Abstract:
The present invention discloses a 3D food printer, which comprises a large hopper in a print head with a cooling system, so as to store and supply a large amount of a food material and print reliably at a high ambient temperature, and an automatic conveying system for printed products, so as to automatically output the food product after printing it, and then proceed with the next one. These features make the printer more effective, easier to operate, and in line with the requirements of food hygiene. The technical solution includes: the 3D food printer comprising a print head for extruding a food material; a cooling system for keeping the food material at a low temperature at which the food material does not melt or agglomerate; a conveying system for automatically outputting a printed food product; a frame for supporting the entire  3 D food printer; a drive system for driving the 3D food printer to move in the X-, Y- and Z-directions; and a control system for controlling the operation of the entire 3D food printer.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a 3D printer, in particular to a 3D printer for making food (for example, chocolate). 
       BACKGROUND 
       [0002]    With the development of 3D printing technology, 3D food printers begin to appear, and particularly there are more and more 3D chocolate printers. However, their structures generally have some defects, which mainly consist in that the material storage device (a syringe, or a hopper) has a small volume, so that frequent supplement is often needed during printing; the chocolate needs to be taken out manually after printing, which is not only complicated in operation and reduces the efficiency, but also disadvantageous for food hygiene; and in hot summer, due to the excessively high ambient temperature, chocolate granules in the hopper may melt and agglomerate, causing the printer unable to work normally. 
       SUMMARY 
       [0003]    A brief summary on one or more aspects is given below to provide the basic understanding for these aspects. The summary is not an exhaustive review for all the conceived aspects, and is intended to neither point out all the critical or decisive factors for all the aspects nor define the scope of any or all of the aspects. Its only aim is to provide some concepts of one or more aspects in a simplified manner as a preface of the more detailed description given later. 
         [0004]    The object of the present invention is to, for solving the above-mentioned problems, provide a 3D food printer, which comprises a large hopper in a print head with a cooling system, so as to store and supply a large amount of a food material and print reliably at a high ambient temperature, and an automatic conveying system for printed products, so as to automatically output the food product after printing it, and then proceed with the next one. These features make the printer more effective, easier to operate, and in line with the requirements of food hygiene. 
         [0005]    The technical solution of the present invention is as follows: the present invention discloses a 3D food printer, comprising: 
         [0006]    a print head for extruding a food material; 
         [0007]    a cooling system for keeping the food material at a low temperature at which the food material does not melt or agglomerate; 
         [0008]    a conveying system for automatically outputting a printed food product; 
         [0009]    a frame for supporting the entire 3D food printer; 
         [0010]    a drive system for driving the 3D food printer to move in the X-, Y- and Z-directions; and 
         [0011]    a control system for controlling the operation of the entire 3D food printer. 
         [0012]    According to an embodiment of the 3D food printer of the present invention, said print head comprises a first stepper motor, a bevel gear pair, a transmission shaft, a screw, a hopper, a material barrel, a material cover, an electric heating jacket, a cross-shaped plate, a blade, a water jacket and a nozzle, wherein: 
         [0013]    for said first stepper motor is horizontally installed on a side of the hopper, an output shaft of the first stepper motor is connected to a small bevel gear in the bevel gear pair, and the base of the first stepper motor is connected to a side of the hopper, for driving the screw; 
         [0014]    for said bevel gear pair comprises a small bevel gear and a large bevel gear, the small bevel gear being engaged with the large bevel gear, and the large bevel gear being fixed to an upper end of the transmission shaft, for transferring the motion of the first stepper motor; 
         [0015]    for said screw, an upper end of the screw is connected to the transmission shaft, a lower end of the screw is connected to the nozzle, and the outer diameter of the screw is fitted with an inner hole of the material barrel, for conveying and extruding the food material; 
         [0016]    for said hopper, an upper end of the hopper is fitted with the material cover, a lower end of the hopper is connected to the material barrel, and a side of the hopper is connected to a base of the first stepper motor, for storing the food material; 
         [0017]    for said material barrel, an upper end of the material barrel is connected to the hopper, a lower end of the material barrel is connected to the electric heating jacket, and a middle part of the material barrel is connected to a Z-direction driving mechanism of the drive system, for guiding the screw and transferring the Z-directional motion; 
         [0018]    for said material cover, a lower surface of the material cover is fitted with the upper end of the hopper, for closing an upper charging opening of the hopper; 
         [0019]    said electric heating jacket comprises an electrical heating rod and a thermocouple, an upper end of the electric heating jacket is connected to the material barrel, and an inner hole of the electric heating jacket is fitted with the nozzle, for heating the food material in the nozzle; 
         [0020]    for said cross-shaped plate, an outer edge of the cross-shaped plate is connected to an inner wall of the hopper, and an inner hole of the cross-shaped plate is fitted with the transmission shaft by means of a bearing therein, for locating the transmission shaft; 
         [0021]    for said blade, an inner hole of the blade is connected to the transmission shaft, for stirring the food material in the hopper; 
         [0022]    for said water jacket, an inner wall of the water jacket is fitted with the outer wall of the hopper, cooling water from the cooling system is circulating in an internal groove in the water jacket, for lowering the temperature of the food material in the hopper; and 
         [0023]    for said nozzle, an upper end of the nozzle is connected to the screw, an outer edge of the nozzle is fitted with the inner hole of the electric heating jacket, for transforming the food material into a molten filament and extruding the material onto a cling film of a conveying system therebelow. 
         [0024]    According to an embodiment of the 3D food printer of the present invention, the first stepper motor in said print head drives the vertically installed screw by means of the engaged bevel gear pair, so as to prevent the first stepper motor from being perpendicular to the hopper and thus blocking the channel for adding the food material and reducing the storage capacity of the hopper. 
         [0025]    According to an embodiment of the 3D food printer of the present invention, the hopper of said print head is cooled by a cooling system comprising a water pump, a cold water tank, a cooling-water machine and water pipes, wherein: 
         [0026]    for said water pump, an inlet of the water pump is connected to the cold water tank via the water pipe, and an outlet of the water pump is connected to the cooling-water machine via the water pipe, so that the water in the cold water tank is cooled by the cooling-water machine and flows into the water jacket of the print head; 
         [0027]    for said cold water tank, an outlet of the cold water tank is connected to the water pump via the water pipe, an inlet of the cold water tank is connected to the water jacket via the water pipe, and a thermocouple is installed inside the cold water tank, for storing cooling water; 
         [0028]    for said cooling-water machine, an inlet of the cooling-water machine is connected to the water pump via the water pipe, an outlet of the cooling-water machine is connected to the water jacket via the water pipe, for keeping the food material in the hopper at a low temperature; and 
         [0029]    said water pipes are used for the communication between the water pump, the cold water tank, the cooling-water machine and the water jacket. 
         [0030]    According to an embodiment of the 3D food printer of the present invention, said conveying system comprises a second stepper motor, a take-up roll, a cling film roll, supports, a tray, a substrate and a platform, wherein: 
         [0031]    for said second stepper motor, an output shaft of the second stepper motor is connected to a spindle of the take-up roll, and a bed of the second stepper motor is connected to the platform, for driving the take-up roll; 
         [0032]    for said take-up roll, the two end faces of the spindle of the take-up roll are supported on the platform by the supports, an end socket of the spindle is connected to an output shaft of the second stepper motor, and an outer edge of the take-up roll is wound by a cling film pulled out of the cling film roll, for outputting printed food products; 
         [0033]    for said cling film roll, two end faces of the spindle of the cling film roll are supported on the platform by the supports, and the cling film winding on the roll serves as a base for printing a food product; 
         [0034]    for said supports, an upper end of one of the supports is fitted with the spindle of the cling film roll for supporting the cling film roll, and an upper end of the other support is fitted with the spindle of the take-up roll for supporting the take-up roll, and lower ends of said two supports are connected to the platform for fixing the supports; 
         [0035]    said tray is disposed on the platform and on the right side of the take-up roll for receiving the printed food product; 
         [0036]    for said substrate, an upper end face of the substrate is tightly attached to the cling film, and a lower end face of the substrate is connected to the platform, for supporting the printed food product; and 
         [0037]    for said platform, an upper end face of the platform is separately connected to lower ends of the said two supports and a lower end face of the substrate for supporting the conveying system, and said platform is further connected to the drive system for moving in X-direction and Y-direction relative to the frame. 
         [0038]    According to an embodiment of the 3D food printer of the present invention, said conveying system actuates the take-up roll by the second stepper motor, drives the cling film roll, and pulls the cling film, so that the printed food product is automatically outputted to the tray, so as to continuously print food product without the need to manually remove the product. 
         [0039]    According to an embodiment of the 3D food printer of the present invention, during the printing, said print head only needs to move in the Z-direction layer by layer intermittently, and the X- and Y-directional motions required for printing are achieved by said conveying system. 
         [0040]    According to an embodiment of the 3D food printer of the present invention, said frame comprises a casing and a bed, the casing being constituted by an aluminium profile and an acrylic board, so that said print head and said conveying system of the printer are resident in an isolated dust-free environment, and said bed being used for supporting the entire 3D food printer. 
         [0041]    According to an embodiment of the 3D food printer of the present invention, said drive system comprises stepper motor for driving in X-, Y- and Z-directions and corresponding transmission devices, for achieving the X-, Y- and Z-directional motions; and said control system consists of a computer numerical control system, for controlling the operation of the entire 3D food printer. 
         [0042]    According to an embodiment of the 3D food printer of the present invention, said food is chocolate. 
         [0043]    With respect to the prior art, the present invention has the beneficial effects as follows: the solution of the present invention adopts a large hopper in the print head with a cooling system, so as to store and supply a large amount of a food material (for example, a chocolate material) and print reliably at a high ambient temperature, and an automatic conveying system for printed products, so as to automatically output the food product after printing it, and then proceed with the next one. These features make the printer more effective, easier to operate, and in line with the requirements of food hygiene. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0044]      FIG. 1  shows a diagram of a preferred embodiment of a 3D food printer of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0045]    After reading the detail description of the embodiments of the present disclosure in conjunction with the following drawings, the above-mentioned features and advantages of the present invention can be better understood. In the drawings, the components are not necessarily drawn to scale, and the components with similar related characteristics or features may have the same or similar reference numerals. 
         [0046]    The 3D food printer of the present invention may be used for 3D printing of food products with food materials, and a common application is for 3D printing of a chocolate product with a chocolate material. The following embodiment is explained with chocolate as an example. 
         [0047]      FIG. 1  shows a diagram of an embodiment of a 3D chocolate printer of the present invention. With reference to  FIG. 1 , the 3D chocolate printer of this embodiment mainly comprises a print head  100 , a cooling system  200 , a conveying system  300 , a frame  400 , a drive system and a control system (not shown). 
         [0048]    The print head  100  extrudes a chocolate material, and comprises a stepper motor  12 , a bevel gear pair (constituted by a large bevel gear  10  and a small bevel gear  11 ), a transmission shaft  13 , a screw  14 , a hopper  8 , a material barrel  3 , a material cover  9 , an electric heating jacket  17 , a cross-shaped plate  5 , a blade  6 , a water jacket  7  and a nozzle  2 . The stepper motor  12  is horizontally installed on a side of the hopper  8 ; an output shaft of the stepper motor  12  is connected to the small bevel gear  11  in the bevel gear pair; and the base of the stepper motor  12  is connected to a side of the hopper  8 . An upper end of the screw  14  is connected to the transmission shaft  13 ; a lower end of the screw  14  is connected to the nozzle  2 ; the outer diameter of the screw  14  is fitted with an inner hole of the material barrel  3 , for conveying and extruding the chocolate material. The small bevel gear  11  is engaged with the large bevel gear  10 , and the large bevel gear  10  is fixed to the upper end of the transmission shaft  13 , for transferring the motion of the stepper motor  12 . The stepper motor  12  drives the vertically installed screw  14  via the small bevel gear  11 , the large bevel gear  10  engaged with the small bevel gear  11 , and the transmission shaft  13 , so that the chocolate granules in the hopper  8  are drawn into the screw channel on the top of the screw  14  and moves downwards along the screw channel so as to prevent the stepper motor from being perpendicular to the hopper and thus blocking the channel for adding the chocolate material and reducing the storage capacity of the hopper, and then the chocolate granules are heated to a molten state by the electric heating jacket  17  and then extruded from the nozzle  2 . The upper end of the nozzle  2  is connected to the screw, and the outer edge of the nozzle is fitted with an inner hole of the electric heating jacket  17 , for transforming the chocolate into a molten filament and extruding them onto a cling film of the conveying system therebelow. For heating the chocolate material in the nozzle, the electric heating jacket  17  comprises an electrical heating rod  1  and a thermocouple  15 , the upper end of the electric heating jacket  17  is connected to the material barrel  3 , and the inner diameter of the electric heating jacket  17  is fitted with the nozzle  2 . The electric heating jacket  17  uses the electrical heating rod  1  for heating, and uses the thermocouple  15  for detecting and controlling temperature. For locating the transmission shaft  13 , the outer edge of the cross-shaped plate  5  is connected to the inner wall of the hopper  8 , and an inner hole of the cross-shaped plate is fitted with the transmission shaft  13  by means of a bearing therein. The transmission shaft  13  is located by means of the bearing (not shown) at the center of the cross-shaped plate  5 , and a plurality of cavities are provided at the periphery of the cross-shaped plate  5 , and used as falling channels for the chocolate granules in the hopper  8 . An inner hole of the blade  6  is connected to the transmission shaft  13 , so that the chocolate granules in the hopper  8  can be stirred, fall smoothly and enter the screw channel in the top of the screw  14 . The material cover  9  on the top end of the hopper  8  can be opened when adding materials. For storing the chocolate material, the upper end of the hopper  8  is fitted with the material cover  9 , the lower end of the hopper  8  is connected to the material barrel  3 , and a side of the hopper  8  is connected to the base of the stepper motor  12 . The inner wall of the water jacket  7  is fitted with the outer wall of the hopper  8 ; cooling water from the cooling system circulates in the internal groove of the water jacket  7 ; the water jacket  7  outside the hopper  8  is used to allow the cooling water to pass through, so as to cool the chocolate granules in the hopper  8  when the ambient temperature is too high and always keep the temperature below 25° C., so that the chocolate granules do not melt or agglomerate and it is ensured that the granules can be extruded from the screw  14  and the nozzle  2 . For guiding the screw  14  and transferring the Z-directional motion, the upper end of the material barrel  3  is connected to the hopper  8 , the lower end is connected to the electric heating jacket  17 , and the middle part is connected to a Z-directional driving mechanism of the drive system (not shown), so as to drive the print head  100  to ascend the thickness of one layer after printing one layer of chocolate cross-section and proceed with the next chocolate cross-section. Since the hopper  8  in the above-mentioned print head  100  has a tall and large cylindrical segment, the stepper motor  12  is horizontally arranged by means of a pair of bevel gears, rather than standing in the hopper  8 , so as to feed materials conveniently, and be capable of storing and supplying much more chocolate material, so that the printer can continuously print many chocolate products without frequent feeding. Furthermore, since the cooling water jacket  7  is provided outside the hopper  8 , the printer can print a chocolate product normally in a hot environment. 
         [0049]    The cooling system  200  cools the hopper  8  of the print head  100  so as to keep the chocolate material at a low temperature at which the chocolate material does not melt or agglomerate, and comprises a water pump  25 , a cold water tank  27 , a cooling-water machine  23 , and water pipes  21 ,  22 ,  24  and  26  for communication between the water pump  25 , the cold water tank  27  and the cooling-water machine  23 . The water pump  25  sucks water from the cold water tank  27  via the water pipe  26  and then conveys the water to the cooling-water machine  23  via the water pipe  24 , and owing to the cooling effect of the cooling-water machine  23 , the water temperature is decreased to the required temperature (for example, about 20° C.), and then the water flows into the water jacket  7  of the print head  100  via the water pipe  22  to cool the hopper  8 , so that the chocolate material therein is always kept below 25° C. The water flowing out of the water jacket  7  flows back to the cold water tank  27  via the water pipe  21 . The outlet of the cold water tank  27  is connected to the water pump  25  via the water pipe  26 , the inlet of the cold water tank  27  is connected to the water jacket  7  via the water pipe  21 , the thermocouple  28  inserted into the cold water tank  27  is used to detect the water temperature in the cold water tank  27 , and the water in the cold water tank  27  is kept at a required constant temperature by means of the control system (not shown). 
         [0050]    The conveying system  300  automatically outputs the printed chocolate product, and consists of a stepper motor  31 , a cling film roll  38 , a take-up roll  32 , a tray  33 , a substrate  35 , a platform  36 , and supports  34  and  37 . For driving the take-up roll  32 , the output shaft of the stepper motor  31  is connected to the spindle of the take-up roll  32 , and the bed of the stepper motor  31  is connected to the platform  36 . The upper end of one of the supports  37  is fitted with the spindle of the cling film roll  38  for supporting the roll, and the upper end of the other support  34  is fitted with the spindle of the take-up roll  32  for supporting the roll. The lower end of the support  37  is connected to the platform  36  for fixing the support. Two end faces of the spindle of the cling film roll  38  are supported on the platform  36  by the supports  37  and rotate relative to the support  37 , and the cling film winding on the roll serves as a base for printing chocolate products. For outputting the printed chocolate product, two end faces of the spindle of the take-up roll  32  are supported on the platform  36  by the supports, the end socket of the spindle is connected to the output shaft of the stepper motor  31 , and the outer edge of the take-up roll  32  is wound by a cling film pulled out of the cling film roll  38 . The spindle of the take-up roll  32  is supported on the platform  36  by the support  34 , and can rotate relative to the support  34 . The spindle of the take-up roll  32  is connected to the output shaft of the stepper motor  31 , and under the drive of the stepper motor  31 , the cling film  39  can be pulled out from the cling film roll  38  and wind around the take-up roll  32 . The lower end face of the substrate  35  is fixed onto the platform  36 , and the upper end face is tightly attached to the lower surface of the cling film  39 . Under the action of the drive system (not shown), the platform  36 , the substrate  35 , the stepper motor  31 , the cling film roll  38 , the take-up roll  32 , the support  34  and the support  37  can move in the X-Y directions. Here, the upper end face of the substrate  35  is tightly attached to the cling film, and the lower end face of the substrate  35  is connected to the platform  36 , for supporting the printed chocolate product. The upper end face of the platform  36  is connected to the lower ends of the two supports and the lower end face of the substrate respectively, for supporting the conveying system, and the platform  36  is further connected to the drive system, for moving in X-direction and Y-direction relative to the frame  400 . 
         [0051]    After printing a chocolate product, the stepper motor  31  rotates in the clockwise direction to drive the take-up roll  32  to drive the cling film roll  38  to pull the cling film  39 , so that the cling film  39  and the chocolate product printed thereon move in the X-direction relative to the substrate  35  and then automatically fall to the tray  33  on the right side, without the need to manually remove the chocolate product, so as to continuously print the chocolate products. The tray  33  is disposed on the platform  36  and on the right side of the take-up roll  32  for receiving the printed chocolate products. 
         [0052]    The frame  400  bears the entire 3D chocolate printer, and comprises a casing  41  and a bed  42 . The casing  41  is a closed body constituted by an aluminium profile and an acrylic board, so that the print head  100  and the conveying system  300  of the 3D printer are in a dust-free environment. The bed  42  is used for supporting the entire 3D chocolate printer. 
         [0053]    The drive system (not shown) comprises stepper motors for driving in X-direction, Y-direction and Z-direction and corresponding transmission devices, for implementing the Z-directional motion of the print head  100  and the X-Y directional motion of the conveying system  300 . The print head  100  only needs to move in the Z-direction layer by layer intermittently, and does not have to perform a transverse motion, and the X- and Y-directional motions required for printing are achieved by the conveying system. 
         [0054]    The control system (not shown) is a computer numerical control system for controlling the motion of the entire 3D chocolate printer. 
         [0055]    Using the structure of the above embodiment of the present invention, according to a CAD model of the chocolate product, many chocolate products can be continuously printed and automatically outputted. 
         [0056]    Not only customized chocolate products but also other customized foods can be formed by printing with flour, jelly powder, cream, etc. using the present invention mentioned above. 
         [0057]    The previous description of the present disclosure is provided to enable any one skilled in the art to make or use the present disclosure. Various modifications to the present disclosure would all be obvious to a person skilled in the art, and the general principles defined herein can be applied to other variations without departing from the spirit or scope of the present disclosure. Thereby, the present disclosure is not intended to be limited to the examples and designs described herein, but should be granted with the widest scope consistent with the principle and novelty features disclosed herein.