High-precision four-axis 3D printing equipment

Abstract

The high-precision four-axis 3D printing equipment comprises a box body and a printing head which is arranged in the box body and is driven by a driving structure to move, and the driving structure has the functions of reducing the rotating angle and improving the precision through bidirectional subtraction. When a stepping motor outputs power, the power is changed through a driving gear and a first transmission gear and then is output to a rotating disc, an adjusting motor on the rotating disc drives an output shaft and the rotating disc to rotate synchronously in a locked state, and when precision needs to be adjusted, the locked state of the adjusting motor is unlocked; reverse power is output on one adjusting motor, secondary speed change is carried out between the adjusting motor and the output shaft through a set of gears, the adjusting motor rotates by a certain angle in the forward direction and then rotates by another angle, the angle value is reduced through forward and reverse rotation and two times of speed change, and a smaller angle is obtained through subtraction. The minimum value of the angle is the minimum precision, and the adjustment precision of the driving structure is effectively improved through hardware improvement.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of additive manufacturing equipment manufacturing technology, in particular to a high-precision four-axis 3D printing device. BACKGROUND

[0002] 3D printing (3DP) is also called additive manufacturing technology (Additive Manufacturing Technologies, AM), which is a technology for manufacturing solid parts by layer-by-layer material accumulation according to three-dimensional CAD data. [1]

[0003] When printing, the print head needs to move, so a multi-axis drive structure is needed. Currently, a transmission structure composed of a motor and a synchronous belt is used to drive. Since 3D printing has high precision requirements, if the precision needs to be improved during motor driving, a stepper motor needs to be used. However, the precision of a 200-step motor can only reach 1.8 degrees, which often cannot meet the requirements. Although the stepper motor can be subdivided, subdivision will lead to increased control complexity, system difficulty in matching, and poor stability, so subdivision from the hardware aspect is an optimal solution to improve precision. SUMMARY

[0004] The present application aims to solve the problem of low precision of the background technology drive structure, and the technical problem to be solved by the present application is to provide a high-precision four-axis 3D printing device.

[0005] The technical scheme adopted by the present application to solve the above technical problem is: The high-precision four-axis 3D printing device comprises a box body, and the box body is provided with: a screw lifting mechanism, a printing workbench following the lifting of the screw lifting mechanism is arranged on the screw lifting mechanism; a synchronous belt translation mechanism for providing forward and backward movement and left and right movement; a printing nozzle arranged on the synchronous belt translation mechanism and moved in the horizontal direction by the synchronous belt translation mechanism; The synchronous belt translation mechanism comprises two sets of high-precision drive mechanisms used as drive sources for forward and backward movement and left and right movement, and the high-precision drive mechanism comprises: a drive motor, the output end of the drive motor is provided with a drive gear; a transmission box, the output shaft of the drive motor extends into the transmission box, and the drive gear is located in the transmission box; a first transmission gear meshing with the drive gear, a first transmission shaft is arranged on the first transmission gear, and a rotating disc is arranged on the first transmission shaft; adjusting motors, at least two adjusting motors are arranged, the adjusting motors have a coding self-locking function, the adjusting motors are arranged on the rotating disc, the output ends of the adjusting motors rotate through the rotating disc and are connected with second transmission gears;​ an output shaft, which is rotatable through the transmission box, has a third transmission gear at its inner end, and has a driving pulley at its outer end, wherein the third transmission gear is simultaneously engaged with each second transmission gear, and the transmission ratio of each set of engaged second transmission gear and third transmission gear is different; wherein the driving motor is a stepping motor, and when driving, the transmission ratio of the driving gear and the first transmission gear is a / b, the transmission ratio of the second transmission gear and the third transmission gear is c / d, and the required rotation angle is C=K(Na / b-Mc / d), wherein N and M represent the degrees of rotation of the driving motor and the adjusting motor, and N=360e / f, e is the number of steps, and 360 / f is the step angle of the driving motor.

[0006] Preferably, the driving of the driving motor and the adjusting motor is based on an integer number of turns, and C=360ea / bf-Mc / d.

[0007] Preferably, the front side of the box body is a protective door with a transparent plate, and a screw mechanism is arranged at the inner wall of the rear side of the box body, and a printing platform is arranged at the output end of the screw mechanism and is driven by the screw mechanism to ascend and descend.

[0008] Preferably, the box body is provided with a first slide rail in the front-rear direction and a second slide rail in the left-right direction, the first slide rail is fixed to the box body, a first slide seat is slidably arranged on the first slide rail and a first synchronous belt is arranged on the first slide seat, the second slide rail is arranged on the first slide seat, a second slide seat is slidably arranged on the second slide rail and a second synchronous belt is arranged on the second slide seat, the first synchronous belt and the second synchronous belt are driven by different driving pulleys, and the printing nozzle is arranged on the second slide seat.

[0009] Preferably, one first slide rail is arranged on each of the left side and the right side, one first slide seat is arranged on each of the first slide rails on the left side and the right side, the two first slide seats are driven by two first synchronous belts, and a connecting shaft with two pulleys is arranged between the two first synchronous belts; and two second slide rails are arranged and are driven by a second synchronous belt.

[0010] Preferably, the first synchronous belt and the second synchronous belt are both annular structures, the annular structure has an upper belt body and a lower belt body, the upper belt body is clamped on the first slide seat and the second slide seat, and the first slide seat and the second slide seat are both provided with a tensioning structure for tensioning the lower belt body.

[0011] Preferably, the tensioning structure comprises: a hinged seat, which is fixed to the first slide seat and the second slide seat; a swing frame, which is rotatably arranged on the hinged seat and has an angle of less than or equal to 90 degrees with the vertical direction; a lower pressing pulley, which is rotatably arranged at the bottom end of the swing frame and presses on the lower belt body; The telescopic adjusting device is fixed on the first slide and the second slide and the output end thereof abuts against or is connected to the swing frame through a pull rope; The telescopic adjusting device drives the swing frame to rotate so as to adjust the pressing degree of the pressing pulleys and to tension the corresponding synchronous belts.

[0012] As preferred, the tensioning structure is provided with two groups, the middle parts of the two groups are provided with feedback mechanisms, the feedback mechanisms comprise air springs vertically slidingly arranged on the first slide and the second slide, auxiliary pulleys arranged at the bottom ends of the air springs and electronic pressure gauges arranged on the first slide and the second slide, the electronic pressure gauges are connected with a controller, the controller is connected with the telescopic adjusting device, wherein the auxiliary pulleys press on the lower belt bodies, the two pressing pulleys and the auxiliary pulleys form a triangular support tensioning structure, when the synchronous belts are worn and loose, the auxiliary pulleys are automatically tensioned to cause the pressure of the electronic pressure gauges to be small, and a feedback signal is fed back to the controller, the controller controls the telescopic adjusting device to adjust the tensioning range of the two pressing pulleys, and after the adjustment, the pressure of the electronic pressure gauges is restored to the preset threshold range, and the adjustment is stopped.

[0013] Compared with the prior art, the application has the following advantages: in the application, when the stepping motor outputs power, the power is output to the rotating disc after speed change through the driving gear and the first transmission gear, when the adjusting motor is locked, the output shaft and the rotating disc are driven to rotate synchronously, when the adjustment precision is required, the locked state of the adjusting motor is released, and reverse power is output on one of the adjusting motors, the adjusting motor and the output shaft are connected through a set of gears for secondary speed change, rotate a certain angle in the positive direction and then rotate another angle, the angle value is reduced through positive and reverse rotation and twice speed change, and a smaller angle is obtained through subtraction, the minimum value of the angle is the minimum precision, and the adjustment precision of the driving structure is effectively improved through the improvement of the hardware. BRIEF DESCRIPTION OF DRAWINGS

[0014] The application will be described in further detail below with reference to the drawings and preferred embodiments, but those skilled in the art will appreciate that the drawings are only drawn for the purpose of explaining the preferred embodiments and therefore should not be regarded as limiting the scope of the application, and in addition, unless specifically indicated, the drawings only schematically represent the composition or structure of the described objects and can include exaggerated display, and the drawings are not necessarily drawn to scale.

[0015] Figure 1 is a front view of the application; Figure 2 and Figure 3 is a perspective view of the application; Figure 4 is a perspective view of the high-precision driving mechanism; Figure 5 is a perspective view of the application (at the transmission box); Figure 6 For Figure 5 Enlarged view at A (inside the transmission box); Figure 7 For front view at the second synchronous belt; Figure 8 For perspective view at the second synchronous belt; In the figure: 10, box; 201, transmission box; 202, drive motor; 2020, rotating disc; 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 sliding seat; 204, coupling shaft; 205, first sliding seat; 206, first synchronous belt; 207, second synchronous belt; 2071, upper belt body; 2072, lower belt body; 208, tensioning structure; 2081, lower pressing pulley; 2082, auxiliary pulley; 2083, gas spring; 2084, telescopic adjusting device; 30, screw rod mechanism; 40, workbench; 50, printing nozzle. DETAILED DESCRIPTION

[0016] The preferred embodiments of the present application will be described in detail below with reference to the attached drawings, which should be considered in conjunction with the description below, and those skilled in the art will appreciate that these descriptions are merely illustrative and exemplary, and should not be construed as limiting the scope of protection of the present application.

[0017] It should be noted that similar reference numerals represent similar items in the following drawings, so once an item is defined in one drawing, it may not be further defined and explained in subsequent drawings. EMBODIMENT

[0018] This embodiment mainly describes the title of the high-precision four-axis 3D printing equipment, which is as follows: As Figures 1-8 shown, the high-precision four-axis 3D printing equipment includes a box 10, which is provided with: A screw rod lifting mechanism 30, which is provided with a printing workbench 40 that follows the lifting thereof; A synchronous belt translation mechanism, which is used to provide forward and backward movement and left and right movement; A printing nozzle 50, which is arranged on the synchronous belt translation mechanism and moves in the horizontal direction by being driven thereby; The synchronous belt translation mechanism includes two sets of high-precision driving mechanisms that are used as driving sources for forward and backward movement and left and right movement, respectively, and the high-precision driving mechanism includes: A drive motor 202, which is provided with a drive gear 2021 at the output end thereof; The transmission box 201, the output shaft of the driving motor 202 extends into its interior and the driving gear 2021 is located inside it; The first transmission gear 2022 is engaged with the driving gear 2021, the first transmission shaft 2024 is arranged on it and the rotating disc 2020 is arranged on the first transmission shaft 2024; The adjusting motor is arranged at least in two and has a coding self-locking function, is arranged on the rotating disc 2020, the output end of which rotates through the rotating disc 2020 and is connected with the second transmission gear 2026; The output shaft 2027 rotates through the transmission box 201, the third transmission gear 2025 is arranged at the inner end of the output shaft 2027, the transmission ratio of each second transmission gear 2026 and the third transmission gear 2025 is different, and the driving pulley 2028 is arranged at the outer end of the output shaft 2027; The driving motor 202 is a stepping motor, when driving, the transmission ratio of the driving gear 2021 and the first transmission gear 2022 is a / b, the transmission ratio of the second transmission gear 2026 and the third transmission gear 2025 is c / d, and the required rotation angle is C=K(Na / b-Mc / d), wherein N and M represent the degrees of rotation of the driving motor 202 and the adjusting motor, wherein N=360e / f, e is the number of steps, and 360 / f is the step angle of the driving motor 202. In this scheme, when the stepping motor outputs power, the power is output to the rotating disc 2020 after speed change through the driving gear 2021 and the first transmission gear 2022, the output shaft 2027 and the rotating disc 2020 rotate synchronously when the adjusting motor on the rotating disc 2020 is in a locked state, when the precision needs to be adjusted, the locked state of the adjusting motor is released, and the adjusting motor outputs reverse power, the adjusting motor and the output shaft 2027 are connected through a set of gears for secondary speed change, rotate a certain angle in the positive direction and then rotate another angle, the angle value is reduced through positive and negative rotation and two times of speed change, and a smaller angle is obtained through subtraction, the minimum value of the angle is the minimum precision, and the adjustment precision of the driving structure is effectively improved through hardware improvement. When the adjusting motor is also a stepping motor, locking is achieved through energization self-locking, and the precision can be further optimized.

[0019] As preferred, the driving of the driving motor 202 and the adjusting motor is based on an integer number of turns, and C=360ea / bf-Mc / d. It should be noted that, due to the gear transmission speed change, even if the driving is carried out through an integer number of turns, higher driving precision can be achieved, for example, the transmission ratios are 1 / 19 and 1 / 20 respectively, and the minimum precision is 360(1 / 19-1 / 20)=18 / 19 degrees. Because for the motor, the smaller the rotation angle is, the more difficult it is to control, and the control difficulty is greatly reduced when rotating an integer number of turns.

[0020] As preferred, the front side of the box 10 is a protective door with a transparent plate, and a lead screw mechanism 30 is arranged on the inner wall of the rear side of the box 10, and 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 ascend and descend.

[0021] As preferred, the box 10 is provided with a front-to-back first slide rail and a left-to-right second slide rail, the first slide rail is fixed on the box 10, a first sliding seat 205 is slidably arranged on the first slide rail, and a first synchronous belt 206 is arranged on the first sliding seat 205, the second slide rail is arranged on the first sliding seat 205, a second sliding seat 203 is slidably arranged on the second slide rail, and a second synchronous belt 207 is arranged on the second sliding seat 203, the first synchronous belt 206 and the second synchronous belt 207 are driven by different drive pulleys 2028, and the printing nozzle 50 is arranged on the second sliding seat 203. One of the transmission boxes 201 is fixed on the left side of the box 10, and the other transmission box 201 is slidably arranged on the right side of the box 10 and fixedly connected with the first sliding seat 205, and the box 10 is provided with a strip-shaped opening for allowing the second transmission belt to move forward and backward with the second transmission box 201 and the first sliding seat 205.

[0022] As preferred, there is one first slide rail on each of the left and right sides, and one first sliding seat 205 is arranged on each of the first slide rails on the left and right sides, the two first sliding seats 205 are driven by two first synchronous belts 206, and a connecting shaft 204 with two pulleys is arranged between the two first synchronous belts 206; and the second slide rail is provided with two second slide rails which are driven by a second synchronous belt 207.

[0023] As preferred, the first synchronous belt 206 and the second synchronous belt 207 are both annular structures, and the annular structure has an upper belt body 2071 and a lower belt body 2072, the upper belt body 2071 is clamped on the first sliding seat 205 and the second sliding seat 203 to form a fixation, and the first sliding seat 205 and the second sliding seat 203 are both provided with a tensioning structure 208 for tensioning the lower belt body 2072.

[0024] As preferred, the tensioning structure 208 comprises: a hinged seat fixed on the first sliding seat 205 and the second sliding seat 203; a swing frame rotatably arranged on the hinged seat and having an angle less than or equal to 90 degrees with the vertical direction; a lower pressing pulley 2081 rotatably arranged at the bottom end of the swing frame and pressing on the lower belt body 2072, wherein a limiting frame is further included, the limiting frame is provided with a circular arc hole, and the shaft of the lower pressing pulley 2081 extends into the circular arc hole to limit the rotation angle; a telescopic adjusting device 2084 fixed on the first sliding seat 205 and the second sliding seat 203 and having an output end abutting against or connected to the swing frame through a pull rope, which is a pneumatic cylinder or an electric push rod; The telescopic adjusting device 2084 pushes the swing frame to rotate, so as to adjust the pressing degree of the pressing pulley 2081, so as to tension the corresponding synchronous belt. The synchronous belt will be loose after use, which will cause vibration, jitter and backlash. The backlash will cause the print head or the heat bed to not move immediately due to the loose belt when starting, stopping and reversing, and the actual movement deviates from the theoretical movement. The combination of the meshing structure of the synchronous belt and the tensioning drive of the belt and the setting of the tensioning structure 208 can automatically compensate the tensioning during use, so as to avoid the problems caused by vibration, jitter and backlash.

[0025] As preferred, the tensioning structure 208 is provided with two groups, the middle parts of the two groups are provided with feedback mechanisms, the feedback mechanisms include air springs 2083 vertically slidingly arranged on the first sliding seat 205 and the second sliding seat 203, auxiliary pulleys 2082 arranged at the bottom ends of the air springs 2083 and electronic pressure gauges arranged on the first sliding seat 205 and the second sliding seat 203, the electronic pressure gauges are connected with a controller, the controller is connected with the telescopic adjusting device 2084, wherein the auxiliary pulleys 2082 are pressed on the lower belt body 2072, the two pressing pulleys 2081 and the auxiliary pulleys 2082 form a triangular supporting tensioning structure, when the synchronous belt is worn and loose, the auxiliary pulleys 2082 are automatically tensioned, so that the pressure of the electronic pressure gauges is reduced, and a feedback signal is fed back to the controller, the controller controls the telescopic adjusting device 2084 to adjust the tensioning range of the two pressing pulleys 2081, and after adjustment, when the pressure of the electronic pressure gauges returns to the preset threshold range, the adjustment is stopped. The triangular supporting tensioning structure is used to realize the tensioning of the synchronous belt. When the synchronous belt is worn and the pressure obtained by the feedback mechanism is reduced during the tensioning process, the pressure at the electronic pressure gauges is increased by adjusting the tensioning range of the two pressing pulleys 2081 according to the change of the pressure value, until the preset threshold is reached. In order to improve the tensioning effect, the synchronous belt is provided with the following structure, the middle part of the synchronous belt is provided with a tapered belt tooth, and the two sides are provided with protruding planes, and the wear resistance of the planes is weaker than that of the middle part of the belt tooth, the pulley is provided with a convex structure in the middle part and a tooth groove, and the two sides are provided with a plane or a textured structure, the two sides of the gear are attached to the plane, and the tooth part of the synchronous belt extends into the tooth groove, the tooth part and the tooth groove can always match each other before and after wear, the power is transmitted by the friction force of the outer side and the meshing of the middle part of the tooth and the tooth groove, and the compensation is performed when the two sides are worn, the compensation and the redundancy of the tooth extending into the tooth groove jointly act, and the transmission error caused by wear is reduced.

[0026] In the description of the application, it should be noted that the terms "upper", "lower", "front", "back", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the product of the application is used, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

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.

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 housing is equipped 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 and a second slide block is slidably mounted on the second slide block 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.

5. The high-precision four-axis 3D printing equipment according to claim 4, characterized in that, There is a first slide rail on each of the left and right sides, and a first slide block 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 set between the two first synchronous belts. There are two second slide rails, which are driven by a second synchronous belt.

6. The high-precision four-axis 3D printing equipment according to claim 4, characterized in that, 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 tensioning structures to tension the lower belt body.

7. The high-precision four-axis 3D printing equipment according to claim 6, characterized in that, The tensioning structure includes: 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.

8. The high-precision four-axis 3D printing equipment according to claim 7, 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.

9. The high-precision four-axis 3D printing equipment according to claim 8, 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 is in contact 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 gear 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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