High-precision four-axis 3D printing device

Abstract

This invention discloses a high-precision four-axis 3D printing device, comprising a housing and a print head disposed within the housing and moved by a drive structure. The drive structure has the functions of reducing the rotation angle and improving accuracy through bidirectional subtraction. In this application, when the stepper motor outputs power, it is output to a rotating disk after speed change via a drive gear and a first transmission gear. When the adjustment motor on the rotating disk is locked, it drives the output shaft and the rotating disk to rotate synchronously. When accuracy adjustment is required, the locking state of the adjustment motor is released, and reverse power is output from one of the adjustment motors. This adjustment motor and the output shaft undergo secondary speed change via a set of gears, rotating a certain angle in the forward direction and then rotating another angle. Through forward and reverse rotation and two speed changes, the angle value is reduced, and a smaller angle is obtained through subtraction. The minimum value of this angle is the minimum accuracy. This hardware improvement effectively enhances the adjustment accuracy of the drive structure.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing equipment technology, and in particular to high-precision four-axis 3D printing equipment. Background Technology

[0002] 3D printing (3DP), also known as additive manufacturing technology [1] Additive Manufacturing Technologies (AM) is a technology that manufactures solid parts by adding materials layer by layer based on 3D CAD data.

[0003] During printing, the print head needs to move, requiring a multi-axis drive structure. Currently, the drive typically uses a transmission structure consisting of a motor and a synchronous belt. Since 3D printing has high precision requirements, stepper motors are needed to improve precision during motor drive. However, stepper motors are limited by the number of steps; for example, a 200-step motor can only achieve a precision of 1.8 degrees, which is often insufficient. Although stepper motors can be subdivided, this subdivision increases control complexity, makes the system difficult to match, and reduces stability. Therefore, subdivision from a hardware perspective has become a preferred solution to improve precision. Summary of the Invention

[0004] This invention addresses the problem of low precision in driven structures in the prior art. The technical problem to be solved by this invention is to provide a high-precision four-axis 3D printing device.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0006] High-precision four-axis 3D printing equipment, including a housing, the housing containing:

[0007] A lead screw lifting mechanism with a printing worktable that moves up and down with it;

[0008] Synchronous belt translation mechanism, which is used to provide forward and backward and left and right movement;

[0009] The print head is mounted on a synchronous belt translation mechanism and moves horizontally by the mechanism.

[0010] The synchronous belt translation mechanism includes two sets of high-precision drive mechanisms, one for forward / backward movement and the other for left / right movement. The high-precision drive mechanisms include:

[0011] A drive motor, the output end of which is equipped with a drive gear;

[0012] The transmission box has the output shaft of the drive motor extending into it and the drive gear located inside it.

[0013] A first transmission gear meshes with a drive gear, and a first transmission shaft is provided on the first transmission shaft, which is provided with a rotating disk.

[0014] The regulating motor, which has at least two motors and has a coding self-locking function, is set on a rotating disk. Its output end rotates through the rotating disk and is connected to a second transmission gear.

[0015] The output shaft rotates through the transmission box, and a third transmission gear is provided at its inner end. The third transmission gear meshes with each of the second transmission gears simultaneously. The transmission ratio of each set of meshing second transmission gears and third transmission gears is different. A drive pulley is provided at its outer end.

[0016] The drive motor is a stepper motor. When driving, let the transmission ratio between the drive gear and the first transmission gear be a / b, and the transmission ratio between the second transmission gear and the third transmission gear be c / d. The required rotation angle is C=K(Na / b-Mc / d), where N and M represent the degree of rotation of the drive motor and the regulating motor, and N=360e / f, where e is the number of steps and 360 / f is the step angle of the drive motor.

[0017] Preferably, the drive motor and the regulating motor are driven based on an integer number of revolutions, then C = 360ea / bf - Mc / d.

[0018] Preferably, the front of the box is a protective door with a transparent panel, and the inner wall of the rear side of the box is equipped with a screw mechanism. The output end of the screw mechanism is equipped with a printing platform, which is driven by the screw mechanism to rise and fall.

[0019] Preferably, the housing is provided with a front-to-back first slide rail and a left-to-right second slide rail. The first slide rail is fixed to the housing. A first slide block is slidably mounted on the first slide rail and a first synchronous belt is mounted on the first slide block. The second slide rail is mounted on the first slide block. A second slide block is slidably mounted on the second slide rail and a second synchronous belt is mounted on the second slide block. The first and second synchronous belts are driven by different drive pulleys. The print head is mounted on the second slide block.

[0020] Preferably, a first slide rail is provided on each of the left and right sides, and a first slide block is provided on each of the first slide rails on the left and right sides. The two first slide blocks are driven by two first synchronous belts, and a connecting shaft with two pulleys is provided between the two first synchronous belts. Two second slide rails are provided, and they are driven by a second synchronous belt.

[0021] Preferably, both the first and second synchronous belts are annular structures, and the annular structure has an upper belt body and a lower belt body. The upper belt body is locked onto the first and second slides, and both the first and second slides are provided with a tensioning structure for tensioning the lower belt body.

[0022] As a preferred embodiment, the tensioning structure includes:

[0023] A hinged seat, which is fixed to the first slide and the second slide;

[0024] A swing frame, which is rotatably mounted on a hinged seat and has an angle of less than or equal to 90 degrees with the vertical direction;

[0025] The lower pulley is rotatably mounted at the bottom of the swing frame and presses against the lower belt body;

[0026] A telescopic adjustment device, which is fixed on the first slide and the second slide, and whose output end abuts against or is connected to the swing frame by a pull rope;

[0027] The telescopic adjustment device pushes the swing frame to rotate, thereby adjusting the pressure of the lower pulley to tension the corresponding synchronous belt.

[0028] Preferably, the tensioning structure is provided in two sets, with a feedback mechanism in the middle of the two sets. The feedback mechanism includes a gas spring vertically slidably mounted on the first and second slides, an auxiliary pulley mounted at the bottom of the gas spring, and an electronic pressure gauge mounted on the first and second slides. The electronic pressure gauge is connected to a controller, which is connected to a telescopic adjustment device. The auxiliary pulley presses against the lower belt body, and the two lower pulleys and the auxiliary pulley form a triangular support tensioning structure. When the synchronous belt wears and loosens, the auxiliary pulley automatically tightens, causing the pressure of the electronic pressure gauge to decrease, and a feedback signal is sent to the controller. The controller controls the telescopic adjustment device to extend and retract to adjust the tension of the two lower pulleys. After adjustment, the adjustment stops when the pressure of the electronic pressure gauge returns to the preset threshold range.

[0029] Compared with the prior art, the present invention has the following advantages: In this application, when the stepper motor outputs power, it is output to the rotating disk after speed change through the drive gear and the first transmission gear. When the adjustment motor on the rotating disk is locked, it drives the output shaft and the rotating disk to rotate synchronously. When the adjustment accuracy is required, the locked state of the adjustment motor is released, and reverse power is output on one of the adjustment motors. The adjustment motor and the output shaft are connected by a set of gears for secondary speed change. It rotates forward by a certain angle and then rotates to another angle. By rotating forward and backward and changing speed twice, the angle value is reduced and a smaller angle is obtained by subtraction. The minimum value of this angle is the minimum accuracy. The adjustment accuracy of the drive structure is effectively improved by hardware improvement. Attached Figure Description

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments. However, those skilled in the art will understand that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be regarded as a limitation on the scope of the present invention. In addition, unless specifically indicated, the drawings are only schematic representations of the composition or structure of the described objects and may contain exaggerated displays, and the drawings are not necessarily drawn to scale.

[0031] Figure 1 This is the front view of this application;

[0032] Figure 2 and Figure 3 This is a perspective view of the present application;

[0033] Figure 4 A 3D view of a high-precision drive mechanism;

[0034] Figure 5 This is a perspective view of the present application (at the transmission box).

[0035] Figure 6 for Figure 5 Enlarged view of point A (inside the transmission box);

[0036] Figure 7 This is the main view at the second synchronization zone;

[0037] Figure 8 This is a 3D view of the second synchronous band.

[0038] In the diagram: 10. Housing; 201. Transmission box; 202. Drive motor; 2020. Rotating disk; 2021. Drive gear; 2022. First transmission gear; 2023; 2024. First transmission shaft; 2025. Third transmission gear; 2026. Second transmission gear; 2027. Output shaft; 2028. Drive pulley; 203. Second slide; 204. Connecting shaft; 205. First slide; 206. First synchronous belt; 207. Second synchronous belt; 2071. Upper belt body; 2072. Lower belt body; 208. Tensioning structure; 2081. Lower pressure pulley; 2082. Auxiliary pulley; 2083. Gas spring; 2084. Telescopic adjustment device; 30. Lead screw mechanism; 40. Worktable; 50. Printing nozzle. Detailed Implementation

[0039] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are merely descriptive and exemplary and should not be construed as limiting the scope of protection of the present invention.

[0040] It should be noted that similar labels in the following figures indicate similar items; therefore, once an item is defined in one figure, it may not be further defined and explained in subsequent figures. Example

[0041] This embodiment mainly describes the title of the high-precision four-axis 3D printing equipment, as follows:

[0042] like Figure 1-8 As shown, the high-precision four-axis 3D printing equipment includes a housing 10, and the housing 10 contains:

[0043] A lead screw lifting mechanism 30 is provided on which a printing worktable 40 is raised and lowered in tandem;

[0044] Synchronous belt translation mechanism, which is used to provide forward and backward and left and right movement;

[0045] The print head 50 is mounted on a synchronous belt translation mechanism and moves horizontally by the mechanism.

[0046] The synchronous belt translation mechanism includes two sets of high-precision drive mechanisms, one for forward / backward movement and the other for left / right movement. The high-precision drive mechanisms include:

[0047] The drive motor 202 has a drive gear 2021 at its output end;

[0048] The transmission box 201 has the output shaft of the drive motor 202 extending into it and the drive gear 2021 located inside it;

[0049] The first transmission gear 2022 meshes with the drive gear 2021, and is provided with a first transmission shaft 2024 and a rotating disk 2020 is provided on the first transmission shaft 2024.

[0050] An adjustment motor, of which at least two are provided and which have a coding self-locking function, is set on a rotating disk 2020, and its output end rotates through the rotating disk 2020 and is connected to a second transmission gear 2026;

[0051] The output shaft 2027 rotates through the transmission box 201. The inner end of the shaft is provided with a third transmission gear 2025. The third transmission gear 2025 meshes with each of the second transmission gears 2026 simultaneously. The transmission ratio between each set of meshing second transmission gears 2026 and third transmission gears 2025 is different. The outer end of the shaft is provided with a drive pulley 2028.

[0052] The drive motor 202 is a stepper motor. When driving, the transmission ratio between the drive gear 2021 and the first transmission gear 2022 is a / b, and the transmission ratio between the second transmission gear 2026 and the third transmission gear 2025 is c / d. The required rotation angle is C=K(Na / b-Mc / d), where N and M represent the degree of rotation of the drive motor 202 and the regulating motor, and N=360e / f, where e is the number of steps and 360 / f is the step angle of the drive motor 202. In this design, when the stepper motor outputs power, it is transmitted to the rotating disk 2020 after speed change via the drive gear 2021 and the first transmission gear 2022. When the adjusting motor on the rotating disk 2020 is locked, it drives the output shaft 2027 and the rotating disk 2020 to rotate synchronously. When adjustment accuracy is required, the locking state of the adjusting motor is released, and reverse power is output to one of the adjusting motors. This adjusting motor and the output shaft 2027 undergo secondary speed change via a set of gears, rotating a certain angle in the forward direction and then rotating another angle. By rotating in both directions and changing speed twice, the angle value is reduced, and a smaller angle is obtained by subtraction. The minimum value of this angle is the minimum accuracy. The hardware improvement effectively improves the adjustment accuracy of the drive structure. When the adjusting motor is also set as a stepper motor, locking is achieved through a power-on self-locking function, and its accuracy can be further optimized.

[0053] Preferably, the drive motor 202 and the regulating motor are driven based on an integer number of revolutions, then C = 360ea / bf - Mc / d. It should be noted that this solution, due to the use of gear transmission, can achieve high driving accuracy even with integer number of revolutions. For example, if the transmission ratios are 1 / 19 and 1 / 20, the minimum accuracy is 360(1 / 19 - 1 / 20) = 18 / 19 degrees. This is because for a motor, the smaller the rotation angle, the more difficult it is to control, while a full rotation significantly reduces the difficulty of control.

[0054] Preferably, the front of the housing 10 is a protective door with a transparent panel, and the inner wall of the rear side of the housing 10 is provided with a lead screw mechanism 30. The output end of the lead screw mechanism 30 is provided with a printing platform 40, which is driven by the lead screw mechanism 30 to rise and fall.

[0055] Preferably, the housing 10 has a front-to-back first slide rail and a left-to-right second slide rail. The first slide rail is fixed to the housing 10, and a first slide block 205 is slidably mounted on the first slide rail, with a first synchronous belt 206 mounted on the first slide block 205. The second slide rail is mounted on the first slide block 205, and a second slide block 203 is slidably mounted on the second slide block 203, with a second synchronous belt 207 mounted on the second slide block 203. The first synchronous belt 206 and the second synchronous belt 207 are driven by different drive pulleys 2028. The print head 50 is mounted on the second slide block 203. One transmission box 201 is fixed to the left side of the housing 10, and the other transmission box 201 is slidably mounted on the right side of the housing 10, with the right-side transmission box 201 fixedly connected to the first slide block 205. The housing 10 has a strip-shaped opening for the second transmission belt to move back and forth with the second transmission box 201 and the first slide block 205.

[0056] Preferably, a first slide rail is provided on each of the left and right sides, and a first slide block 205 is provided on each of the first slide rails on the left and right sides. The two first slide blocks 205 are driven by two first synchronous belts 206, and a connecting shaft 204 with two pulleys is provided between the two first synchronous belts 206. Two second slide rails are provided and are driven by a second synchronous belt 207.

[0057] Preferably, both the first synchronous belt 206 and the second synchronous belt 207 are annular structures, and the annular structure has an upper belt body 2071 and a lower belt body 2072. The upper belt body 2071 is fixed by being engaged with the first slide block 205 and the second slide block 203. Both the first slide block 205 and the second slide block 203 are provided with a tensioning structure 208 for tensioning the lower belt body 2072.

[0058] Preferably, the tensioning structure 208 includes:

[0059] The hinged seat is fixed to the first slide 205 and the second slide 203;

[0060] A swing frame, which is rotatably mounted on a hinged seat and has an angle of less than or equal to 90 degrees with the vertical direction;

[0061] The lower pulley 2081 is rotatably mounted at the bottom of the swing frame and presses against the lower belt body 2072. It also includes a limiting frame with an arc-shaped hole. The axle of the lower pulley 2081 extends into the arc-shaped hole and is restricted from rotating.

[0062] The telescopic adjustment device 2084 is fixed on the first slide 205 and the second slide 203 and its output end abuts against or is connected to the swing frame by a pull rope. It is a cylinder or an electric push rod.

[0063] The telescopic adjustment device 2084 pushes the swing frame to rotate, thereby adjusting the pressure of the pressure pulley 2081 to tension the corresponding synchronous belt. After use, the synchronous belt may become loose, leading to vibration, shaking, and backlash. Backlash can cause the print head or heated bed to not move immediately during startup, shutdown, and reversal due to belt slack, resulting in a deviation between actual and theoretical movement. By combining the synchronous belt's meshing structure with the belt tensioning drive and setting the tensioning structure 208 for automatic compensation tensioning during use, problems caused by vibration, shaking, and backlash can be avoided.

[0064] Preferably, the tensioning structure 208 is provided in two sets, with a feedback mechanism in the middle of the two sets. The feedback mechanism includes a gas spring 2083 vertically slidably mounted on the first slide 205 and the second slide 203, an auxiliary pulley 2082 mounted on the bottom of the gas spring 2083, and an electronic pressure gauge mounted on the first slide 205 and the second slide 203. The electronic pressure gauge is connected to a controller, which is connected to a telescopic adjustment device 2084. The auxiliary pulley 2082 presses against the lower belt body 2072. The two lower pulleys 2081 and the auxiliary pulley 2082 form a triangular support tensioning structure. When the synchronous belt wears and loosens, the auxiliary pulley 2082 automatically tightens, causing the pressure of the electronic pressure gauge to decrease, and a feedback signal is sent to the controller. The controller controls the telescopic adjustment device 2084 to telescopically adjust the tension of the two lower pulleys 2081. After adjustment, the adjustment stops when the pressure of the electronic pressure gauge returns to the preset threshold range. This solution achieves synchronous belt tensioning through a triangular support tensioning structure. During tensioning, if wear occurs in the synchronous belt, leading to a decrease in pressure from the feedback mechanism, the pressure at the electronic pressure gauge is increased by adjusting the tension amplitude of the two lower pulleys 2081 according to the pressure value change, until a preset threshold is reached. To improve the tensioning effect, the synchronous belt is configured as follows: the central part of the synchronous belt has tapered teeth, while the two sides are protruding flat surfaces, with the flat surfaces having weaker wear resistance than the central teeth. The pulleys have a central protruding structure with tooth grooves, while the two sides are flat or textured structures. When the two sides of the pulley are in contact with the flat surfaces, the teeth extend into the tooth grooves. Before and after wear, the teeth and tooth grooves can always match each other. This solution transmits power through the friction on the outer side and the meshing of the central teeth and tooth grooves. When wear occurs on the two sides, compensation is performed. The compensation and the redundancy of the teeth extending into the tooth grooves work together to reduce transmission errors caused by wear.

[0065] In the description of this invention, it should be noted that the terms "upper," "lower," "front," "rear," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed when in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

Claims

1. High-precision four-axis 3D printing equipment, including a housing, the housing containing: A lead screw lifting mechanism with a printing worktable that moves up and down with it; Synchronous belt translation mechanism, which is used to provide forward and backward and left and right movement; The print head is mounted on a synchronous belt translation mechanism and moves horizontally by the mechanism. Its features are, The synchronous belt translation mechanism includes two sets of high-precision drive mechanisms, one for forward / backward movement and the other for left / right movement. The high-precision drive mechanisms include: A drive motor, the output end of which is equipped with a drive gear; The transmission box has the output shaft of the drive motor extending into it and the drive gear located inside it. A first transmission gear meshes with a drive gear, and a first transmission shaft is provided on the first transmission shaft, which is provided with a rotating disk. The regulating motor, which has at least two motors and has a coding self-locking function, is set on a rotating disk. Its output end rotates through the rotating disk and is connected to a second transmission gear. The output shaft rotates through the transmission box, and a third transmission gear is provided at its inner end. The third transmission gear meshes with each of the second transmission gears simultaneously. The transmission ratio of each set of meshing second transmission gears and third transmission gears is different. A drive pulley is provided at its outer end. The drive motor is a stepper motor. When driving, let the transmission ratio between the drive gear and the first transmission gear be a / b, and the transmission ratio between the second transmission gear and the third transmission gear be c / d. The required rotation angle is C=K(Na / b-Mc / d), where N and M represent the degree of rotation of the drive motor and the regulating motor, and N=360e / f, where e is the number of steps and 360 / f is the step angle of the drive motor. The housing contains a front-to-back first slide rail and a left-to-right second slide rail. The first slide rail is fixed to the housing. A first slide block slides on the first slide rail and a first synchronous belt is mounted on the first slide block. The second slide rail is mounted on the first slide block, and a second slide block slides on the second slide rail and a second synchronous belt is mounted on the second slide block. The first and second synchronous belts are driven by different drive pulleys. The print head is mounted on the second slide block. There is one first slide rail on each of the left and right sides, and a first slide block is mounted on each of the left and right first slide rails. The two first slide blocks are driven by two first synchronous belts, and a connecting shaft with two pulleys is positioned between the two first synchronous belts. There are two second slide rails, each driven by a second synchronous belt. Both the first and second synchronous belts are annular structures with an upper belt body and a lower belt body. The upper belt body is engaged with the first and second slide blocks. Both the first and second slide blocks have tensioning structures for tensioning the lower belt body. The tensioning structures include: A hinged seat, which is fixed to the first slide and the second slide; A swing frame, which is rotatably mounted on a hinged seat and has an angle of less than or equal to 90 degrees with the vertical direction; The lower pulley is rotatably mounted at the bottom of the swing frame and presses against the lower belt body; A telescopic adjustment device, which is fixed on the first slide and the second slide, and whose output end abuts against or is connected to the swing frame by a pull rope; The telescopic adjustment device pushes the swing frame to rotate, thereby adjusting the pressure of the lower pulley to tension the corresponding synchronous belt.

2. The high-precision four-axis 3D printing equipment according to claim 1, characterized in that, The drive motor and the regulating motor are driven based on integer revolutions, so C = 360ea / bf - Mc / d.

3. The high-precision four-axis 3D printing equipment according to claim 1, characterized in that, The front of the box has a protective door with a transparent panel, and the inner wall of the rear of the box is equipped with a lead screw mechanism. The output end of the lead screw mechanism is equipped with a printing platform, which is driven by the lead screw mechanism to rise and fall.

4. The high-precision four-axis 3D printing equipment according to claim 1, characterized in that, The tensioning structure has two sets, with a feedback mechanism in the middle of each set. The feedback mechanism includes a gas spring vertically sliding on the first and second slides, an auxiliary pulley at the bottom of the gas spring, and an electronic pressure gauge on the first and second slides. The electronic pressure gauge is connected to a controller, which is connected to a telescopic adjustment device. The auxiliary pulley presses against the lower belt, and the two lower pulleys and the auxiliary pulley form a triangular support tensioning structure. When the synchronous belt wears and loosens, the auxiliary pulley automatically tensions, causing the pressure of the electronic pressure gauge to decrease, and a feedback signal is sent to the controller. The controller controls the telescopic adjustment device to adjust the tension of the two lower pulleys. After adjustment, the adjustment stops when the pressure of the electronic pressure gauge returns to the preset threshold range.

5. The high-precision four-axis 3D printing equipment according to claim 4, characterized in that, The synchronous belt has tapered teeth in the middle and protruding flat surfaces on both sides. The wear resistance of the flat surfaces is weaker than that of the teeth in the middle. Each pulley that mates with the synchronous belt has a raised structure in the middle and tooth grooves, and flat or textured structures on both sides. When the sides of the pulley are in contact with the flat surfaces, the teeth extend into the tooth grooves. When wear occurs, the teeth and tooth grooves can always match each other.

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