Abstract:
A feeding apparatus for forming 3D object includes a frame structure, a transmission set, an actuator, a swing unit and a controller having a sensor. The feeding apparatus is arranged on a 3D printer equipped with printing mechanism and a filament spool. When the filament is fed into a passageway of the frame structure to push the swing unit, the sensor senses the displacement of swing unit to generate a sensing signal. The controller controls the actuator to drive the transmission set according to the sensing signal, whereby the wire can be smoothly fed into the printing mechanism.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The technical field relates to a printer; in particular, relates to a 3D printer for forming a 3D object. 
     2. Description of Related Art 
     The 3D printing technology is to stack the powdered metal or plastic materials which are adhesive to print a 3D object. 
     Take a 3D printing device in a FDM type (Fused Deposition Modeling) for example, it is usually to feed the thermoplastic material into a printing mechanism first. After the thermoplastic material is heated and melted, it would be coated layer by layer on the base of the 3D printing device so as to cool and harden the thermoplastic material. The thermoplastic material would be modeled layer by layer to form a 3D object. 
     To be concrete, the FDM type 3D printer has an open type or a partial open type machine body, and there is a 3D moving mechanism configured inside the machine body. A printing mechanism such as a printing head or a printing nozzle is configured on the guiding rod of the 3D moving mechanism. The thermoplastic material used for printing might be the filament, the filament is placed in the filament spool, and the filament spool is arranged on the external surface of the machine body. The filament in the filament spool would be withdrawn to the printing mechanism. During the printing process, when the printing mechanism determines the filament is positioned and placed into the printing mechanism via the sensing element, the motor drives the printing mechanism to feed the filament to print out a 3D object. 
     However, the sensing element used in the printing mechanism is a shielded sensing element and the filament used by the 3D printer is translucent, so it would result in sensing errors by the sensing element. Also, there is a distance between the printing mechanism and the filament spool arranged on the external surface of the machine body, so the motor of the feeding mechanism might not transmit the filament smoothly. As a result, the filament could not be effectively transmitted to the printing mechanism so that it might decrease the printing quality of 3D object. 
     SUMMARY OF THE INVENTION 
     The disclosure is directed to a feeding apparatus configured between the printing mechanism and the filament spool in the disclosure so as to smoothly transmitting the filament for the 3D printer. 
     One of the exemplary embodiments provides feeding apparatus for forming 3D object, for feeding filaments in a filament spool of a 3D printer to a printing mechanism. The feeding apparatus at least comprises a frame structure, a transmission set, an actuator, a swing unit and a controller. 
     The frame structure has a passageway, and the passageway communicates the printing mechanism and the filament spool. 
     The transmission set is fastened on the passageway of the frame structure. 
     The actuator is fastened on the frame structure and used to drive the transmission set. 
     The swing unit is configured at one port of the passageway, wherein the port is near the filament spool. 
     The controller is fixed on the frame structure. The controller has a sensor and is electrically connected to the actuator and the sensor. Particularly, when the filaments in the filament spool enters the passageway and pushes the swing unit, the sensor senses a displacement of the swing unit so as to generate a sensing signal. Thereby, the controller controls the actuator to drive the transmission set so as to feed the filaments to the printing mechanism according to the sensing signal. 
     In one embodiment of the present invention, the actuator has at least a motor and the motor has a drive shaft. 
     In one embodiment of the present invention, the feeding apparatus further comprises a bearing plate that is fastened with the frame structure. The bearing plate has a plurality of retaining holes. A via hole is adjacent to the retaining holes. The via hole is also adjacent to a set of grouping holes. Particularly, a screw is through two of retaining holes so as to fasten the motor on the bearing plate, and the drive shaft of the motor is through the via hole after fastening the motor. 
     In one embodiment of the present invention, the frame structure is fastened on the bearing plate and has two symmetrical support parts. The support parts have a plurality of fastening holes, and the fastening holes are corresponded to the retaining holes at two edges of the bearing plate and fastened by the crew. 
     In one embodiment of the present invention, a beam section is configured between the two support parts. The passageway is configured on the beam section and has an open-type channel and an enclosed-type channel. The open-type channel has pivot portions on two sidewalls, and the pivot portions are to pivotally connect the swing unit. One end of the swing unit has a pivot shaft, and the pivot shaft is pivotally connected to the pivot portions so as to swing down one end of the swing unit into the open-type channel. 
     In one embodiment of the present invention, the beam section has a fastening portion, and the fastening portion is to fasten the controller. 
     In one embodiment of the present invention, the transmission set is consisted of a retaining bracket, an driving roller and a driven roller. The retaining bracket is fastened on the bearing plate of the actuator. A grouping portion is configured on the retaining bracket. The grouping portion has a through hole corresponding to the grouping hole of the bearing plate. The crew is through the through hole and the grouping hole for grouping, so as to fasten the retaining bracket on the bearing plate. 
     In one embodiment of the present invention, the grouping portion has a protrusion, and the protrusion has a pivot axis. The pivot axis has a groove, and the groove is grouped with a fastening sheet with a C-shaped buckle. The driven roller is pivotally connected to the pivot axis. 
     In one embodiment of the present invention, the driving roller is grouped on the drive shaft of the motor of the actuator and is configured to be corresponded with the driven roller. Also, the driving roller has a circle of rubber layer. 
     In one embodiment of the present invention, the driving roller and the driven roller of the transmission set are configured between the open-type channel and the enclosed-type channel of the frame structure. 
     In one embodiment of the present invention, the driven roller is a V-shaped roller or a V-shaped belt roller. 
     In one embodiment of the present invention, the controller comprises a circuit board and the sensor that is electrically connected to the circuit board. The sensor has a base body, and the base body has a concave slot. A sensing element is configured on two sidewalls of the concave slot, and the through holes corresponding to the rack are configured on the circuit board so as to fasten the circuit on the frame structure. 
     In one embodiment of the present invention, when the circuit board is fastened on the frame structure, the concave slot of the sensor is above the open-type channel. The swing unit on the open-type channel is pushed to have a displacement into the concave slot of the sensor, and the sensor senses the displacement of the swing unit to generate the sensing signal. 
     In one embodiment of the present invention, the swing unit is made of an opaque material. 
     For further understanding of the instant disclosure, reference is made to the following detailed description illustrating the embodiments and examples of the instant disclosure. The description is only for illustrating the instant disclosure, not for limiting the scope of the claim. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which: 
         FIG. 1  is an exploded schematic view of the feeding apparatus according to one embodiment of the present invention. 
         FIG. 2  is a schematic view of combination appearance of the feeding apparatus according to one embodiment of the present invention. 
         FIG. 3  is another schematic view of combination appearance, from a different view angle, of the feeding apparatus according to one embodiment of the present invention. 
         FIG. 4  is a top sectional view of the feeding apparatus according to one embodiment of the present invention. 
         FIG. 5  is a side sectional view of the feeding apparatus according to one embodiment of the present invention. 
         FIG. 6  is a schematic view of using status of the feeding apparatus according to one embodiment of the present invention. 
         FIG. 7  is an upper schematic view of filament transmission of the feeding apparatus according to one embodiment of the present invention. 
         FIG. 8  is a side schematic view of filament transmission of the feeding apparatus according to one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Based on one of embodiments of the present invention, it is described with figures as below. 
     Please refer to  FIGS. 1 ˜ 3 ,  FIG. 1  is an exploded schematic view of the feeding apparatus according to one embodiment of the present invention,  FIG. 2  is a schematic view of combination appearance of the feeding apparatus according to one embodiment of the present invention, and  FIG. 3  is another schematic view of combination appearance, from a different view angle, of the feeding apparatus according to one embodiment of the present invention. Also see  FIGS. 4 ˜ 5 ,  FIG. 4  is an upper sectional view of the feeding apparatus according to one embodiment of the present invention, and  FIG. 5  is a side sectional view of the feeding apparatus according to one embodiment of the present invention. As shown in figures, the feeding apparatus for forming a 3D object  10  of the present invention at least comprises an actuator  1 , a transmission set  2 , a frame structure  3  and a controller  4 . 
     The actuator  1  is fastened on a bearing plate  36  of the frame structure  3 . The actuator  1  has at least one motor  11 , and the motor  11  has a drive shaft  111 . 
     The transmission  2  is fastened on a passageway  33  of the frame structure  3 . The transmission set  2  is consisted of a retaining bracket  21 , an driving roller  22  and a driven roller  23 . The retaining bracket  21  is fastened on the bearing plate  36 , and the retaining bracket  21  has a grouping portion  211 . The grouping portion  211  has a through hole  2111  corresponded to the grouping hole  363 . A screw  2112  is through the through hole  2111  and is assembled with the grouping hole  363  of the bearing plate  36 , so as to fasten the retaining bracket  21  on the bearing plate  36 . The grouping portion  211  has a protrusion  212 , and the protrusion  212  has a pivot axis  213 . The pivot axis  213  has a groove  214 , and the groove  214  is assembled with a fastening sheet  215  with a C-shaped buckle. The driving roller  22  is assembled with the drive shaft  111  of the motor  11 . The driving roller  22  has an annular rubber layer  221  on outer surface thereof, and the rubber layer  221  contacts with the transmitted article (not shown) so as to transmit the article via friction. The driven roller  23  is pivotally connected to the pivot axis  213  and configured to be corresponded to the driving roller  22 . Then, the driven roller  23  is grouped on the groove  214  via the fastening sheet  215  so that the driven roller  23  would not loosen when rolling at the pivot axis  213 . In the figure, the driven roller  23  may be a V-shaped roller or a V-shaped belt roller. 
     A bearing plate  36  is fastened on the frame structure  3 , and the bearing plate  36  has a plurality of retaining holes  361 . A via hole  362  is adjacent to the retaining holes  361 , and a grouping hole  363  is adjacent to the via hole  362 . A screw is through two of the retaining holes  361  so as to fasten the motor  11  on the bearing plate  36 , and also to make the drive shaft  111  of the motor  1  through the via hole  362  so as to be assembled with the driving roller  22 . Besides, the frame structure  3  has two symmetrical support parts  31 , and the support parts  31  have a plurality of fastening holes  311 , and the fastening holes  311  are corresponded to the retaining holes  361  on two sides of the bearing plate  36 . Screws  312  are through the fastening holes and the retaining holes for fixing the bearing plate  36  on the supports  31 . A beam section  32  is arranged between the two support parts  31 , and at least one passageway  33  is arranged on the beam section  32 . The passageway  33  has an open-type channel  331  and an enclosed passageway  332 . The driving roller  22  and the driven roller  23  of the transmission set  2  are configured between the open-type channel  331  and the enclosed passageway  332  (as shown in  FIG. 4 ). Moreover, a pivot portion  3311  is configured on two sidewalls of the open-type channel. The pivot portion  3311  is pivotally connected to a swing unit  34  so that the swing unit  34  is configured at a port that is near the filament spool (not shown). A pivot shaft  341  is configured at one end of the swing unit  34 , and the pivot shaft  341  is pivotally connected to the pivot portion  3311  so that one end of the swing unit  34  swings down into the open-type channel  331  (as shown in  FIG. 5 ). Also, a fastening portion  55  is configured on the beam section  32 , and the fastening portion  35  is to fasten the controller  4 . In the figure, the swing unit is made of an opaque material so as to prevent false actions because of the light transmittance into the filament in the filament spool, 
     The controller  4  comprises a circuit board  41  and a sensor  42  that is electrically connected to the circuit board  41 . The sensor  42  has a base body  421 , and the base body  421  has a concave slot  422 . Sensing elements  423  are arranged on two sidewalls of the concave slot  422 . The circuit board  41  has a through hole  41  corresponded to the fastening portion  35 , and a screw  412  is through the through hole  411  to fasten the circuit board  41  on the beam section  32  of the frame structure  3 . When the circuit board  41  is fastened on the beam section  32 , the concave slot  422  of the sensor  42  is arranged above the open-type channel  311 . In the figure, the sensing element  423  is a shielded sensing element. 
     Please refers to  FIGS. 6 ˜ 8 ,  FIG. 6  is a schematic view of using status of the feeding apparatus according to one embodiment of the present invention,  FIG. 7  is an upper schematic view of filament transmission of the feeding apparatus according to one embodiment of the present invention, and  FIG. 8  is a side schematic view of filament transmission of the feeding apparatus according to one embodiment of the present invention. As shown in figures, the feeding apparatus  10  is configured inside the frame  201  of the 3D printer  20 , and one end of the enclosed passageway  332  of the feeding apparatus  10  is connected to a tube  202  so as to be further connected to the printing mechanism  203 . 
     When the 3D printer  20  is operating, the filament spool  204  is configured on the external side of the frame  201  of the 3D printer  29 . After the filament  205  in the filament spool  204  is fed into a side port of the open-type channel  331 , the filament  205  fed into the open-type channel  331  pushes the swing unit  34 . Thus, the swing unit  34  has a displacement to move in the concave slot  422  of the base body  421  of the sensor  42  so that the swing unit  34  would block the light of the sensing element  423 . As a result, the sensing element  423  of the controller  4  outputs a sensing signal, and the sensing signal drives the actuator  1 , so that the motor  11  of the actuator  1  drives the driving roller  22  of the transmission set  2  to rotate and thus to further transmit the filament  205 . At this moment, the driven roller  33  also rotates with the transmission of the filament  205 . Therefore, the filament  205  can be fed into the enclosed-type channel  432 , and then be fed to the printing mechanism  203  through the enclosed-type channel  432  and via the tube  202 . 
     From the above, the feeding apparatus  10  is configured between the printing mechanism  203  and the filament spool  204 , so that the filament  205  can be smoothly transmitted to the printing mechanism  203  without influencing the printing of the printing mechanism  203 . 
     Moreover, in addition to the actuator  1 , other elements such as the transmission set  2 , the frame structure  3  and the controller  4  can also be arranged on the printing mechanism  203 . When the sensing element  423  of the controller  4  senses the filament, the controller  4  would output a control signal to drive the actuator (not shown) of the printing mechanism  203 . After that, the actuator of the printing mechanism  203  would drive the transmission  2  to feed the filament  205  to the printing mechanism  203  so as to print for a 3D object. 
     It should be understood that the exemplary embodiments described therein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more embodiments of the present invention have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.