Continuous carbon fiber extruder

Abstract

The utility model discloses a continuous carbon fiber extruder which comprises a pressure block, a feed driving assembly, a speed detection assembly and a fixed seat, the feed driving assembly is used for feeding carbon fiber yarns into the pressure block, the speed detection assembly is used for detecting the feeding condition of the extruder, and the fixed seat is used for fixing the extruder on a 3D printer. The utility model provides a novel continuous carbon fiber extruder applied to a 3D printer. The continuous carbon fiber extruder can efficiently finish the extrusion work of continuous carbon fiber composite material filaments.

Description

Technical Field

[0001] The utility model belongs to the technical field of 3D printing, and in particular relates to an extruder for continuous carbon fibers. Background Art

[0002] With the rapid development of science and technology, 3D printing technology, as an important part of modern manufacturing, has been widely used and recognized around the world. 3D printing technology, also known as additive manufacturing, builds three-dimensional entities by adding materials layer by layer. At present, this technology has been widely used in aerospace, automobile manufacturing, medical equipment, architectural design, consumer goods manufacturing and other fields.

[0003] The extrusion principle of a 3D printer is to feed the filament into the heating block through the extruder. After the heating filament is melted, the liquid filament flows out of the nozzle hole and solidifies to the specified position, building the printed part layer by layer. The extruder needs to accurately control the length of the extruded wire and is one of the core components of the 3D printer.

[0004] Fiber-reinforced composite materials have been widely used in various industrial fields due to their excellent mechanical properties. However, due to the limitations of traditional manufacturing processes, composite materials are still not applicable to some structures with complex configurations. In recent years, the rapid development of 3D printing technology is expected to achieve effective manufacturing of composite structures with complex geometric shapes, thereby further expanding the application scope of composite materials. The mature application of continuous fiber-reinforced composite 3D printing technology is of great significance to the manufacturing of high-end equipment in China.

[0005] At present, there are few 3D printing devices and solutions for continuous fiber reinforced polymer composites. The mainstream solution is that the 3D printer uses a dual-nozzle print head and a dual extruder (i.e., a traditional thermoplastic material extruder and a continuous carbon fiber wire extruder). During the printing process, the nozzles need to be constantly switched to complete the mixed laying of the same layer of composite materials and matrix materials. When switching from the 3D print head of the continuous fiber composite material to the matrix material print head, the continuous fiber filaments must be cut off to facilitate printing by the matrix print head. The existing technology using this solution mainly has the following shortcomings and problems that need to be solved:

[0006] (1) At present, 3D printing of continuous carbon fiber materials in China is just starting. 3D printers using this solution are rare, and therefore continuous carbon fiber extruders used in conjunction with it are also rare.

[0007] (2) Continuous carbon fiber reinforced composite materials are easy to break, which is not conducive to feeding and causes faults in printing;

[0008] (3) Since the continuous fiber material is supplied intermittently during the printing process, in order to better impregnate and bond the carbon fiber filaments to the substrate, the extrusion length needs to be precisely controlled. This requires the extruder to monitor the extrusion rate and condition of the fiber filaments well. Once an abnormality occurs, it will affect the quality of the entire printer and may even prevent the printer from completing printing.

[0009] Therefore, it is necessary to design a new type of continuous carbon fiber extruder to solve the problems existing in the above 3D printing equipment of continuous fiber reinforced polymer composites. Utility Model Content

[0010] The main purpose of the utility model is to provide a continuous carbon fiber extruder, thereby overcoming the shortcomings of the prior art.

[0011] In order to achieve the above-mentioned utility model purpose, the technical solution adopted by the utility model includes: a continuous carbon fiber extruder, including:

[0012] a pressure block having a cavity;

[0013] A feeding drive assembly, comprising a support block located in the cavity and a drive assembly mounted on the support block, wherein the drive assembly comprises a motor and a unidirectionally rotating knurling wheel assembly, wherein the motor is mounted on the support block, and the knurling wheel assembly is connected to the motor shaft of the motor and rotates unidirectionally under the drive of the motor, thereby driving the carbon fiber filaments to be fed into the pressure block;

[0014] The speed detection component specifically includes a passive wheel component installed on the pressure block and arranged close to the knurling wheel component and a detection component connected to the passive wheel component. During feeding, the carbon fiber filaments pass between the passive wheel component and the knurling wheel component. When the knurling wheel component rotates, the friction between the carbon fiber filaments and the passive wheel component drives the passive wheel component and the detection component to rotate together. The detection component obtains the rotation speed of the passive wheel component through rotation detection, and further obtains the feeding speed of the carbon fiber filaments and the rotation speed of the motor according to the rotation speed of the passive wheel component.

[0015] In a preferred embodiment, the knurling wheel assembly includes a knurling wheel, a one-way bearing and a rotating sleeve, the one-way bearing is installed in the knurling wheel and both are installed on the rotating sleeve, and the rotating sleeve is connected to the motor shaft.

[0016] In a preferred embodiment, the knurling wheel assembly further includes two ordinary bearings located inside the knurling wheel and at both ends of the one-way bearing.

[0017] In a preferred embodiment, the passive wheel assembly includes a passive wheel and a passive wheel shaft, the passive wheel is mounted on the passive wheel shaft via a bearing, and the passive wheel shaft axially passes through the pressure block.

[0018] In a preferred embodiment, the detection component includes a coding wheel, a photoelectric switch and a circuit board. The coding wheel is installed on the passive wheel shaft and rotates with the passive wheel shaft and the passive wheel. The photoelectric switch and the circuit board are installed on the coding wheel. The photoelectric switch is triggered when the coding wheel rotates. The rotation speed of the coding wheel, that is, the rotation speed of the passive wheel, is obtained by the number of triggering times of the photoelectric switch.

[0019] In a preferred embodiment, the feeding speed of the carbon fiber filaments and the rotation speed of the motor are obtained according to the rotation speed of the passive wheel, the radius of the passive wheel and the radius of the knurling wheel.

[0020] In a preferred embodiment, whether the feed slip occurs is determined based on the matching of the rotation speed of the encoder wheel and the rotation speed of the motor.

[0021] In a preferred embodiment, the pressure block and the support block are movably connected via an idler shaft; and / or, the pressure block and the support block are also elastically connected via a spring.

[0022] In a preferred embodiment, a limiting assembly for guiding the carbon fiber filaments is provided on each side of the support block, and the limiting assembly is opposite to the gap between the knurling wheel assembly and the passive wheel assembly; and / or, the limiting assembly includes a feed limiting column and a feed pipe, and the feed limiting column is installed on the feed pipe, and the feed pipe passes through the side of the support block and is opposite to the gap between the knurling wheel assembly and the passive wheel assembly.

[0023] In a preferred embodiment, the extruder is fixed to the printer via a fixing base.

[0024] Compared with the prior art, the beneficial effects of the present invention are at least:

[0025] 1. The utility model provides a novel continuous carbon fiber extruder for 3D printers, which can efficiently complete the extrusion of continuous carbon fiber composite material filaments.

[0026] 2. The utility model designs the extruder to have one-way feeding, that is, only feeding but not withdrawing, so as to match the 3D printer without winding function. Moreover, since the continuous carbon fiber filaments are easy to break, the fiber filaments are easily broken once the material is withdrawn. In order to avoid this situation, the carbon fiber filaments are only fed but not withdrawn, that is, the continuous carbon fiber extruder has the function of only automatic feeding but not automatic withdrawing.

[0027] 3. The utility model adds a speed detection component to obtain the extrusion speed of the carbon fiber filament and the motor speed, so that the motor speed can be adjusted according to the actual production situation. At the same time, it can be known whether the wire is slipping or there is no material abnormality according to the motor speed and the actual speed of the encoder wheel, which effectively avoids the ineffective operation of the printer.

[0028] 4. The utility model elastically connects the pressure block and the support block, so that the pressure block has a certain elasticity. When the carbon fiber filaments pass through, the pressure given by the pressure block is elastic, that is, the pressure has a buffering function, so that the carbon fiber filaments will not be broken due to excessive pressure, thereby ensuring the quality of the entire printer and enabling the printer to complete printing smoothly. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 This is an overall stereogram of a continuous carbon fiber extruder provided by the utility model;

[0031] Figure 2 It is an exploded view of the extruder of the utility model;

[0032] Figure 3 This is the front view of the extruder of the utility model;

[0033] Figure 4 yes Figure 3 Sectional view in the AA direction;

[0034] Figure 5 It is a partial structural schematic diagram of the extruder of the utility model;

[0035] Reference numerals:

[0036] 1. Fixed seat, 11. Support block fixing part, 12. Printer fixing part, 2. Support block, 3. Pressure block, 4. Passive wheel, 5. Passive wheel shaft, 6. Encoder wheel, 7. Rotating sleeve, 8. Knurled wheel, 9. Feed limit column, 16. Idle wheel shaft, 17. Bearing, 19. Spring, 20. One-way bearing, 21. Ordinary bearing, 22. Retaining ring, 23. Feed pipe, 24. Motor, 25. Photoelectric switch, 26. Circuit board. DETAILED DESCRIPTION

[0037] The present invention will be more fully understood through the following specific embodiments that should be read together with the accompanying drawings. Detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are only exemplary of the present invention, and the present invention can be embodied in various forms. Therefore, the specific functional details disclosed herein should not be interpreted as limiting, but only as the basis of the claims and as a representative basis for teaching those skilled in the art to adopt the present invention in different ways in any appropriate detailed embodiment.

[0038] like Figure 1 to Figure 5 As shown, the utility model discloses a continuous carbon fiber extruder, which belongs to the field of 3D printing technology. It mainly includes a pressure block 3, a feed drive component, a speed detection component and a fixed seat 1. The feed drive component is used to feed carbon fiber filaments into the pressure block 3, the speed detection component is used to detect the feeding situation of the extruder, and the fixed seat 1 is used to fix the extruder to a 3D printer (not shown).

[0039] A cavity is provided in the pressure block 3. The feed drive assembly specifically includes a support block 2 and a drive assembly. The support block 2 is located in the cavity of the pressure block 3 and is used to install the drive assembly. In the present embodiment, the drive assembly includes a motor 24 and a knurling wheel assembly. The motor 24 is mounted on the support block 2, specifically fixed to the front side of the support block 2, and the motor 24 can be fixed to the support block 2 by screws. A stepper motor can be specifically selected for the motor 24. The knurling wheel assembly is fixedly connected to the motor shaft of the motor 24, and specifically includes a knurling wheel 8, a bearing assembly and a rotating sleeve 7. The bearing assembly is located in the knurling wheel 8 and is installed on the rotating sleeve 7 together with the knurling wheel 8, and the rear end is limited by a retaining ring 22. In the present embodiment, the bearing assembly includes a one-way bearing 20 and two ordinary bearings 21 located at the front and rear ends of the one-way bearing 20. The front end of the rotating sleeve 7 is fixedly connected to the motor shaft of the motor 24. During installation, first install the one-way bearing 20 into the knurling wheel 8, pay attention to the installation direction of the one-way bearing 20, install the ordinary bearings 21 at both ends, and then install it on the rotating sleeve 7, and limit it with the retaining ring 22; then install the rotating sleeve 7 on the motor shaft and fix it with the set screw. Since the one-way bearing 20 is installed in the knurling wheel 8, the motor can only drive the knurling wheel 8 to rotate in one direction, realizing the function of the continuous carbon fiber extruder only automatically feeding but not automatically withdrawing. This is because the general 3D printer does not have a winding function, and the continuous carbon fiber filament is easy to break. Once the material is withdrawn, it is easy to break the fiber filament. In order to avoid this situation, the carbon fiber filament only feeds but does not withdraw.

[0040] The speed detection assembly is fixed on the pressure block 3 and is located above the knurled wheel 8. In this embodiment, the speed detection assembly specifically includes a passive wheel assembly and a detection assembly, wherein the passive wheel assembly includes a passive wheel 4 and a passive wheel shaft 5, the passive wheel 4 is located above the rolling wheel 8, and a gap is formed between the two for the carbon fiber filaments to pass through, and when the carbon fiber filaments pass through, friction will be generated between the passive wheel 4. The passive wheel 4 is mounted on the passive wheel shaft 5 through a bearing, and the passive wheel 4 is located in the cavity of the pressure block 3, and the passive wheel shaft 5 axially (i.e., the front-to-back direction) penetrates the pressure block 3. The detection assembly is fixed to the rear end of the passive wheel shaft 5 passing through the pressure block 3. In this embodiment, the detection assembly specifically includes a coding wheel 6, a photoelectric switch 25 and a circuit board 26, wherein the coding wheel 6 is fixed to one end of the passive wheel shaft 5 by screws, and a circle of holes of equal distance and size are opened on the coding wheel 6 (not shown in the figure), which is mounted on the passive wheel shaft 5 and rotates together with the passive wheel 4. The photoelectric switch 25 and the circuit board 26 are installed above the encoding wheel 6 . Specifically, the photoelectric switch 25 is fixed to the pressure block 3 by screws, and the circuit board 26 is electrically connected to the photoelectric switch 25 . When feeding is needed, the motor 24 drives the knurling wheel 8 to rotate, and the carbon fiber filaments are driven to feed in through friction, and then the friction between the carbon fiber filaments and the passive wheel 4 causes the passive wheel 4 to rotate, and the encoding wheel 6 rotates with the passive wheel 84. When the encoding wheel 6 rotates, the photoelectric switch 25 will be triggered. By recording the number of triggering times of the photoelectric switch 25, the rotation speed of the encoding wheel 6, that is, the rotation speed v1 of the passive wheel 4, can be known; according to the rotation speed v1 of the passive wheel 4 and the radius r1 of the passive wheel 4 and the radius r2 of the knurling wheel 8, the feeding speed (v2=2Πr1×v1) of the carbon fiber filaments and the rotation speed of the knurling wheel 8, that is, the rotation speed (v3=v1×r1 / r2) of the motor 24 can be known, so that the motor speed v3 can be adjusted according to the actual printing situation to control the feeding speed v2 of the carbon fiber filaments, so that it is not too slow to cause printing faults, and the feeding speed is too fast and the printing speed cannot keep up, which also easily causes the carbon fiber filaments to break; at the same time, it is also possible to judge whether the feeding slip occurs according to the matching situation of the rotation speed of the encoding wheel and the motor speed. Since the rotation of the passive wheel is driven by the friction with the carbon fiber filaments, once slippage or lack of material occurs, the passive wheel will not rotate. In this way, the photoelectric switch can immediately detect abnormalities in the carbon fiber filament feeding, quickly issue a warning to indicate the abnormality and suspend the printer's printing work, which can effectively improve the printer's printing work and avoid invalid operations of the printer.

[0041] The pressure block 3 and the support block 2 are movably connected via an idler shaft 16, and / or the pressure block 3 and the support block 2 are also elastically connected via a spring 19. Specifically, there is a groove on the side of the support block 2, and the spring 19 is installed inside to press against the pressure block 3, so that the pressure block 3 has a certain buffering function. In this way, the pressure block 3 can compress the carbon fiber filaments while having a certain elasticity. When the carbon fiber filaments pass through, the pressure applied by the pressure block 3 has a certain elasticity, so that the carbon fiber filaments will not be broken due to excessive pressure. This design can reduce the risk of carbon fiber filaments being broken.

[0042] A limiting assembly for guiding the carbon fiber filaments is also provided on both sides of the support block 2, and the limiting assembly is directly opposite to the gap between the knurling wheel assembly and the passive wheel assembly. In this embodiment, the limiting assembly includes a feed limiting column 9 and a feed pipe 23, and the feed limiting column 9 is installed on the feed pipe 23, and the feed pipe 23 passes through the side of the support block 2 and directly faces the gap between the knurling wheel assembly and the passive wheel assembly, so as to guide the carbon fiber filaments.

[0043] The fixing base 1 is provided with a support block fixing part 11 and a printer fixing part 12. The support block fixing part 11 and the motor 24 are distributed at the front and rear ends of the support block 2. The fixing base 1, the support block 2 and the motor 24 are fixed together by screws. The printer fixing part 12 is located at the bottom of the extruder and is used to fix the extruder to the printer.

[0044] A continuous carbon fiber extruder provided by the embodiment of the utility model has the following advantages: 1. The utility model provides a new type of continuous carbon fiber extruder applied to 3D printers, which can efficiently complete the extrusion of continuous carbon fiber composite material filaments. 2. The utility model designs the extruder as a one-way feeder, that is, only feeds but does not withdraw the material, so as to match the 3D printer without a winding function. Since the continuous carbon fiber filaments are easy to break, once the material is withdrawn, it is easy to break the fiber filaments. In order to avoid this situation, the carbon fiber filaments can only be fed but not withdrawn, that is, the continuous carbon fiber extruder can realize the function of only automatic feeding but not automatic withdrawal. 3. The utility model adds a speed detection component to obtain the extrusion speed and motor speed of the carbon fiber filaments, so that the motor speed can be adjusted according to the actual production situation. At the same time, it can be known whether the wire is slipping or there is no material abnormality according to the motor speed and the actual speed of the encoder wheel, which well avoids the ineffective work of the printer. 4. The utility model elastically connects the pressure block and the support block, so that the pressure block has a certain elasticity. When the carbon fiber filaments pass through, the pressure given by the pressure block is elastic, that is, the pressure has a buffering function, so that the carbon fiber filaments will not be broken due to excessive pressure, thereby ensuring the quality of the entire printer and enabling the printer to complete printing smoothly.

[0045] The various aspects, embodiments, features and examples of the present invention should be considered as illustrative in all aspects and are not intended to limit the present invention, the scope of which is defined solely by the claims. Other embodiments, modifications and uses will be apparent to those skilled in the art without departing from the spirit and scope of the present invention as claimed.

[0046] The use of titles and sections in the present invention is not meant to limit the present invention; each section may apply to any aspect, embodiment or feature of the present invention.

Claims

1. A continuous carbon fiber extruder, characterized in that: The extruder comprises: a pressure block having a cavity; A feeding drive assembly, comprising a support block located in the cavity and a drive assembly mounted on the support block, wherein the drive assembly comprises a motor and a unidirectionally rotating knurling wheel assembly, wherein the motor is mounted on the support block, and the knurling wheel assembly is connected to the motor shaft of the motor and rotates unidirectionally under the drive of the motor, thereby driving the carbon fiber filaments to be fed into the pressure block; The speed detection component specifically includes a passive wheel component installed on the pressure block and arranged close to the knurling wheel component and a detection component connected to the passive wheel component. During feeding, the carbon fiber filaments pass between the passive wheel component and the knurling wheel component. When the knurling wheel component rotates, the friction between the carbon fiber filaments and the passive wheel component drives the passive wheel component and the detection component to rotate together. The detection component obtains the rotation speed of the passive wheel component through rotation detection, and further obtains the feeding speed of the carbon fiber filaments and the rotation speed of the motor according to the rotation speed of the passive wheel component.

2. A continuous carbon fiber extruder according to claim 1, characterized in that: The knurling wheel assembly comprises a knurling wheel, a one-way bearing and a rotating sleeve, wherein the one-way bearing is installed in the knurling wheel and both are installed on the rotating sleeve, and the rotating sleeve is connected to the motor shaft.

3. A continuous carbon fiber extruder according to claim 2, characterized in that: The knurling wheel assembly also includes two ordinary bearings located inside the knurling wheel and at both ends of the one-way bearing.

4. The continuous carbon fiber extruder according to claim 2, characterized in that: The passive wheel assembly comprises a passive wheel and a passive wheel shaft. The passive wheel is mounted on the passive wheel shaft via a bearing, and the passive wheel shaft axially passes through the pressure block.

5. The continuous carbon fiber extruder according to claim 4, characterized in that: The detection component includes a coding wheel, a photoelectric switch and a circuit board. The coding wheel is installed on the passive wheel shaft and rotates with the passive wheel shaft and the passive wheel. The photoelectric switch and the circuit board are installed on the coding wheel. When the coding wheel rotates, the photoelectric switch is triggered. The rotation speed of the coding wheel, that is, the rotation speed of the passive wheel, is obtained by the number of triggering times of the photoelectric switch.

6. A continuous carbon fiber extruder according to claim 5, characterized in that: The feeding speed of the carbon fiber filaments and the rotating speed of the motor are obtained according to the rotating speed of the passive wheel, the radius of the passive wheel and the radius of the knurling wheel.

7. A continuous carbon fiber extruder according to claim 6, characterized in that: Whether the feeding slip occurs is determined based on the matching of the rotation speed of the encoding wheel and the rotation speed of the motor.

8. The continuous carbon fiber extruder according to claim 1, characterized in that: The pressure block and the support block are movably connected via an idler shaft; and / or, the pressure block and the support block are also elastically connected via a spring.

9. The continuous carbon fiber extruder according to claim 1, characterized in that: A limiting assembly for guiding the carbon fiber filaments is also provided on each side of the support block, and the limiting assembly is opposite to the gap between the knurling wheel assembly and the passive wheel assembly; and / or, the limiting assembly includes a feed limiting column and a feed pipe, and the feed limiting column is installed on the feed pipe, and the feed pipe passes through the side of the support block and is opposite to the gap between the knurling wheel assembly and the passive wheel assembly.

10. The continuous carbon fiber extruder according to claim 1, characterized in that: The extruder is fixed to the printer via a fixing base.

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