CN107962774A - A kind of tow pressure enforcement body for continuous fiber 3D printing - Google Patents

Abstract

The invention relates to a tow pressure implementing mechanism for continuous fiber 3D printing, including a pressure device, a space movement mechanism, a transverse connection bracket, and a nozzle device fixed below the space movement mechanism, for controlling the pressure device and the space movement mechanism The control system one; the pressure device is fixed on one end of the transverse connecting bracket, and moves up and down relative to the transverse connecting bracket under the control of the control system one; the space movement mechanism is fixed on the other end of the transverse connecting bracket, and the space When the movement mechanism is in operation, it drives the horizontal connecting bracket to rotate around the space movement mechanism, and at the same time drives the pressure device to rotate together. The invention integrates the functions of pressure, temperature, space verticality and rotation movement, and at the same time satisfies the requirements of high-performance molding of fiber 3D printing for compactness, path jumping, and complex paths. It has the characteristics of simple device structure, adjustable parameters, and complete functions. , providing a basis for the realization of high-performance fiber material 3D printing.

Description

A tow pressure implementing mechanism for continuous fiber 3D printing

technical field

The invention relates to a real-time implementing mechanism for applying pressure to laying tow in the continuous fiber 3D printing process, and belongs to the technical field of additive manufacturing.

technical background

3D printing technology is used in the three-dimensional molding of continuous fiber composite materials, which can give full play to the advantages of 3D printing without molds, integral molding and light weight and high strength of fiber materials, and improves the traditional fiber laying or winding molding methods that are highly dependent on molds and complex models It has broad prospects in aerospace, automobile industry, parts manufacturing and other fields.

In the traditional continuous fiber laying and forming method, a simple fixed pressing wheel device is used to compress the fiber tow on the mold. However, for the 3D printing technology that uses layer-by-layer additive manufacturing as the molding method, since it does not require mold support and is not limited by the complexity of the model, it is necessary to plan reasonably according to the mechanical performance requirements of the molded parts and the characteristics of fiber continuity and directionality. The print path ensures high-performance 3D molding. On the one hand, during the 3D printing process, it is necessary to apply temperature and pressure to the printed filaments in real time to increase the density between layers; at the same time, for the empty paths or jump points of complex models, it is necessary to be able to lift the pressure in real time. device to increase the printing speed and avoid interference with the formed part; on the other hand, due to the complexity of the path, in addition to the straight line path, for irregular paths such as broken lines and curves, the pressure device also needs to achieve real-time tracking of the spatial position and Transform to ensure the molding effect. Therefore, for the pressure device of fiber 3D printing, requirements are put forward in terms of pressure and temperature implementation, three-dimensional space position transformation and so on.

In view of this, in the 3D printing process of continuous fiber materials, a pressure device suitable for forming path jumps and complex path space tracking capabilities is needed to implement real-time pressure on the fiber tow to improve the compactness of the multi-layer molded parts. Improve print quality.

Contents of the invention

The purpose of the present invention is to provide a compaction mechanism capable of real-time tracking of the trajectory of laid fiber tows in response to the requirements for the compactness and performance of continuous fiber 3D printing parts.

In order to achieve the above object, the technical solution adopted in the present invention is:

A tow pressure implementing mechanism for continuous fiber 3D printing, comprising a pressure device, a space movement mechanism, a transverse connection bracket connected between the pressure device and the space movement mechanism, and a nozzle device fixed below the space movement mechanism, used for Control system 1 for controlling the vertical movement of the pressure device and controlling the operation of the space movement mechanism;

The pressure device is fixed at one end of the horizontal connecting bracket, and moves up and down vertically relative to the horizontal connecting bracket under the control of control system 1, and the lowest point of the downward movement of the pressure device is lower than the lowest point of the sprinkler device The space movement mechanism is fixed on the other end of the transverse connection bracket. When the space movement mechanism is in operation, it drives the transverse connection bracket to rotate around the space movement mechanism, and at the same time drives the pressure device to rotate together.

Further, the pressure device includes a connecting column, an ordinary magnet support block, an ordinary magnet embedded in an ordinary magnet support block, an electromagnet support block, an electromagnet embedded in an electromagnet support block, an electromagnet connected to an ordinary magnet support block and an electromagnetic The spring between the iron support blocks, the support bar connected to the outside of the ordinary magnet support block and extending downward, also includes a pressure wheel and a heating rod, and the electromagnet is a de-energized electromagnet; the upper end of the connecting column is fixed on the One end of the horizontal connection bracket, the lower end of the connecting column is fixedly connected with the electromagnet support block; the heating rod passes through the pressure roller and is fixed on the lower end of the support rod; column and slides up and down along the connecting column, thereby driving the pressure roller on the support bar to move up and down.

Further, the spatial motion mechanism includes a large synchronous wheel, a small synchronous wheel, a belt connecting the large synchronous wheel and the small synchronous wheel, a motor shaft, and a motor for controlling the motor shaft, and the large synchronous wheel is fixed on the horizontal Connect the other end of the bracket, and the small synchronous wheel is fixed on the motor shaft.

Further, the nozzle device includes a nozzle bracket, a material conduit, a heating aluminum block and a printing nozzle fixed under the nozzle bracket, the nozzle bracket is fixed under the motor, and the heating aluminum block is fixed on the printing nozzle, so The upper end of the material conduit is fixed on the horizontal connecting bracket, and passes through the horizontal connecting bracket, the large synchronous wheel, the nozzle bracket, and the heating aluminum block at the same time, and the lower end is connected with the printing nozzle.

Further, the control system one separately controls the magnetism of the electromagnet in the pressure device and the motor operation of the space movement mechanism. When the electromagnet is magnetic, the mutual attraction with the ordinary magnet drives the ordinary magnet support block to slide down along the connecting column , so that the pressure wheel on the support bar moves downward, and the lowest position of the pressure wheel is lower than the horizontal plane where the print head is located; when the control system controls the electromagnet to lose its magnetism, the ordinary magnet returns to drive the ordinary magnet support block along the connecting column Slide upward, so that the pressure roller on the support rod moves upward, and the highest position of the upward movement of the pressure roller is higher than the horizontal plane where the print head is located; when the control system controls the operation of the motor, the motor shaft drives the small synchronous wheel to rotate, and the small synchronous wheel passes through the belt. The rotation angle information is transmitted to the large synchronous wheel, and the large synchronous wheel drives the horizontal connecting bracket to rotate, so that the pressure device rotates.

Further, the lowest position of the downward movement of the pressure wheel is 0.2 mm lower than the horizontal plane where the printing nozzle is located, and the highest position of the upward movement of the pressure wheel is 0.2 mm or above higher than the horizontal plane where the printing nozzle is located.

Further, the support rod is integrally formed in three sections including the upper support rod, the middle heat insulation block and the lower support rod, and the support rod and the ordinary magnet support block are integrally formed.

Further, it also includes a temperature sensor fixed at the lower end of the support rod and adjacent to the heating rod, and a control system 2 connected with the temperature sensor and used to control the heating rod. When the temperature sensor detects that the temperature is lower than a certain temperature value, The control system 2 controls the heating rod to heat up; when the temperature sensor detects that the temperature is higher than a certain temperature value, the control system 2 controls the heating rod to stop heating and cool down naturally.

Further, the material conduits, pressure rollers, and lower support rods are all made of metal.

Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: the present invention aims at the pressure and temperature requirements of the 3D printing density of fiber materials, as well as the fiber continuity and directional characteristics, and the pressure device needs to be able to adapt to path jumping and alignment Requirements for real-time tracking capabilities of complex paths, based on the interaction between demagnetization electromagnets and ordinary magnets, to complete the implementation of pressure and the elimination of pressure during path jumps; through the integrated device of pressure roller and heating rod to meet the needs of pressure and temperature at the same time ; Complete the trajectory tracking of the printing tow through the spatial movement mechanism around the printing nozzle. The invention integrates the functions of pressure, temperature, space verticality and rotation movement, and at the same time meets the requirements of high-performance molding of fiber 3D printing for compactness, path jumping, and complex paths. It has the characteristics of simple device structure, adjustable parameters, and complete functions. , providing a basis for the realization of high-performance fiber material 3D printing.

Description of drawings

Fig. 1 is a schematic front view of the structure of the present invention;

Fig. 2 is a schematic side view of the structure of the present invention;

In the figure: 1, ordinary magnet 2, electromagnet 3, ordinary magnet support block 4, electromagnet support block 5, spring 6, upper support rod 7, lower support rod 8, pressure roller 9, heating rod 10, connecting column 11, Horizontal connection bracket 12, material conduit 13, large synchronous wheel 14, belt 15, motor shaft 16, motor 17, nozzle support 18, heating aluminum block 19, printing nozzle 20, heat insulation block 21, temperature sensor 22, small synchronous wheel.

Detailed ways

Below in conjunction with accompanying drawing and concrete implementation the utility model is further described:

The structure of the present invention is shown in accompanying drawing 1 and Fig. 2, comprises common magnet 1, electromagnet 2, common magnet supporting block 3, electromagnet supporting block 4, spring 5, upper supporting bar 6, lower supporting bar 7, pressure wheel 8. Heating rod 9, connecting column 10, horizontal connecting bracket 11, material conduit 12, large synchronous wheel 13, belt 14, motor shaft 15, motor 16, nozzle bracket 17, heating aluminum block 18, printing nozzle 19, heat insulation block 20, temperature sensor 21, small synchronous wheel 22.

Connecting column 10, ordinary magnet support block 3, ordinary magnet 1 embedded in the ordinary magnet support block, electromagnet support block 4, electromagnet 2 embedded in the electromagnet support block, connected to the ordinary magnet support block 3 and the electromagnet support The spring 5 between the blocks 5, the support rod connected to the outside of the common magnet support block 3 and extending downward, the pressure roller 8 and the heating rod 9 constitute a pressure device;

The large synchronous wheel 13, the small synchronous wheel 22, the belt 14 connecting the large synchronous wheel 13 and the small synchronous wheel 22, the motor shaft 15, and the motor 16 used to control the motor shaft 15 form a space movement mechanism;

The nozzle holder 19, the material conduit 12, the heating aluminum block 18 and the print nozzle 19 fixed under the nozzle holder 17 form a nozzle device.

The upper end of the connecting column 10 is fixed on one end of the horizontal connecting bracket 11, the ordinary magnet 1 is embedded in the ordinary magnet support block 3, there is a hole between the ordinary magnet 1 and the support block 3, and the upper end of the connecting column 10 passes through the middle hole; the electromagnet 2 is embedded Into the electromagnet support block 4, and fixed with the lower end of the connecting column 10; there is a spring 5 between the ordinary magnet support block 3 and the electromagnet support block 4, which also passes through the connecting column 10, and the space that together constitutes the pressing mechanism falls vertically with lifting device. The common magnet support block 3 is integrally connected with the upper support rod 6, the lower support rod 7, and the middle heat insulation block 20, and is fixed by screws. The purpose of the heat insulation block is to prevent the excessive heat generated by the heating rod from being transmitted upwards; It is made of metal, with a hole at the end, passing through the heating rod 9 in the middle, and the pressing wheel 8 is a metal roller. The heating rod 9 passes through the pressing wheel 8, and the end is fixed to provide heat for the pressing wheel 8. During the pressing process, the melting part is high Molecular material; temperature sensor 21 is inserted in the end hole of lower support bar 7, and temperature sensor 21 is a thermistor, is used for detecting the temperature of pressing wheel 8 under the action of heating rod 9, and the critical temperature that temperature sensor 21 detects is by concrete The fiber composite material is determined, such as the fiber composite material based on polylactic acid, the melting temperature of the matrix material polylactic acid is 180 degrees, due to the heat dissipation effect of the non-enclosed space, the appropriate temperature detected by the temperature sensor 21 is set to 200 degrees. If the heating temperature is higher than 200 degrees, then under the action of the control system 2, the heating rod 8 stops heating and cools down naturally; if the heating temperature is lower than 200 degrees, the control system 2 sends a heating command to continue heating. The control system generally adopts PID (proportional-integral-derivative) control algorithm to ensure the stability of temperature and avoid excessive rise or fall. The above-mentioned devices together constitute a "pressure-temperature" implementing mechanism. The relative positions of electromagnet 2, electromagnet support block 4, and connecting column 10 are kept fixed. Ordinary magnet 1, ordinary magnet support block 3, upper support rod 6, lower support rod 7, pressure roller 8, heating rod 9, heat insulation block 20 1. The temperature sensor 21 remains integrated and can move vertically up and down on the connecting column under the action of the electromagnet.

Specific working process: During the 3D printing process, the requirements for the pressure device are: always be able to follow the rear of the tow printed by the printing nozzle 19, lower than a certain height of the printing nozzle, and perform pressure under the action of temperature; when the path jumps, The pressure device can be lifted to avoid interference; in the curved path, the pressure device can change the angle and maintain the relative position with the printing tow. Since the electromagnet 2 cannot work with electricity for a long time, the de-energized electromagnet 2 is selected, and the characteristic is that the magnetic force disappears when it is energized. During the 3D printing process, the electromagnet 2 is not energized and has magnetism. It generates an attractive force F with the upper ordinary magnet 1, and the attractive force F is greater than the spring force K. Under the action of the magnetic force, the pressure device is driven down and is 0.2mm lower than the nozzle. , used to apply pressure to the printing filament; when the path jumps and moves in vain, the control system 1 can recognize the jump command flag G0 in the GCode command, and output a high level to energize the electromagnet 2, and the electromagnet 2 loses its magnetism. The elastic force F generated by the compression of the spring 5 is greater than the gravity G of the pressure device, then the pressure device is lifted upwards, and the nozzle moves in idling. The pressure device does not interfere with the printed model, and the upward movement distance is 0.2mm or more. . Among them, the attractive force F is generated between the ordinary magnet 1 and the electromagnet 2; the gravity G of the pressure mechanism is the ordinary magnet 1, the ordinary magnet support block 3, the upper support rod 6, the lower support rod 7, the pressure wheel 8, and the heating rod 9 , heat insulation block 20, and temperature sensor 21; the elastic force K is generated by the compression of the spring 5 under the action of magnet attraction, and the relationship among the three is: F>K>G. Through the above process, the spatial up and down movement of the pressure device is satisfied.

The upper end of the large synchronous wheel 13 is fixed on the other end of the transverse connection bracket 11 and rotates around the guide tube 12 . The small synchronous wheel 22 is fixed on the motor shaft 15, and is connected with the large synchronous wheel by the belt 14. The motor 16 is fixed on the shower head support 17, the metal material conduit 12 passes through the transverse support 11, the large synchronous wheel 13, the shower head support 17, and the heating aluminum block 18 is connected with the printing nozzle 19. During the printing process, the control system continuously calculates the position information between two points in the 3D printed GCode code file, and fits its walking trajectory. If the two points on the line are on a straight line or have a small slope change, but the line change distance is within the pressure range of the effective width of the roller, the position of the pressure device relative to the nozzle remains unchanged; if the 3D printing curve or the empty path jump Finally, when the new track point exceeds the effective range of the pressure wheel relative to the current track point, the angle change between the new track and the current track is calculated, and the control system sends a motion command to the motor 16, and the motor shaft 15 rotates to drive the small synchronous wheel 22 movement, the small synchronous wheel transmits the rotation angle information to the large synchronous wheel 13 through the belt 14, and the large synchronous wheel drives the transverse support 11 to perform rotational motion. Under the action of the horizontal connecting bracket 11, the pressure device composed of the pressure wheel and the like is driven to rotate at the same time, completing the spatial rotation of the motion trajectory, and satisfying the real-time follow-up implementation of the 3D printing filament tow pressure.

The content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims (9)

1. A tow pressure implementing mechanism for continuous fiber 3D printing, characterized in that it includes a pressure device, a space movement mechanism, a transverse connection bracket connected between the pressure device and the space movement mechanism, and is fixed under the space movement mechanism The spray head device is used to control the vertical movement of the pressure device and the control system 1 for controlling the operation of the space movement mechanism; The pressure device is fixed at one end of the horizontal connecting bracket, and moves up and down vertically relative to the horizontal connecting bracket under the control of control system 1, and the lowest point of the downward movement of the pressure device is lower than the lowest point of the sprinkler device The space movement mechanism is fixed on the other end of the transverse connection bracket. When the space movement mechanism is in operation, it drives the transverse connection bracket to rotate around the space movement mechanism, and at the same time drives the pressure device to rotate together. 2. A tow pressure implementing mechanism for continuous fiber 3D printing according to claim 1, characterized in that: the pressure device includes a connecting column, a common magnet support block, and a common magnet support block embedded in a common magnet support block. The magnet, the electromagnet support block, the electromagnet embedded in the electromagnet support block, the spring connected between the ordinary magnet support block and the electromagnet support block, the support bar connected to the outside of the ordinary magnet support block and extending downward, also includes Pressing wheel and heating rod, the electromagnet is a de-energized electromagnet; the upper end of the connecting column is fixed on one end of the horizontal connecting bracket, and the lower end of the connecting column is fixedly connected with the electromagnet support block; the heating rod passes through The pressure roller is fixed on the lower end of the support rod; the ordinary magnet support block, ordinary magnet and spring pass through the connecting column in turn and slide up and down along the connecting column, thereby driving the pressure roller on the support rod to move up and down. 3. A tow pressure implementing mechanism for continuous fiber 3D printing as claimed in claim 2, characterized in that: said spatial motion mechanism includes a large synchronous wheel, a small synchronous wheel, a connecting large synchronous wheel and a small synchronous wheel The belt, the motor shaft, and the motor used to control the motor shaft, the large synchronous wheel is fixed on the other end of the transverse connection bracket, and the small synchronous wheel is fixed on the motor shaft. 4. A tow pressure implementing mechanism for continuous fiber 3D printing according to claim 3, characterized in that: the nozzle device includes a nozzle bracket, a material conduit, a heating aluminum block, and a printing nozzle fixed under the nozzle bracket. The nozzle, the nozzle bracket is fixed under the motor, the heating aluminum block is fixed on the printing nozzle, the upper end of the material conduit is fixed on the horizontal connection bracket, and passes through the horizontal connection bracket, the large synchronous wheel, the nozzle bracket, The aluminum block is heated, and the lower end is connected with the printing nozzle. 5. A tow pressure implementing mechanism for continuous fiber 3D printing as claimed in claim 4, characterized in that: the control system controls the electromagnet magnetism and the motor operation of the space movement mechanism in the pressure device respectively , when the electromagnet is magnetic, the mutual attraction with the ordinary magnet drives the ordinary magnet support block to slide down along the connecting column, so that the pressure wheel on the support rod moves downward, and the lowest position of the pressure wheel downward movement is lower than the print head It is located on the horizontal plane; when the control system controls the electromagnet to lose its magnetism, the ordinary magnet returns to drive the ordinary magnet support block to slide upward along the connecting column, so that the pressure roller on the support rod moves upward, and the highest position of the upward movement of the pressure roller is higher than that of the print head When the control system controls the operation of the motor, the motor shaft drives the small synchronous wheel to rotate, and the small synchronous wheel transmits the rotation angle information to the large synchronous wheel through the belt, and the large synchronous wheel drives the horizontal connecting bracket to rotate, so that The pressure unit rotates. 6. A tow pressure implementing mechanism for continuous fiber 3D printing according to claim 5, characterized in that: the lowest position of the downward movement of the pressure wheel is 0.2 mm lower than the horizontal plane where the printing nozzle is located, and the pressure wheel moves upward The highest position of the movement is 0.2mm or more above the horizontal plane where the print head is located. 7. A tow pressure implementing mechanism for continuous fiber 3D printing according to any one of claims 2-6, characterized in that: the support rod is an upper support rod, a middle heat insulation block, and a lower support rod. Segmental integral molding, and the support rod and ordinary magnet support block are integrally formed. 8. A tow pressure implementing mechanism for continuous fiber 3D printing according to any one of claims 2-6, characterized in that: it also includes a temperature sensor fixed at the lower end of the support rod and adjacent to the heating rod, and The control system 2 connected with the temperature sensor and used to control the heating rod, when the temperature sensor detects that the temperature is lower than a certain temperature value, the control system 2 controls the heating rod to heat up; when the temperature sensor detects that the temperature is higher than a certain temperature value , the control system 2 controls the heating rod to stop heating. 9. A tow pressure implementing mechanism for continuous fiber 3D printing according to claim 4, characterized in that: the material conduit, the pressure wheel, and the lower support rod are all made of metal.