Mechanism capable of switching multiple printing heads for 3D printer

Abstract

The invention relates to the technical field of 3D printing, in particular to a mechanism capable of switching multiple printing heads for a 3D printer, which comprises a top plate, a horizontal rotating positioner is arranged in the middle of the lower plate surface of the top plate, vertical cross frames are arranged below the top plate at intervals, and the central axis of the vertical cross frames and the central axis of a rotating part of the horizontal rotating positioner are located on the same vertical line. The vertical cross frame is provided with a plurality of vertical frames, and each vertical frame is in up-down sliding fit with a mounting plate used for mounting a printing head. Due to the fact that the vertical cross frame is provided with the multiple vertical frames, and each vertical frame can be matched with one printing head, three or more printing heads can be arranged, and the printing heads needing to be used can move downwards to the working position only under the action of the horizontal rotating positioner and the driving rod; and the rest of the unused printing heads are higher than the used printing heads under the action of the reset springs, so that normal operation can be ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to a mechanism for switchable multiple print heads for a 3D printer. Background Art

[0002] 3D printing technology is a rapid prototyping technology that uses digital three-dimensional model files as the basis. It uses metal, plastic, photosensitive resin and other molding materials to form objects by printing layer by layer. It belongs to additive manufacturing.

[0003] 3D printers with multiple print heads can support the printing of multiple materials at the same time. They are often used to print the main material and support material separately, or to print materials of different colors or materials in different parts of the model to meet specific needs.

[0004] Existing multi-print head 3D printers basically use a dual print head structure with two print heads fixed together. This method is simple to implement, and the nozzles of the two print heads are at the same height. In theory, the two print heads can print alternately without adjustment. However, due to the problems of processing and assembly accuracy, it is difficult for the two print heads to be perfectly at the same height, so it is very easy for the print heads to interfere with each other. For example, when one print head is printing, the other print head is likely to scratch the model, affecting the printing effect. In severe cases, the model may even be scraped down and the printing may fail. For three or more print heads, the interference problem of this method becomes more serious, making it almost impossible to use.

[0005] For this reason, the existing Chinese patent with publication number CN205889903U discloses a dual-print head linkage FDM three-dimensional printing structure based on bidirectional lead screw reversing, which specifically adopts a bidirectional lead screw with a guide rail to realize the reverse movement of the dual print heads. When a print head is needed, its height is lowered and the height of the other print head is raised, thereby solving the problem of mutual interference between the dual print heads. Another example is a Chinese patent with publication number CN105291436B that discloses a dual-wire print head of a 3D printer, which specifically adopts fixing the two print heads on a rotatable bracket, and realizing dual-head switching by rotating, thereby solving the problem of mutual interference between the dual print heads. Another example is a Chinese patent with publication number CN109866423A that discloses a multi-print head switching structure of a 3D printer, which specifically adopts a guide rail with two print heads, and the drive devices respectively arranged at the two ends of the guide rail independently drive the print heads, so that the unused print heads move to the ends of the guide rail, thereby solving the problem of mutual interference between the dual print heads. However, when the above technology switches three or more print heads, it is necessary to repeatedly set the above switching structure (each switching structure can only match two print heads), which will cause the overall structure to become very complicated, bloated, or even impossible to implement. In addition, the above technology does not solve the problem of processing and assembly accuracy. Therefore, when using the above technology, after switching the print head, it is still necessary to pay attention to the height of the print head in the working position after switching to prevent the print head from being too close or too far from the model; for example, if the height of the print head before switching is higher than the height of the print head to be switched, the print head after switching may be too close to the printing layer or even scrape the model.

[0006] To this end, we designed a mechanism for switchable multi-print heads for a 3D printer. Summary of the invention

[0007] In order to overcome the deficiencies in the background technology, the present invention discloses a switchable multi-print head mechanism for a 3D printer.

[0008] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme:

[0009] A switchable multi-print head mechanism for a 3D printer, comprising:

[0010] The top plate has a horizontal rotary positioner in the middle of its lower plate surface;

[0011] A vertical cross frame, which is arranged below the top plate at intervals, and whose central axis is located on the same vertical line as the central axis of the rotating part of the horizontal rotary positioner, the vertical cross frame has a plurality of vertical frames, and each vertical frame is slidably matched with a mounting plate for mounting a print head, and the mounting plate is provided with a vertical extension rod, and the upper end of the extension rod extends to a position between the vertical cross frame and the top plate;

[0012] A return spring is provided between the vertical frame and the mounting plate to facilitate the upward movement and return of the mounting plate;

[0013] A driving rod, the inner end of which is fixedly connected to the rotating part of the horizontal rotary positioner;

[0014] Wherein, a matching structure capable of driving the extension rod to move downward is provided on the bottom surface of the outer end portion of the driving rod or the upper end surface of the extension rod.

[0015] Preferably, the matching structure includes a rolling ball embedded in the bottom surface of the outer end of the driving rod or the upper end surface of the extension rod.

[0016] Preferably, the matching structure includes an embedding groove which is provided at the middle of the upper end surface of the extension rod or the bottom surface of the outer end of the driving rod and can match with the rolling ball.

[0017] Preferably, the extension rod has a compensating elastic section to prevent the mounting plate from rebounding after moving to the lower limit position.

[0018] Preferably, a guide column is provided on the inner side of the vertical frame, and a sliding sleeve is provided on the surface of the mounting plate and is slidably mounted on the guide column body up and down;

[0019] Wherein, the return spring sleeve is arranged at a position where the guide column body is located below the sliding sleeve.

[0020] Preferably, a damping spring is provided at a position of the guide column body above the sliding sleeve.

[0021] Preferably, the surface of the mounting plate is provided with an extension plate extending to the inner side of the vertical frame, and the lower end of the extension rod is correspondingly connected to the extension plate.

[0022] Preferably, the lower side wall of the vertical frame is threadedly matched with a vertical adjustment screw to limit the lower limit position of the corresponding mounting plate.

[0023] Preferably, it also includes an air supply structure, and the air supply structure includes:

[0024] A vertical air supply duct, the lower end of which vertically passes through the middle of the vertical cross frame;

[0025] An inclined air supply pipe, the upper end of which is correspondingly connected to the lower end of the vertical air supply pipe, and the lower end is provided with an air outlet nozzle that can match the corresponding print head;

[0026] A blower fan is arranged on the top surface of the vertical cross frame, and an air outlet of the blower fan is correspondingly connected to the vertical air supply pipe;

[0027] The driving rod is correspondingly connected to the upper end of the vertical air supply pipe so as to drive the vertical air supply pipe to rotate so that the air outlet nozzle matches the corresponding print head.

[0028] Preferably, the upper surface of the top plate is provided with a lower slider that slides with the bottom surface of the 3D printer slide rail beam, and the upper surface of the top plate is provided with vertical connecting plates at positions corresponding to the two sides of the lower slider, and the upper end of the vertical connecting plate is connected to a pressing plate spaced therefrom by bolts, and the lower surface of the pressing plate is provided with an upper slider that slides with the top surface of the 3D printer slide rail beam.

[0029] Due to the adoption of the above-mentioned technical solution, the present invention has the following beneficial effects:

[0030] 1. Since the vertical cross frame has multiple vertical frames, each vertical frame can be equipped with a print head, so three or more print heads can be set, and the print head to be used can be moved downward to the working position only under the action of the horizontal rotary positioner and the driving rod, and the remaining unused print heads are higher than the used print heads under the action of the reset spring, ensuring normal operation, and solving the technical problem in the prior art that when switching three or more print heads, it is necessary to repeatedly set the switching structure, which will cause the overall structure to become very complicated, bloated, or even impossible to implement;

[0031] 2. The arrangement of the rolling ball and the embedding groove. Since the rolling ball will not easily fall out of the embedding groove after the rolling ball and the embedding groove are matched, in this embodiment, the horizontal rotary positioner may not be provided with a braking structure, thereby reducing the cost of the horizontal rotary positioner. Combined with the arrangement of the compensating elastic section, after the rolling ball enters the embedding groove, the compensating elastic section can be stretched to compensate, so that the mounting plate is still in the lower limit position;

[0032] 3. The lower limit position of the mounting plate is adjusted by adjusting the screws, and then the lower limit position of the corresponding print head is adjusted, so that the lower limit position height of all print heads can be guaranteed to be consistent, which solves the technical problem in the prior art that the distance between the print head located in the working position and the model after switching is too small or too large due to the problem of processing and assembly accuracy;

[0033] 4. The setting of the air supply structure can enable the horizontal rotary positioner rotating part to drive the driving rod to rotate when switching the print head, and the driving rod can also drive the vertical air supply pipe to rotate, so that the position of the air outlet nozzle changes, so that the air outlet nozzle matches the corresponding print head. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of a first structure of the present invention;

[0035] Figure 2 A bottom view of the first structure of the present invention;

[0036] Figure 3 for Figure 2 AA section view;

[0037] Figure 4 is a schematic diagram of a second structure of the present invention;

[0038] Figure 5 It is the installation schematic diagram when the present invention is used.

[0039] In the figure: 1. top plate; 11. lower slider; 12. vertical connecting plate; 13. pressing plate; 14. upper slider; 2. horizontal rotary positioner; 3. vertical cross frame; 31. vertical frame; 32. guide column; 33. vibration damping spring; 34. adjustment screw; 4. mounting plate; 41. sliding sleeve; 42. extension plate; 5. extension rod; 51. compensation elastic section; 6. reset spring; 7. driving rod; 8. matching structure; 81. rolling ball; 82. embedded groove; 9. air supply structure; 91. vertical air supply duct; 92. inclined air supply duct; 93. air outlet nozzle; 94. air supply fan. DETAILED DESCRIPTION

[0040] The present invention can be explained in detail through the following embodiments. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "front", "back", "left", "right", etc. indicating directions or positional relationships, they only correspond to the drawings of the present application and are for the convenience of describing the present invention; it should be understood that if there are terms such as "end", "side", "end portion", "lateral", "lateral", "transverse", "longitudinal", etc. indicating directions or positional relationships, they only correspond to the length and width of the corresponding components, that is, the "end portion" indicates the head and tail areas in the length direction of the corresponding component, and the "side portion" indicates the head and tail areas in the width direction of the corresponding component; this is for the convenience of describing the present invention and is not to indicate or imply that the device or element referred to must have a specific direction.

[0041] Embodiment 1, in combination with the attached Figure 1-3 A switchable multi-print head mechanism for a 3D printer includes a top plate 1, a horizontal rotary positioner 2 is provided in the middle of the lower plate surface of the top plate 1; specifically, the rotating part of the horizontal rotary positioner 2 faces downward and is fixedly installed with a driving rod 7; that is, the moving track of the outer end of the driving rod 7 is a circle. A vertical cross frame 3 is provided below the top plate 1, and the central axis of the vertical cross frame 3 and the central axis of the rotating part of the horizontal rotary positioner 2 are located on the same vertical line.

[0042] As required, there are connecting members between the top plate 1 and the vertical cross frame 3, such as columns, vertical plates, etc., so that the top plate 1 and the vertical cross frame 3 are connected together.

[0043] Specifically, the vertical cross frame 3 has a plurality of vertical frames 31, and each vertical frame 31 is slidably matched with a mounting plate 4 for mounting a print head; that is, the inner sides of the plurality of vertical frames 31 are connected together to form the vertical cross frame 3. As required, the plurality of vertical frames 31 are arranged at equal angles, for example, when there are three vertical frames 31, the angle between two adjacent vertical frames 31 is 120 degrees; when there are four vertical frames 31, the angle between two adjacent vertical frames 31 is 90 degrees. Specifically, the number of vertical frames 31 is set as required, and no specific number limitation is made here.

[0044] As needed, the horizontal rotary positioner 2 can use a servo motor or a stepper motor as a driving source. For example, when there are three print heads, the rotating part of the horizontal rotary positioner 2 can rotate 120 degrees each time; when there are four print heads, the rotating part of the horizontal rotary positioner 2 can rotate 90 degrees each time.

[0045] A reset spring 6 is provided between the vertical frame 31 and the mounting plate 4, and the reset spring 6 is used to reset the mounting plate 4 upward. The mounting plate 4 is provided with a vertical extension rod 5, and the upper end of the extension rod 5 extends to a position between the vertical cross frame 3 and the top plate 1. A matching structure 8 capable of driving the extension rod 5 to move downward is provided on the bottom surface of the outer end of the driving rod 7 or the upper end surface of the extension rod 5; that is, when the outer end of the driving rod 7 moves above the upper end surface of one of the extension rods 5, the extension rod 5 can move downward under the action of the driving rod 7.

[0046] As required, the matching structure 8 can be a slope matching structure or a spherical structure.

[0047] Furthermore, a guide column 32 is provided inside the vertical frame 31, and a sliding sleeve 41 is provided on the surface of the mounting plate 4 and is slidably sleeved on the column body of the guide column 32 up and down;

[0048] The return spring 6 is sleeved on the position where the body of the guide column 32 is located below the sliding sleeve 41. In this embodiment, the return spring 6 is a compression spring.

[0049] Furthermore, to prevent the sliding sleeve 41 from colliding with the vertical frame 31 when the sliding sleeve 41 is reset under the action of the reset spring 6, thereby causing the print head to malfunction, a damping spring 33 is provided on the guide column 32 above the sliding sleeve 41.

[0050] As required, the mounting plate 4 is provided with an extension plate 42 extending to the inner side of the vertical frame 31 , and the lower end of the extension rod 5 is correspondingly connected to the extension plate 42 .

[0051] Specifically, the top plate 1 can move along the corresponding slide rail beam of the 3D printer, that is, all the print heads can move along the corresponding slide rail beam of the 3D printer at the same time.

[0052] As needed, combine with Figure 4-5 , a lower slider 11 is provided on the upper surface of the top plate 1 to slide with the bottom surface of the 3D printer slide rail beam, and a vertical connecting plate 12 is provided on the upper surface of the top plate 1 at positions corresponding to both sides of the lower slider 11, and a pressing plate 13 is connected to the upper end of the vertical connecting plate 12 by bolts and arranged at a distance therefrom, and an upper slider 14 is provided on the lower surface of the pressing plate 13 to slide with the top surface of the 3D printer slide rail beam. Since there is a gap between the upper end of the vertical connecting plate 12 and the pressing plate 13, it can be ensured that the upper slider 14 and the lower slider 11 are not affected by the processing accuracy, and can slide smoothly with the corresponding 3D printer slide rail beam.

[0053] Since the vertical cross frame 3 has multiple vertical frames 31, each vertical frame 31 can be equipped with a print head, so three or more print heads can be set, and the print head that needs to be used can be moved downward to the working position only under the action of the horizontal rotating positioner 2 and the driving rod 7, and the remaining unused print heads are higher than the used print heads under the action of the reset spring 6, ensuring normal operation. It can also solve the technical problem in the prior art that when switching three or more print heads, it is necessary to repeatedly set the switching structure, which will cause the overall structure to become very complicated, bloated, or even impossible to implement.

[0054] Embodiment 2, combined with the attached Figure 1-3 , a switchable multi-print head mechanism for a 3D printer, based on the first embodiment, the matching structure 8 includes a rolling ball 81 embedded in the bottom surface of the outer end of the driving rod 7 or the upper end surface of the extension rod 5.

[0055] In order to improve the stability of the fit between the outer end of the driving rod 7 or the upper end of the extension rod 5, the fitting structure 8 includes an embedding groove 82 provided at the middle of the upper end surface of the extension rod 5 or the bottom surface of the outer end of the driving rod 7 and capable of fitting with the rolling ball 81. In this way, since the rolling ball 81 and the embedding groove 82 fit together, the rolling ball 81 will not easily fall out of the embedding groove 82, so in this embodiment, the horizontal rotary positioner 2 does not need to be provided with a braking structure, thereby reducing the cost of the horizontal rotary positioner 2.

[0056] As required, the embedding groove 82 may be a spherical groove, a conical groove or other grooves, as long as it can ensure that the rolling ball 81 does not shift in position after the rolling ball 81 is matched with the embedding groove 82. The above-mentioned position shift is the shift of the center of gravity.

[0057] Furthermore, in order to prevent the rebound phenomenon of the corresponding print head height before and after the rolling ball 81 enters the embedding groove 82, resulting in the uncontrollable height of the print head during use: the extension rod 5 has a compensating elastic section 51; that is, before the rolling ball 81 enters the embedding groove 82, the mounting plate 4 drops to the lower limit position, at which time the compensating elastic section 51 is in a compressed state, and after the rolling ball 81 enters the embedding groove 82, the compensating elastic section 51 extends, at which time the mounting plate 4 is still in the lower limit position. It should be noted that: before the rolling ball 81 enters the embedding groove 82, the driving rod 7 and the extension rod 5 are already in a matching state, and the mounting plate 4 has dropped to the lower limit position.

[0058] It should be noted that the lower limit position of the mounting plate 4 is the position where the mounting plate 4 cannot continue to descend.

[0059] As required, the compensating elastic section 51 may be a spring or a rubber column.

[0060] Embodiment 3, in combination with the attached Figure 1-3 A switchable multi-print head mechanism for a 3D printer, based on the first or second embodiment, a vertical adjustment screw 34 is threadedly matched on the lower side wall of the vertical frame 31 to limit the lower limit position of the corresponding mounting plate 4.

[0061] This setting can adjust the lower limit position of the mounting plate 4 by adjusting the screw 34, and then adjust the lower limit position of the corresponding print head, so as to ensure that the lower limit position height of all print heads is consistent, which leads to the technical problem that the distance between the print head in the working position and the model is too small or too large after switching.

[0062] Embodiment 4, in combination with the attached Figure 1-3 A switchable multi-print head mechanism for a 3D printer, based on any one of the first to third embodiments, further includes an air supply structure 9, the air supply structure 9 includes a vertical air supply pipe 91 and an air blower 94, the lower end of the vertical air supply pipe 91 vertically passes through the middle of the vertical cross frame 3, the lower end of the vertical air supply pipe 91 is correspondingly connected to an inclined air supply pipe 92, and the lower end of the inclined air supply pipe 92 is provided with an air outlet nozzle 93 that can match the corresponding print head; the air blower 94 is arranged on the top surface of the vertical cross frame 3, and the air outlet end of the air blower 94 is correspondingly connected to the vertical air supply pipe 91;

[0063] The driving rod 7 is correspondingly connected to the upper end of the vertical air supply pipe 91 so as to drive the vertical air supply pipe 91 to rotate so that the air outlet nozzle 93 matches the corresponding print head.

[0064] In this arrangement, when the print head is switched, when the rotating part of the horizontal rotary positioner 2 drives the driving rod 7 to rotate, the driving rod 7 can also drive the vertical air supply pipe 91 to rotate, so that the position of the air outlet nozzle 93 changes, so that the air outlet nozzle 93 matches the corresponding print head. It should be noted that the corresponding print head is a print head located in the working position area. In other words, when a certain print head is located in the working position area, the air outlet nozzle 93 faces the print head, specifically located at a position below the print head, to achieve the function of accelerating drying.

[0065] Furthermore, a fixed flange plate is provided at the upper end of the vertical air supply pipe 91 , and the fixing portion of the air supply fan 94 is mounted on the fixed flange plate by screws, so that the air supply fan 94 rotates along with the vertical air supply pipe 91 .

[0066] As needed, the vertical air supply duct 91 is provided with an expanded top portion at a position corresponding to the vertical cross frame 3, which is used to limit the lower limit position of the vertical air supply duct 91 to prevent the vertical air supply duct 91 from sliding down, causing the air outlet nozzle 93 to slide down to the height of the print head in the working position area, thereby scratching the model.

[0067] As required, the fixed part of the blower 94 can also be installed below the rotating part of the horizontal rotary positioner (2).

[0068] The parts of the present invention that are not described in detail are prior art. It is obvious to those skilled in the art that the present invention is not limited to the details of the above-mentioned exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention; therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and it is intended that all changes that fall within the meaning and scope of equivalent elements are included in the present invention.

Claims

1. A switchable multi-print head mechanism for a 3D printer, characterized in that: include: A top plate (1) having a horizontal rotary positioner (2) disposed in the middle of its lower plate surface; A vertical cross frame (3) is arranged below the top plate (1) at intervals, and its central axis is located on the same vertical line as the central axis of the rotating part of the horizontal rotary positioner (2). The vertical cross frame (3) has a plurality of vertical frames (31), and each vertical frame (31) is slidably matched with a mounting plate (4) for mounting a print head. The mounting plate (4) is provided with a vertical extension rod (5), and the upper end of the extension rod (5) extends to a position between the vertical cross frame (3) and the top plate (1); A reset spring (6) is arranged between the vertical frame (31) and the mounting plate (4) to facilitate the mounting plate (4) to move upward and reset; A driving rod (7), the inner end of which is fixedly connected to the rotating part of the horizontal rotary positioner (2); Wherein, a matching structure (8) capable of driving the extension rod (5) to move downward is provided on the bottom surface of the outer end of the driving rod (7) or the upper end surface of the extension rod (5).

2. The switchable multi-print head mechanism for a 3D printer according to claim 1, characterized in that: The matching structure (8) comprises a rolling ball (81) embedded in the bottom surface of the outer end of the driving rod (7) or the upper end surface of the extension rod (5).

3. The switchable multi-print head mechanism for a 3D printer according to claim 2, characterized in that: The matching structure (8) comprises an embedding groove (82) which is arranged at the middle of the upper end surface of the extension rod (5) or the bottom surface of the outer end of the driving rod (7) and can match with the rolling ball (81).

4. The switchable multi-print head mechanism for a 3D printer according to claim 3, characterized in that: The extension rod (5) has a compensating elastic section (51) so as to prevent the mounting plate (4) from rebounding after moving to the lower limit position.

5. The switchable multi-print head mechanism for a 3D printer according to claim 1, characterized in that: A guide column (32) is provided inside the vertical frame (31), and a sliding sleeve (41) is provided on the surface of the mounting plate (4) and is slidably sleeved up and down on the column body of the guide column (32); Wherein, the return spring (6) is sleeved on the position where the body of the guide column (32) is located below the sliding sleeve (41).

6. The switchable multi-print head mechanism for a 3D printer according to claim 5, characterized in that: A damping spring (33) is provided on the body of the guide column (32) at a position above the sliding sleeve (41).

7. The switchable multi-print head mechanism for a 3D printer according to claim 5, characterized in that: The surface of the mounting plate (4) is provided with an extension plate (42) extending to the inner side of the vertical frame (31), and the lower end of the extension rod (5) is correspondingly connected to the extension plate (42).

8. The switchable multi-print head mechanism for a 3D printer according to claim 1, characterized in that: The lower side wall of the vertical frame (31) is threadedly matched with a vertical adjustment screw (34) so ​​as to limit the lower limit position of the corresponding mounting plate (4).

9. The switchable multi-print head mechanism for a 3D printer according to claim 1, characterized in that: It also includes an air supply structure (9), wherein the air supply structure (9) includes: A vertical air supply pipe (91), the lower end of which vertically passes through the middle of the vertical cross frame (3); An inclined air supply pipe (92), the upper end of which is correspondingly connected to the lower end of the vertical air supply pipe (91), and the lower end of which is provided with an air outlet nozzle (93) that can match the corresponding print head; A blower (94) is arranged on the top surface of the vertical cross frame (3), and an air outlet end of the blower (94) is correspondingly connected to the vertical air supply pipe (91); The driving rod (7) is correspondingly connected to the upper end of the vertical air supply pipe (91) so as to drive the vertical air supply pipe (91) to rotate, so that the air outlet nozzle (93) matches the corresponding print head.

10. The switchable multi-print head mechanism for a 3D printer according to claim 1, characterized in that: The upper plate surface of the top plate (1) is provided with a lower slider (11) which is slidably matched with the bottom surface of the slide rail beam of the 3D printer, and the upper plate surface of the top plate (1) is provided with vertical connecting plates (12) at positions corresponding to the two sides of the lower slider (11), and the upper end of the vertical connecting plate (12) is connected to a pressing plate (13) spaced therefrom by bolts, and the lower plate surface of the pressing plate (13) is provided with an upper slider (14) which is slidably matched with the top surface of the slide rail beam of the 3D printer.

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