IDEX structure double-end independent automatic leveling structure and method

Abstract

The application relates to the field of printing equipment leveling, in particular to an IDEX structure double-head independent automatic leveling device and method. The application relates to an IDEX structure double-head independent automatic leveling device, which comprises a main frame, an XY motion frame, a Z-axis screw assembly, a left printing head, a right printing head and a printing platform, and the left and right printing heads are respectively provided with independent leveling mechanisms comprising separable screw transmission assemblies, gravity trigger type limiting devices and bidirectional mechanical limiting assemblies; the application also relates to an IDEX structure double-head independent automatic leveling method, which comprises the steps of Z-axis frame lifting, zero return operation, leveling operation and real-time compensation. The application has the technical effects of improving the leveling efficiency and precision of the printing head, guaranteeing the printing quality and realizing independent automatic leveling of the double printing heads.

Description

Technical Field

[0001] This application relates to the field of fused deposition modeling 3D printing technology, and in particular to an IDEX structure with dual-head independent automatic leveling structure and method. Background Technology

[0002] 3D printing technology is based on additive manufacturing principles. Using computer digital models as a foundation, 3D printers can manufacture products quickly and efficiently. Fused deposition modeling (FDM) 3D printing technology is currently a typical type of 3D printing technology.

[0003] IDEX (Independent Dual Extruder) is a 3D printing structure design that allows two printheads to move independently along the X or Y axis, enabling more efficient mirroring / copying / multi-material / multi-color printing. However, because the two printheads in IDEX need to move independently, the traditional manual calibration process is cumbersome and easily affected by installation accuracy (such as guide rail parallelism and printhead mounting perpendicularity). This results in a Z-axis height deviation of 0.1-0.3mm between the two printheads, far exceeding the print layer thickness tolerance (typically 0.05-0.2mm). This causes one printhead to scrape the model or become suspended during dual-head printing. According to actual measurements, this problem leads to a printing failure rate of up to 25%.

[0004] Furthermore, the actual flatness of the printing platform inevitably contains wavy geometric errors (such as ±0.5mm / m²). The existing IDEX structure uses a single Z-axis to drive the printing platform. When the left and right printheads are located in the left and right zones of the platform respectively, the overall platform height adjustment cannot compensate for the independent height errors of the two zones. Especially when printing mirror images simultaneously with both heads, the error difference between the left and right zones can lead to poor interlayer bonding or dimensional deviations. The algorithm under the existing hardware architecture can only achieve global platform compensation and cannot meet the requirements for independent leveling of the two zones.

[0005] Therefore, there is an urgent need for an independent dual-head leveling solution for IDEX that does not rely on overall platform adjustments, in order to solve the height error and platform compensation limitations during dual-zone printing, and improve printing accuracy and efficiency. Summary of the Invention

[0006] The purpose of this application is to overcome the above-mentioned technical problems and provide an IDEX structure dual-head independent automatic leveling device and method. An IDEX structure dual-head independent automatic leveling device includes a main frame, an XY motion frame installed within the main frame, a Z-axis lead screw assembly connecting the XY motion frame, a left print head and a right print head mounted on the X-axis assembly of the XY motion frame, and a printing platform fixed to the bottom of the main frame. The left and right print heads are each equipped with an independent leveling mechanism. Each independent leveling mechanism includes a separable lead screw drive assembly, a gravity-triggered limiting device, and a bidirectional mechanical limiting assembly. The separable lead screw drive assembly comprises an upper threaded section and a lower unthreaded guide section. The gravity-triggered limiting device is located below the print head connecting plate. The bidirectional mechanical limiting assembly is symmetrically arranged on both sides of the lead screw motor to form a double-contact positioning.

[0007] By adopting the above technical solution, the IDEX structure is constructed using the main frame, XY motion frame, Z-axis lead screw assembly, left print head, right print head, and printing platform. The upper threaded section and lower unthreaded guide section of the separable lead screw drive assembly of the independent leveling mechanism cooperate to allow the main body assembly of the print head to be separated as needed. The gravity-triggered limit device can perform relevant detection when the main body assembly of the print head falls freely onto the print head connecting plate. The bidirectional mechanical limit assembly is symmetrically arranged on both sides of the lead screw motor for two-way contact positioning. These features enable the IDEX structure to achieve independent automatic leveling of both heads, ensuring that the printing effect of the left and right print heads is the same during mirror and copy printing. At the same time, because the leveling mechanism and platform compensation action are performed in the print head, the printing accuracy is improved.

[0008] Preferably, the threadless guide section of the separable lead screw drive assembly forms a drag engagement with the printhead connecting plate, allowing the printhead main body assembly to fall freely to the printhead connecting plate in a triggered / untriggered state after disengaging from the threaded section.

[0009] By adopting the above technical solution, the threadless guide section of the separable lead screw drive assembly forms a drag engagement with the print head connecting plate, allowing the main body assembly of the print head to fall freely to the trigger-untriggered state of the print head connecting plate after disengaging from the threaded section. This allows the gravity-triggered limit device to return to the untriggered distance that can be used for leveling measurement, providing accurate starting conditions for the leveling operation, which helps to improve the leveling accuracy and thus improve the overall accuracy of 3D printing.

[0010] Preferably, the bidirectional mechanical limiting component includes a mechanical limiting block disposed on the right side of the lead screw motor and a leveling limiting sensor disposed on the left side, wherein the mechanical limiting block forms a two-way contact positioning with the movement trajectory of the printhead main body component.

[0011] By adopting the above technical solution, a bidirectional mechanical limiting component is formed by using mechanical limit blocks and leveling limit sensors. The mechanical limit blocks and the main body of the print head are positioned by contact twice, which can achieve high-precision positioning, avoid positioning accuracy deviation by single rapid triggering, improve the positioning accuracy of zeroing and leveling, and thus improve printing accuracy.

[0012] Preferably, the XY motion frame includes a left Y-axis guide rail group and a right Y-axis guide rail group arranged in parallel, which are rigidly connected by a front reinforcing connecting plate. The front reinforcing connecting plate is provided with a Y-axis idler gear transmission assembly in the middle to enhance synchronization.

[0013] By adopting the above technical solution, the parallel left Y-axis guide rail group and right Y-axis guide rail group are rigidly connected by the front reinforcing connecting plate, which can ensure the stability of the XY motion frame structure; the Y-axis idler gear transmission assembly set in the middle of the front reinforcing connecting plate can enhance the synchronization of the left Y-axis guide rail group and right Y-axis guide rail group, and improve the stability of equipment operation and printing accuracy.

[0014] Preferably, the bottom of the main frame is provided with a zero-return positioning component, which includes a vertically arranged Z-axis limiting baffle and a horizontally arranged contact trigger sensor. The contact trigger sensor is located at the front end of the printing platform and has a position repeatability accuracy of ±0.001mm.

[0015] By adopting the above technical solution, the vertically arranged Z-axis limiting baffle can limit the movement of the XY motion frame in the Z-axis direction; the horizontally arranged contact trigger sensor located at the front of the printing platform and with a position repeatability accuracy of ±0.001mm can accurately detect the position of the left and right print heads, thereby obtaining the installation difference between the two print heads, preparing for subsequent leveling, helping to improve the accuracy of zero-return positioning, and thus improving the leveling accuracy and printing precision of the entire ID EX structure dual-head independent automatic leveling device.

[0016] Preferably, the Z-axis lead screw assembly is arranged symmetrically at four corners, and each lead screw nut is driven by a synchronous pulley group. The synchronous pulley group is equipped with a tension adjustment mechanism to maintain transmission accuracy.

[0017] By adopting the above technical solution, the Z-axis lead screw assembly is symmetrically arranged at the four corners. Each lead screw nut is driven by a synchronous belt pulley group and is equipped with a tension adjustment mechanism, which can maintain transmission accuracy and thus ensure the stability and accuracy of the XY motion frame in the Z-axis direction. This provides stable support for the independent automatic leveling of the left and right print heads, which helps to improve the accuracy and quality of 3D printing.

[0018] A dual-head independent automatic leveling method for an IDEX structure includes: after the Z-axis lead screw assembly drives the XY motion frame to rise and fall to a preset safe distance, the left and right print heads are respectively zeroed out, the zeroing operation includes moving along the X-axis to the corresponding limit and then adjusting to the zero point; then a leveling operation is performed, the leveling operation includes the print head body assembly disengaging from the lead screw drive assembly and falling freely to a preset position, triggering a gravity-triggered limit device to detect the current position, repeatedly collecting multi-point leveling data to establish a platform error model; finally, during the printing process, the Z-axis leveling data of the print head position is calculated in real time and the height difference between the two print heads is compensated synchronously.

[0019] By adopting the above technical solution, the Z-axis lead screw assembly first drives the XY motion frame to rise and fall to a preset safe distance, ensuring the safety of the printhead movement process; the left and right printhead zeroing operations are performed to return the printhead to its initial accurate position, providing a reference for subsequent operations; the printhead main body assembly detaches from the lead screw transmission assembly and falls freely to the preset position, triggering a gravity-triggered limit device, which can detect the current position and repeatedly collect multi-point leveling data to establish a platform error model, accurately grasping the printing platform error; during the printing process, the Z-axis leveling data of the printhead position is calculated in real time and the height difference between the two printheads is compensated synchronously, effectively avoiding printing failures caused by Z-axis height deviation of the two printheads and printing platform flatness issues, improving printing accuracy and success rate, and realizing independent automatic leveling of the dual heads in the IDEX structure.

[0020] Preferably, the zeroing operation includes: after the Z-axis frame moves 20mm in the Z+ direction, the left print head triggers the X-limit along the X- direction and moves 18mm, the right print head triggers the X+ limit along the X+ direction and moves 18mm, and the Y-axis assembly triggers the Y-limit and moves 27mm to complete the zeroing.

[0021] By adopting the above technical solution, the zeroing operation of the left print head, right print head and Y-axis assembly can be accurately realized, providing a precise starting position reference for subsequent leveling and printing operations, ensuring the accuracy of leveling data acquisition and printing process, and improving the precision and success rate of 3D printing.

[0022] Preferably, the leveling operation includes: when it is detected that the printhead main body assembly is not in the threaded section of the lead screw drive assembly, the Z-axis frame moves in the Z- direction to lift the printhead main body assembly, while the lead screw motor rotates rapidly until it triggers the mechanical limit block, and then slowly resets to complete the precise positioning.

[0023] By adopting the above technical solution, when it is detected that the main body assembly of the print head is not in the threaded section of the lead screw drive assembly, the Z-axis frame moves in the Z- direction to lift the main body assembly of the print head. At the same time, the lead screw motor rotates rapidly until it triggers the mechanical limit block, which allows the main body assembly of the print head to reach the predetermined position as soon as possible. Then it slowly resets, which can ensure positioning accuracy and complete the precise leveling operation, thereby improving the accuracy and quality of 3D printing.

[0024] Preferably, the real-time compensation includes: calculating the Z-axis height of non-sampling points using cubic spline interpolation based on the leveling point data, and superimposing the height difference detected when the dual printheads return to zero to form the final compensation value.

[0025] By adopting the above technical solution, the Z-axis height of non-sampling points is calculated using cubic spline interpolation based on the leveling point data, which can accurately determine the Z-axis height of the print head at non-leveling points. The height difference detected when the two print heads return to zero is superimposed to form the final compensation value, which can effectively compensate for the height difference between the two print heads caused by factors such as installation, thereby adjusting the Z-axis position of the print head in real time and accurately, compensating for the difference in the printing platform, and improving printing accuracy.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. The left and right printheads are each equipped with an independent leveling mechanism, which realizes independent automatic leveling of the dual heads in the IDEX structure. This solves the problem of the traditional manual calibration process being cumbersome and easily affected by the installation accuracy, resulting in Z-axis height deviation of the dual printheads. This ensures that the printing effect of the left and right printheads is exactly the same when mirroring and copying prints, reducing the printing failure rate. 2. The leveling mechanism and platform compensation during the printing process are performed on the print head. The Z-axis leveling data of the print head position can be calculated in real time and the height difference between the two print heads can be compensated synchronously. This solves the problem that the existing IDEX structure, which uses a single Z-axis to drive the printing platform, cannot compensate for the independent height error of the two zones, thus improving printing accuracy. 3. Through the design of separable lead screw drive assembly, gravity-triggered limit device and bidirectional mechanical limit assembly, the printhead main body assembly can be accurately zeroed and leveled, further improving the accuracy and stability of printing. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a dual-head independent automatic leveling structure for an IEDX structure. Figure 2 This is a schematic diagram of the XY motion frame structure; Figure 3 This is a schematic diagram of the Z-axis lead screw assembly. Figure 4 This is a schematic diagram of the printhead structure; Figures 5 to 11This is a diagram illustrating the zeroing process; Figure 12-13 This is a diagram illustrating the leveling process; Figure 14-15 This is a diagram illustrating the printing process.

[0028] Explanation of reference numerals in the attached diagram: 1. Main frame; 101. Z+ limit; 102. Z- limit; 103. Zero return sensor; 2. XY motion frame; 201. Left Y-axis assembly; 202. Right Y-axis assembly; 203. X-axis assembly; 204. Front reinforcing connecting plate; 205. Rear motor drive assembly; 206. Y-guide rail mounting plate; 207. Y-guide rail slide; 208. X-axis connecting plate; 209. Y+ limit; 210. Y-limit; 211. Z-axis limit baffle; 212. Y-axis idler pulley; 213. Y-axis motor assembly; 214. Synchronous belt drive assembly; 215. X-guide rail mounting plate; 216. X-guide rail slide; 217. 1. Motor synchronous pulley and synchronous belt assembly; 218. X-limit; 219. X+limit; 3. Z-axis lead screw assembly; 301. Z-axis lead screw; 302. Z-axis motor; 303. Z-axis synchronous pulley; 304. Z-axis synchronous belt; 305. Lead screw nut; 4. Left printhead; 401. Printhead connecting plate; 402. Printhead guide rail slide; 403. Lead screw motor; 404. Printhead main body assembly; 405. Printhead main body leveling limit; 406. Trigger rod; 407. Lead screw motor limit; 408. Lead screw nut; 409. Pressure plate; 410. Synchronous belt; 5. Right printhead; 6. Printing platform; 7. Main control system. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] This invention discloses an IEDX structure with dual independent automatic leveling, such as... Figure 1 The diagram shows a main frame 1, an XY motion frame 2, a Z-axis lead screw assembly 3, a left print head 4, a right print head 5, a printing platform 6, and a main control system 7. The XY motion frame is fixed and connected to the main frame by the Z-axis lead screw assembly; the left print head 4 and the right print head 5 are mounted on the X-axis assembly 203 of the XY motion frame 2; the printing platform 6 is located at the bottom of the main frame; and the main control system 7 is located at the rear right side of the main frame.

[0031] A Z+ limit switch 101 is located at the top left of the main frame 1, and a Z- limit switch 102 is located at the bottom. Below the main frame 1, in front of the printing platform 6, a zero-return sensor 103 is located. The Z-limit switch 102 is an emergency stop limit switch, used to stop movement and protect the frame in case the XY motion frame overtravels during printing or other situations. The zero-return sensor 103 is a contact sensor with a 3mm travel, a 0.5mm trigger travel, and a position repeatability accuracy of ±0.001mm (the main control system 7 starts detecting the zero-return sensor 103 during zero-return; otherwise, it is not detected).

[0032] XY motion frame 2, as shown Figure 2 The diagram shows a component 205 consisting of a left Y-axis assembly 201, a right Y-axis assembly 202, an X-axis assembly 203, a front reinforcing connecting plate 204, and a rear motor drive assembly. Both the left Y-axis assembly 201 and the right Y-axis assembly 202 are composed of a Y-guide rail mounting plate 206, a Y-guide rail slide 207, and an X-axis connecting plate 208 on the Y-guide rail slide 207. The left Y-axis assembly 201 is equipped with a Y+ limit 209, a Y- limit 210, and a Z-axis limit baffle 211. The front reinforcing connecting plate 204 is connected and reinforced to the left Y-axis assembly 201 and the right Y-axis assembly 202, and has a Y-axis idler pulley 212 on it. The rear motor drive assembly 205 consists of a Y-axis motor assembly 213 and a synchronous belt drive assembly 214 located above the left Y-axis assembly 201 and the right Y-axis assembly 202. It is also connected to the left Y-axis assembly 201 and the right Y-axis assembly 202. The X-axis assembly 203 consists of an X-guide rail mounting plate 215, an X-guide rail slide 216, an X+ limit 219, an X- limit 218, and synchronous belt assemblies 217 for the motors at both ends. The two ends of the X-axis assembly 203 are bolted to the X-axis connecting plates 208 on the left Y-axis assembly 201 and the right Y-axis assembly 202. The front reinforcing connecting plate 204 and the rear motor drive assembly 205 are connected to the two ends of the X-axis drive assembly 203 via the synchronous belt drive assembly 214. That is, the X-axis assembly 203 can be driven by the rear motor drive assembly 205 to move in the Y-axis direction.

[0033] Z-axis lead screw assembly 3, such as Figure 3 The structure shown consists of a Z-axis lead screw 301, a Z-axis motor 302, a Z-axis synchronous pulley 303, and a Z-axis synchronous belt 304. The Z-axis lead screw assembly 3 is located at each of the four corners, with its lead screw nut 305 connected to the XY motion frame 2. Both ends of the Z-axis lead screw assembly 3 are fixed to the upper and lower positions of the main frame 1. When the Z-axis motor 302 drives the Z-axis lead screw 301 to rotate via the Z-axis synchronous pulley 303 and the Z-axis synchronous belt 304, the XY motion frame 2 can move in the Z-axis direction.

[0034] Left printhead 4 Figure 4The diagram shows a printhead assembly consisting of a printhead connecting plate 401, a printhead guide slide 402, a lead screw motor 403, a printhead main body assembly 404, a printhead main body leveling limit 405, a trigger rod 406, and a lead screw motor limit 407. The printhead connecting plate 401 is bolted to the X-guide slide 216, on which the lead screw motor 403 is mounted. The printhead main body assembly 404 is mounted on the printhead guide slide 402 and connected to the lead screw nut 408 of the lead screw motor 403. That is, the printhead main body assembly 404 can be moved in the Z-direction by the lead screw motor 403. The upper half of the lead screw of the lead screw motor 403 is threaded, while the lower half is unthreaded. This arrangement allows the printhead main body assembly 404 to move a certain distance in the Z-direction, after which it can freely fall onto the printhead connecting plate 401 and be held in place by the printhead connecting plate 401. This causes the trigger lever 406 on the right side, which triggers the printhead leveling limit 405, to return to the non-triggered distance for measurement during leveling. (The printhead leveling limit 405 only begins detection after the printhead main body assembly 404 falls onto the printhead connecting plate 401.) The printhead leveling limit 405 and the lead screw motor limit 407 are respectively located on both sides of the lead screw motor 403 for leveling and zeroing the lead screw motor 403. The upper end of the printhead connecting plate 401 connects and fixes the left printhead 4 to the timing belt 410 via a pressure plate 409 and bolts. The right printhead 5 has the same structure. When the motor timing pulleys and timing belt assemblies 217 at both ends of the X-axis assembly 203 move, they can drive the left printhead 4 and the right printhead 5 to move independently in the X-axis direction.

[0035] The printing platform 6 is located below the main frame 1.

[0036] Please refer to the zeroing process. Figures 5 to 11 : like Figure 5 The Z-axis (XY motion frame 2) shown first moves A in the Z+ direction (A is the distance moved, which is a fixed value set by the system. In this example, A is set to 20mm. It is the safe distance between the left print head 4 and the right print head 5 and the printing platform 6 when they move).

[0037] Then as Figure 6 The left printhead 4 moves in the X- direction until it stops moving when the X- limit 218 is triggered. Then it moves in the X+ direction by a distance B (B is a fixed system value, set to 18mm in this example; it is the distance the left printhead 4 and right printhead 5 travel on the X-axis from the trigger X- limit 218 and trigger X+ limit 219 to the zero-return point). That is, the left printhead 4 returns to zero.

[0038] The right print head 5 moves in the X+ direction as follows Figure 7As shown in Figure 8, the movement stops when the X+ limit 219 is triggered. Then, it moves a distance B in the X- direction. This completes the return of the right printhead 5 to zero. Next, the Y-axis (X-axis assembly 203) moves in the Y- direction as shown... Figure 6 As shown, the movement stops until the Y-limit 210 is triggered. Then, it moves a distance C in the Y+ direction (C is a fixed value set by the system; in this example, it is set to 27mm. It is the distance the Y-axis (X-axis component 203) moves from the trigger Y-limit 210 to the zero point on the Y-axis). That is, the Y-axis (X-axis component 203) returns to zero.

[0039] Then as Figure 9 As shown, the left printhead 4 leadscrew motor 403 drives the printhead body assembly 404 to move in the Z+ direction until the mechanical limit 407 on the right side of the left printhead 4 leadscrew motor 403 is triggered and then the movement stops. Next, the left printhead 4 leadscrew motor 403 drives the printhead body assembly 404 to move a distance D in the Z- direction (D is a fixed system value, set to 5mm in this example; it is the distance the printhead body assembly 404 moves along the Z-axis from the point where the mechanical limit 407 on the right side of the left printhead 4 leadscrew motor 403 is triggered to the zero point). That is, the right printhead body assembly 404 completes its zeroing process.

[0040] The right printhead 5 performs a symmetrical operation, following the same procedure as above.

[0041] Then as Figure 10 As shown, the Y-axis (X-axis assembly 203) moves E in the Y-direction (E is the distance moved in the Y-direction, which is the distance from the zero point of the Y-axis (X-axis assembly 203) to the zero-return sensor 103 in the Y-direction, which is set to 22mm in this example).

[0042] Then as Figure 11The left printhead 4 moves from its zero-return position on the X-axis assembly 203 towards the X+ limit 129 until it is directly above the zero-return sensor 103. Then, the Z-axis (XY motion frame 2) moves in the Z- direction until the zero-return sensor 103 is triggered to stop moving (at this point, the main control system 7 detects the distance the left printhead 4 has traveled from the start of its movement on the Z-axis (XY motion frame 2) until the zero-return sensor 103 is triggered to stop). Then, the Z-axis (XY motion frame 2) moves in the Z+ direction back to position A before the Z-axis (XY motion frame 2) moved in the Z- direction, and the left printhead returns to its zero-return position on the X-axis assembly 203. Next, the right printhead 5 moves from its zero-return position on the X-axis assembly 203 towards the X- limit 218 until it is directly above the zero-return sensor 103. Next, the Z-axis (XY motion frame 2) moves in the Z- direction until the zero-return sensor 103 is triggered and the movement stops (at this time, the main control system 7 detects the distance the right printhead 5 has traveled from the start of movement on the Z-axis (XY motion frame 2) until the zero-return sensor 103 is triggered and the movement stops). At this point, the main system can determine the installation difference between the left printhead 4 and the right printhead 5, preparing for subsequent leveling.

[0043] Finally, the Z-axis (XY motion frame 2) moves F in the Z+ direction (F is the distance moved, a fixed value set by the main control system 7, which is the distance the left printhead 4 triggers the zero-return sensor 103 to move in the Z+ direction, and is also the zero-return position of the Z-axis (XY motion frame 2). In this example, it is set to 15mm). This completes the Z-axis (XY motion frame 2) zero-return. Then, the right printhead 5 returns to its zero-return position on the X-axis assembly 203; the Y-axis (X-axis assembly 203) moves E in the Y+ direction. That is, the Y-axis (X-axis assembly 203) returns to its zero-return position in the Y-axis direction.

[0044] That is, the zeroing operation is completed.

[0045] If the left printhead main assembly 404 is not in the lead screw motor 403's driveable lead screw section, such as... Figure 12 As shown, if the left printhead 4 lead screw motor 403 cannot drive the printhead main body assembly 404 to move in the Z+ direction, the mechanical limit 407 on the right side of the left printhead 4 lead screw motor 403 will be triggered. If the main control system 7 is not triggered within a certain period of time, it is determined that the left printhead main body assembly 404 is not in the filament part that can be driven by the lead screw motor 403.

[0046] At this point, the main control system 7 issues a command to move the Z-axis (XY motion frame 2) in the Z- direction. During this movement, the left printhead main body assembly 404 is pushed up in the Z+ direction. Simultaneously, the left printhead lead screw motor 403 rotates rapidly until it can drive the printhead main body assembly 404, until it stops when the mechanical limit 407 on the right side of the lead screw motor 403 is triggered. At the same time, the Z-axis (XY motion frame 2) also stops moving.

[0047] Then, the lead screw motor 403 slowly rotates, driving the printhead main body assembly 404 to move a distance B in the Z- direction. It then moves in the Z+ direction until it triggers the mechanical limit 407 on the right side of the lead screw motor 403, stopping it. Next, the left printhead lead screw motor 403 again drives the printhead main body assembly 404 to move a distance B in the Z- direction, completing the return of the left printhead main body assembly 404 to zero (this process triggers the mechanical limit 407 twice and then moves a distance B in the Z- direction because the first rapid trigger may have some positioning accuracy deviation; a second slow movement is needed to ensure positioning accuracy). Finally, continue the same operation as above to complete the return to zero.

[0048] Please refer to the leveling process. Figure 12 / 13 (Leveling only requires either the left printhead 4 or the right printhead 5; this example uses the left printhead 4 as an example.): The left printhead 4 moves to the first leveling point set in advance, and then the Z-axis (XY motion frame 2) moves a distance A in the Z+ direction. Next, the left printhead lead screw motor 403 drives the printhead body assembly 404 to move in the Z- direction until the printhead body assembly 404 detaches from the lead screw motor 403 and falls freely to the lowest position.

[0049] At this point, the main control system 7 activates the detection of the left printhead lead screw motor 403 and the left printhead body leveling limit 405. Then, the Z-axis (XY motion frame 2) moves in the Z- direction, lifting the printhead body assembly 404 of the left printhead 4. This continues until the left printhead lead screw motor 403 and the left printhead body leveling limit 405 are triggered. The position of the first leveling point triggered in the Z-direction is recorded, thus completing the first leveling point. Similarly, after completing the last leveling point, the main control system 7 deactivates the detection of the printhead leveling limit 405 and records all leveling point data.

[0050] Then the Z-axis (XY motion frame 2) slowly moves in the Z- direction, lifting the printhead body assembly 404 of the left printhead 4. At this time, the left printhead lead screw motor 403 rotates rapidly until the lead screw motor 403 can drive the printhead body assembly 404.

[0051] Next, the printhead main body assembly 404, driven by the lead screw motor 403, moves rapidly in the Z+ direction until it stops at the mechanical limit 407 on the right side of the lead screw motor 403. At this time, the Z-axis (XY motion frame 2) stops moving in the Z- direction. Then, the left printhead lead screw motor 403 slowly rotates, causing the printhead main body assembly 404 to move a distance D in the Z- direction. Then, the printhead main body assembly 404, driven by the lead screw motor 403, slowly moves again in the Z+ direction until it stops at the mechanical limit 407 on the right side of the lead screw motor 403. Then, the left printhead lead screw motor 403 slowly rotates, causing the printhead main body assembly 404 to move a distance D in the Z- direction, completing the return of the left printhead main body 404 to zero. Then, the main control system 7 issues a command to initiate the zeroing process.

[0052] Please refer to the printing process. Figure 12 , Figure 13 : If the main control system 7 detects that leveling has just been completed before printing, it will start printing directly; if the main control system 7 detects that leveling has not been performed before printing, it will use the previous leveling point data during printing, and the zeroing process will be run again to ensure accuracy.

[0053] For example Figure 12 When the left-center printhead 4 moves from point W to point N on the printing platform 6, point N may not be exactly at the leveling point. In this case, the control system 7 calculates the position of point N in the Z-axis based on the known leveling points around it (i.e., simulates the leveling data). This calculation is completed before point W moves to point N. Therefore, during the movement of point W to point N, the printhead lead screw motor 403 adjusts the position of the printhead main assembly 404 in the Z-axis in real time according to the instructions of the control system 7, thereby compensating for the difference in the printing platform 6. If point A is also not at the leveling point, the control system 7 will also complete the calculation in advance. (The main control system 7 calculates the Z-axis leveling data of the printhead position in real time during the printing process based on the leveling point data.) When the right printhead 5 moves from point J to point K on the print platform 6 (the right printhead 5 uses the left printhead leveling data), due to external factors such as installation, the left printhead 4 and the right printhead 5 may not be on the same horizontal plane (e.g., Figure 13(As shown). At this time, the difference between the left printhead 4 and the right printhead 5 obtained during the zeroing process, plus the value of the difference, is used by the control system 7 to calculate the position of point J in the Z direction based on the known leveling points around point J (i.e., simulating the leveling data). That is, as point J moves to K, the printhead lead screw motor 403 will adjust the position of the printhead main body assembly 404 in the Z direction in real time according to the instructions of the control system 7, thereby compensating for the difference in the printing platform 6. (The main control system 7 will calculate the Z-axis leveling data of the printhead position in real time during the printing process based on the leveling point data, and add the difference between the left printhead 4 and the right printhead 5 to obtain the Z-axis leveling data of the right printhead.) The advantages of this invention are: based on the IDEX (Independent Dual Extruder) structure of a 3D printer, it achieves independent automatic leveling of both print heads, ensuring completely identical printing results for both print heads during mirror and copy printing. Furthermore, since the leveling mechanism and platform compensation during printing are performed on the print head, printing accuracy is further improved.

Claims

1. An IDEX structure dual-head independent automatic leveling device, characterized in that, The system includes a main frame, an XY motion frame installed within the main frame, a Z-axis lead screw assembly connecting the XY motion frame, a left print head and a right print head mounted on the X-axis assembly of the XY motion frame, and a printing platform fixed to the bottom of the main frame. The left and right print heads each have independent leveling mechanisms. Each independent leveling mechanism includes a separable lead screw drive assembly, a gravity-triggered limiting device, and a bidirectional mechanical limiting assembly. The separable lead screw drive assembly comprises an upper threaded section and a lower unthreaded guide section. The gravity-triggered limiting device is located below the print head connecting plate. The bidirectional mechanical limiting assembly is symmetrically arranged on both sides of the lead screw motor to form a two-stage contact positioning. The unthreaded guide section of the separable lead screw drive assembly engages with the print head connecting plate, allowing the main body of the print head to detach from the threaded section and fall freely to the print head connecting plate in a triggered / untriggered state. The bidirectional mechanical limiting component includes a mechanical limiting block on the right side of the lead screw motor and a leveling limiting sensor on the left side. The mechanical limiting block forms a two-way contact positioning with the movement trajectory of the printhead main body component. The bottom of the main frame is provided with a zero-return positioning component, which includes a vertically arranged Z-axis limiting baffle and a horizontally arranged contact trigger sensor. The contact trigger sensor is located at the front end of the printing platform and has a position repeatability accuracy of ±0.001mm.

2. The IDEX structure dual-head independent automatic leveling device according to claim 1, characterized in that, The XY motion frame includes a left Y-axis guide rail group and a right Y-axis guide rail group arranged in parallel. The two are rigidly connected by a front reinforcing connecting plate. A Y-axis idler gear transmission assembly is provided in the middle of the front reinforcing connecting plate to enhance synchronization.

3. The IDEX structure dual-head independent automatic leveling device according to claim 1, characterized in that, The Z-axis lead screw assembly is arranged symmetrically at four corners. Each lead screw nut is driven by a synchronous pulley group, which is equipped with a tension adjustment mechanism to maintain transmission accuracy.

4. A dual-head independent automatic leveling method for an IDEX structure, characterized in that, include: After the Z-axis lead screw assembly drives the XY motion frame to rise and fall to a preset safe distance, the left and right printheads respectively perform zero-return operations. The zero-return operation includes moving along the X-axis to the corresponding limit and then adjusting to the zero point. Then, a leveling operation is performed. The leveling operation includes the printhead body assembly disengaging from the lead screw drive assembly and falling freely to a preset position. The gravity-triggered limit device is triggered to detect the current position, and multiple leveling data are repeatedly collected to establish a platform error model. Finally, during the printing process, the Z-axis leveling data of the print head position is calculated in real time and the height difference between the two print heads is compensated synchronously. The zeroing operation includes: after the Z-axis frame moves 20mm in the Z+ direction, the left print head moves 18mm along the X- direction after triggering the X-limit, the right print head moves 18mm along the X+ direction after triggering the X+limit, and the Y-axis assembly moves 27mm after triggering the Y-limit to complete the zeroing operation; the leveling operation includes: when it is detected that the print head main body assembly is not in the threaded section of the lead screw drive assembly, the Z-axis frame moves in the Z- direction to lift the print head main body assembly, and at the same time the lead screw motor rotates rapidly until it triggers the mechanical limit stop, and then slowly resets to complete the precise positioning.

5. The IDEX structure dual-head independent automatic leveling method according to claim 4, characterized in that, The real-time compensation includes: calculating the Z-axis height of non-sampling points using cubic spline interpolation based on the leveling point data, and superimposing the height difference detected when the dual printheads return to zero to form the final compensation value.

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