3D printing equipment

Abstract

The utility model belongs to the technical field of additive manufacturing, and discloses 3D printing equipment which comprises a rack, a forming cylinder capable of intermittently rotating by 180 degrees, a driving mechanism capable of intermittently acting, a guide rail, a printing mechanism, a limiting sensor and a control system, the forming cylinder is rotationally installed on the rack, and a printing platform is arranged at the top of the forming cylinder; the power output end of the driving mechanism is in transmission connection with the forming cylinder; the guide rail is located above the printing platform and arranged in the printing direction of the printing platform. The printing mechanism is slidably connected to the guide rail. The two limiting sensors are correspondingly installed at the two ends of the guide rail, and the distance between the two limiting sensors corresponds to the single-time printing stroke distance of the printing platform. The control system is in electric control connection with the limiting sensor, the driving mechanism and the printing mechanism. The printing direction of the printing mechanism during printing can be guaranteed to be the same as the powder spreading direction on the printing platform, the printing mechanism does not need to return to the initial end for printing, and the printing efficiency and the overall size precision of a printed piece are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of additive manufacturing, and more specifically to a 3D printing device. Background Art

[0002] At present, the printing cylinder in the 3D printing method is printed at a fixed position during the printing process without position movement. A printing nozzle is installed on the printing mechanism. During the printing process, the nozzle will move and spray the binder onto the powder bed of the molding cylinder. Because there is a certain distance between the nozzle and the powder bed surface, the binder sprayed from the nozzle is in the form of very small drops. Under the action of external forces, a certain curved movement will occur instead of falling vertically, causing the landing point to be not at the originally determined position. Therefore, the binder will produce a certain deviation while falling on the powder bed. In order to ensure the consistency of the printing direction, after the printing nozzle moves from one end of the guide rail to the other end, it needs to return to the initial end and then print the next layer. Since the width of the molding cylinder is very large, the printing needs to be repeated many times to fill the entire width of the molding cylinder, which prolongs the printing time.

[0003] In addition, when the position of the forming cylinder is fixed, direct reciprocating printing will result in two printing directions in opposite directions during the back-and-forth printing process, causing the adhesive sprayed by the nozzle onto the printing platform to deviate in opposite directions, which will cause a certain deviation in the overall dimensional accuracy of the printed part.

[0004] Therefore, how to provide a forming cylinder that can intermittently rotate 180° during the printing process, and rotate after contacting the limit sensor after the printing mechanism moves for printing, so as to ensure that the printing direction of the printing mechanism is the same as the powder laying direction of the printing platform, and improve the printing efficiency and the overall dimensional accuracy of the printed part of the 3D printing device is a problem that technical personnel in this field urgently need to solve. Utility Model Content

[0005] In view of this, the utility model provides a 3D printing device with a forming cylinder that can intermittently rotate 180°, and controls the forming cylinder to rotate only when the printing mechanism contacts the limit sensor to ensure that the printing direction of the printing mechanism is the same as the powder spreading direction on the printing platform during printing. There is no need to return the printing mechanism to the initial end for printing, thereby improving the printing efficiency and the overall dimensional accuracy of the printed part.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A 3D printing device, comprising a frame, a molding cylinder that intermittently rotates 180 degrees, an intermittently moving driving mechanism, a guide rail, a printing mechanism, a limit sensor and a control system, wherein the molding cylinder is rotatably mounted on the frame and the top of the molding cylinder is a printing platform; the power output end of the driving mechanism is drivingly connected to the molding cylinder;

[0008] The guide rail is located above the printing platform and is arranged along the printing direction on the printing platform; the printing mechanism is slidably connected to the guide rail; there are two limit sensors and they are correspondingly installed at the two ends of the guide rail, and the distance between the two corresponds to the single printing stroke distance of the printing platform; the control system is electrically controlled and connected to the limit sensor, the driving mechanism and the printing mechanism respectively.

[0009] It can be known from the above technical scheme that compared with the prior art, the utility model discloses a 3D printing device, which is provided with an intermittent action driving mechanism, and the driving mechanism is controlled by a control system so that the driving mechanism drives the forming cylinder to rotate, and the angle of each rotation of the forming cylinder is controlled to be 180°. At the same time, a guide rail is provided on the frame and is located above the printing platform, and the printing mechanism is slidably installed on the guide rail so that the printing mechanism can reciprocate on the guide rail, and limit sensors are provided at both ends of the guide rail, and the distance between the two limit sensors is a single printing distance of the printing platform. When the printing mechanism moves to either end and contacts the limit sensor, the limit sensor transmits a signal to the control system. At this time, the control system controls the driving mechanism to start, so that the forming cylinder rotates 180°, so that the printing mechanism can also print during the return stroke, and the printing direction is the same as the printing direction on the printing platform during the incoming stroke, so that even if the powder material deviates during the falling process, the consistency of the deflection direction of the powder material falling to the printing platform during the reciprocating movement can be ensured, so that the direction of the powder material is consistent when it is bonded by the printing mechanism, and the overall dimensional accuracy of the printed part is improved while improving the printing efficiency.

[0010] Furthermore, a bearing seat is fixed at the bottom of the frame, a bearing is installed in the bearing seat, a forming cylinder fixing plate is fixed to the bottom end of the forming cylinder, a driven gear is fixed to the bottom end of the forming cylinder fixing plate, the bottom end of the driven gear is fixedly connected to the inner ring of the bearing through a connecting block, and the driving mechanism is transmission-connected to the driven gear.

[0011] The beneficial effects of adopting the above technical solution are: the bearing seat has the characteristics of simple structure, compact construction, sensitive rotation, easy device maintenance, etc., and is very suitable for use in the rotating mechanism of the present application.

[0012] Furthermore, the bearing is a thrust cylindrical roller bearing.

[0013] The beneficial effect of adopting the above technical solution is: using thrust cylindrical roller bearings, which have the characteristics of high rigidity, small space occupation, large axial load capacity, and low sensitivity to impact loads, and are suitable for low-speed rotational motion.

[0014] Furthermore, the driving mechanism includes: a driving motor and a driving gear, the driving motor is fixed at the bottom of the frame and is located on one side of the driven gear, the driving end of the driving motor is fixed to the driving gear, and the driving gear is meshed and transmission-connected with the driven gear.

[0015] Furthermore, the driving motor is a servo motor.

[0016] The beneficial effects of adopting the above technical solution are: the selection of servo motors has the following advantages over traditional motors: 1. High control accuracy. It only rotates when a control command is transmitted and stops when there is no command. It will not continue to rotate due to inertia after power failure, which is beneficial to control the 180-degree rotation of the forming cylinder 2; 2. Good low-speed operation stability. At a lower speed, the servo motor still runs very smoothly and has a low vibration frequency; 3. Good torque-frequency characteristics. The servo motor has a constant force output. Regardless of whether it is high or low speed, the torque will not change much; 4. The servo motor has a certain overload capacity. Even if it exceeds the rated torque, it can still work normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0018] Figure 1 The accompanying drawing is a schematic diagram of the axial structure of the 3D printing device provided by the utility model.

[0019] Figure 2 The attached picture is Figure 1 The front view of the accompanying drawing is a schematic diagram of the structure.

[0020] Figure 3 The attached picture is Figure 1 The top view of the structure is shown in the accompanying drawing.

[0021] Figure 4 The accompanying drawing is a front view structural schematic diagram of the bearing seat provided by the utility model.

[0022] Figure 5 The attached picture is Figure 4 The sectional structural diagram of the accompanying drawing.

[0023] Figure 6 The accompanying drawing is a schematic diagram of the structure of the bearing.

[0024] Among them, 1-frame, 2-forming cylinder, 21-printing platform, 22-cylinder door, 3-driving mechanism, 31-driving gear, 32-driving motor, 4-guide rail, 5-printing mechanism, 51-printer, 511-printing end, 52-powder spreader, 521-spraying end, 53-printer mounting plate, 54-powder spreader mounting plate, 541-through hole, 55-powder supply mechanism, 551-discharge port, 552-powder discharge trough, 553-powder storage tank, 5531-feed port, 6-bearing seat, 61-bearing, 611-seat ring, 612-shaft ring, 613-cylindrical roller layer, 62-fixed seat, 63-rotating seat, 7-forming cylinder fixed plate, 8-driven gear. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] The utility model embodiment discloses a 3D printing device, including a frame 1, a forming cylinder 2 that intermittently rotates by 180 degrees, a driving mechanism 3 that intermittently moves, a guide rail 4, a printing mechanism 5, a limit sensor and a control system, wherein the forming cylinder 2 is rotatably mounted on the frame 1 and its top is a printing platform 21; the power output end of the driving mechanism 3 is transmission-connected with the forming cylinder 2; the guide rail 4 is located above the printing platform 21 and is arranged along the printing direction on the printing platform 21; the printing mechanism 5 is slidably connected to the guide rail 4; there are two limit sensors and they are correspondingly mounted at both ends of the guide rail 4, and the distance between the two corresponds to the single printing stroke distance of the printing platform 21; the control system is electrically controlled and connected with the limit sensor, the driving mechanism 3 and the printing mechanism 5 respectively.

[0027] In one embodiment of the forming cylinder 2 of the utility model, a lifting mechanism for intermittently lifting and lowering the printing platform 21 is installed in the forming cylinder 2, and the control system is electrically connected to the lifting mechanism. The printing platform 21 can be accurately lifted and lowered during the printing process. Every time the printing mechanism 5 contacts the limit sensor, the lifting device controls the printing platform 21 to descend, and the height of the lowering is the thickness of a single printing layer, ensuring that the distance between the printing end of the printing mechanism 5 and the printing layer on the printing platform 21 remains unchanged, thereby improving the printing accuracy.

[0028] In the above embodiment, a plurality of cylinder doors 22 are installed on the axial side cylinder wall of the forming cylinder 2. During printing, the lifting device in the cylinder can be checked and repaired by opening the cylinder door 22 to ensure normal printing.

[0029] In one embodiment of the utility model, a bearing seat 6 is fixed at the bottom of the frame 1, a bearing 61 is installed in the bearing seat 6, a forming cylinder fixing plate 7 is fixed at the bottom end of the forming cylinder 2, a driven gear 8 is fixed at the bottom end of the forming cylinder fixing plate 7, the bottom end of the driven gear 8 is fixedly connected to the inner ring of the bearing 61 through a connecting block, and the driving mechanism 3 is transmission-connected to the driven gear 8. The bearing seat 6 has the characteristics of simple structure, compact structure, sensitive rotation, and convenient device maintenance, and is very suitable for use in the rotating mechanism of the present application.

[0030] For details, see Figure 4-6 As shown, the bearing 61 is a thrust cylindrical roller bearing, including a seat ring 611, a shaft ring 612 and a cylindrical roller layer 613. The bearing seat 6 includes a fixed seat 62 and a rotating seat 63. The seat ring 611 is embedded in the groove of the fixed seat 62, and the bottom of the rotating seat 63 is fixedly connected to the shaft ring 62. The thrust cylindrical roller bearing is selected, which has the characteristics of high rigidity, small space occupation, large axial load capacity, and low sensitivity to impact load, and is suitable for low-speed rotation.

[0031] An embodiment of the driving mechanism 3 in the utility model includes: a driving motor 31 and a driving gear 32. The driving motor 31 is fixed to the bottom of the frame 1 and is located on one side of the driven gear 8. The driving end of the driving motor 31 is fixed to the driving gear 32, and the driving gear 32 is meshed and connected with the driven gear 8.

[0032] Specifically, the driving motor 32 is a servo motor, which has the following advantages over traditional motors: 1. High control accuracy. It rotates only when a control command is transmitted and stops when there is no command. It will not continue to rotate due to inertia after power failure, which is beneficial to control the 180-degree rotation of the forming cylinder 2; 2. Good stability during low-speed operation. At a lower speed, the servo motor still runs very smoothly with a low vibration frequency; 3. Good torque-frequency characteristics. The servo motor has a constant force output. Regardless of whether it is a high speed or a low speed, the torque will not change much; 4. The servo motor has a certain overload capacity. Even if it exceeds the rated torque, it can still work normally.

[0033] In addition, in one embodiment of the printing mechanism 5 of the present invention, the printing mechanism 5 includes a printer 51 and a powder spreader 52, the printer 51 and the powder spreader 52 are fixedly mounted on a printer mounting plate 53 and a powder spreader mounting plate 54, respectively, the printer mounting plate 53 and the powder spreader mounting plate 54 are respectively slidably connected to the guide rail 4 and can abut against the limit sensor, and the control system is respectively electrically controlled and connected to the printer 51 and the powder spreader 52. The track 4 is arranged as two tracks arranged at intervals, so that the two ends of the printer mounting plate 53 and the powder spreader mounting plate 54 are respectively slidably connected to the two tracks 4, thereby improving the stability of the printer 51 and the powder spreader 52 when they move back and forth.

[0034] In the above embodiment, the printer 51 is fixedly installed by passing through the printer mounting plate 53 vertically, and the printing end 511 is located at the bottom of the printer mounting plate 53. The stability of the printer 51 during mobile printing is improved, and the printing effect is improved.

[0035] In the above embodiment, a through hole 541 is longitudinally formed in the powder spreader mounting plate 54 and is communicated with the top of the powder spreader 52 , and the bottom of the powder spreader 52 is a material spraying end 521 .

[0036] Specifically, the length of the spraying end 521 of the powder spreader 52 is the same as the width of the printing platform 21, so that the powder spreader 52 can completely cover the printing platform 21 with powder. At the same time, the printer 51 is fixed on the printer mounting plate 53 and its printing end 511 length is half the width of the printing platform 21. Its installation position is also located directly above one-half the width of the printing platform 21. That is, there is no need to control the movement of the printer 51 on the printer mounting plate 53. Only by rotating the forming cylinder 2 intermittently by 180°, when the printer 51 moves to the other end, the unprinted area on the printing platform 21 will rotate with the forming cylinder 2 to the printing path of the printer 51. In this way, full-width printing can be completed, and the printing directions of the two prints are the same.

[0037] In the above embodiment, the printing mechanism 5 further includes a powder supply mechanism 55 , which is fixedly mounted on the top of the frame 1 , and a discharge port 551 is provided at the bottom of the powder supply mechanism 55 , and the discharge port 551 is arranged corresponding to the through hole 541 .

[0038] In the above embodiment, the powder supply mechanism 55 includes a powder outlet trough 552 and a powder storage tank 553. The powder outlet trough 552 is hollow inside, and the powder storage tank 553 is fixedly installed on one side of the top of the powder outlet trough 552. The bottom of the powder storage tank 553 is open and communicated with the inside of the powder outlet trough 552. A feed port 5531 is provided on the top of the powder storage tank 553. Sufficient powder can be provided for the powder spreader 52 to ensure sufficient powder supply under different powder spreading efficiencies and improve the continuity of powder spreading.

[0039] The use principle of the 3D printing device of the utility model is as follows:

[0040] In the utility model, the forming cylinder and the forming cylinder fixing plate are fixed on the top of the rotatable driven gear. The rotation of the driven gear is controlled by the driving motor through the gear transmission. The rotation angle can be accurately adjusted to 180° through the control system. The powder spreader and the printer can reciprocate along the guide rail. The powder spreader is responsible for spreading powder on the printing platform of the forming cylinder, and the printer will spray the binder on the powder bed for printing. The powder supply mechanism is responsible for storing the powder and supplying the powder to the powder spreader.

[0041] Taking the example of a printing mechanism that needs one round trip to print the full format of the forming cylinder, after the printer whose printing end length is half the width of the printing platform moves from right to left, it only prints half of the format. The forming cylinder needs to be rotated 180 degrees and then moved from left to right to print the full format. During use, the powder spreader moves through the guide rail, and at the same time, it spreads powder on the printing platform in the forming cylinder to form a powder bed. After completion, the printer moves from right to left through the guide rail. During the movement, the print head sprays the binder to print the powder bed, and stops after contacting the limit sensor. Printing is completed for half of the format. At this time, the control system receives the signal of the limit sensor and controls the drive motor to control the meshing active gear and driven gear, so that the forming cylinder on the top of the driven gear rotates, and sets the number of rotations to make the forming cylinder rotate 180 degrees. The printer then moves from left to right through the guide rail to print, and stops at the position of the limit sensor at the right end of the guide rail to complete the full-width printing. At this time, the control system controls the active gear to rotate, and the forming cylinder rotates 180 degrees again. At the same time, the control system also controls the lifting device to lower the printing platform in the forming cylinder by a distance of the thickness of the printing powder layer. The powder spreader moves through the guide rail to continue to lay the next layer of powder bed for the forming cylinder. After completion, the printing mechanism moves along the guide rail to start printing the next layer, and the above process is repeated until the entire print is completed. During the printing process, when there is no powder in the powder spreader, it is controlled to move to the bottom of the feeding mechanism, and the feeding mechanism drops the powder into the powder spreader.

[0042] Because the forming cylinder rotates 180 degrees every time the printing mechanism completes half-width printing, there is no need to return the printing mechanism to the initial end to continue printing, which improves printing efficiency. The offset direction of the powder spreader nozzle sprayed onto the printing platform is consistent, and the offset direction of the printing adhesive sprayed by the printing nozzle of the printing mechanism is also consistent, so that the printing direction of the printing mechanism on the printing platform is always unchanged, reducing printing deviation and improving the overall dimensional accuracy of the printed part.

[0043] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0044] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A 3D printing device, characterized in that: The invention comprises a frame (1), a molding cylinder (2) that can intermittently rotate at 180 degrees, a driving mechanism (3) that can intermittently move, a guide rail (4), a printing mechanism (5), a limit sensor and a control system. The molding cylinder (2) is rotatably mounted on the frame (1) and the top of the molding cylinder is a printing platform (21); the power output end of the driving mechanism (3) is drivingly connected to the molding cylinder (2); The guide rail (4) is located above the printing platform (21) and is arranged along the printing direction on the printing platform (21); the printing mechanism (5) is slidably connected to the guide rail (4); there are two limit sensors and they are correspondingly installed at the two ends of the guide rail (4), and the distance between the two corresponds to the single printing stroke distance of the printing platform (21); the control system is electrically controlled and connected to the limit sensors, the driving mechanism (3) and the printing mechanism (5) respectively.

2. A 3D printing device according to claim 1, characterized in that: A bearing seat (6) is fixed at the bottom of the frame (1), a bearing (61) is installed in the bearing seat (6), a forming cylinder fixing plate (7) is fixed at the bottom end of the forming cylinder (2), a driven gear (8) is fixed at the bottom end of the forming cylinder fixing plate (7), the bottom end of the driven gear (8) is fixedly connected to the inner ring of the bearing (61) via a connecting block, and the driving mechanism (3) is transmission-connected to the driven gear (8).

3. A 3D printing device according to claim 2, characterized in that: The bearing (61) is a thrust cylindrical roller bearing.

4. A 3D printing device according to claim 2, characterized in that: The driving mechanism (3) comprises: a driving motor (31) and a driving gear (32); the driving motor (31) is fixed at the bottom of the frame (1) and is located on one side of the driven gear (8); the driving end of the driving motor (31) is fixed to the driving gear (32); and the driving gear (32) is meshed and transmission-connected with the driven gear (8).

5. A 3D printing device according to claim 4, characterized in that: The driving motor (31) is a servo motor.

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