechanism and right feed mechanism, left side feed mechanism and right feed mechanism symmetrical arrangement.

The left feeding mechanism is provided with a motor 110 and an end cover 120.

The end cover 120 is fixed to the motor 110 by bolts, and the end cover 120 includes: a drive gear 140, a left-hand shaft 101, a right-hand shaft 201, and a stop pin arrangement 150.

The driving gear 140 is driven by the motor spindle to mesh with the left driven gear 102 and drive the left rotating shaft 101 to rotate the left driven gear 102 and then mesh with the right driven gear 202 to drive the right rotating shaft 201 to rotate.

The feeding gear 104 is in wedge surface fit with the left rotating shaft 101 and rotates at the same speed, wherein the pressure sensor 105 is arranged on the wedge surface of the feeding gear 104 contacting with the left rotating shaft 101 and is used for detecting the pressure between the left rotating shaft 101 and the feeding gear 104.

The V-shaped grooved wheel and the pressing spring 206 are all on the right rotating shaft 201 and rotate at the same speed with the right rotating shaft 201.

The printing wire 130 is driven by the feeding gear 104 and the V-groove profile to be transported to the feeding pipe composing mechanism 400 by a double-sided friction force.

The guide tube composing mechanism 400 controls the guide tube mechanism to move up and down under the cooperative cooperation of the shifting fork mechanism 300 and the pressing spring 206, thereby controlling the nozzle to move up and down.

In the embodiment of the invention, the V-shaped grooved wheel mechanism comprises a V-shaped grooved wheel inner half 204, a V-shaped grooved wheel outer half 205 and a pressing spring 206, the V-shaped grooved wheel inner half and the V-shaped grooved wheel outer half are respectively connected with the right rotating shaft 201 through threads, and the V-shaped grooved wheel inner half and the V-shaped grooved wheel outer half are automatically locked relative to the right gear shaft threads under the action of the pressing spring 206.

When the force value of the pressure sensor 105 between the left rotating shaft 101 and the feeding gear 104 is reduced, the speed of the stepping motor 301 is reduced, the stop pin device 150 pops out of the stop pin and is clamped into the groove of the outer ring of the V-shaped wheel, the outer half 205 of the V-shaped wheel rotates relative to the thread of the right rotating shaft 201, the distance between the inner half and the outer half of the V-shaped grooved wheel is reduced, the extrusion force of the printing wire 130 is increased, and the driving friction force of the downward movement of the wire is improved.

The nozzle height adjusting mechanism comprises a material guide pipe forming mechanism 400 and a shifting fork mechanism 300. The stepping motor 301 in the shifting fork mechanism 300 rotates counterclockwise to drive the cam on the outer side of the stepping motor to rotate counterclockwise, and the shifting fork compresses the spring upper stop 402 downwards to drive the material guide pipe assembly mechanism 400 to move downwards, so that the height of the left nozzle from the printing bottom plate is reduced, and the proper extrusion height of the wire rod is controlled.

A height spring upper stop 402 is arranged on a height spring 403 of the feeding mechanism of the invention; the left rotating shaft 101 is provided with a left bearing 103 and a left rotating shaft 101, and the right rotating shaft 201 is provided with a right bearing 201 and a right rotating shaft 201.

The guide tube composing mechanism 400 comprises a guide tube 401, a height spring upper stop 402 and a throat 404.

In the embodiment of the invention, the right feeding mechanism and the left feeding mechanism have the same structure.

The invention provides a printing method of a 3D printing self-adaptive pressing and feeding mechanism, which comprises the following steps:

the stepping motor in the shifting fork mechanism rotates anticlockwise to drive the cam on the outer side of the stepping motor to rotate anticlockwise, the shifting fork compresses the upper stop of the left spring downwards to drive the left guide pipe to move downwards, the distance between the left nozzle and the printing bottom plate is reduced, and the wire rod is controlled to be extruded out properly.

The method specifically comprises the following steps:

The invention is further described below in connection with the working principle.

When the mechanism works, the driven gear I and the driven gear II are respectively meshed with the driving gear and the driven gear I, the feeding gear and the V-shaped groove wheel are formed by the inner half edge and the outer half edge of the V-shaped wheel and the pressing spring through the rotation of the motor, and the inner half edge and the outer half edge of the V-shaped wheel and the thread of the right gear shaft generate an automatic locking effect under the action of the pressing spring. The inner half edge, the outer half edge and the gear shaft II of the V-shaped wheel form a whole, relative movement and relative rotation do not exist between the two halves, downward friction force is jointly given to the printing wire, and the printing wire is guaranteed to stably enter the heating cavity.

When the force value of the pressure sensor between the left gear shaft and the feeding gear is detected to be reduced, the extrusion force obtained by the wire rod is reduced, the downward friction force is insufficient, the motor speed is reduced, the stop pin popped out by the stop pin device is clamped into the groove of the outer ring of the V-shaped wheel, at the moment, the outer half side of the V-shaped wheel rotates relative to the thread of the right gear shaft, the distance between the inner half side and the outer half side of the V-shaped wheel is reduced, the extrusion force obtained by printing the wire rod is increased, the downward conveying force is enhanced, and the normal discharging of the printer is ensured.

As shown in fig. 5, when the left nozzle assembly works, the stepping motor rotates anticlockwise, the left shifting fork forms a downward compression height spring with the left material guide pipe, the cam on the outer side of the stepping motor shaft enables the right shifting fork to rotate anticlockwise, the left shifting fork compresses the left material guide pipe to form downward movement, so that the height of the left nozzle from the bottom plate of the printer is reduced, and the printing wire extruded by the left nozzle assembly is firmly bonded with the bottom plate. When the left nozzle stops working, the stepping motor rotates clockwise, the left material guide pipe assembly moves upwards under the action of the height spring, and at the moment, the height of the left nozzle from the bottom plate is increased. The right nozzle works in the same principle.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When used in whole or in part, can be implemented in a computer program product that includes one or more computer instructions. When loaded or executed on a computer, cause the flow or functions according to embodiments of the invention to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, the computer instructions may be transmitted from one website site, computer, server, or data center to another website site, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL), or wireless (e.g., infrared, wireless, microwave, etc.)). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that includes one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A3D printing self-adaptive pressing and feeding mechanism is characterized in that the 3D printing self-adaptive pressing and feeding mechanism is provided with a double-nozzle 3D printer feeding mechanism; the feeding mechanism of the double-nozzle 3D printer comprises a left feeding mechanism and a right feeding mechanism, and the left feeding mechanism and the right feeding mechanism are symmetrically arranged;

the left feeding mechanism is provided with a motor and an end cover;

the end cover passes through the bolt fastening on the motor, includes on the end cover: the gear mechanism comprises a driving gear, a left gear shaft, a right gear shaft and a stop pin device, wherein the driving gear, the left gear shaft and the right gear shaft are connected with an end cover through bearings;

the driving gear is driven by the motor spindle to be meshed with the driven gear I and drive the left gear shaft to rotate, and the driven gear I is meshed with the driven gear II to drive the right gear shaft to rotate;

the feeding gear is connected with the wedge surface of the left gear shaft and rotates at the same speed, and the pressure sensor is positioned on the wedge surface of the feeding gear, which is contacted with the left gear shaft, and is used for detecting the pressure between the left gear shaft and the feeding gear;

the V-shaped grooved wheel and the compression spring are both arranged on the right gear shaft and rotate at the same speed with the right gear shaft;

the printing wire is conveyed to the material guide pipe to form a mechanism under the driving of double-side friction force provided by the feeding gear and the V-shaped groove wheel surface;

the material guide pipe forming mechanism controls the material guide pipe mechanism to move up and down under the cooperative coordination of the shifting fork mechanism and the height spring and controls the nozzle to move up and down;

2. The 3D printing self-adaptive pressing and feeding mechanism as claimed in claim 1, wherein the V-shaped grooved wheel mechanism comprises an inner half side and an outer half side of a V-shaped grooved wheel and a pressing spring, the inner half side and the outer half side of the V-shaped grooved wheel are respectively connected with the right gear shaft through threads, and the inner half side and the outer half side of the V-shaped grooved wheel are automatically locked relative to the threads of the right gear shaft under the action of the pressing spring.

3. The 3D printing self-adaptive pressing and feeding mechanism according to claim 1, wherein when a force value of a pressure sensor between a left gear shaft and a feeding gear is reduced, the speed of a motor is reduced, a stop pin ejected by a stop pin device is clamped into a groove in an outer ring of a V-shaped grooved wheel, an outer half side of the V-shaped grooved wheel rotates relative to a thread of a right gear shaft, and a distance between the inner half side and the outer half side of the V-shaped grooved wheel is reduced, so that the extrusion force of a printing wire is increased.

4. The 3D printing adaptive pressing feeding mechanism according to claim 1, wherein the nozzle height adjusting mechanism comprises a material guide pipe composition structure and a shifting fork mechanism; the stepping motor in the shifting fork mechanism rotates anticlockwise to drive the cam on the outer side of the stepping motor to rotate anticlockwise, the shifting fork compresses the upper stop of the left spring downwards to drive the left guide pipe to move downwards, the distance between the left nozzle and the printing bottom plate is reduced, and the wire rod is controlled to be extruded out properly.

5. The 3D printing self-adaptive pressing feeding mechanism according to claim 4, wherein when the left nozzle stops working, the stepping motor rotates clockwise, the left guide pipe assembly moves upwards under the action of the height spring, the height of the left nozzle structure of the nozzle height adjusting mechanism from the printing bottom plate is increased, the distance of the corresponding right nozzle structure from the printing bottom plate is correspondingly decreased, and the printing work is prepared.

6. A printing method of the 3D printing adaptive pressing feeding mechanism according to any one of claims 1 to 5, wherein the printing method comprises the following steps:

firstly, before printing each layer of sample, a working left nozzle prints a detection sample in advance at a proper position away from the printing sample; meanwhile, the flow at the working nozzle is completely adhered to the detection sample;

step two, in the printing process or the feeding process, when the force value detected by a force sensor between a left gear shaft and a roller is reduced, the system judges that the extrusion pressure of the material is reduced according to a feedback signal, controls a stepping motor in a shifting fork mechanism to rotate anticlockwise so as to drive a cam on the outer side of the stepping motor to rotate anticlockwise, and simultaneously, a shifting fork downwards compresses an upper stop of a height spring so as to drive a left material guide pipe assembly to move downwards, so that the height of a left nozzle from a printing bottom plate is reduced, and the proper extrusion height of a wire rod is controlled so as to adhere the material together;

and step three, when the working left nozzle stops working, the stepping motor rotates clockwise, the left guide pipe assembly moves upwards under the action of the height spring, the height of the left nozzle structure of the nozzle height adjusting mechanism from the printing bottom plate is increased, the distance of the corresponding right nozzle from the printing bottom plate is correspondingly reduced, and printing work is prepared.

7. The printing method of claim 6, wherein in the second step, when the force value detected by the force sensor between the left gear shaft and the roller increases, the system determines that the extrusion pressure of the material increases according to the feedback signal, and controls the stepping motor in the shifting fork mechanism to rotate clockwise to drive the outer cam of the stepping motor to rotate clockwise, and meanwhile, the shifting fork releases the upper stop of the height spring upwards to drive the left material guiding pipe assembly to move upwards, so that the height of the left nozzle from the printing bottom plate increases, and the proper extrusion height of the wire rod is controlled, so that the material is extruded smoothly.

8. A double-nozzle 3D printer suitable for adjusting the heights of nozzles with different hardness, which is provided with the feeding mechanism of the double-nozzle 3D printer suitable for adjusting the heights of nozzles with different hardness, as defined in claim 1.

9. A terminal having a controller mounted thereon for implementing the printing method according to any one of claims 6 to 7.

10. A computer-readable storage medium comprising instructions which, when executed on a computer, cause the computer to perform the printing method of any one of claims 6-7.