Three-dimensional printer with jetting function

Abstract

The application discloses a three-dimensional printer with a jet function, which comprises a workbench, a circular material tank and a rotating device installed on the workbench, the material tank is used for containing liquid photosensitive resin, a circular annular pipe is arranged in the material tank, an inlet and an outlet are formed in the annular pipe, and a magnetic ball is movably arranged in the annular pipe; the magnetic ball rotates in the annular pipe along the extension direction of the annular pipe, the liquid photosensitive resin is sucked into the annular pipe and can be sprayed from the annular pipe, so that the liquid photosensitive resin in the material tank flows. The application utilizes the magnetism to make the ball rotate in the annular pipe, sprays the liquid photosensitive resin in the annular pipe into the material tank, sucks the liquid photosensitive resin in the material tank into the annular pipe, makes the liquid photosensitive resin in the material tank flow, mixes the liquid photosensitive resin in the material tank, and avoids the solid particle stratification phenomenon caused by the liquid photosensitive resin in a stable state.

Description

TECHNICAL FIELD

[0001] The present application relates to a three-dimensional printer with a jet function. BACKGROUND

[0002] Three-dimensional printing technology, also known as 3D printing, has developed rapidly in recent years and provides a new production method for modern product production. In the three-dimensional light curing printing technology using the pull-up type, the light source irradiates the liquid photosensitive resin in the trough from the bottom to the top, so that the liquid photosensitive resin is cured and gradually stacked on the printing platform. At the same time, the printing platform is lifted 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 printing process of the three-dimensional product, due to the instability of the solid particles in the liquid photosensitive resin, the solid particles are layered downward, and due to the temperature change and the continuous accumulation of the energy of the irradiation light in the liquid photosensitive resin, part of the liquid photosensitive resin changes in quality. After a long period of accumulation, part of the liquid photosensitive resin may be cured, thereby affecting the continuous printing. Therefore, in the printing process, the liquid photosensitive resin in the trough needs to flow to avoid the occurrence of curing. For this purpose, a swing rod is added at the bottom of the trough to make the liquid photosensitive resin in the trough flow. However, the swing rod can only work after the completion of a curing layer and the lifting of the printing platform upward, so that the curing layer attached to the printing platform is separated from the bottom of the trough. Therefore, the printing speed is affected and the production efficiency of the three-dimensional product is reduced. Therefore, how to make the liquid photosensitive resin in the trough flow without affecting the printing efficiency and avoid the downward layering of the solid particles still needs further research. SUMMARY

[0004] To solve the problem of affecting the production efficiency of the three-dimensional product in the prior art for making the liquid photosensitive resin flow, the application first proposes a three-dimensional printer with a spraying function, which comprises a workbench, a circular tank and a rotating device are installed on the workbench, the tank is used for containing liquid photosensitive resin, a circular annular pipe is arranged in the tank, a plurality of inlets and outlets are formed on the annular pipe, a ball is movably arranged in the annular pipe, the ball is made of ferromagnetic material; a magnet is installed on the rotating device, the rotating device can drive the magnet to rotate around the tank, and the ball is driven by the magnet to rotate in the annular pipe along the extension direction of the annular pipe; when the ball rotates in the annular pipe, the liquid photosensitive resin in the tank can be sucked into the annular pipe through the upstream inlet and outlet, and the liquid photosensitive resin in the annular pipe can be sprayed into the tank through the downstream inlet and outlet, so that the liquid photosensitive resin in the tank flows. In order to improve the adsorption capacity of the magnet to the ball, the center of the ball is preferably at the same height as the center of the magnet in the height direction.

[0005] In the application, the annular pipe is arranged in the tank, the attraction of the magnet is used to make the ball rotate in the annular pipe along the extension direction of the annular pipe, and the pushing force of the ball when it rotates in the annular pipe is used to spray the liquid photosensitive resin in the annular pipe into the tank through the downstream inlet and outlet, and the negative pressure generated on the upstream side of the ball is used to suck the liquid photosensitive resin in the tank into the annular pipe, so that the liquid photosensitive resin in the tank flows, the liquid photosensitive resin in the tank is mixed, and the solid particle stratification phenomenon caused by the liquid photosensitive resin in a stable state is avoided. At the same time, due to the flow of the liquid photosensitive resin in the tank, the liquid photosensitive resin in a certain area of the tank can be prevented from being solidified due to the accumulation of light energy. The annular pipe in the application can be arranged in the area of the tank that does not affect printing, so as not to affect the printing speed, and the liquid photosensitive resin in the tank can flow smoothly.

[0006] Further, to ensure that the liquid photosensitive resin in the central area of the tank flows, each inlet and outlet is directed to the central part of the tank along the horizontal direction.

[0007] The liquid photosensitive resin sprayed from the inlet and outlet can flow radially to the central part of the tank, in 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 pipe, and the liquid photosensitive resin in the annular pipe on the downstream side of the ball is sprayed to the central part of the tank through the downstream inlet and outlet, so that the liquid photosensitive resin in the whole tank flows.

[0008] Specifically, the annular tube is located radially outside the vat. This design can make the central region of the vat the setting region of the printing platform, and the annular tube will not interfere with the printing platform and affect the normal work of the printing platform. In addition, when the annular tube is working, the liquid photosensitive resin radially outside the vat is sucked into the annular tube and then sprayed into the central region of the vat, so that the liquid photosensitive resin in the vat flows rapidly, avoids the downward stratification of solid particles in the liquid photosensitive resin, and reduces the tendency of the liquid photosensitive resin to change in quality due to the continuous accumulation of temperature changes and irradiation light energy in the liquid photosensitive resin.

[0009] Further, to ensure the smooth progress of printing, the three-dimensional printer further comprises a printing platform, the bottom surface of the vat 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 vat, and the non-working area surrounds the working area. The printing platform can enter the vat in the vertical direction and be located in the working area, and the annular tube is located in the non-working area. The setting of the working area and the non-working area can make the functions of each region in the vat more clear, 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 influence of the annular tube on the normal work during printing.

[0010] Specifically, the rotator comprises an outer-tooth slewing bearing and a driving motor. The outer-tooth slewing bearing comprises an outer ring and an inner ring combined by balls, the inner ring is fixed on the workbench, and the outer ring has teeth protruding radially outward. The outer-tooth slewing bearing is coaxially arranged with the vat. The driving motor is fixed on the workbench, a gear is mounted on the output shaft of the driving motor, the gear is engaged with the outer ring, and a magnet is mounted on the outer ring. Under the driving of the driving motor, the outer ring can drive the magnet to rotate around the central axis of the vat, and synchronously drive the spherical 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 the spherical ball rotates in the annular tube through the magnet, so that the liquid photosensitive resin in the vat flows rapidly. By adjusting the rotating speed of the driving motor, the moving speed of the spherical ball in the annular tube can be adjusted, the spraying speed of the liquid photosensitive material sprayed from the annular tube can be adjusted, and the flow speed of the liquid photosensitive material in the vat can be adjusted.

[0012] Specifically, to adapt to the structure of the outer-tooth type 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 at the middle part of the trough wall, and the annular pipe is located at the bottom of the trough. Since the release film is located at the middle part of the trough wall, the height center of the magnet can be the same as the height center of the annular pipe, so that the magnet can be as close as possible to the height position of the annular pipe, thereby being able to generate greater attraction to the spherical ball. The distance between the magnet and the outer circumferential surface of the trough wall is controlled to be between 0.1-1mm.

[0013] Specifically, the rotator includes a hollow shaft torque motor, the hollow shaft torque motor includes a stator and a rotor rotatably arranged in the stator, a central axis of the hollow shaft torque motor extends in the vertical direction, a hollow shaft is fixedly installed on the rotor, the stator is fixedly installed on the workbench, the rotor, the hollow shaft and the trough are coaxially arranged, the magnet is installed on the inner side of the hollow shaft, when the hollow shaft torque motor works, the rotor can drive the magnet to rotate around the central axis of the trough, and simultaneously drive the spherical ball to rotate in the annular pipe, and the hollow shaft torque motor is a servo motor.

[0014] The rotor of the hollow shaft torque motor is used to drive the magnet, so that the rotation speed of the spherical ball in the annular pipe can be flexibly adjusted, the ejection speed of the liquid photosensitive resin ejected in the annular pipe is adjusted, and the flow speed of the liquid photosensitive material in the trough is adjusted.

[0015] Further, the trough includes a cylindrical trough wall and a trough flange arranged at 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 at the bottom of the trough wall, and the annular pipe 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 caused by the trough flange can be avoided. The design can make the magnet as close as possible to the outer circumferential surface of the trough wall of the trough, so that the magnet can have greater attraction to the spherical ball. The distance between the magnet and the outer circumferential surface of the trough wall is controlled to be between 0.1-1mm.

[0016] Secondly, the application also provides another three-dimensional printer with a spraying function, which includes a workbench, a circular trough is installed on the workbench, the trough is used to contain liquid photosensitive resin, an annular pipe is arranged in the trough, the annular pipe is located at the radial outside of the trough, a plurality of inlets and outlets are arranged on the annular pipe, and each inlet and outlet faces the central part of the trough in the horizontal direction; a spherical ball is movably arranged in the annular pipe, and the spherical ball is made of ferromagnetic material.

[0017] The spiral coil is wound on the annular tube, and two ends of the spiral coil are connected to a plug which is used to be plugged into a direct current power supply. When the spiral coil is connected to the direct current, 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 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 trough through the inlet and outlet on the downstream side, so that the liquid photosensitive resin in the trough flows.

[0018] The spiral coil is made of enameled wire or metal wire with an insulating protective layer, and generally uses 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 same end of each spiral coil is used as the positive end and the other end is used as the negative end to avoid confusion.

[0019] When the spiral coil is just powered on, the ball cannot rotate due to the adhesion of the liquid photosensitive resin. A magnet is needed to drive the ball to rotate outside the third trough. When the ball rotates, the voltage of the direct current power supply needs to be adjusted in time when the rotation speed of the ball reaches the set speed, so that the ball maintains a constant speed by using the resistance of the liquid photosensitive resin. Otherwise, the ball will continue to accelerate under the influence of acceleration, and finally the annular tube and the trough will be damaged.

[0020] In this scheme, when starting to work, a voltage higher than 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 the set voltage, so that the ball maintains the set speed. Due to the damping of the liquid photosensitive resin, the rotation speed of the ball is slow at the beginning. Since the spiral coil continuously applies a pushing force to the ball and generates an acceleration, if the voltage is always maintained above the set voltage, the rotation speed of the ball will become faster and faster, and finally the annular tube and the trough will be damaged. Therefore, when the rotation speed of the ball reaches the set speed, the voltage needs to be adjusted downward to the set voltage. When the voltage is at the set voltage, the pushing force generated by the spiral coil on the ball is the same as the resistance received by the ball, so that the rotation speed of the ball remains stable.

[0021] The spiral coil forms an electromagnetic driver after being powered on, which can continuously rotate the ball along the annular tube. This design eliminates the need for external mechanical driving devices, which can greatly simplify the equipment structure.

[0022] In order to ensure the liquid photosensitive resin in the central region of the vat to flow, each inlet and outlet is horizontally directed to the central region of the vat. The liquid photosensitive resin sprayed from the inlet and outlet can flow radially to the central region of the vat. In the rotation of the ball, the inlet and outlet on the upstream side of the ball suck the liquid photosensitive resin around the ball into the annular pipe, and the liquid photosensitive resin in the annular pipe on the downstream side of the ball is sprayed to the central region of the vat through the downstream side of the inlet and outlet, thereby enabling the liquid photosensitive resin in the entire vat to flow.

[0023] Specifically, the annular pipe is located radially outside the vat. This design can make the central region of the vat the setting region of the printing platform, and the annular pipe will not interfere with the normal work of the printing platform. In addition, when the annular pipe is working, the liquid photosensitive resin radially outside the vat is sucked into the annular pipe and then sprayed to the central region of the vat, thereby enabling the liquid photosensitive resin in the vat to flow, avoiding the downward stratification of solid particles in the liquid photosensitive resin, and reducing the tendency of the liquid photosensitive resin to change in quality due to the continuous accumulation of temperature changes and irradiation light energy in the liquid photosensitive resin.

[0024] In order to reduce the impact on the printing work, the three-dimensional printer further comprises a printing platform, the bottom surface of the vat is divided into a working area and a non-working area, the working area is located in the central region of the bottom surface of the vat, and the non-working area surrounds the working area. The printing platform can enter the vat in the vertical direction and be located in the working area, and the annular pipe is located in the non-working area. The setting of the working area and the non-working area can make the functions of each region in the vat more clear, the working area is used to accommodate the printing platform, and the non-working area is used to accommodate the annular pipe, thereby avoiding the impact of the annular pipe on the normal work during printing.

[0025] Further, in order to facilitate the control of the rotation speed of the ball, the three-dimensional printer further comprises a voltage adjustment system, the voltage adjustment system comprises a central processing unit, a first pressure sensor, a second pressure sensor and a direct current voltage regulator connected to the central processing unit, wherein:

[0026] The central processing unit is used to receive information sent by the first pressure sensor and the second pressure sensor, process the information, and send a control instruction according to the processing result to coordinate the work of the direct current voltage regulator;

[0027] The first pressure sensor is used to detect the pressure in the annular pipe and send the detection data to the central processing unit;

[0028] The second pressure sensor is used to detect the pressure in the annular pipe and send the detection data to the central processing unit;

[0029] The direct current voltage regulator receives the control of the central processing unit and adjusts the voltage output by the direct current power supply.

[0030] Two input terminals of the DC voltage regulator are connected to the connecting columns of the plug respectively, and two output terminals of the DC voltage regulator are connected to two ends of the spiral coil, so that the two ends of the spiral coil are connected to the plug through the DC voltage regulator, and the output voltage of the DC power supply is adjusted by the DC voltage regulator. The specific connection mode and use of the DC voltage regulator are in accordance with the existing mature technology, and will not be described here.

[0031] The first pressure sensor and the second pressure sensor are used to detect the pressure at two positions in the annular pipe. When the ball rotates in the annular pipe, the place passed will extrude and push the liquid photosensitive resin, thereby causing the change of the pressure in the annular pipe. The position of the ball is detected by the change of the pressure in the annular pipe, and the rotation speed of the ball is calculated by the time difference of the ball passing 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 through the DC voltage regulator, and 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 DRAWINGS

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

[0033] Figure 2 is a structural schematic diagram of an embodiment in the present application. Figure 1 is a view of A-A direction in

[0034] Figure 3 is a structural schematic diagram of an embodiment in the present application. Figure 1 is an enlarged view of B part in

[0035] Figure 4 is a structural schematic diagram of an embodiment in the present application. Figure 2 is an enlarged view of C part in

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

[0037] Figure 6 is a structural schematic diagram of another embodiment in the present application. Figure 5 is an enlarged view of D part in

[0038] Figure 7 is a structural schematic diagram of still another embodiment in the present application.

[0039] Figure 8 is a structural schematic diagram of still another embodiment in the present application. Figure 7 is a view of E-E direction in

[0040] Figure 9 is a structural schematic diagram of still another embodiment in the present application. Figure 8 is an enlarged view of G part in

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

[0042] Embodiment 1

[0043] Please refer to Figures 1-4 In this embodiment, the three-dimensional printer with the spraying function comprises a workbench 10, the workbench 10 comprises a vertical wall 11 extending in the vertical direction and in the shape of a rectangular cylinder, 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 at the central part of the top plate, and a UV light system 14 is installed in the inner cavity of the workbench, the UV light emitted by the UV light system can irradiate the liquid crystal screen, in this embodiment, the UV light system adopts the existing mature technology, and thus will not be described herein.

[0044] A transmission mechanism is installed on the workbench, the transmission mechanism comprises two vertical columns 15 fixedly installed on the top plate, the two vertical columns 15 are symmetrically arranged on both sides of the liquid crystal screen 18, a lifting motor 21 is installed at the bottom of each vertical 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 a cross beam 16 are respectively installed on a ball screw, and a printing platform 17 is installed on the lower side of the cross beam, under the drive of the lifting motor, the cross beam can move up and down along the ball screw, and the printing platform moves up and down under the drive of the cross beam, the lifting motor 21 specifically adopts a servo motor, and the specific transmission mechanism can be known from the prior art, and thus will not be described herein.

[0045] A first trough 30 in the shape of a circle and a first rotator 70 are installed on the workbench, the first trough 30 is used for containing liquid photosensitive resin, a ring-shaped pipe 33 in the shape of a ring is arranged in the first trough, a plurality of inlets and outlets 35 are formed in the ring-shaped pipe, and each inlet and outlet faces the central part of the first trough in the horizontal direction. The first trough 30 comprises a first trough wall 31 in the shape of a circle and a first release film 32 fixedly installed on the first trough wall.

[0046] A spherical ball 34 made of ferromagnetic material is movably arranged in the ring-shaped pipe, specifically, in this embodiment, the spherical ball is a nickel-plated iron ball, and it can be understood that, in other embodiments, the spherical ball can also be an iron ball without nickel plating, or the spherical ball can also be made of 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, in Figure 2 In this embodiment, the working area 316 and the non-working area 317 are divided by a double-dot line 318, the working area 316 is located at the central part of the bottom surface of the first trough, the non-working area 317 surrounds the working area, the printing platform 17 can enter the first trough in the vertical direction and be located in the working area 316, Figure 2In the embodiment, the position of the printing platform 17 in the first tank is indicated by a dashed line. The annular tube is located in the non-working area, i.e. the annular tube is located radially outside the first tank.

[0048] In the embodiment, the annular tube 33 is fixed to the inner circumferential surface of the first tank by a clamp 331, which is welded to the inner circumferential surface of the first side wall 31 of the first tank. The first side wall is made of stainless steel.

[0049] The first rotator 70 comprises an outer-toothed slewing bearing 60 and a driving motor 72. The driving motor is a servo motor. The outer-toothed slewing bearing 60 comprises an outer ring 62 and an inner ring 61 combined by balls 63. The inner ring 61 is fixed to the workbench by locking bolts 64. The outer ring has teeth projecting radially outward, so that the outer ring forms an outer-toothed ring. The outer-toothed slewing bearing is coaxial with the tank.

[0050] The driving motor 72 is fixed to the workbench and located below the top plate. A gear 71 is mounted on the output shaft of the driving motor 72 and engages the outer ring 62. A connecting plate 65 is fixedly mounted on the upper surface of the outer ring by connecting bolts 66. The connecting plate extends radially inward of the outer ring towards the first tank and has a magnet 67 mounted on the end thereof facing the first tank by bolts, i.e. the magnet is mounted on the outer ring by the connecting plate. The magnet is adjacent to the outer wall of the first tank wall 31 and has a gap of 0.2 mm between the outer circumferential surface of the magnet and the first tank wall, so that the magnet is as close as possible to the spherical ball and does not rub against the first tank.

[0051] Under the driving of the driving motor, the outer ring can drive the magnet to rotate around the central axis of the first tank, and simultaneously drive the spherical ball to rotate in the annular tube.

[0052] To reduce the influence on the printing operation, a first annular groove 191 is formed in the top plate of the workbench. When viewed in the vertical direction, the first annular groove 191 extends around the first tank 30 and penetrates the upper surface 131 of the top plate upward. The outer-toothed slewing bearing is mounted in the annular groove and does not protrude above the upper surface of the top plate.

[0053] In the embodiment, to better attract the spherical ball by the magnet, the spherical ball center is at the same height as the magnet center in the height direction. To achieve the above goal, a first trough flange 36 is arranged at the bottom of the first trough wall 31 in the embodiment, the first trough flange is fixed in the annular groove by bolts, and the first release film is fixed at the middle part of the first trough wall in the height direction. An annular film pressing groove 311 is arranged at the middle of the inner wall of the first trough wall in the height direction, the outer peripheral edge pressing ring 313 of the release film is tightly pressed in the film pressing groove, the screw 314 is screwed on the first trough wall after passing through the pressing ring 313, the release film is fixed on the first trough wall, and the sealing ring 312 is arranged between the pressing ring 313 and the release film to ensure the sealing performance. The annular pipe is located at the bottom of the first trough.

[0054] When the motor 72 drives the outer ring 62 of the outer-toothed slewing bearing 60 to rotate, the magnet 67 can be synchronously rotated through the connecting plate 65, and under the attraction of the magnetic force, the spherical ball can rotate in the extension direction of the annular pipe, so that the spherical ball circulates in the inner cavity of the annular pipe, the liquid photosensitive resin in the first trough can be sucked into the annular pipe through the upstream inlet and outlet, and the liquid photosensitive resin in the annular pipe can be sprayed into the first trough through the downstream inlet and outlet, so that the liquid photosensitive resin in the first trough flows.

[0055] The upstream inlet and outlet and the downstream inlet and outlet are relative to the rotation direction and position of the spherical ball. Please refer to the first arrow P in Figure 2 and Figure 4 , Figure 2 , the direction of the first arrow P indicates the rotation direction of the outer ring, Figure 4 , the direction of the second arrow S indicates the rotation direction of the spherical ball in the annular pipe 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 rotation direction of the spherical ball, and the downstream side refers to the front of the rotation direction of the spherical ball. For the convenience of description, the upstream inlet and outlet are called the upstream inlet and outlet 351, and the downstream inlet and outlet are called the downstream inlet and outlet 352. When the spherical ball rotates along the direction of the second arrow S, the liquid photosensitive resin in front of the spherical ball is sprayed outwards by the downstream inlet and outlet 352 under the action of the pushing force of the spherical ball, and at the same time, a vacuum is generated behind the spherical ball, the liquid photosensitive resin in the first trough is sucked into the annular pipe through the upstream inlet and outlet 351 under the action of the negative pressure, so that the liquid photosensitive resin in the first trough flows. The direction of the third arrow F indicates the flow direction of the liquid photosensitive resin in the first trough into the annular pipe, and the direction of the fourth arrow J indicates the spraying direction of the liquid photosensitive resin in the annular pipe into the first trough.

[0057] It can be understood that, since the upstream inlet and outlet and the downstream inlet and outlet are relative to the rotating direction and position of the spherical ball, each inlet and outlet will become the upstream inlet and outlet or the downstream inlet and outlet as the spherical ball continuously rotates in the annular pipe.

[0058] Embodiment 2

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

[0060] In this embodiment, a second trough 40 in the shape of a circle and a second rotating device are installed on the workbench, the second trough 40 is used to hold liquid photosensitive resin, and an annular pipe 33 in the shape of a circle is arranged in the second trough. The structure of the annular pipe in this embodiment is the same as that of the annular pipe in Embodiment 1, and a spherical ball is movably placed in the annular pipe 33. The second trough 40 includes a second trough wall 41 in the shape of a circle 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 at 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 be located in the working area, and the annular pipe is located in the non-working area, i.e., the annular pipe is located radially outside the second trough.

[0061] In this embodiment, the second rotating device is a hollow shaft torque motor 50, which is a servo motor. The hollow shaft torque motor 50 includes a stator 51 and a rotor 53 rotatably arranged inside the stator, and 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. A hollow shaft 54 is fixedly installed on the rotor.

[0062] An upper flange 511 and a lower flange 512 are respectively arranged 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, a first bolt 551 fixes the first flange on the upper flange, the lower end cover 56 has a second flange corresponding to the lower flange, and a second bolt 561 fixes the second flange on the lower flange, so that the upper end cover and the lower end cover are respectively detachably installed at 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 formed by the outer circumferential surface of the hollow shaft 54 protruding radially outward. The upper end cover has an inwardly protruding abutting flange 553, the lower surface of which is a downwardly facing step surface. The abutting flange 553 abuts the upper side of the outer ring of the upper angular contact bearing via its lower surface, and the upper flange abuts the lower side of the inner ring of the upper angular contact bearing. Thus, the upper end cover is rotatably abutted to 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 formed by the outer circumferential surface of the hollow shaft 54 recessed radially inward, and has a downwardly facing step surface. The inner side of the lower end cover has an upwardly facing abutting surface 563, which is an upwardly facing step surface. The abutting surface 563 abuts the lower side of the outer ring of the lower angular contact bearing, and the step portion 544 abuts the upper side of the inner ring of the lower angular contact bearing. Thus, the lower end cover is rotatably abutted to the hollow shaft via the lower bearing. The stator has a winding 52 on the inner side thereof. The structure of the hollow shaft torque motor can be completed using existing mature technology, and thus will not be described in detail.

[0065] To reduce the influence of the hollow shaft torque motor on the printing operation, a second annular groove 192 is formed in the top plate of the workbench, extends around the second trough 40, and penetrates the upper surface 131 of the top plate upward. The hollow shaft torque motor is installed in the second annular groove, specifically, the lower end cover of the hollow shaft torque motor is bolted to the bottom of the second annular groove.

[0066] The mover, the hollow shaft, and the second trough are coaxially arranged. The magnet 67 is bolted to the inner side of the hollow shaft, and the center of the ball and the center of the magnet are at the same height in the height direction. 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 simultaneously drive the ball to rotate in the annular pipe. The magnet 67 and the outer circumferential surface of the second trough wall have a gap of 0.2 mm.

[0067] In this embodiment, 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 a conventional method. The second trough flange 46 is bolted to the upper end cover 55, i.e., the second trough flange is fixedly installed on the stator via the upper end cover. The annular pipe is located at the bottom of the second trough.

[0068] When the mover of the hollow shaft torque motor rotates, the magnet 67 can rotate synchronously, and under the attraction of the magnetic force, the circular ball rotates in the extension direction of the annular pipe, so that the circular ball rotates in the inner cavity of the annular pipe, and the liquid photosensitive resin in the second tank can be sucked into the annular pipe through the inlet and outlet on the upstream side, and the liquid photosensitive resin in the annular pipe can be sprayed into the second tank through the inlet and outlet on the downstream side, so that the liquid photosensitive resin in the second tank flows. In this embodiment, the principle of the liquid photosensitive resin entering and exiting the annular pipe is the same as that of embodiment 1, and specific reference can be made to the related contents in embodiment 1, which will not be repeated here.

[0069] Embodiment 3

[0070] Please refer to Figures 7-9 In this embodiment, the three-dimensional printer with the spraying function comprises a workbench 10, which comprises a vertical wall 11 extending in a rectangular cylindrical shape, a bottom plate 12 mounted at the bottom of the vertical wall, and a top plate 13 mounted at the top of the vertical wall, and a liquid crystal screen 18 is mounted at the central part of the top plate. An ultraviolet light system 14 is mounted in the inner cavity of the workbench, and 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, which will not be repeated here.

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

[0072] A circular third tank 85 is mounted on the workbench, which is used to contain liquid photosensitive resin, and the third tank is directly fixed on the surface 131 of the top plate 13 through bolts. A circular annular pipe 33 is arranged in the third tank, and a plurality of inlets and outlets 35 are formed on the annular pipe, and each inlet and outlet is horizontally directed to the central part of the tank. The fixing mode of the annular pipe is the same as that of embodiment 1. A circular ball 34 made of ferromagnetic material is movably placed in the annular pipe.

[0073] In this embodiment, the bottom surface of the third tank 30 is divided into a working area 316 and a non-working area 317, and the working area 316 is located in the central part of the third tank 30, and the non-working area 317 is located on the periphery of the third tank 30. Figure 2In the embodiment, the working area 316 is located in the central part of the bottom surface of the third tank, and the non-working area 317 surrounds the working area. The annular pipe is located outside the working area in the radial direction of the third tank.

[0074] A plurality of spiral coils 80 are wound on the annular pipe. In the embodiment, one spiral coil 80 is arranged between every two adjacent inlets and outlets. Each spiral coil is formed as an electromagnetic driver. Two ends of the spiral coil are formed as a positive electrode end 81 and a negative electrode end 82. The positive electrode end 81 and the negative electrode end 82 of the spiral coil are connected to a plug, which is used to be plugged into a direct current power supply. In the embodiment, the winding directions of the spiral coils are the same, and the same end of each spiral coil is used as the positive electrode end, and the other end is used as the negative electrode end. After the direct current power supply is turned on, the magnetic force generated by each spiral coil has the same direction, which can drive the circular ball in the annular pipe to rotate circularly, so that the liquid photosensitive resin in the third tank can be sucked into the annular pipe through the inlet and outlet on the upstream side, and the liquid photosensitive resin in the annular pipe can be sprayed into the third tank through the inlet and outlet on the downstream side, so that the liquid photosensitive resin in the third tank flows.

[0075] When the spiral coil is powered on, the circular ball may not rotate due to the adhesion of the liquid photosensitive resin. At this time, a magnet can be used to drive the circular ball to rotate outside the third tank. After the circular ball rotates, when the rotation speed of the circular ball reaches a set speed, the voltage of the direct current power supply needs to be adjusted in time to maintain the uniform speed of the circular ball by using the resistance of the liquid photosensitive resin. Otherwise, the circular ball will continue to accelerate under the influence of acceleration, and finally the annular pipe and the tank will be damaged.

[0076] In order to facilitate the adjustment of the rotation speed of the circular ball, the embodiment further comprises a voltage adjustment system, which comprises a central processing unit 101, a first pressure sensor 102, a second pressure sensor 103 and a direct current voltage regulator 104 connected to the central processing unit 101.

[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 send control instructions according to the processing result to coordinate the work of the direct current voltage regulator.

[0078] The first pressure sensor is used to detect the pressure in the annular pipe and send the detection data to the central processing unit.

[0079] The second pressure sensor is used to detect the pressure in the annular pipe and send the detection data to the central processing unit.

[0080] The direct current voltage regulator receives the control of the central processing unit and adjusts the voltage outputted by the direct current power supply.

[0081] In this embodiment, the pressure detection points of the first pressure sensor and the second pressure sensor are 60mm apart, so as to avoid the pressure fluctuation between the two pressure detection points from affecting each other.

[0082] The two input terminals of the direct current voltage regulator are connected to the connecting columns of the plug respectively, and the two output terminals of the direct current voltage regulator are connected to the two ends of the spiral coil, so that the two ends of the spiral coil are connected to the plug through the direct current voltage regulator, and the output voltage of the direct current power supply is adjusted by the direct current voltage regulator. The specific connection mode and use of the direct current voltage regulator are in accordance with the existing mature technology, and will not be described in detail. That is, the two ends of the spiral coil are connected to the plug through the direct current voltage regulator.

[0083] The first pressure sensor and the second pressure sensor are used to detect the pressure at two positions in the annular pipe. When the ball rotates in the annular pipe, the place passed will extrude and push the liquid photosensitive resin, thereby causing the change of the pressure in the annular pipe. The position of the ball is detected by the change of the pressure in the annular pipe, and the rotation speed of the ball is calculated by the time difference of the ball passing 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 direct current power supply is reduced by the direct current voltage regulator; when the rotation speed of the ball is lower than the set speed, the output voltage of the direct current power supply is increased by the direct current voltage regulator. The set speed of the ball needs to be determined according to the experiment, so as to ensure that the ball can rotate stably in the annular pipe.

Claims

1. A three-dimensional printer with jetting function, characterized in that, The device includes a worktable on which a circular material tank and a rotator are mounted. The material tank is used to hold liquid photosensitive resin. An annular tube with several inlets and outlets is installed inside the material tank. A sphere made of ferromagnetic material is movably placed inside the annular tube. A magnet is installed on the rotator, which drives the magnet to rotate around the material tank. The magnet, in turn, drives the sphere to rotate within the annular tube along its extension direction. As the sphere rotates within the annular tube, the liquid photosensitive resin in the material tank is drawn into the annular tube through the upstream inlets and outlets, and the liquid photosensitive resin in the annular tube is sprayed into the material tank through the downstream inlets and outlets, thus causing the liquid photosensitive resin in the material tank to flow.

2. The three-dimensional printer according to claim 1, characterized in that, All inlets and outlets are oriented horizontally toward the center of the trough.

3. The three-dimensional printer according to claim 1, characterized in that, The annular tube is located on the radial outer side inside 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 tank is divided into a working area and a non-working area. The working area is located in the center of the bottom surface of the material tank, and the non-working area surrounds the working area. The printing platform can enter the material tank vertically and is located in the working area. 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 gear slewing bearing and a drive motor. The external gear slewing bearing includes an outer ring and an inner ring joined together by balls. The inner ring is fixed to the worktable, and the outer ring has teeth that protrude radially outward. The external gear slewing bearing is coaxially arranged with the material trough. The drive motor is fixed to the worktable, and a gear is mounted on the output shaft of the drive motor. The gear meshes with the outer ring, and a magnet is mounted on the outer ring. Driven by the drive 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 inside the annular tube. The drive motor is a servo motor.

6. The three-dimensional printer according to claim 5, characterized in that, The material trough includes a cylindrical trough wall and a material trough flange located at the bottom of the trough wall, which is fixedly mounted on the worktable; in the height direction, the release film is fixed in the middle 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 disposed within the stator. The central axis of the hollow shaft torque motor extends vertically. A hollow shaft is fixedly mounted on the mover. The stator is fixedly mounted on the worktable. The mover, hollow shaft, and material trough are coaxially arranged. A magnet is installed inside 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, synchronously driving the ball to rotate within 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 includes a cylindrical trough wall and a material trough flange disposed on the top of the trough wall, which is fixedly mounted on the stator; in the height direction, a release film is fixed to the bottom of the trough wall, and an annular tube is located at the bottom of the material trough.

9. A three-dimensional printer with jetting function, characterized in that, The device includes a workbench with a circular material tank for holding liquid photosensitive resin. An annular tube is installed inside the material tank, located radially outside the tank. Several inlets and outlets are provided on the annular tube, all of which are horizontally oriented towards the center of the material tank. A sphere made of ferromagnetic material is movably placed inside the annular tube. A spiral coil is wound around a ring tube, and the two ends of the spiral coil are connected to a plug for plugging into a DC power supply. When the spiral coil is connected to DC power, it can drive the sphere to rotate inside the ring tube along the extension direction of the ring tube. When the sphere rotates inside the ring tube, the liquid photosensitive resin in the material tank can be drawn into the ring tube through the upstream inlet and outlet, and the liquid photosensitive resin in the ring tube can be sprayed into the material tank through the downstream inlet and outlet, so that the liquid photosensitive resin in the material tank flows.

10. The three-dimensional printer according to claim 9, characterized in that, It also includes a voltage regulation system, which comprises a central processing unit, a first pressure sensor, a second pressure sensor, and a DC voltage regulator connected to the central processing unit, wherein: The central processing unit is used to receive information from the first pressure sensor and the second pressure sensor, process the information, and issue control commands based on the processing results to coordinate the operation of the DC voltage regulator. The first pressure sensor is used to detect the pressure inside the annular tube and send the detection data to the central processing unit. The second pressure sensor is used to detect the pressure inside the annular tube and send 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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