Method and device for detecting stalling of light-curing 3D printed anti-pressure screens

Abstract

The present invention provides four methods for detecting stalls in light-cured 3D printed anti-pressure screens and a device for detecting stalls in light-cured 3D printed anti-pressure screens. The device comprises: a control unit, a door drive unit, a full-bridge chopper unit, a motor, a current detection and comparison unit, a storage unit, a display and operation unit, a limit detection module, an abnormality prompt unit, a Z-axis, a molding platform, a base, an LCD screen, a UVLED light source module, a liquid tank, a base film, and a photosensitive resin. The method mainly comprises the following steps: the control unit controls the motor to drive the molding platform to move downward along the Z-axis; the current detection and comparison unit obtains a sampled current at the ground terminal and / or output terminal of the full-bridge chopper unit and converts it into a digital current value; the control unit compares the digital current value with a preset current threshold; if the digital current value is greater than the preset current threshold, it is determined that a stall fault has occurred in the motor, and the motor is controlled to stop running and a warning signal is issued.

Description

Technical Field

[0001] The present application relates to the field of 3D printing technology, and in particular to a method and device for detecting stalling of a pressure shield in a light-curing 3D printing. Background Art

[0002] Before using the current LCD rising light-curing 3D printer, there are generally four usage scenarios. The first is the use of single zeroing, which is to return the molding platform to zero and lower it for tidying up and putting it away. When the user issues the zeroing command, the 3D printer will return the molding platform at the highest position of the Z axis after the last demoulding to the historically saved zero position below the Z axis, and then cover it with a dark box cover; the second is the use of zeroing and calibration without printing. At this time, it is necessary to first return the molding platform at the highest position of the Z axis after the last demoulding to the historically saved zero position below the Z axis, and then perform platform level calibration or adjust the distance between the molding platform and the bottom film of the liquid tank; the third is the use of automatic zeroing for printing. It will automatically return to zero each time it is used for printing. That is, each time the user imports a print slice file and issues a print command, the 3D printer will return the forming platform, which was at the highest position of the Z axis after the last demolding, to the historically saved zero position below the Z axis, and then perform the layer-by-layer printing action; fourthly, the use of the anti-pressure screen during printing. After the user imports the model data and issues a print command, and the forming platform automatically returns to zero, during normal light-curing printing, the forming platform will continue to repeat the lifting action. When two or more models are being light-cured and printed at the same time, if one model falls off and falls into the liquid tank, then when the forming platform descends normally, other models may squeeze the detached model and cause it to press the lower LCD screen downward.

[0003] During the zeroing process of the build platform, current LCD ascending light-curing 3D printers generally have a limit switch or limit sensor installed under the Z-axis. Firstly, this allows the controller to detect the position of the build platform when the motor drives the build platform to the bottom, facilitating further precise movement to the zero starting position based on this position; secondly, it prevents the build platform from directly crossing the zero starting position and squeezing into the selectively translucent LCD screen located very close to the bottom film of the liquid tank.

[0004] However, in actual use, there are often three problems that cannot be solved. First, after the last print is completed, when the user demoulds the cured model from the forming platform, there is a risk of residual curing blocks remaining on the forming platform. If they are not cleaned up, during the next print, when the forming platform descends to zero, the remaining curing blocks may begin to squeeze the LCD screen below, and the forming platform has not yet reached the limit trigger position, which will squeeze and damage the LCD screen. Second, in order to prevent the photosensitive resin from being cured by external light, the LCD light-curing 3D printer generally works in a dark room, and the LCD light Curing 3D printers generally have a dark box cover on the top, and the LCD light curing process is generally slow. If the user forgets to remove the model after printing the last time, the new user may directly start a new round of printing due to unclear light. In this case, the LCD screen below will be damaged by the previous model before the build platform reaches the limit trigger position. Third, during normal light curing printing, when two or more models are being printed at the same time, if one model falls off and falls into the liquid tank, then when the build platform descends normally, the other models will squeeze the detached model and cause it to press the lower LCD screen downward.

[0005] Therefore, in order to solve the above problems, it is necessary to provide a corresponding light-curing 3D printed anti-pressure screen stall detection method and device. Summary of the Invention

[0006] In order to solve the problems in the above background technology, the present invention provides four methods for detecting stalling of a light-cured 3D printed anti-pressure shield and a device for detecting stalling of a light-cured 3D printed anti-pressure shield. The technical solutions adopted by the present invention are as follows:

[0007] Method 1, a method for detecting stalling of a light-curing 3D printed anti-pressure screen, for use in a single zeroing operation, includes the following steps:

[0008] SA01, the user sends a command to the control unit 1 via the display and operation unit 6 to return the building platform 32 to zero;

[0009] SA02, the control unit 1 sends a control instruction to the door drive unit 2 to control it to drive the motor 3 through the full-bridge chopper unit 20 to drive the forming platform 32 to move downward along the Z axis 31;

[0010] SA03, the current detection and comparison unit 4 obtains the sampling current of the ground terminal and / or output terminal of the full-bridge chopper unit 20;

[0011] SA04, the current detection and comparison unit 4 converts the analog signal of the sampled current into a digital signal and sends the digital current value to the control unit 1 after obtaining it;

[0012] SA05: Control unit 1 compares the digital current value with a preset current threshold and determines whether the digital current value is greater than the preset current threshold; if the digital current value is greater than the preset current threshold, proceed to step SA08; if the digital current value is not greater than the preset current threshold, proceed to step SA06;

[0013] SA06, the motor 3 drives the forming platform 32 to move downward along the Z axis 31 until the limit detection module 7 is triggered and sends a limit trigger signal to the control unit 1;

[0014] SA07: The control unit 1 uses the position of the forming platform 32 on the Z-axis 31 corresponding to when the limit detection module 7 is triggered as a mark point to control the forming platform 32 to shift X mm to the zero starting position, and then proceeds to step SA09;

[0015] SA08: After the control unit 1 determines that the motor 3 has a stall fault, it controls the motor 3 to stop running and issues a warning signal through the abnormal prompt unit 8;

[0016] SA09, process ends.

[0017] Method 2, a method for detecting stalling of a light-curing 3D printing anti-pressure screen, is designed for use in situations where zero calibration is performed without printing. The method includes the following steps:

[0018] SB01, the user sends an instruction to the control unit 1 to return the building platform 32 to zero through the display and operation unit 6;

[0019] SB02, the control unit 1 sends a control instruction to the door drive unit 2 to control it and drive the motor 3 through the full-bridge chopper unit 20 to drive the forming platform 32 to move downward along the Z axis 31;

[0020] SB03, the current detection and comparison unit 4 obtains the sampling current at the output end and / or the ground end of the full-bridge chopper unit 20;

[0021] SB04, the current detection and comparison unit 4 converts the analog signal of the sampled current into a digital signal and sends the digital current value to the control unit 1 after obtaining it;

[0022] SB05. Control unit 1 compares the digital current value with a preset current threshold and determines whether the digital current value is greater than the preset current threshold; if the digital current value is greater than the preset current threshold, proceed to step SB10; if the digital current value is not greater than the preset current threshold, proceed to step SB06;

[0023] SB06, the motor drives the forming platform 32 to move downward along the Z axis 31 until the limit detection module 7 is triggered and sends a limit trigger signal to the control unit 1;

[0024] SB07, the control unit 1 uses the position of the forming platform 32 on the Z axis 31 when the limit detection module 7 is triggered as a mark point to control the forming platform 32 to shift X mm to the zero starting position;

[0025] SB08. The user determines whether the current zero-start position needs to be corrected; if it is determined that the current zero-start position does not need to be corrected, step SB11 is performed; if it is determined that the current zero-start position needs to be corrected, step SB09 is performed;

[0026] SB09, the user operates the display and operation unit 6 to make the motor 3 drive the forming platform 32 to lift or lower Y mm to the target position and then save it as the new zero starting position, and then proceed to step SB11;

[0027] SB10, the control unit 1 determines that the motor 3 has a stall fault and controls the motor 3 to stop running and sends a warning signal through the abnormal prompt unit 8;

[0028] SB11, process ends.

[0029] Method 3, a method for detecting stalling of a light-curing 3D printing anti-pressure screen, targeting the use of automatic zeroing for printing, comprises the following steps:

[0030] SC01, the user imports the model printing slice file into the storage unit 5 of the light-curing printing device;

[0031] SC02: The user sends a model slice file printing instruction to the control unit 1 through the display and operation unit 6;

[0032] SC03, the control unit 1 sends a control instruction to the door drive unit 2 to control it and drive the motor 3 through the full-bridge chopper unit 20 to drive the forming platform 32 to move downward along the Z axis 31;

[0033] SC04 and the current detection and comparison unit 4 obtain the sampling current of the ground terminal and / or the output terminal of the full-bridge chopper unit 20;

[0034] SC05 and the current detection and comparison unit 4 convert the analog signal of the sampled current into a digital signal and send it to the control unit 1 after obtaining the digital current value;

[0035] SC06: Control unit 1 compares the digital current value with a preset current threshold and determines whether the digital current value is greater than the preset current threshold; if the digital current value is greater than the preset current threshold, proceed to step SC10; if the digital current value is not greater than the preset current threshold, proceed to step SC07;

[0036] SC07 and motor 3 drive the forming platform 32 to move downward along the Z axis 31 until the limit detection module 7 is triggered and sends a limit trigger signal to the control unit 1;

[0037] SC08, the control unit 1 uses the position of the forming platform 32 on the Z axis 31 when the limit detection module 7 is triggered as a mark point to control the forming platform 32 to shift X mm to the zero starting position;

[0038] SC09, the control unit 1 reads the model printing slice file in the storage unit 5 and performs light-curing printing on the model slice data layer by layer in sequence, and then proceeds to step SC11;

[0039] SC10, the control unit 1 determines that the motor 3 has a stall fault and controls the motor 3 to stop running and sends a warning signal through the abnormal prompt unit 8;

[0040] SC11, process ends.

[0041] Method 4, a method for detecting stalling of a light-curing 3D printing anti-pressure screen, is based on the use of the anti-pressure screen during printing, and includes the following steps:

[0042] SD01, the user imports the model printing slice file into the storage unit 5 of the light-curing printing device and sends a printing instruction to the control unit 1 through the display and operation unit 6;

[0043] SD02, the control unit 1 controls and drives the motor 3 to drive the forming platform 32 to complete zeroing;

[0044] SD03, the control unit 1 reads the model printing slice file in the storage unit 5 and performs light-curing printing on the model slice data layer by layer in sequence;

[0045] SD04, the control unit 1 sends a control instruction to the door drive unit 2 to control it and drive the motor 3 through the full-bridge chopper unit 20 to drive the forming platform 32 to move or stop along the Z axis 31;

[0046] SD05, the current detection and comparison unit 4 obtains the sampling current of the ground terminal and / or output terminal of the full-bridge chopper unit 20;

[0047] SD06, the current detection and comparison unit 4 converts the analog signal of the sampled current into a digital signal and sends it to the control unit 1 after obtaining the digital current value;

[0048] SD07, the control unit 1 determines whether the molding platform 32 is in a downward state; if it is determined that the molding platform 32 is not in a downward state, proceed to step SD09; if it is determined that the molding platform 32 is in a downward state, proceed to step SD08;

[0049] SD08, the control unit 1 compares the digital current value with the preset current threshold and determines whether the digital current value is greater than the preset current threshold; if the digital current value is greater than the preset current threshold, the process proceeds to step SD11; if the digital current value is not greater than the preset current threshold, the process proceeds to step SD09;

[0050] SD09 and motor 3 drive the forming platform 32 to continue moving along the Z axis 31 until it reaches the target position;

[0051] SD10: All the slice data of the layers in the model printing slice file are all cured by light. The next step is step SD12.

[0052] SD11, the control unit 1 determines that the motor 3 has a stall fault and controls the motor 3 to stop running and sends a warning signal through the abnormal prompt unit 8;

[0053] SD12, the process ends.

[0054] Preferably, in steps SA06, SB06, and SC07, the motor 3 drives the forming platform 32 to trigger the limit detection module 7 in a manner including electromagnetic induction triggering, photoelectric induction triggering, or direct contact pressure triggering.

[0055] Preferably, in steps SA03, SB03, SC04 and SD05, the current detection and comparison unit 4 obtains the sampling current of the ground terminal and / or output terminal of the full-bridge chopper unit 20 by directly inputting the sampling current or collecting the sampling current by current sensing detection.

[0056] Preferably, in steps SA05, SB05, SC06, and SD08, the preset current threshold is a fixed current value, or a dynamic follow-up ratio value of a minimum drive current, or a dynamic follow-up ratio value of a maximum drive current.

[0057] A device for detecting stalling of a light-curing 3D printed pressure-resistant screen comprises: a control unit 1, a gate drive unit 2, a full-bridge chopper unit 20, a motor 3, a current detection and comparison unit 4, a storage unit 5, a display and operation unit 6, a limit detection module 7, an abnormality prompt unit 8, a Z-axis 31, a molding platform 32, a base 10, an LCD screen 11, a UVLED light source module 12, a liquid tank 9, a base film 90, and a photosensitive resin 91;

[0058] The door drive unit 2, the current detection and comparison unit 4, the storage unit 5, the display and operation unit 6, the limit detection module 7, the abnormality prompt unit 8, the LCD screen 11, and the UVLED light source module 12 are electrically connected to the control unit 1; the user sends an instruction to reset the forming platform or a model slice file printing instruction to the control unit 1 through the display and operation unit 6; the storage unit 5 is used to import and store the model print slice file;

[0059] The door drive unit 2 is electrically connected to the full-bridge chopper unit 20 and controls the on and off of each switch tube in the full-bridge chopper unit 20; the full-bridge chopper unit 20 is electrically connected to the windings in the motor 3 and drives the motor 3 to operate; the control unit 1 controls the operation and start and stop of the motor 3 by issuing control instructions to the door drive unit 2, thereby driving the building platform 32 to move up and down or stop along the Z-axis 31; the motor 3 drives the building platform 32 to move downward along the Z-axis 31 until the limit detection module 7 is triggered, causing it to send a limit trigger signal to the control unit 1, so as to record the corresponding position mark point of the building platform 32 on the Z-axis 31;

[0060] The current detection and comparison unit 4 is connected to and obtains a sampled current at the ground terminal and / or the output terminal of the full-bridge chopper unit 20, converts an analog signal of the sampled current into a digital signal and obtains a digital current value, and then sends the digital current value to the control unit 1; the control unit 1 compares the obtained digital current value with a preset current threshold value to determine whether a stall fault has occurred in the motor 3; after the control unit 1 determines that a stall fault has occurred, it controls the motor 3 to stop running and issues a warning signal through the abnormality prompt unit 8, thereby preventing the light-curing 3D printing device from squeezing the LCD screen 11 when the forming platform 32 descends during the zeroing process;

[0061] The Z-axis 31, LCD screen 11, UVLED light source module 12, and liquid tank 9 are fixed to the base 10; the bottom film 90 is set at the bottom of the liquid tank 9 for light transmission; the liquid tank 9 is used to hold the photosensitive resin 91 liquid; the motor 3 is installed on the Z-axis 31 to realize electric drive lifting and lowering and drive the molding platform 32 to rise or fall with it;

[0062] The user sends a model slicing file printing instruction to the control unit 1 through the display and operation unit 6. After the control unit 1 controls the motor 3 to return the forming platform 32 to the zero starting position, the control unit 1 reads the model printing slicing file in the storage unit 5 and performs photocuring printing on the model slicing data layer by layer in sequence. During this process, the LCD screen 11 loads and switches the layer slicing mask image in the model printing slicing file layer by layer, and the UVLED light source module 12 emits ultraviolet light and visible light through the mask image in the LCD screen 11 and the base film 90 to expose the photosensitive resin 91 in the liquid tank 9 to cure and form it; the forming platform 32 is used to adhere to the cured model molding resin layer during the curing and forming process so that it continues to rise and grow until the 3D printing is completed.

[0063] Furthermore, the light-curing 3D printing anti-pressure screen stall detection device also includes: a current sensor 30; the current sensor 30 is electrically connected to the current detection and comparison unit 4; the current sensor 30 is also arranged on the line between the full-bridge chopper unit 20 and the motor 3 and performs current detection on the line, and sends the detected current sample to the current detection and comparison unit 4; the number of the current sensors 30 is one, two, three, or four.

[0064] Furthermore, the light-curing 3D printing anti-pressure shield stall detection device further includes: an encoder 33; the encoder 33 is arranged on the motor 3 to detect the angular displacement of the rotor of the motor 3, record the rotor pulse count or the rotor starting position, and send the information to the control unit 1 for controlling the forming platform 32 to achieve precise offset.

[0065] Preferably, the motor 3 is a stepper motor, a servo motor, or a brushless DC motor; the full-bridge chopper unit 20 includes a three-phase six-switch tube full-bridge chopper unit, or two single-phase four-switch tube full-bridge chopper units.

[0066] Preferably, the abnormality prompt unit 8 adopts a diode, or a buzzer, or a speaker, or a liquid crystal display module.

[0067] Compared with the prior art, the present invention has the following beneficial effects:

[0068] 1. Methods 1-4 of the present invention provide four methods for detecting stalling of a light-curing 3D printing anti-pressure screen. During the zeroing process of the build platform, if the motor driving the build platform to descend is blocked, the motor will stall. Then, the sampling current at the output end and / or ground end of the full-bridge chopper unit will increase and exceed the preset current threshold. The control unit will determine that the motor has stalled, stop the motor, and issue a warning signal, thereby preventing the build platform from squeezing and damaging the LCD screen below before the limit protection function is triggered.

[0069] 2. To organize and store a light-curing 3D printer, users can use Method 1 to reset the 3D printer individually. This will lower the build platform back to its starting position and prevent the LCD screen from being squeezed and damaged before the build platform triggers the limit protection function.

[0070] 3. If you only need to zero and calibrate without printing, you can use Method 2 to perform zero and calibration on the 3D printer separately. This will return the build platform to its zero starting position and prevent damage to the LCD screen below from being squeezed before the build platform triggers the limit protection function. The build platform can then be calibrated after returning to its zero starting position. Finally, the calibrated position can be saved as the new zero starting position.

[0071] 4. To enable automatic zeroing of printing, users can import the model print slice file using Method 3 and directly issue a print command. The control unit will automatically control the build platform to return to the zero starting position, and avoid squeezing and damaging the LCD screen below before the build platform triggers the limit protection function. Then, the model slice data is sequentially processed layer by layer based on the zero starting position for light-curing printing.

[0072] 5. To prevent the build platform from being squeezed during printing, the user can use Method 4 to detect each lift or descent of the build platform. If the build platform is in the descent process, the digital current value is compared with the preset current threshold. Before the build platform triggers the limit protection function, the machine can be shut down and a warning issued to prevent the LCD screen from being squeezed and damaged.

[0073] 6. Methods 1-4 of the present invention provide four methods for detecting stalling of light-cured 3D printed anti-pressure screens. By detecting and comparing the sampled current at the output end and / or ground end of the full-bridge chopper unit with a preset current threshold, it is determined whether the motor has a stall fault, and the limit protection function is triggered by the limit detection module, forming a dual protection mechanism. Even if the limit detection module is damaged and not triggered, a stall fault can still occur when the forming platform squeezes the LCD screen downward through the base film, causing the motor to stop.

[0074] 7. The light-curing 3D printed anti-pressure screen stall detection device provided by the present invention can also use two single-phase four-switch tube full-bridge chopper units to drive a stepper motor, or use a three-phase six-switch tube full-bridge chopper unit to drive a three-phase DC brushless motor or servo motor, while following the above four methods. In terms of the specific current detection method, direct current input detection or isolated detection using a current sensor can be used, which can make the circuit design flexible and diverse. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 This is a flow chart of the light-curing 3D printing anti-pressure screen stall detection method 1 of the present invention;

[0076] Figure 2 This is a flow chart of the light-curing 3D printing anti-pressure screen stall detection method 2 of the present invention;

[0077] Figure 3 This is a flow chart of the light-curing 3D printing anti-pressure screen stall detection method 3 of the present invention;

[0078] Figure 4 This is a flow chart of the light-curing 3D printing anti-pressure screen stall detection method 4 of the present invention;

[0079] Figure 5 This is the overall embodiment 1 of the light-curing 3D printing anti-pressure screen stall detection device of the present invention;

[0080] Figure 6 The circuit principle of the light-curing 3D printing anti-pressure screen stall detection device of the present invention Figure 1 ;

[0081] Figure 7 The circuit principle of the light-curing 3D printing anti-pressure screen stall detection device of the present invention Figure 2 ;

[0082] Figure 8 The circuit principle of the light-curing 3D printing anti-pressure screen stall detection device of the present invention Figure 3 ;

[0083] Figure 9 The principle structure and state of the light-curing 3D printing anti-pressure screen stall detection device of the present invention Figure 1 ;

[0084] Figure 10 The principle structure and state of the light-curing 3D printing anti-pressure screen stall detection device of the present invention Figure 2 ;

[0085] Figure 11 This is a three-dimensional demonstration of the light-curing 3D printing anti-pressure screen stall detection device of the present invention. Figure 1 ;

[0086] Figure 12 This is a three-dimensional demonstration of the light-curing 3D printing anti-pressure screen stall detection device of the present invention. Figure 2 .

[0087] Description of labels:

[0088] Control unit 1; gate drive unit 2; full-bridge chopper unit 20; single-phase four-switch tube full-bridge chopper units 21 and 22; three-phase six-switch tube full-bridge chopper unit 23; switch tubes 211 and 221; freewheeling diodes 212 and 222; detection resistors 201 and 202; motor 3; current detection and comparison unit 4; storage unit 5; display and operation unit 6; limit detection module 7; abnormal prompt unit 8; liquid tank 9; base 10; LCD screen 11; UVLED light source module 12; current sensor 30; Z axis 31; molding platform 32; encoder 33; base film 90; photosensitive resin 91; resin molding model 92; controller 100. DETAILED DESCRIPTION

[0089] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0090] Figure 1 This is a flow chart of the light-curing 3D printing anti-pressure screen stall detection method 1 of the present invention. As shown in the figure, it is for the use of a single zeroing, and includes the following steps:

[0091] SA01, the user sends a command to the control unit 1 via the display and operation unit 6 to return the building platform 32 to zero;

[0092] SA02, the control unit 1 sends a control instruction to the door drive unit 2 to control it to drive the motor 3 through the full-bridge chopper unit 20 to drive the forming platform 32 to move downward along the Z axis 31;

[0093] SA03, the current detection and comparison unit 4 obtains the sampling current of the ground terminal and / or output terminal of the full-bridge chopper unit 20;

[0094] SA04, the current detection and comparison unit 4 converts the analog signal of the sampled current into a digital signal and sends the digital current value to the control unit 1 after obtaining it;

[0095] SA05: Control unit 1 compares the digital current value with a preset current threshold and determines whether the digital current value is greater than the preset current threshold; if the digital current value is greater than the preset current threshold, proceed to step SA08; if the digital current value is not greater than the preset current threshold, proceed to step SA06;

[0096] SA06, the motor 3 drives the forming platform 32 to move downward along the Z axis 31 until the limit detection module 7 is triggered and sends a limit trigger signal to the control unit 1;

[0097] SA07: The control unit 1 uses the position of the forming platform 32 on the Z-axis 31 corresponding to when the limit detection module 7 is triggered as a mark point to control the forming platform 32 to shift X mm to the zero starting position, and then proceeds to step SA09;

[0098] SA08: After the control unit 1 determines that the motor 3 has a stall fault, it controls the motor 3 to stop running and issues a warning signal through the abnormal prompt unit 8;

[0099] SA09, process ends.

[0100] Figure 2 This is a flow chart of the light-curing 3D printing anti-pressure screen stall detection method 2 of the present invention. As shown in the figure, it is aimed at the use case of only zeroing calibration without printing, and includes the following steps:

[0101] SB01, the user sends an instruction to the control unit 1 to return the building platform 32 to zero through the display and operation unit 6;

[0102] SB02, the control unit 1 sends a control instruction to the door drive unit 2 to control it and drive the motor 3 through the full-bridge chopper unit 20 to drive the forming platform 32 to move downward along the Z axis 31;

[0103] SB03, the current detection and comparison unit 4 obtains the sampling current at the output end and / or the ground end of the full-bridge chopper unit 20;

[0104] SB04, the current detection and comparison unit 4 converts the analog signal of the sampled current into a digital signal and sends the digital current value to the control unit 1 after obtaining it;

[0105] SB05. Control unit 1 compares the digital current value with a preset current threshold and determines whether the digital current value is greater than the preset current threshold; if the digital current value is greater than the preset current threshold, proceed to step SB10; if the digital current value is not greater than the preset current threshold, proceed to step SB06;

[0106] SB06, the motor drives the forming platform 32 to move downward along the Z axis 31 until the limit detection module 7 is triggered and sends a limit trigger signal to the control unit 1;

[0107] SB07, the control unit 1 uses the position of the forming platform 32 on the Z axis 31 when the limit detection module 7 is triggered as a mark point to control the forming platform 32 to shift X mm to the zero starting position;

[0108] SB08. The user determines whether the current zero-start position needs to be corrected; if it is determined that the current zero-start position does not need to be corrected, step SB11 is performed; if it is determined that the current zero-start position needs to be corrected, step SB09 is performed;

[0109] SB09, the user operates the display and operation unit 6 to make the motor 3 drive the forming platform 32 to lift or lower Y mm to the target position and then save it as the new zero starting position, and then proceed to step SB11;

[0110] SB10, the control unit 1 determines that the motor 3 has a stall fault and controls the motor 3 to stop running and sends a warning signal through the abnormal prompt unit 8;

[0111] SB11, process ends.

[0112] Figure 3 This is a flow chart of the light-curing 3D printing anti-pressure screen stall detection method 3 of the present invention. As shown in the figure, it is aimed at the use of automatic zeroing of printing, and includes the following steps:

[0113] SC01, the user imports the model printing slice file into the storage unit 5 of the light-curing printing device;

[0114] SC02: The user sends a model slice file printing instruction to the control unit 1 through the display and operation unit 6;

[0115] SC03, the control unit 1 sends a control instruction to the door drive unit 2 to control it and drive the motor 3 through the full-bridge chopper unit 20 to drive the forming platform 32 to move downward along the Z axis 31;

[0116] SC04 and the current detection and comparison unit 4 obtain the sampling current of the ground terminal and / or the output terminal of the full-bridge chopper unit 20;

[0117] SC05 and the current detection and comparison unit 4 convert the analog signal of the sampled current into a digital signal and send it to the control unit 1 after obtaining the digital current value;

[0118] SC06: Control unit 1 compares the digital current value with a preset current threshold and determines whether the digital current value is greater than the preset current threshold; if the digital current value is greater than the preset current threshold, proceed to step SC10; if the digital current value is not greater than the preset current threshold, proceed to step SC07;

[0119] SC07 and motor 3 drive the forming platform 32 to move downward along the Z axis 31 until the limit detection module 7 is triggered and sends a limit trigger signal to the control unit 1;

[0120] SC08, the control unit 1 uses the position of the forming platform 32 on the Z axis 31 when the limit detection module 7 is triggered as a mark point to control the forming platform 32 to shift X mm to the zero starting position;

[0121] SC09, the control unit 1 reads the model printing slice file in the storage unit 5 and performs light-curing printing on the model slice data layer by layer in sequence, and then proceeds to step SC11;

[0122] SC10, the control unit 1 determines that the motor 3 has a stall fault and controls the motor 3 to stop running and sends a warning signal through the abnormal prompt unit 8;

[0123] SC11, process ends.

[0124] Figure 4 This is a flow chart of the light-curing 3D printing anti-pressure screen stall detection method 4 of the present invention. As shown in the figure, it is aimed at the use of the anti-pressure screen during the printing process, and includes the following steps:

[0125] SD01, the user imports the model printing slice file into the storage unit 5 of the light-curing printing device and sends a printing instruction to the control unit 1 through the display and operation unit 6;

[0126] SD02, the control unit 1 controls and drives the motor 3 to drive the forming platform 32 to complete zeroing;

[0127] SD03, the control unit 1 reads the model printing slice file in the storage unit 5 and performs light-curing printing on the model slice data layer by layer in sequence;

[0128] SD04, the control unit 1 sends a control instruction to the door drive unit 2 to control it and drive the motor 3 through the full-bridge chopper unit 20 to drive the forming platform 32 to move or stop along the Z axis 31;

[0129] SD05, the current detection and comparison unit 4 obtains the sampling current of the ground terminal and / or output terminal of the full-bridge chopper unit 20;

[0130] SD06, the current detection and comparison unit 4 converts the analog signal of the sampled current into a digital signal and sends it to the control unit 1 after obtaining the digital current value;

[0131] SD07, the control unit 1 determines whether the molding platform 32 is in a downward state; if it is determined that the molding platform 32 is not in a downward state, proceed to step SD09; if it is determined that the molding platform 32 is in a downward state, proceed to step SD08;

[0132] SD08, the control unit 1 compares the digital current value with the preset current threshold and determines whether the digital current value is greater than the preset current threshold; if the digital current value is greater than the preset current threshold, the process proceeds to step SD11; if the digital current value is not greater than the preset current threshold, the process proceeds to step SD09;

[0133] SD09 and motor 3 drive the forming platform 32 to continue moving along the Z axis 31 until it reaches the target position;

[0134] SD10: All the slice data of the layers in the model printing slice file are all cured by light. The next step is step SD12.

[0135] SD11, the control unit 1 determines that the motor 3 has a stall fault and controls the motor 3 to stop running and sends a warning signal through the abnormal prompt unit 8;

[0136] SD12, the process ends.

[0137] In addition, based on Figure 1 、 Figure 2 、 Figure 3 、 Figure 4In the four method flow steps shown in the above, in steps SA06, SB06, and SC07, the motor 3 drives the forming platform 32 to trigger the limit detection module 7 by electromagnetic induction triggering, photoelectric induction triggering, or direct touch pressure triggering. In steps SA03, SB03, SC04, and SD05, the current detection comparison unit 4 obtains the sampling current of the ground terminal and / or output terminal of the full-bridge chopper unit 20 by directly inputting the sampling current or collecting the sampling current by current sensing detection. In steps SA05, SB05, SC06, and SD08, the preset current threshold is a fixed current value, or a dynamic follow-up ratio value of the minimum drive current, or a dynamic follow-up ratio value of the maximum drive current. A specific feasible method is to make the full-bridge chopper unit 20 output the minimum drive current to drive the operation of the motor 3 when the forming platform 32 descends to zero, and then set the preset current threshold to 1.1 times or 1.2 times the minimum drive current. The user only needs to determine the minimum drive current, and then adjust this proportional coefficient to achieve the dynamic follow-up ratio value of the minimum drive current to determine the preset current. Threshold; after determining the preset current threshold, if the forming platform 32 is blocked from descending, the motor 3 will be blocked and stalled, and the back electromotive force will disappear, which will cause the current of each phase of the motor 3 to increase. As long as the increased current exceeds the preset current threshold, the motor 3 can be controlled to stop running and a warning signal can be issued; when the forming platform 32 rises, the full-bridge chopper unit 20 can output the normal required driving current to drive the operation of the motor 3. At the same time, the comparison between the sampling current and the preset current threshold is shielded or canceled, or no shutdown and warning actions are taken for the comparison results of the two.

[0138] Figure 5 This is the overall embodiment 1 of the light-curing 3D printing anti-pressure shield stall detection device of the present invention. As shown in the figure, the door drive unit 2, current detection and comparison unit 4, storage unit 5, display and operation unit 6, limit detection module 7, abnormality prompt unit 8, LCD screen 11, and UVLED light source module 12 are electrically connected to the control unit 1. The user issues a command to reset the build platform or print a model slice file to the control unit 1 through the display and operation unit 6. The storage unit 5 is used to import and store model print slice files.

[0139] The door drive unit 2 is electrically connected to the two single-phase four-switch full-bridge chopper units 21 and 22, and controls the on and off of each switch tube in the two single-phase four-switch full-bridge chopper units 21 and 22; the two single-phase four-switch full-bridge chopper units 21 and 22 are electrically connected to the windings in the motor 3 and drive the motor 3 to operate; the control unit 1 controls the operation and start and stop of the motor 3 by issuing control instructions to the door drive unit 2, thereby driving the forming platform 32 to move up and down or stop along the Z-axis 31; the motor 3 drives the forming platform 32 to move downward along the Z-axis 31 until the limit detection module 7 is triggered, causing it to send a limit trigger signal to the control unit 1, so as to record the corresponding position mark point of the forming platform 32 on the Z-axis 31;

[0140] The ground terminals and output terminals of the two single-phase four-switch full-bridge chopper units 21 and 22 in this figure are directly electrically connected to the current detection and comparison unit 4, so that the current detection and comparison unit 4 can obtain the sampled currents at the ground terminals and output terminals of the two single-phase four-switch full-bridge chopper units 21 and 22, convert the analog signals of the sampled currents into digital signals and obtain digital current values, and then send the digital current values to the control unit 1; the control unit 1 compares the obtained digital current value with a preset current threshold to determine whether a stall fault has occurred in the motor 3; after the control unit 1 determines that a stall fault has occurred, it controls the motor 3 to stop running and sends a warning signal through the abnormal prompt unit 8, thereby preventing the light-curing 3D printing device from squeezing the LCD screen 11 when the forming platform 32 descends during the zeroing process;

[0141] The Z-axis 31, LCD screen 11, UVLED light source module 12, and liquid tank 9 are fixed to the base 10; the bottom film 90 is set at the bottom of the liquid tank 9 for light transmission; the liquid tank 9 is used to hold the photosensitive resin 91 liquid; the motor 3 is installed on the Z-axis 31 to realize electric drive lifting and lowering and drive the molding platform 32 to rise or fall with it;

[0142] The user sends a model slicing file printing instruction to the control unit 1 through the display and operation unit 6. After the control unit 1 controls the motor 3 to return the forming platform 32 to the zero starting position, the control unit 1 reads the model printing slicing file in the storage unit 5 and performs photocuring printing on the model slicing data layer by layer in sequence. During this process, the LCD screen 11 loads and switches the layer slicing mask image in the model printing slicing file layer by layer, and the UVLED light source module 12 emits ultraviolet light and visible light through the mask image in the LCD screen 11 and the base film 90 to expose the photosensitive resin 91 in the liquid tank 9 to cure and form it; the forming platform 32 is used to adhere to the cured model molding resin layer during the curing and forming process so that it continues to rise and grow until the 3D printing is completed.

[0143] Similarly, the control unit 1, the door drive unit 2, the current detection and comparison unit 4, the limit detection module 7, and the abnormal prompt unit 8 in this figure together constitute the controller 100, which corresponds to Figure 9 、 Figure 10 Controller 100 in.

[0144] Figure 6 The circuit principle of the light-curing 3D printing anti-pressure screen stall detection device of the present invention Figure 1 As shown in the figure, two single-phase four-switch full-bridge chopper units 21 and 22 are used to drive the motor 3. Among them, the single-phase four-switch tube full-bridge chopper unit 21 is composed of four switching tubes 211 to form a full-bridge chopper structure, and each switching tube 211 has a freewheeling diode 212 connected in reverse parallel to its current input and output ends, which is used to freewheel and protect the switching tube 211 during switching chopping; similarly, the single-phase four-switch tube full-bridge chopper unit 22 is composed of four switching tubes 221 to form a full-bridge chopper structure, and each switching tube 221 has a freewheeling diode 222 connected in reverse parallel to its current input and output ends, which is used to freewheel and protect the switching tube 221 during switching chopping; secondly, the ground ends of the two single-phase four-switch tube full-bridge chopper units 21 and 22 are respectively connected to detection resistors 201 and 202 and then grounded. The function of the two detection resistors 201 and 202 is to directly electrically connect the ground end and raise the ground voltage when sampling current, so that the current detection comparison unit 4 can effectively sample the ground end current. Specifically, in selecting the switch tubes 211 and 221 , controllable switch tubes such as MOSFET tubes, BJT tubes, and thyristors can be selected, or the two single-phase four-switch tube full-bridge chopper units 21 and 22 can directly use four-unit IGBT modules.

[0145] In addition, as shown in the figure, the door drive unit 2, the current detection and comparison unit 4, the storage unit 5, the display and operation unit 6, the limit detection module 7, and the abnormal prompt unit 8 are electrically connected to the control unit 1; the user sends an instruction to reset the forming platform or a model slice file printing instruction to the control unit 1 through the display and operation unit 6; the storage unit 5 is used to import and store the model print slice file;

[0146] The door drive unit 2 is electrically connected to the two single-phase four-switch full-bridge chopper units 21 and 22, and controls the on and off of each switch in the two single-phase four-switch full-bridge chopper units 21 and 22; the two single-phase four-switch full-bridge chopper units 21 and 22 are electrically connected to the windings in the motor 3 and drive the motor 3 to operate; the control unit 1 controls the operation and start and stop of the motor 3 by issuing control instructions to the door drive unit 2; the limit detection module 7 can send a limit trigger signal to the control unit 1 when triggered;

[0147] The ground terminal and output terminal of the single-phase four-switch tube full-bridge chopper unit 21 described in this figure are directly electrically connected to the current detection and comparison unit 4, so that the current detection and comparison unit 4 can obtain the sampling current of the ground terminal and output terminal of the single-phase four-switch tube full-bridge chopper unit 21, and convert the analog signal of the sampling current into a digital signal to obtain a digital current value, and then send the digital current value to the control unit 1; the control unit 1 compares the obtained digital current value with a preset current threshold to determine whether the motor 3 has a stall fault; after the control unit 1 determines that a stall fault has occurred, it controls the motor 3 to stop running and sends a warning signal through the abnormal prompt unit 8, thereby preventing the light-curing 3D printing device from squeezing the LCD screen 11 during the zeroing process.

[0148] In this figure, the single-phase four-switch tube full-bridge chopper unit 22 and the current detection and comparison unit 4 are connected by a dotted line. This is because, in actual needs, if the current of the motor 3 increases, it is sufficient to detect the current of only one set of windings. Therefore, the current detection and comparison unit 4 can detect the current on the single-phase four-switch tube full-bridge chopper unit 22, or it may not detect it.

[0149] In addition, the control unit 1, the door drive unit 2, the current detection and comparison unit 4, the limit detection module 7, and the abnormal prompt unit 8 in this figure together constitute the controller 100, which corresponds to Figure 9 、 Figure 10 Controller 100 in.

[0150] Figure 7 The circuit principle of the light-curing 3D printing anti-pressure screen stall detection device of the present invention Figure 2 As shown in the figure, this figure is consistent with Figure 6 The same thing is that both use two single-phase four-switch full-bridge chopper units 21 and 22 to drive the motor 3. The single-phase four-switch full-bridge chopper unit 21 is composed of four switches 211 forming a full-bridge chopper structure, and each switch 211 has a freewheeling diode 212 connected in reverse parallel to its current input and output terminals, which is used to freewheel and protect the switch 211 during switching chopping. Similarly, the single-phase four-switch full-bridge chopper unit 22 is composed of four switches 221 forming a full-bridge chopper structure, and each switch 221 has a freewheeling diode 222 connected in reverse parallel to its current input and output terminals, which is used to freewheel and protect the switch 221 during switching chopping. Furthermore, the ground terminals of the two single-phase four-switch full-bridge chopper units 21 and 22 are respectively connected to detection resistors 201 and 202 and then to ground. The two detection resistors 201 and 202 serve as grounding protection in this scheme.

[0151] In addition, this figure and Figure 6The difference is that in this figure, a current sensor 30 is provided on the A-phase circuit of motor 3 and is electrically connected to the current detection and comparison unit 4. The B-phase circuit of motor 3 can be provided with a current sensor 30, or it can be omitted. Therefore, a dashed line is used to connect it to the current detection and comparison unit 4 to indicate that both are possible. This is because, in actual use, if the current of motor 3 increases, it is sufficient to detect the current of only one winding. Furthermore, current sensor 30 can select any one or more of the four circuits of motor 3 for detection without any specific limitation.

[0152] Figure 8 The circuit principle of the light-curing 3D printing anti-pressure screen stall detection device of the present invention Figure 3 As shown in the figure, this figure is consistent with Figure 6 The difference is that the motor 3 in this figure adopts a three-phase winding structure, and its full-bridge chopper unit 20 includes a three-phase six-switch tube full-bridge chopper unit 23, which also uses six switch tubes to form a full-bridge chopper structure, and each switch tube is reversely connected in parallel with a freewheeling diode. Secondly, it uses a current sensor 30 to select any one, two, or three of the lines of the motor 3 for detection, so that it feeds back the motor winding current to the current detection comparison unit 4. When the current of the motor 3 increases and exceeds the preset current threshold, the control unit 1 can stop the motor 3. In addition, the motor 3 in the figure also uses an encoder 33; the encoder 33 is set on the motor 3 to detect the angular displacement of the rotor of the motor 3, record the rotor pulse count or the rotor starting position, and send this information to the control unit 1 for controlling the precise motor 3 to achieve precise angular displacement.

[0153] Figure 9 The principle structure and state of the light-curing 3D printing anti-pressure screen stall detection device of the present invention Figure 1 As shown in the figure, the Z-axis 31, LCD screen 11, UVLED light source module 12, and liquid tank 9 are fixed to the base 10; the bottom film 90 is set at the bottom of the liquid tank 9 for light transmission; the liquid tank 9 is used to hold the photosensitive resin 91 liquid; the motor 3 is installed on the Z-axis 31 to realize electric drive lifting and lowering, and drives the molding platform 32 to rise or fall with it;

[0154] Generally, after the last resin molding model 92 is printed, the molding platform 32 will remain stationary at the highest position, so it is necessary to manually demold and remove the resin molding model 92, and then issue a zeroing operation instruction to it to return it to the zero starting position; or after manually demolding and removing the resin molding model 92, a new printing instruction can be directly issued to it, and it will automatically return to the zero starting position first, and then start printing layer by layer. Therefore, when the molding platform 32 is descending, if the user forgets to remove the resin molding model 92 or there are solidified blocks left on the molding platform 32, it will easily squeeze the LCD screen 11 under the bottom film 90 during the descent process.

[0155] In addition, the limit detection module 7 in the figure can use electronic devices such as proximity switches, optical couplers, micro switches or touch buttons to realize the limit trigger function.

[0156] Figure 10 The principle structure and state of the light-curing 3D printing anti-pressure screen stall detection device of the present invention Figure 2 As shown in the figure, Figure 9 On the basis of this, if the user forgets to remove the resin molding model 92 or there are adhered solidified blocks left on the molding platform 32, when the molding platform 32 is descending, the resin molding model 92 will first touch the base film 90 and further squeeze downwards to the LCD screen 11 under the base film 90, causing it to break. At this time, the limit detection module 7 has not been triggered. Therefore, it is necessary to use the detection method and device of the present invention to determine whether the molding platform 32 is blocked from descending and whether it causes the motor 3 winding current to increase and exceed the preset current threshold to control the operation and stop of the motor 3, so as to avoid the molding platform 32 from squeezing the LCD screen 11 during the descent process.

[0157] Figure 11 This is a three-dimensional demonstration of the light-curing 3D printing anti-pressure screen stall detection device of the present invention. Figure 1 As shown in the figure, under normal circumstances, after the last resin molding model 92 is printed, the molding platform 32 will remain stationary at the highest position, so it is necessary to manually demold the resin molding model 92 and then issue a zeroing operation instruction to it to return it to the zero starting position; or after manually demolding the resin molding model 92, a new printing instruction can be directly issued to it, and it will automatically return to the zero starting position before starting to print layer by layer. Therefore, during the descent of the molding platform 32, if the user forgets to remove the resin molding model 92 or there are solidified blocks remaining on the molding platform 32, it will be easy to squeeze the LCD screen 11 under the bottom film 90 during the descent. In addition, the limit detection module 7 in the figure can use electronic devices such as proximity switches, optical couplers, micro switches or touch buttons to realize the limit trigger function.

[0158] Figure 12 This is a three-dimensional demonstration of the light-curing 3D printing anti-pressure screen stall detection device of the present invention. Figure 2As shown in the figure, if the user forgets to remove the resin molding model 92 or there are solidified blocks left adhering to the molding platform 32, the resin molding model 92 will first touch the base film 90 during the descent of the molding platform 32 and further squeeze the LCD screen 11 under the base film 90 downward, causing it to break. At this time, the limit detection module 7 has not been triggered. Therefore, it is necessary to use the detection method and device of the present invention to determine whether the descent of the molding platform 32 is blocked, causing the winding current of the motor 3 to increase and exceed the preset current threshold to control the operation and stop of the motor 3, so as to prevent the molding platform 32 from squeezing the LCD screen 11 during the descent.

[0159] The above embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A method for detecting stalling of a light-cured 3D printed pressure-resistant screen, characterized in that: The following steps are involved: SA01, the user sends an instruction to the control unit (1) via the display and operation unit (6) to reset the molding platform (32); SA02, the control unit (1) sends a control instruction to the door drive unit (2) to control the motor (3) through the full-bridge chopper unit (20) to drive the forming platform (32) to move downward along the Z axis (31); SA03, a current detection and comparison unit (4) obtains a sampling current of a ground terminal and / or an output terminal of a full-bridge chopper unit (20); SA04, the current detection and comparison unit (4) converts the analog signal of the sampled current into a digital signal and sends the digital current value to the control unit (1); SA05, the control unit (1) compares the digital current value with a preset current threshold and determines whether the digital current value is greater than the preset current threshold; if the digital current value is determined to be greater than the preset current threshold, step SA08 is performed; if the digital current value is determined to be not greater than the preset current threshold, step SA06 is performed; SA06, the motor (3) drives the forming platform (32) to move downward along the Z axis (31) until the limit detection module (7) is triggered and sends a limit trigger signal to the control unit (1); SA07, the control unit (1) uses the position of the molding platform (32) on the Z axis (31) corresponding to when the limit detection module (7) is triggered as a mark point to control the molding platform (32) to shift X millimeters to the zero starting position, and then proceeds to step SA09; SA08, the control unit (1) determines that the motor (3) has a stall fault, controls the motor (3) to stop running, and issues a warning signal through the abnormality prompt unit (8); SA09, process ends.

2. A method for detecting stalling of a light-curing 3D printed pressure-resistant screen, characterized in that: The following steps are involved: SB01, the user sends an instruction to the control unit (1) to reset the forming platform (32) via the display and operation unit (6); SB02, the control unit (1) sends a control instruction to the door drive unit (2) to control the motor (3) through the full-bridge chopper unit (20) to drive the forming platform (32) to move downward along the Z axis (31); SB03, a current detection comparison unit (4) obtains a sampling current at the output end and / or the ground end of the full-bridge chopper unit (20); SB04, the current detection and comparison unit (4) converts the analog signal of the sampled current into a digital signal and sends the digital current value to the control unit (1); SB05, the control unit (1) compares the digital current value with a preset current threshold and determines whether the digital current value is greater than the preset current threshold; If it is determined that the digital current value is greater than the preset current threshold, proceed to step SB10; if it is determined that the digital current value is not greater than the preset current threshold, proceed to step SB06; SB06, the motor drives the forming platform (32) to move downward along the Z axis (31) until the limit detection module (7) is triggered and sends a limit trigger signal to the control unit (1); SB07, the control unit (1) uses the position of the molding platform (32) on the Z axis (31) corresponding to when the limit detection module (7) is triggered as a mark point to control the molding platform (32) to shift X millimeters to the zero starting position; SB08, the user determines whether the current zero-start position needs to be corrected; if it is determined that the current zero-start position does not need to be corrected, proceed to step SB11; If it is determined that the current zero position needs to be corrected, proceed to step SB09; SB09, the user operates the display and operation unit (6) to make the motor (3) drive the forming platform (32) to lift or lower Y millimeters to the target position and then save it as the new zero starting position, and then proceed to step SB11; SB10, the control unit (1) determines that the motor (3) has a stall fault, controls the motor (3) to stop running, and issues a warning signal through the abnormality prompt unit (8); SB11, process ends.

3. A method for detecting stalling of a light-cured 3D printed pressure-resistant screen, characterized in that: The following steps are involved: SC01, the user imports the model printing slice file into the storage unit (5) of the light-curing printing device; SC02, the user sends a model slice file printing instruction to the control unit (1) through the display and operation unit (6); SC03, the control unit (1) sends a control instruction to the door drive unit (2) to control the motor (3) through the full-bridge chopper unit (20) to drive the forming platform (32) to move downward along the Z axis (31); SC04, a current detection and comparison unit (4) obtains a sampling current of a ground terminal and / or an output terminal of a full-bridge chopper unit (20); SC05, the current detection and comparison unit (4) converts the analog signal of the sampled current into a digital signal and sends the digital current value to the control unit (1); SC06, the control unit (1) compares the digital current value with a preset current threshold and determines whether the digital current value is greater than the preset current threshold; if the digital current value is determined to be greater than the preset current threshold, step SC10 is performed; if the digital current value is determined to be not greater than the preset current threshold, step SC07 is performed; SC07 and the motor (3) drive the forming platform (32) to move downward along the Z axis (31) until the limit detection module (7) is triggered and sends a limit trigger signal to the control unit (1); SC08, the control unit (1) uses the position of the molding platform (32) on the Z axis (31) corresponding to when the limit detection module (7) is triggered as a mark point to control the molding platform (32) to shift X millimeters to the zero starting position; SC09, the control unit (1) reads the model printing slice file in the storage unit (5) and performs light-curing printing on the model slice data layer by layer in sequence, and then proceeds to step SC11; After SC10 and the control unit (1) determine that the motor (3) has a stall fault, the control unit (1) controls the motor (3) to stop running and issues a warning signal through the abnormality prompt unit (8); SC11, process ends.

4. A method for detecting stalling of a light-curing 3D printed pressure-resistant screen, characterized in that: The following steps are involved: SD01, the user imports the model printing slice file into the storage unit (5) of the light-curing printing device and sends a printing instruction to the control unit (1) through the display and operation unit (6); SD02, the control unit (1) controls and drives the motor (3) to drive the forming platform (32) to complete zeroing; SD03, the control unit (1) reads the model printing slice file in the storage unit (5) and performs light-curing printing on the model slice data layer by layer in sequence; SD04, the control unit (1) sends a control instruction to the door drive unit (2) to control the motor (3) through the full-bridge chopper unit (20) to drive the forming platform (32) to move or stop along the Z axis (31); SD05, a current detection and comparison unit (4) obtains a sampling current at the ground terminal and / or output terminal of the full-bridge chopper unit (20); SD06, the current detection and comparison unit (4) converts the analog signal of the sampled current into a digital signal and sends the digital current value to the control unit (1); SD07, the control unit (1) determines whether the molding platform (32) is in a downward state; if it is determined that the molding platform (32) is not in a downward state, step SD09 is performed; if it is determined that the molding platform (32) is in a downward state, step SD08 is performed; SD08, the control unit (1) compares the digital current value with a preset current threshold and determines whether the digital current value is greater than the preset current threshold; if the digital current value is determined to be greater than the preset current threshold, the step SD11 is performed; if the digital current value is determined to be not greater than the preset current threshold, the step SD09 is performed; SD09 and the motor (3) drive the forming platform (32) to continue moving along the Z axis (31) until it reaches the target position; SD10: All the slice data of the layers in the model printing slice file are all cured by light. The next step is step SD12. SD11, the control unit (1) determines that the motor (3) has a stall fault, controls the motor (3) to stop running, and issues a warning signal through the abnormal prompt unit (8); SD12, the process ends.

5. A method for detecting stalling of a light-cured 3D printed anti-pressure screen according to any one of claims 1 to 3, characterized in that: In the steps SA06, SB06, and SC07, the motor (3) drives the forming platform (32) to trigger the limit detection module (7) in a manner including electromagnetic induction triggering, photoelectric induction triggering, or direct touch pressure triggering.

6. A method for detecting stalling of a light-cured 3D printed pressure-resistant screen according to any one of claims 1 to 4, characterized in that: In the steps SA03, SB03, SC04, and SD05, the current detection comparison unit (4) obtains the sampling current of the ground terminal and / or the output terminal of the full-bridge chopper unit (20) by directly inputting the sampling current or collecting the sampling current by current sensing detection; in the steps SA05, SB05, SC06, and SD08, the preset current threshold is a fixed current value, a dynamic follow-up ratio value of the minimum drive current, or a dynamic follow-up ratio value of the maximum drive current.

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