Three-dimensional printer with jet function

Abstract

The invention discloses a three-dimensional printer with an injection function, which comprises a workbench, a circular trough and a rotator are arranged on the workbench, the trough is used for containing liquid photosensitive resin, an annular pipe is arranged in the trough, the annular pipe is provided with an inlet and an outlet, and the inlet and the outlet are communicated with the rotator. The magnetic ball is movably placed in the annular pipe, the magnetic ball rotates in the annular pipe in the extending direction of the annular pipe through magnetism, the liquid photosensitive resin is sucked into the annular pipe and can be sprayed out of the annular pipe, and therefore the liquid photosensitive resin in the material groove flows. According to the device, the round ball circularly rotates in the annular pipe by utilizing magnetism, liquid photosensitive resin in the annular pipe is sprayed into the material groove, and meanwhile, the liquid photosensitive resin in the material groove is sucked into the annular pipe, so that the liquid photosensitive resin in the material groove flows, and the liquid photosensitive resin in the material groove is mixed; and the layering phenomenon of solid particles caused by the stable state of the liquid photosensitive resin is avoided.

Description

Technical Field

[0001] The invention relates to a three-dimensional printer with a jetting function. Background Art

[0002] Three-dimensional printing technology, also known as 3D printing, has developed rapidly in recent years and has provided a new production method for the production of modern products. In the top-up three-dimensional light-curing printing technology, the light source irradiates the liquid photosensitive resin in the material tank from bottom to top, so that the liquid photosensitive resin is cured and gradually stacked onto the printing platform. At the same time, the printing platform is lifted upward layer by layer in the vertical direction, so that the liquid photosensitive resin is cured layer by layer and finally stacked to form a three-dimensional product.

[0003] In the process of printing three-dimensional products, due to the instability of solid particles in the liquid photosensitive resin, the solid particles fall and stratify, and due to the temperature change and the continuous accumulation of the energy of the irradiated light in the liquid photosensitive resin, some of the liquid photosensitive resin undergoes qualitative changes. After a long period of accumulation, some of the liquid photosensitive resin may be solidified, thereby affecting the continuous progress of subsequent printing. Therefore, in the printing process, it is necessary to make the liquid photosensitive resin in the material tank flow to avoid the occurrence of solidification. To this end, people have added a swing rod at the bottom of the material tank to make the liquid photosensitive resin in the material tank flow, but the swing rod can only work after completing a solidified layer and lifting the printing platform upward to make the solidified layer attached to the printing platform detach from the bottom of the material tank, so that the liquid photosensitive resin in the material tank flows, thereby affecting the printing speed and reducing the production efficiency of three-dimensional products. Therefore, how to make the liquid photosensitive resin in the material tank flow and avoid the falling stratification of solid particles without affecting the printing efficiency still needs further research. Summary of the invention

[0004] In order to solve the problem of affecting the production efficiency of three-dimensional products in the prior art by making the liquid photosensitive resin flow, the present application first proposes a three-dimensional printer with a jetting function, which includes a workbench, on which a circular material trough and a rotator are installed, the material trough is used to hold the liquid photosensitive resin, a ring-shaped annular tube is arranged in the material trough, a plurality of inlets and outlets are opened on the annular tube, a ball is movably placed in the annular tube, and the ball is made of ferromagnetic material; a magnet is installed on the rotator, the rotator can drive the magnet to rotate around the material trough, and the magnet drives the ball to rotate in the annular tube along the extension direction of the annular tube; when the ball rotates in the annular tube, the liquid photosensitive resin in the material trough can be sucked into the annular tube through the inlet and outlet on the upstream side, and the liquid photosensitive resin in the annular tube can be ejected into the material trough through the inlet and outlet on the downstream side, so that the liquid photosensitive resin in the material trough flows. In order to improve the adsorption capacity of the magnet to the ball, it is preferred that the center of the ball is at the same height as the center point of the magnet in the height direction.

[0005] In the present application, an annular tube is provided in the material trough, and the attraction of the magnet is utilized to enable the ball to circulate and rotate in the annular tube along the extension direction of the annular tube, and the driving force of the ball when rotating in the annular tube is utilized to spray the liquid photosensitive resin in the annular tube from the inlet and outlet on the downstream side into the material trough, and at the same time, the negative pressure generated by the upstream side of the ball is utilized to suck the liquid photosensitive resin in the material trough into the annular tube, so that the liquid photosensitive resin in the material trough flows, and the liquid photosensitive resin in various places in the material trough is mixed, thereby avoiding the solid particle stratification phenomenon caused by the liquid photosensitive resin being in a stable state. At the same time, since the liquid photosensitive resin in the material trough flows, it is possible to avoid the situation where the liquid photosensitive resin in a certain area of ​​the material trough tends to solidify due to the accumulation of irradiated light energy. The annular tube in the present application can be provided in an area of ​​the material trough that does not affect printing, thereby avoiding affecting the printing speed, and can smoothly cause the liquid photosensitive resin in the material trough to flow.

[0006] Furthermore, in order to ensure that the liquid photosensitive resin in the central area of ​​the material tank flows, each inlet and outlet is horizontally oriented toward the central part of the material tank.

[0007] The liquid photosensitive resin sprayed from the inlet and outlet can flow radially toward the center of the material trough. During the rotation of the ball, the inlet and outlet on the upstream side of the ball suck the liquid photosensitive resin around it into the annular tube, and the liquid photosensitive resin on the downstream side of the ball in the annular tube is sprayed toward the center of the material trough through the inlet and outlet on the downstream side, thereby causing the liquid photosensitive resin in the entire material trough to flow.

[0008] Specifically, the annular tube is located radially outside the material tank. This design enables the central area of ​​the material tank to become the setting area of ​​the printing platform, and the annular tube will not interfere with the printing platform and affect the normal operation of the printing platform. In addition, when the annular tube is working, the liquid photosensitive resin on the radial outside of the material tank is sucked into the annular tube and then sprayed into the central area of ​​the material tank, so that the liquid photosensitive resin in the material tank flows rapidly, avoiding the descending stratification of solid particles in the liquid photosensitive resin, and reducing the tendency of the liquid photosensitive resin to undergo qualitative changes due to temperature changes and the continuous accumulation of irradiation light energy in the liquid photosensitive resin.

[0009] Furthermore, to ensure smooth printing, the 3D printer also includes a printing platform. The bottom surface of the trough is divided into a working area and a non-working area. The working area is located in the central part of the bottom surface of the trough, and the non-working area surrounds the working area. The printing platform can enter the trough in a vertical direction and is located in the working area. The annular tube is located in the non-working area. Setting the working area and the non-working area can make the functions of each area in the trough clearer. The working area is used to accommodate the printing platform, and the non-working area is used to accommodate the annular tube, so as to avoid the annular tube from affecting the normal operation during printing.

[0010] Specifically, the rotator includes an externally-toothed slewing bearing and a driving motor. The externally-toothed slewing bearing includes an outer ring and an inner ring connected together by balls. The inner ring is fixed on a workbench. The outer ring has teeth protruding radially outward. The externally-toothed slewing bearing is coaxially arranged with the material trough. The driving motor is fixed on the workbench. A gear is installed on the output shaft of the driving motor. The gear is meshed with the outer ring. A magnet is installed on the outer ring. Driven by the driving motor, the outer ring can drive the magnet to rotate around the central axis of the material trough, and synchronously drive the ball to rotate in the annular tube. The driving motor is a servo motor.

[0011] The driving motor drives the outer ring through the gear, and drives the ball to rotate in the annular tube through the magnet, so that the liquid photosensitive resin in the material tank can flow. By adjusting the speed of the driving motor, the moving speed of the ball in the annular tube can be adjusted, and the injection speed of the liquid photosensitive material sprayed from the annular tube can be adjusted, thereby adjusting the flow speed of the liquid photosensitive material in the material tank.

[0012] Specifically, in order to adapt to the structure of the external gear slewing bearing, the trough includes a cylindrical trough wall and a trough flange arranged at the bottom of the trough wall, and the trough flange is fixed on the workbench; in the height direction, the release film is fixed to the middle part of the trough wall, and the annular tube is located at the bottom of the trough. Since the release film is located in the middle part of the trough wall, the height center of the magnet can be the same as the height center of the annular tube, so that the magnet can be as close to the height position of the annular tube as possible, thereby generating a greater attraction for the ball. The distance between the magnet and the outer peripheral surface of the trough wall is controlled between 0.1-1mm.

[0013] Specifically, the rotator includes a hollow shaft torque motor, which includes a stator and a mover rotatably arranged in the stator. The central axis of the hollow shaft torque motor extends in the vertical direction. A hollow shaft is fixedly installed on the mover. The stator is fixedly installed on a workbench. The mover, the hollow shaft and the material trough are coaxially arranged. The magnet is installed on the inner side of the hollow shaft. When the hollow shaft torque motor is working, the mover can drive the magnet to rotate around the central axis of the material trough, and synchronously drive the ball to rotate in the annular tube. The hollow shaft torque motor is a servo motor.

[0014] The mechanism of using the mover of the hollow shaft torque motor to drive the magnet can flexibly adjust the rotation speed of the ball in the annular tube to adjust the injection speed of the liquid photosensitive resin sprayed out of the annular tube, thereby adjusting the flow speed of the liquid photosensitive material in the material tank.

[0015] Furthermore, the trough includes a cylindrical trough wall and a trough flange arranged on the top of the trough wall, and the trough flange is fixedly mounted on the stator; in the height direction, the release film is fixed to the bottom of the trough wall, and the annular tube is located at the bottom of the trough. After the trough flange is arranged at the top of the trough wall and installed on the stator, the problem of excessive distance between the magnet and the trough due to the trough flange can be avoided. This design can make the magnet as close as possible to the outer peripheral surface of the trough wall of the trough, so that the magnet can have a greater attraction to the ball. The distance between the magnet and the outer peripheral surface of the trough wall is controlled between 0.1-1mm.

[0016] Secondly, the present application also proposes another three-dimensional printer with a jetting function, which includes a workbench, on which a circular material trough is installed, the material trough is used to hold liquid photosensitive resin, a ring-shaped annular tube is arranged in the material trough, the annular tube is located radially outside the material trough, and a plurality of inlets and outlets are opened on the annular tube, each of which is horizontally oriented toward the central part of the material trough; a spherical ball is movably placed in the annular tube, and the spherical ball is made of ferromagnetic material;

[0017] A spiral coil is wound on the annular tube, and both ends of the spiral coil are connected to a plug, which is used to be plugged into a DC power supply; when the spiral coil is connected to DC power, it can drive the ball to rotate in the annular tube along the extension direction of the annular tube; when the ball rotates in the annular tube, the liquid photosensitive resin in the material tank can be sucked into the annular tube through the inlet and outlet on the upstream side, and the liquid photosensitive resin in the annular tube can be sprayed into the material tank through the inlet and outlet on the downstream side, so that the liquid photosensitive resin in the material tank flows.

[0018] The spiral coil specifically uses enameled wire or metal wire with an insulating protective layer, generally copper wire, such as copper enameled wire or copper wire with a rubber insulating layer. When multiple spiral coils are used, the spiral directions of the spiral coils are the same, and the ends of the spiral coils facing the same direction are all used as the positive terminal, and the other ends facing the same direction are all used as the negative terminal to avoid confusion.

[0019] When the spiral coil is just energized, the ball cannot rotate due to the adhesion of the liquid photosensitive resin. In this case, a magnet is needed to drive the ball to rotate outside the third material trough. After the ball starts to rotate, when the rotation speed reaches the set speed, the voltage of the DC power supply needs to be adjusted in time, and the resistance of the liquid photosensitive resin is used to keep the ball at a constant speed. Otherwise, the ball will continue to accelerate under the influence of acceleration and eventually destroy the annular tube and the material trough.

[0020] In this scheme, when starting to work, a voltage exceeding the set voltage is applied to the spiral coil to speed up the rotation speed of the ball. When the rotation speed of the ball reaches the set speed, the voltage is adjusted downward to reach the set voltage so that the ball remains at the set speed. Due to the damping of the liquid photosensitive resin, the ball rotates slowly for a period of time at the beginning. Since the spiral coil will continuously apply thrust to the ball and generate acceleration, if the voltage is always maintained above the set voltage, the ball will rotate faster and faster, and eventually the annular tube and the material trough will be destroyed. Therefore, when the rotation speed of the ball reaches the set speed, the voltage needs to be adjusted downward to the set voltage. When at the set voltage, the thrust generated by the spiral coil on the ball is the same as the resistance encountered by the ball, so that the rotation speed of the ball remains stable.

[0021] The spiral coil forms an electromagnetic drive when energized, which can make the ball rotate continuously along the annular tube. This design eliminates the complex external mechanical drive device and can greatly simplify the equipment structure.

[0022] In order to ensure that the liquid photosensitive resin in the central area of ​​the trough flows, each inlet and outlet are horizontally oriented toward the central part of the trough. The liquid photosensitive resin sprayed from the inlet and outlet can flow radially toward the central part of the trough. During the rotation of the ball, the inlet and outlet on the upstream side of the ball suck the liquid photosensitive resin around it into the annular tube, and the liquid photosensitive resin on the downstream side of the ball in the annular tube is sprayed toward the central part of the trough through the inlet and outlet on the downstream side, thereby enabling the liquid photosensitive resin in the entire trough to flow.

[0023] Specifically, the annular tube is located radially outside the material tank. This design enables the central area of ​​the material tank to become the setting area of ​​the printing platform, and the annular tube will not interfere with the printing platform and affect the normal operation of the printing platform. In addition, when the annular tube is working, the liquid photosensitive resin on the radial outside of the material tank is sucked into the annular tube and then sprayed into the central area of ​​the material tank, thereby causing the liquid photosensitive resin in the material tank to flow, avoiding the descending stratification of solid particles in the liquid photosensitive resin, and reducing the tendency of the liquid photosensitive resin to undergo qualitative changes due to temperature changes and the continuous accumulation of irradiation light energy in the liquid photosensitive resin.

[0024] In order to reduce the impact on printing work, the 3D printer also includes a printing platform. The bottom surface of the trough is divided into a working area and a non-working area. The working area is located in the central part of the bottom surface of the trough, and the non-working area surrounds the working area. The printing platform can enter the trough in the vertical direction and is located in the working area, and the annular tube is located in the non-working area. Setting the working area and the non-working area can make the functions of each area in the trough clearer. The working area is used to accommodate the printing platform, and the non-working area is used to accommodate the annular tube, so as to avoid the annular tube from affecting the normal work during printing.

[0025] Furthermore, in order to facilitate the control of the rotation speed of the ball, the 3D printer also includes a voltage regulation system, which includes a central processing unit, a first pressure sensor, a second pressure sensor and a DC voltage regulator connected to the central processing unit, wherein:

[0026] A central processing unit, used for receiving information sent by the first pressure sensor and the second pressure sensor, processing the information, and issuing control instructions according to the processing results to coordinate the work of the DC voltage regulator;

[0027] A first pressure sensor, used for detecting the pressure in the annular tube and sending the detection data to the central processing unit;

[0028] A second pressure sensor, used for detecting the pressure in the annular tube and sending the detection data to the central processing unit;

[0029] The DC voltage regulator receives control from the central processing unit and adjusts the voltage output by the DC power supply.

[0030] The two input terminals of the DC voltage regulator are respectively connected to the connection posts of the plug, and the two output terminals of the DC voltage regulator are respectively connected to the two ends of the spiral coil, so that the two ends of the spiral coil are connected to the plug via the DC voltage regulator, and the DC voltage regulator is used to adjust the output voltage of the DC power supply. The specific connection method and use of the DC voltage regulator are in accordance with existing mature technologies and will not be described in detail.

[0031] The first pressure sensor and the second pressure sensor are used to detect the pressure at two positions in the annular tube. When the ball rotates in the annular tube, the places it passes through will squeeze and push the liquid photosensitive resin, thereby causing a change in the pressure in the annular tube. The change in pressure in the annular tube is used to detect the position of the ball, and the time difference when the ball passes through the two pressure detection points and the distance between the two pressure detection points are used to calculate the rotation speed of the ball. When the rotation speed of the ball exceeds the set speed, the output voltage of the DC power supply is reduced through a DC voltage regulator. When the rotation speed of the ball is lower than the set speed, the output voltage of the DC power supply is increased through the DC voltage regulator. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural diagram of an embodiment of the present application.

[0033] Figure 2 yes Figure 1 Center AA view.

[0034] Figure 3 yes Figure 1 Enlarged view of part B.

[0035] Figure 4 yes Figure 2 Magnified view of part C.

[0036] Figure 5 It is a structural schematic diagram of another embodiment of the present application.

[0037] Figure 6 yes Figure 5 Enlarged view of part D.

[0038] Figure 7 It is a structural diagram of yet another embodiment of the present application.

[0039] Figure 8 yes Figure 7 The view from the EE direction.

[0040] Fig. 9 yes Figure 8 Enlarged view of section G.

[0041] Fig.10 is a schematic diagram of the voltage regulation system. DETAILED DESCRIPTION

[0042] Example 1

[0043] See also Figure 1-Figure 4 In this embodiment, the three-dimensional printer with a jetting function includes a workbench 10, which includes a vertical wall 11 extending in a vertical direction and in a rectangular cylindrical shape, a bottom plate 12 installed at the bottom of the vertical wall, and a top plate 13 installed at the top of the vertical wall. A liquid crystal screen 18 is installed in the central part of the top plate, and an ultraviolet light system 14 is installed in the inner cavity of the workbench. The ultraviolet light emitted by the ultraviolet light system can irradiate the liquid crystal screen. In this embodiment, the ultraviolet light system adopts existing mature technology and will not be described in detail.

[0044] A transmission mechanism is installed on the workbench, and the transmission mechanism includes two columns 15 fixedly installed on the top plate, and the two columns 15 are symmetrically arranged along the liquid crystal screen 18. A lifting motor 21 is installed at the bottom of each column, and a ball screw 22 extending in the vertical direction is installed on the output shaft of each lifting motor 21. The two ends of the crossbeam 16 are respectively installed on a ball screw, and a printing platform 17 is installed on the lower side of the crossbeam. Under the drive of the lifting motor, the crossbeam can move up and down along the ball screw and drive the printing platform to move up and down. The lifting motor 21 specifically adopts a servo motor. The specific transmission mechanism can be learned from the prior art and will not be repeated.

[0045] A circular first material trough 30 and a first rotator 70 are installed on the workbench. The first material trough 30 is used to contain liquid photosensitive resin. A ring-shaped annular tube 33 is arranged in the first material trough. A plurality of inlets and outlets 35 are opened on the annular tube. Each inlet and outlet is horizontally oriented toward the center of the first material trough. The first material trough 30 includes a circular first trough wall 31 and a first release film 32 fixed on the first trough wall.

[0046] A sphere 34 made of ferromagnetic material is movably placed in the annular tube. Specifically, in the present embodiment, the sphere is an iron ball with a nickel-plated surface. It can be understood that in other embodiments, the sphere may also be an iron ball without nickel plating, or the sphere may also be made of ferromagnetic materials such as nickel-iron alloy or iron-cobalt alloy.

[0047] In this embodiment, the bottom surface of the first trough 30 is divided into a working area 316 and a non-working area 317. Figure 2 In the figure, the working area 316 and the non-working area 317 are divided by a double-dotted line 318, wherein the working area 316 is located in the central part of the bottom surface of the first material trough, and the non-working area 317 surrounds the working area. The printing platform 17 can enter the first material trough in the vertical direction and be located in the working area 316. Figure 2In the figure, the dotted line is used to indicate the position of the printing platform 17 in the first material tank. The annular tube is located in the non-working area, that is, the annular tube is located radially outside the first material tank.

[0048] Specifically in this embodiment, the annular tube 33 is fixed to the inner circumference of the first material trough via a clamp 331 to facilitate disassembly of the annular tube, wherein the clamp is welded to the inner circumference of the first side wall 31 of the first material trough, and the first side wall is made of stainless steel.

[0049] The first rotator 70 includes an externally-toothed slewing bearing 60 and a driving motor 72, wherein the driving motor is a servo motor. The externally-toothed slewing bearing 60 includes an outer ring 62 and an inner ring 61 which are connected together by balls 63. The inner ring 61 is fixed to the workbench by locking bolts 64. The outer ring has teeth protruding radially outward, so that the outer ring is formed into an outer gear ring. The externally-toothed slewing bearing is coaxially arranged with the material trough.

[0050] The driving motor 72 is fixed on the workbench and located at the lower side of the top plate. A gear 71 is installed on the output shaft of the driving motor 72. The gear 71 is meshed on the outer ring 62. The connecting plate 65 is fixedly installed on the upper surface of the outer ring through the connecting bolts 66. The connecting plate extends radially inward toward the first material trough along the outer ring, and a magnet 67 is installed at the end of the connecting plate 65 facing the first material trough by bolts, that is, the magnet is installed on the outer ring through the connecting plate. The magnet is close to the outer wall of the first slot wall 31 of the first material trough, and there is a gap of 0.2mm between the magnet and the outer peripheral surface of the first slot wall, so that the magnet is as close to the ball as possible and does not generate friction with the first material trough.

[0051] Driven by the driving motor, the outer ring can drive the magnet to rotate around the central axis of the first material trough, and synchronously drive the ball to rotate in the annular tube.

[0052] In order to reduce the impact on the printing operation, in this embodiment, a first annular groove 191 is opened on the top plate of the workbench. When viewed in the vertical direction, the first annular groove 191 extends around the first material trough 30. The first annular groove 191 penetrates the upper surface 131 of the top plate upward. The external gear slewing bearing is installed in the annular groove, and the external gear slewing bearing does not exceed the upper surface of the top plate upward.

[0053] In this embodiment, in order to make the magnet attract the ball better, the center of the ball is at the same height as the center point of the magnet in the height direction. In order to achieve the above-mentioned goal, in this embodiment, a first material slot flange 36 is provided at the bottom of the first slot wall 31, and the first material slot flange is fixed in the annular slot by bolts, and the first release film is fixed in the middle of the first slot wall in the height direction. An annular film pressing groove 311 is provided in the middle of the height direction of the inner wall of the first slot wall, and the outer peripheral edge pressing ring 313 of the release film is tightly pressed in the film pressing groove. The screw 314 passes through the pressing ring 313 and is screwed on the first slot wall to fix the release film on the first slot wall. In order to ensure the sealing performance, a sealing ring 312 is provided between the pressing ring 313 and the release film. The annular tube is located at the bottom of the first material slot.

[0054] When the driving motor 72 drives the outer ring 62 of the external gear slewing bearing 60 to rotate, it can drive the magnet 67 to rotate synchronously through the connecting plate 65, and under the attraction of the magnetic force, drive the ball to rotate in the annular tube along the extension direction of the annular tube, so that the ball circulates in the inner cavity of the annular tube, so that the liquid photosensitive resin in the first material trough can be sucked into the annular tube through the inlet and outlet on the upstream side, and the liquid photosensitive resin in the annular tube can be sprayed into the first material trough through the inlet and outlet on the downstream side, so that the liquid photosensitive resin in the first material trough flows.

[0055] The inlet and outlet on the upstream side and the inlet and outlet on the downstream side are relative to the rotation direction and position of the ball. Please also refer to Figure 2 and Figure 4 , Figure 2 The direction of the first arrow P in the figure indicates the direction of rotation of the outer ring. Figure 4 The direction of the second arrow S in the diagram indicates the rotation direction of the ball in the annular tube 33, and the directions of the first arrow P and the second arrow S are the same.

[0056] The upstream side refers to the rear of the ball's rotation direction, and the downstream side refers to the front of the ball's rotation direction. For ease of description, the inlet and outlet on the upstream side are called the upstream inlet and outlet 351, and the inlet and outlet on the downstream side are called the downstream inlet and outlet 352. When the ball rotates along the direction of the second arrow S, the liquid photosensitive resin in front of the ball is pushed by the ball and sprayed out from the downstream inlet and outlet 352, while a vacuum is generated behind the ball. The liquid photosensitive resin in the first material tank is subjected to negative pressure and is sucked into the annular tube through the upstream inlet and outlet 351, thereby causing the liquid photosensitive resin in the first material tank to flow. The direction of the third arrow F indicates the flow direction of the liquid photosensitive resin in the first material tank into the annular tube, and the direction of the fourth arrow J indicates the spray direction of the liquid photosensitive resin in the annular tube into the first material tank.

[0057] It can be understood that since the upstream inlet and the downstream inlet and the downstream inlet are relative to the rotation direction and position of the ball, as the ball continues to rotate in the annular tube, each inlet and the outlet will become an upstream inlet and the outlet or a downstream inlet and the outlet.

[0058] Example 2

[0059] This embodiment is a variation of the embodiment 1. Figure 5 and Figure 6 , Figure 5-Figure 6 and Figure 1-Figure 4 The same reference numerals in the figure represent the same technical features. In this embodiment, the three-dimensional printer with a jetting function includes a workbench 10, which is the same as the workbench in Embodiment 1 and will not be described in detail. As in Embodiment 1, a liquid crystal screen 18, an ultraviolet light system 14 and a transmission mechanism are also installed on the workbench. For the corresponding contents, please refer to the corresponding contents in Embodiment 1 and will not be described in detail.

[0060] In this embodiment, a second circular trough 40 and a second rotator are installed on the workbench. The second trough 40 is used to hold liquid photosensitive resin. The annular ring tube 33 is arranged in the second trough. The annular tube in this embodiment has the same structure as the annular tube in the embodiment, and the ball is movably placed in the annular tube 33. The second trough 40 includes a second circular trough wall 41 and a second release film 42 fixed on the second trough wall. In this embodiment, the bottom surface of the second trough 40 is also divided into a working area and a non-working area, wherein the working area is located in the central part of the bottom surface of the second trough, and the non-working area surrounds the working area. The printing platform 17 can enter the second trough in the vertical direction and is located in the working area. The annular tube is located in the non-working area, that is, the annular tube is located radially outside the second trough.

[0061] In this embodiment, the second rotator is a hollow shaft torque motor 50, which is a servo motor. The hollow shaft torque motor 50 includes a stator 51 and a mover 53 rotatably arranged inside the stator. The hollow shaft torque motor 50 is coaxially arranged with the second trough so that the central axis of the hollow shaft torque motor extends in the vertical direction, and a hollow shaft 54 ​​is fixedly mounted on the mover.

[0062] An upper flange 511 and a lower flange 512 are respectively provided at the upper and lower ends of the stator 51. The upper flange 511 is located above the lower flange 512. The upper end cover 55 has a first flange corresponding to the upper flange. The first bolt 551 fixes the first flange to the upper flange. The lower end cover 56 has a second flange corresponding to the lower flange. The second bolt 561 fixes the second flange to the lower flange, so that the upper end cover and the lower end cover are respectively detachably mounted on the top and bottom of the stator.

[0063] The upper end cover is rotatably connected to the hollow shaft 54 ​​via the upper angular contact bearing 591. An upper flange 543 is provided on the upper part of the outer circumference of the hollow shaft 54. The upper flange 543 is formed by the outer circumference of the hollow shaft protruding outward in the radial direction. The upper end cover has an inwardly protruding abutting flange 553. The lower surface of the abutting flange 553 is a step surface facing downward. The abutting flange 553 is pressed against the upper side of the outer ring of the upper angular contact bearing via its lower surface, and the upper flange is pressed against the lower side of the inner ring of the upper angular contact bearing. The upper end cover is rotatably abutted against the hollow shaft via the upper bearing.

[0064] The lower end cover is rotatably connected to the hollow shaft 54 ​​via the lower angular contact bearing 592. A step portion 544 is provided at the lower end of the hollow shaft 54. The step portion is formed by the outer circumference of the hollow shaft being recessed radially inward, and the step portion has a step surface facing downward; the inner side of the lower end cover has a pressing surface 563 facing upward, and the pressing surface is a step surface facing upward. The pressing surface 563 presses against the lower side of the outer ring of the lower angular contact bearing, and the step portion 544 presses against the upper side of the inner ring of the lower angular contact bearing, so that the lower end cover is rotatably abutted against the hollow shaft via the lower bearing. A winding 52 is provided on the inner side of the stator. The structure of the hollow shaft torque motor can be completed by using existing mature technology, and will not be described in detail.

[0065] In order to reduce the influence of the hollow shaft torque motor on the printing operation, in this embodiment, a second annular groove 192 is opened on the top plate of the workbench, and the second annular groove 192 extends around the second material trough 40. The second annular groove 192 penetrates the upper surface 131 of the top plate upward, and the hollow shaft torque motor is installed in the second annular groove. Specifically, the lower end cover of the hollow shaft torque motor is fixed to the bottom of the second annular groove by bolts.

[0066] The mover, the hollow shaft and the second trough are coaxially arranged, and the magnet 67 is fixedly installed on the inner side of the hollow shaft by bolts, and in the height direction, the center of the ball is at the same height as the center point of the magnet. When the hollow shaft torque motor is working, the mover can drive the magnet to rotate around the central axis of the second trough, and synchronously drive the ball to rotate in the annular tube. There is a gap of 0.2mm between the magnet 67 and the outer peripheral surface of the second trough wall of the second trough.

[0067] In this embodiment, in order to adapt to the hollow shaft torque motor, the second trough flange 46 of the second trough 40 is arranged at the top of the second trough wall 41, and the second release film 42 is installed at the bottom of the second trough wall by conventional methods. The second trough flange 46 is fixed to the upper end cover 55 by bolts, that is, the second trough flange is fixedly installed on the stator through the upper end cover. The annular tube is located at the bottom of the second trough.

[0068] When the rotor of the hollow shaft torque motor rotates, it can drive the magnet 67 to rotate synchronously, and under the attraction of the magnetic force, drive the ball to rotate in the annular tube along the extension direction of the annular tube, so that the ball circulates in the inner cavity of the annular tube, so that the liquid photosensitive resin in the second material tank can be sucked into the annular tube through the inlet and outlet on the upstream side, and the liquid photosensitive resin in the annular tube can be sprayed into the second material tank through the inlet and outlet on the downstream side, so that the liquid photosensitive resin in the second material tank flows. In this embodiment, the principle of the liquid photosensitive resin entering and exiting the annular tube is the same as that in Example 1. Please refer to the relevant content in Example 1 for details, and no further description is given.

[0069] Example 3

[0070] See also Figure 7-Figure 9 In this embodiment, the three-dimensional printer with a jetting function includes a workbench 10, which includes a vertical wall 11 extending in a vertical direction and in a rectangular cylindrical shape, a bottom plate 12 installed at the bottom of the vertical wall, and a top plate 13 installed at the top of the vertical wall. A liquid crystal screen 18 is installed in the central part of the top plate, and an ultraviolet light system 14 is installed in the inner cavity of the workbench. The ultraviolet light emitted by the ultraviolet light system can irradiate the liquid crystal screen. In this embodiment, the ultraviolet light system adopts existing mature technology and will not be described in detail.

[0071] A transmission mechanism is installed on the workbench, and the transmission mechanism includes two columns 15 fixedly installed on the top plate, and the two columns 15 are symmetrically arranged along the liquid crystal screen 18. A lifting motor 21 is installed at the bottom of each column, and a ball screw 22 extending in the vertical direction is installed on the output shaft of each lifting motor 21. The two ends of the crossbeam 16 are respectively installed on a ball screw, and a printing platform 17 is installed on the lower side of the crossbeam. Under the drive of the lifting motor, the crossbeam can move up and down along the ball screw and drive the printing platform to move up and down. The lifting motor 21 specifically adopts a servo motor. The specific transmission mechanism can be learned from the prior art and will not be repeated.

[0072] A third material trough 85 in a circular shape is installed on the workbench. The third material trough 85 is used to contain liquid photosensitive resin. The third material trough is directly fixed to the surface 131 of the top plate 13 by bolts. An annular ring tube 33 in a circular shape is arranged in the third material trough. A plurality of inlets and outlets 35 are opened on the annular tube, and each inlet and outlet is horizontally oriented toward the center of the material trough. The fixing method of the annular tube is the same as that of the embodiment 1. A spherical ball 34 made of ferromagnetic material is movably placed in the annular tube.

[0073] In this embodiment, the bottom surface of the third trough 30 is divided into a working area 316 and a non-working area 317. Figure 2In the figure, the working area 316 and the non-working area 317 are divided by a double-dotted line 318, wherein the working area 316 is located in the central part of the bottom surface of the third material trough, and the non-working area 317 surrounds the working area, and the printing platform 17 can enter the third material trough in the vertical direction and be located in the working area 316. The annular tube is located in the non-working area, that is, the annular tube is located radially outside the third material trough.

[0074] A number of spiral coils 80 are wound on the annular tube. The spiral coils are made of copper enameled wire. In this embodiment, a spiral coil 80 is arranged between every two adjacent inlets and outlets. Each spiral coil is formed into an electromagnetic driver. The two ends of the spiral coil are formed into a positive terminal 81 and a negative terminal 82 respectively. The positive terminal 81 and the negative terminal 82 of the spiral coil are connected to a plug, which is used to be plugged into a DC power supply. In this embodiment, the winding direction of each spiral coil is the same, and the end of each spiral coil facing the same direction is used as the positive terminal, and the other end facing the same direction is used as the negative terminal, so that after the DC power supply is turned on, the direction of the magnetic force generated by each spiral coil is the same, which can drive the ball in the annular tube to rotate in a circle, so that the liquid photosensitive resin in the third material tank can be sucked into the annular tube through the inlet and outlet on the upstream side, and the liquid photosensitive resin in the annular tube can be sprayed into the third material tank through the inlet and outlet on the downstream side, so that the liquid photosensitive resin in the third material tank flows.

[0075] When the spiral coil is just energized, the ball may not rotate due to the adhesion of the liquid photosensitive resin. At this time, a magnet can be used to drive the ball to rotate outside the third material trough. After the ball starts to rotate, when the rotation speed of the ball reaches the set speed, it is necessary to adjust the voltage of the DC power supply in time, and use the resistance of the liquid photosensitive resin to keep the ball at a constant speed. Otherwise, the ball will continue to accelerate under the influence of acceleration, and eventually destroy the annular tube and the material trough.

[0076] In order to adjust the rotation speed of the ball, the present embodiment further provides a voltage regulation system, which includes a central processing unit 101, a first pressure sensor 102, a second pressure sensor 103 and a DC voltage regulator 104 connected to the central processing unit 101, wherein:

[0077] The central processing unit 101 is used to receive information sent by the first pressure sensor and the second pressure sensor, process the information, and issue control instructions according to the processing results to coordinate the work of the DC voltage regulator;

[0078] A first pressure sensor, used for detecting the pressure in the annular tube and sending the detection data to the central processing unit;

[0079] A second pressure sensor, used for detecting the pressure in the annular tube and sending the detection data to the central processing unit;

[0080] The DC voltage regulator receives control from the central processing unit and adjusts the voltage output by the DC power supply.

[0081] In this embodiment, the pressure detection points of the first pressure sensor and the second pressure sensor are spaced 60 mm apart to avoid mutual influence of pressure fluctuations between the two pressure detection points.

[0082] The two input terminals of the DC voltage regulator are respectively connected to the connection posts of the plug, and the two output terminals of the DC voltage regulator are respectively connected to the two ends of the spiral coil, so that the two ends of the spiral coil are connected to the plug via the DC voltage regulator, and the DC voltage regulator is used to adjust the output voltage of the DC power supply. The specific connection method and use of the DC voltage regulator are in accordance with the existing mature technology and will not be repeated. That is, the two ends of the spiral coil are connected to the plug via the DC voltage regulator.

[0083] The first pressure sensor and the second pressure sensor are used to detect the pressure at two positions in the annular tube. When the ball rotates in the annular tube, the places it passes through will squeeze and push the liquid photosensitive resin, thereby causing changes in the pressure in the annular tube. The position of the ball is detected by using the changes in the pressure in the annular tube, and the rotation speed of the ball is calculated by using the time difference when the ball passes through the two pressure detection points and the distance between the two pressure detection points. When the rotation speed of the ball exceeds the set speed, the output voltage of the DC power supply is reduced by the DC voltage regulator. When the rotation speed of the ball is lower than the set speed, the output voltage of the DC power supply is increased by the DC voltage regulator. The set speed of the ball needs to be determined based on experiments to ensure that the ball can rotate stably in the annular tube.

Claims

1. A three-dimensional printer with a jetting function, characterized in that: The invention comprises a workbench, on which a circular material trough and a rotator are installed. The material trough is used to contain liquid photosensitive resin. A ring-shaped annular tube is arranged in the material trough. A plurality of inlets and outlets are opened on the annular tube. A ball is movably placed in the annular tube. The ball is made of ferromagnetic material. A magnet is installed on the rotator. The rotator can drive the magnet to rotate around the material trough, and the ball is driven by the magnet to rotate in the annular tube along the extension direction of the annular tube. When the ball rotates in the annular tube, the liquid photosensitive resin in the material trough can be sucked into the annular tube through the inlet and outlet on the upstream side, and the liquid photosensitive resin in the annular tube can be sprayed into the material trough through the inlet and outlet on the downstream side, so that the liquid photosensitive resin in the material trough flows.

2. The three-dimensional printer according to claim 1, characterized in that: Each inlet and outlet is oriented toward the center of the trough in a horizontal direction.

3. The three-dimensional printer according to claim 1, characterized in that: The annular tube is located radially outside the trough.

4. The three-dimensional printer according to claim 1, characterized in that: It also includes a printing platform. The bottom surface of the material trough is divided into a working area and a non-working area. The working area is located in the central part of the bottom surface of the material trough, and the non-working area surrounds the working area. The printing platform can enter the material trough in a vertical direction and be located in the working area, and the annular tube is located in the non-working area.

5. The three-dimensional printer according to claim 1, characterized in that: The rotator includes an external-toothed slewing bearing and a driving motor. The external-toothed slewing bearing includes an outer ring and an inner ring connected together by balls. The inner ring is fixed on a workbench and has teeth protruding radially outward on the outer ring. The external-toothed slewing bearing is coaxially arranged with the material trough. The driving motor is fixed on the workbench, and a gear is installed on the output shaft of the driving motor. The gear is meshed with the outer ring, and a magnet is installed on the outer ring. Under the drive of the driving motor, the outer ring can drive the magnet to rotate around the central axis of the material trough, and synchronously drive the ball to rotate in the annular tube. The driving motor is a servo motor.

6. The three-dimensional printer according to claim 5, characterized in that: The material trough comprises a cylindrical trough wall and a trough flange arranged at the bottom of the trough wall, and the trough flange is fixed on a workbench; in the height direction, the release film is fixed to the middle part of the trough wall, and the annular tube is located at the bottom of the material trough.

7. The three-dimensional printer according to claim 1, characterized in that: The rotator includes a hollow shaft torque motor, which includes a stator and a mover rotatably arranged in the stator. The central axis of the hollow shaft torque motor extends in the vertical direction. A hollow shaft is fixedly installed on the mover. The stator is fixedly installed on a workbench. The mover, the hollow shaft and the material trough are coaxially arranged. The magnet is installed on the inner side of the hollow shaft. When the hollow shaft torque motor is working, the mover can drive the magnet to rotate around the central axis of the material trough, and synchronously drive the ball to rotate in the annular tube. The hollow shaft torque motor is a servo motor.

8. The three-dimensional printer according to claim 7, characterized in that: The material trough comprises a cylindrical trough wall and a trough flange arranged on the top of the trough wall, and the trough flange is fixedly installed on the stator; in the height direction, the release film is fixed on the bottom of the trough wall, and the annular tube is located at the bottom of the material trough.

9. A three-dimensional printer with a jetting function, characterized in that: The invention comprises a workbench, on which a circular material trough is installed, the material trough is used to contain liquid photosensitive resin, a ring-shaped annular tube is arranged in the material trough, the annular tube is located radially outside the material trough, a plurality of inlets and outlets are opened on the annular tube, and each inlet and outlet is horizontally oriented to the central part of the material trough; a ball is movably placed in the annular tube, and the ball is made of ferromagnetic material; A spiral coil is wound on the annular tube, and both ends of the spiral coil are connected to a plug, which is used to be plugged into a DC power supply; when the spiral coil is connected to DC power, it can drive the ball to rotate in the annular tube along the extension direction of the annular tube; when the ball rotates in the annular tube, the liquid photosensitive resin in the material tank can be sucked into the annular tube through the inlet and outlet on the upstream side, and the liquid photosensitive resin in the annular tube can be sprayed into the material tank through the inlet and outlet on the downstream side, so that the liquid photosensitive resin in the material tank flows.

10. The three-dimensional printer according to claim 9, characterized in that: Also included is a voltage regulation system, the voltage regulation system including a central processing unit, a first pressure sensor connected to the central processing unit, a second pressure sensor and a DC voltage regulator, wherein: A central processing unit, used for receiving information sent by the first pressure sensor and the second pressure sensor, processing the information, and issuing control instructions according to the processing results to coordinate the work of the DC voltage regulator; A first pressure sensor, used for detecting the pressure in the annular tube and sending the detection data to the central processing unit; A second pressure sensor, used for detecting the pressure in the annular tube and sending the detection data to the central processing unit; The DC voltage regulator receives control from the central processing unit and adjusts the voltage output by the DC power supply.

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