Patent Publication Number: US-2020282651-A1

Title: Feeding control system of 3d printer and feeding control method thereof

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a peripheral apparatus of a 3D (3-dimensional) printer, and in particular, to a feeding control system of a 3D printer and a feeding control method thereof. 
     Description of Related Art 
     FDM (Fused Deposition Modeling) is one of the object-forming principles of the 3d printer. The main process of FDM is as follows. The material is heated to an elevated temperature in a semi-molten state, then extruded on a platform and reverts to a solid state quickly. In this way, the stacking process is repeated to form a 3D object. 
     To increase the feeding speed of the above-mentioned material, a rear feeding motor and a front feeding motor are currently used to convey the filament sequentially to the front feeding nozzle, which can save the time of delivering the filament to the nozzle by the user and thus improves use convenience in which when the filament is carried to the front feeding motor, the front feeding motor synchronizes with the rear feeding motor to deliver the filament. 
     However, when the front feeding motor starts to pull the filament, the rear feeding motor will start synchronously to push the filament. During the fast printing process or the pull-back process, the issue that the speed of the front feeding motor does not synchronize with that of the rear feeding motor is particularly prone to occur. As a result, the filament is worn, squeezed, blocked, or broken, which causes poor printing quality. 
     In view of foregoing, the inventor pays special attention to research with the application of related theory to propose the cooling fan of the present invention, a reasonable design, to overcome the above disadvantages regarding the above related art. 
     SUMMARY OF THE INVENTION 
     The present invention provides a feeding control system of a 3D printer and a feeding control method thereof, which uses the mechanism when the second feeding apparatus holds the filament, the first feeding apparatus releases the filament immediately and stops pulling the filament to solve the problem of different feeding speeds and enhance the printing quality of the 3D printer. 
     In an embodiment, the present invention provides a feeding control system of a 3D printer, used with a filament. The feeding control system comprises a first feeding apparatus, a second feeding apparatus, and a feeding sensor. The first feeding apparatus comprises an outlet, a fixed wheel set, a movable wheel set, and a controller. The fixed wheel set and the movable wheel set hold and deliver the filament to the outlet; the controller is disposed corresponding to the movable wheel set. The second feeding apparatus is installed in the interior of the 3D printer. The feeding sensor is disposed corresponding to the second feeding apparatus and used to sense entrance of the filament and is held by the second feeding apparatus to generate a release signal in which after receiving the release signal, the controller drives the movable wheel set to move away from the fixed wheel set to release the filament. 
     In an embodiment, the present invention provides a feeding control method of a 3D printer, which comprises the steps of (a) providing a first feeding apparatus comprising an outlet and a driving wheel which drives and delivers a filament, (b) providing a second feeding apparatus installed in the interior of the 3D printer in which when the filament enters the 3D printer, the second feeding apparatus drives and delivers the filament, (c) causing the first feeding apparatus to drive and deliver the filament to the 3D printer through the outlet, and (d) controlling the second feeding apparatus to drive and deliver the filament and causing the first feeding apparatus to stop delivering the filament when the filament enters the 3D printer. 
     According to the above-mentioned description, when the second feeding apparatus holds the filament, the first feeding apparatus releases the filament immediately and stops pushing the filament. At this moment, only the second feeding apparatus pulls the filament which can solve the problem of different feeding speeds and prevent the filament from being worn, squeezed, blocked, and broken to improve the printing quality of the 3D printer. 
    
    
     
       BRIEF DESCRIPTION OF DRAWING 
         FIG. 1  is a perspective view of the feeding control system of the present invention; 
         FIG. 2  is a perspective view of the first feeding apparatus of the present invention; 
         FIG. 3  is a cross-sectional view of the first feeding apparatus of the present invention; 
         FIG. 4  is a perspective view of the first feeding apparatus of the present invention in an operational state; 
         FIG. 5  is a cross-sectional view of the first feeding apparatus of the present invention in an operational state; 
         FIG. 6  is a perspective view of the first feeding apparatus of the present invention in another operational state; 
         FIG. 7  is a cross-sectional view of the first feeding apparatus of the present invention in another operational state; 
         FIG. 8  is the flow chart of the feeding control method of a 3D printer of the present invention; 
         FIG. 9  is a perspective view of the first feeding apparatus according to another embodiment of the present invention in an operational state; 
         FIG. 10  is a cross-sectional view of the first feeding apparatus according to another embodiment of the present invention in an operational state; and 
         FIG. 11  is a perspective view of the feeding control system according to another embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The detailed description and technical details of the present invention will be explained below with reference to accompanying figures. However, the accompanying figures are only for reference and explanation, but not to limit the scope of the present invention. 
     Please refer to  FIGS. 1-7 . The present invention provides a feeding control system of a 3D printer and a feeding control method thereof, used with a filament  200 . The feeding control system  10  mainly comprises a first feeding apparatus  1 , a second feeding apparatus  2 , a feeding tube  3 , and a feeding sensor  4 . 
       FIG. 8  shows the steps of the feeding control method of a 3D printer of the present invention. As shown in step a and  FIGS. 1-7 , the first feeding apparatus  1  is provided and comprises a main frame  11 , an outlet  12 , a fixed wheel set  13 , a movable wheel set  14 , and a controller  15 . The fixed wheel set  13  and the movable wheel set  14  hold and deliver the filament  200  together to the outlet  12 ; the controller  15  is disposed corresponding to the movable wheel set  14 . 
     The detailed description is given below. The fixed wheel set  13  has a driving wheel  131  installed on the main frame  11 ; the driving wheel  131  drives and delivers the filament  200 . The outlet  12  is formed on the main frame  11  and disposed corresponding to the rotating direction of the driving wheel  131 . The movable wheel set  14  comprises a movable bracket  141  hinged to main frame  11  and a driven wheel  142  installed on the movable bracket  141  and disposed corresponding to the driving wheel  131 . The bottom of the movable bracket  141  is provided with a gear tooth  143 . 
     Moreover, the controller  15  comprises a motor  151  and a worm  152  rotating with the motor  151 . The movable bracket  141  drives the driven wheel  142 , by means of the screw linkage between the gear tooth  143  and the worm  152 , to approach the driving wheel  131  to hold and deliver the filament  200  or to move away from the driving wheel  131  to release the filament  200 . 
     In addition, the first feeding apparatus  1  further comprises two auxiliary wheels  16  installed on the main frame  11 . The two auxiliary wheels  16  are disposed between the outlet  12  and the driving wheel  131  to hold and delver the filament  200 . The two auxiliary wheels  16  are used to direct the filament  200  to be delivered from the driving wheel  131  to the outlet  12 . Therefore, the number of the auxiliary wheels  16  can be adjusted or the auxiliary wheels  16  can be omitted depending on the distance from the driving wheel  131  to the outlet  12 . 
     As shown in step b and  FIG. 1 , the second feeding apparatus  2  is installed in the interior of the 3D printer  100  and is used to deliver the filament  200  to the feeding nozzle (not shown) so that the second feeding apparatus  2  drives to deliver the filament  200  when the filament  200  enters the 3D printer  100 . 
     As shown in step c and  FIGS. 1-5 , the first feeding apparatus  1  drives and delivers the filament  200  to the 3D printer  100  through the outlet  12 . The description is detailed below. The feeding tube  3  is connected between the outlet  12  and the second feeding apparatus  2 ; the feeding tube  3  is used to direct the filament  200  to be delivered from the outlet  12  to the second feeding apparatus  2 . 
     Besides, in an embodiment, the feeding tube  3  can be optionally omitted and instead the user places the filament  200  manually to the second feeding apparatus  2  (or the interior of the 3D printer  100 ) after the first feeding apparatus  1  delivers the filament  200  to the outlet  12 . The second feeding apparatus  2  which has at least one driving wheel to pull the filament  200  can be a mechanism design with which a person having general knowledge and ordinary skills in the art is familiar or an identical or similar design to the above-mentioned first feeding apparatus  1 . 
     As shown in step d and  FIGS. 1-7 , when the filament  200  enters the 3D printer  100 , the second feeding apparatus  2  is controlled to drive and deliver the filament  200  and the first feeding apparatus  1  stops delivering the filament  200 . 
     The further explanation is given below. A feeding sensor  4  is provided and disposed corresponding to the second feeding apparatus  2  to sense entrance of the filament  200  driven and delivered by the second feeding apparatus  2  to generate a release signal. That is, the feeding sensor  4  is used to sense the second feeding apparatus  2  holds the filament  200  to generate a release signal. 
     A controller  15  is provided and disposed corresponding to the first feeding apparatus  1  such that the delivery of the filament  200  by the first feeding apparatus  1  is stopped after the controller  15  receives the release signal. 
     The detailed description is as follows. A fixed wheel set  13  and a movable wheel set  14  are provided. The driving wheel  131  is disposed at the fixed wheel set  13 . The movable wheel set  14  and the fixed wheel set  13  are controlled apart from each other to release the filament  200  and the driving wheel  131  is caused to stop the delivery of the filament  200  by the first feeding apparatus  1 . That is, after receiving the release signal, the motor  151  rotates the worm  152  to drive the movable bracket  141  to move away from the driving wheel  131  to release the filament  200 ; the driving wheel  131  stops rotating after receiving the release signal. 
     As shown in  FIG. 1 , the feeding control system  10  of the present invention further comprises a material bin  5  and a spool  6 . The material bin  5  is disposed at one side of the 3D printer  100 ; the first feeding apparatus  1  and the spool  6  are both disposed in the material bin  5 . The spool  6  is disposed at one side of the first feeding apparatus  1  and used to wind the filament  200  such that the filament  200  can be wound into a roll through the spool  6  for easy replacement. 
     The operational states of the feeding control system  10  of the present invention are explained as follows. First, as shown in  FIGS. 1-3 , the filament  200  wound around the spool  6  is placed in the material bin  5 . Then, the filament  200  is penetrated into the first feeding apparatus  1  such that the filament  200  is clamped between the driven wheel  142  and driving wheel  131  and passed through the outlet  12 . At this moment, the preparations for the automatic feeding are completed. 
     Also, as shown in  FIGS. 1-5 , after the driving wheel  131  rotates, the driving wheel  131  and the driven wheel  142  hold and deliver the filament  200  together to the outlet  12 . Next, the feeding tube  3  directs the filament  200  to be delivered from the outlet  12  to the second feeding apparatus  2 . 
     Furthermore, as shown in  FIGS. 1, 6, and 7 , the feeding sensor  4  senses that the second feeding apparatus  2  holds the filament  200  and generates the release signal. After receiving the release signal, the motor  151  rotates the worm  152  to drive the movable bracket  141  to move away from the driving wheel  131  such that the driven wheel  142  moves away from the driving wheel  131  to release the filament  200  in order that after receiving the release signal, the controller  15  drives the movable wheel set  14  to move away from the fixed wheel set  13  to release the filament  200 ; simultaneously, after receiving the release signal, the driving wheel  131  stops operating and only the second feeding apparatus  2  pulls the filament  200 . At this moment, the automatic feeding is completed. 
     In the prior art, when the front feeding motor starts to pull the filament, the rear feeding motors synchronizes to start pushing the filament, which easily results in asynchronous speeds of the front feeding motor and the rear feeding motor. Compared with the prior art, when the second feeding apparatus  2  of the present invention holds the filament  200 , the first feeding apparatus  1  releases the filament  200  immediately to stop pushing the filament  200  and only the second feeding apparatus  2  pulls the filament  200 . Consequently, the problem of different feeding speeds is overcome and the filament is prevented from being worn, squeezed, blocked, or broken to improve the printing quality of the 3D printer  100 . 
     Please refer to  FIGS. 9 and 10 , which refer to the first feeding apparatus  1  according to another embodiment of the present invention. The embodiment shown in  FIGS. 9 and 10  is roughly similar to that shown in  FIGS. 1-7 . The major difference between the above two embodiments is the structure of the controller  15 . 
     The further explanation is as follows. A projecting plate  144  protrudes from the movable bracket  141 . The controller  15  comprises a motor  151 , a cam  153 , and a return spring  154 ; the cam  153  rotates with the motor  151  and is disposed corresponding to one side of the projecting plate  144 ; the return spring  154  is clamped between the main frame  11  and the other side of the projecting plate  144 . When the motor  151  drives the cam  153  to press against the projecting plate  144 , the recovering spring force of the return spring  154  can be resisted such that the driven wheel  142  is driven to approach the driving wheel  131  to hold and deliver the filament  200 . When the motor  151  drives the cam  153  to release the projecting plate  144 , the recovering spring force of the return spring  154  immediately presses against the projecting plate  144  to drive the driven wheel  142  to move away from the driving wheel  131  to release the filament  200 . The person having general knowledge and ordinary skills in the art should realize the above control mechanism can be adjusted to become a reverse design. That is, when the motor  151  drives the cam  153  to press against the projecting plate  144 , the driven wheel  142  is caused to move away from the driving wheel  131 ; when the motor  151  drives the cam  153  to release the projecting plate  144 , the driven wheel  142  is caused to approach the driving wheel  131 . 
     After receiving the release signal, the motor  151  drives the cam  153  to release the projecting plate  144  such that the return spring  154  pushes the movable bracket  141  to move away from the driving wheel  131 . In this way, the current embodiment can achieve the same function and effect as the embodiment in  FIGS. 1-7 . 
     Please refer to  FIG. 11 , which is a perspective view of the feeding control system  10  according to another embodiment of the present invention. The embodiment shown in  FIG. 11  is roughly similar to that shown in  FIGS. 1-7 . The difference between the above two embodiments in  FIG. 11  and in  FIGS. 1-7  is that the first feeding apparatus  1  in  FIG. 11  is plural in number. 
     The details are given below. The filament  200  and the first feeding apparatus  1  are both plural in number. The filaments  200  are disposed corresponding to the respective first feeding apparatuses  1 . The feeding tube  3  has a main tube  31  disposed at one end thereof and a plurality of split tubes  32  which extend from the other end thereof and communicate with the main tube  31 . The main tube  31  is connected to the second feeding apparatus  2  and the split tubes  32  are connected to the respective outlets  12 . 
     Furthermore, the feeding control system  10  of the present invention further comprises a calculator  7  and a plurality of reloading sensors  8 . The calculator  7  is electrically connected to each of the first feeding apparatuses  1  and the reloading sensors  8  are disposed corresponding to the respective first feeding apparatuses  1 . Each of the reloading sensors  8  is used to detect the separation due to shortage of the filament  200  from the outlet  12  to generate a reloading signal. That is, the filament  200  in the first feeding apparatus  1  runs out, the reloading sensor  8  will send a reloading signal. 
     When the calculator  7  receives the reloading signal sent from one of the first feeding apparatuses  1 , another first feeding apparatus  1  will deliver the filament  200  to the main tube  31  through the corresponding split tube  32 . That is, the fixed wheel set  13  and the movable wheel set  14  of another first feeding apparatus  1  are driven to hold and deliver the filament  200  to the split tube  32  (or the filament  200  has been delivered to the corresponding split tube  32  when installed in advance) such that the main tube  31  has sufficient filament  200  to be delivered to the second feeding apparatus  2  at any time, which can prevent the 3D printer  100  from stopping by lack of filament  200  to make the feeding control system  10  have the feature of automatic feeding. 
     In summary, the feeding control system of a 3D printer and the feeding control method thereof of the present invention have never been anticipated by similar products in the market and used in public. Also, the present invention is useful, novel and non-obvious to be patentable. Please examine the application carefully and grant it as a formal patent for protecting the rights of the inventor.