Precision control method for photocuring forming platform

Abstract

The invention provides a precision control method for a photocuring forming platform, which comprises the following steps: at least one group of piezoelectric sensors are arranged below the forming platform, and in the operation process of the forming platform, the self weight of the forming platform is used as an input signal of the piezoelectric sensors, namely the initial value of pressure borne by the piezoelectric sensors is gi; when the self weight received by each piezoelectric sensor changes, the piezoelectric sensor serves as a driving part, the piezoelectric sensor at the pressed end automatically outputs and executes expansion action, so that the forming platform automatically returns to zero or the non-pressed end executes contraction action, and the leveling effect of the forming platform is achieved. By adjusting the structure of the forming platform, arranging a piezoelectric sensor and matching a scraper structure, the forming platform can be leveled in time according to the borne weight, so that the problem of local density difference of a formed product caused by unevenness of the forming platform is well solved; therefore, the product forming quality and the printing precision are improved.

Description

Technical Field

[0001] The present invention belongs to the field of precision control of photocuring 3D printing forming, and particularly relates to a method for controlling the precision of a photocuring forming platform. Background Art

[0002] With the development of additive manufacturing technology, additive manufacturing equipment has become an indispensable forming equipment in advanced manufacturing. In the field of ceramic 3D printing forming, the forming precision is jointly determined by various influencing factors, among which the leveling precision of the forming platform has a greater impact. Currently, the forming platforms of ceramic 3D printers generally adopt the method of fixed installation after being leveled by equipment manufacturers. Although the leveling of the forming platform can be achieved, due to the sedimentation of ceramic slurry and the change of the curing area of ceramic slurry with the slicing area during the forming process, there is a certain heterogeneity between the slurry in the newly replenished area and the uncured slurry laid in the early stage, resulting in continuous change of the ceramic solid content in each actual slurry layer, and large differences in local density of the final formed product. In the lightest case, it affects the final performance of the product, and in the worst case, it causes the ceramic formed part to collapse during the debinding stage, with a high rejection rate, which greatly affects the industrial promotion of ceramic 3D printing forming equipment.

[0003] Therefore, there is an urgent need in this technical field for a forming platform and a precision control method that can achieve the uniformity of slurry laying under the premise of automatic feeding to solve the above technical problems, so as to improve the printing precision and the yield rate of printed products. Summary of the Invention

[0004] Object of the Invention: To overcome the above deficiencies, the object of the present invention is to provide a method for controlling the precision of a photocuring forming platform. Through the setting of piezoelectric sensors and the adaptation of the scraper structure, it can level the forming platform in a timely manner according to the weight borne, thus well solving the problem of local density differences in the formed product caused by the unevenness of the forming platform, and further improving the forming quality of the product and the printing precision.

[0005] Technical Solution: To achieve the above object, the present invention provides a method for controlling the precision of a photocuring forming platform, including: a forming platform, at least one group of piezoelectric sensors are arranged below the forming platform, and the piezoelectric sensors are connected to a power supply to form an automatic leveling mechanism of the forming platform; During the operation of the forming platform, the self-weight of the forming platform itself is used as the input signal of the piezoelectric sensor, that is, the initial value of the pressure borne by the piezoelectric sensor is g i ; when the self-weight received by each piezoelectric sensor changes, the piezoelectric sensor serves as a driving member, and the piezoelectric sensor at the compressed end will automatically output and perform an expansion action to make the forming platform automatically return to zero or the non-compressed end perform a contraction action to achieve the leveling effect.

[0006] Among them, at least four piezoelectric sensors are provided below the forming platform.

[0007] Preferably, the forming platform is made of glass or a compound eye lens, which promotes the leveling of the slurry and facilitates the detachment of the product from the platform after forming.

[0008] Further preferably, the glass is quartz glass-ceramics, and the compound eye lens is made of a scintillator material or an up / down conversion material.

[0009] Furthermore, a release film device is provided above the forming platform. The release film serves as a separation layer between the forming platform and the product, facilitating the detachment of the product from the platform after forming.

[0010] Further preferably, the release film device includes a release film and a tensioning mechanism. The tensioning mechanism is provided below or above the release film, and the tension of the release film is adjusted through the tensioning mechanism. The setting of the tensioning mechanism can adjust the tension of the release film to prevent the release film located on the forming platform from being too loose, which affects the forming quality of the lower part of the product.

[0011] Furthermore, the present invention further includes a slurry scraping device, and the slurry scraping plate in the slurry scraping device is located above the release film device.

[0012] Preferably, the slurry scraping plate is a negative pressure adsorption type scraping plate. The use of the negative pressure adsorption type scraping plate facilitates the uniform spreading of the slurry on the finished product platform. Fixed through negative pressure adsorption, it prevents the slurry from splashing or moving. At the same time, it can also improve the formability of the slurry, avoid the accumulation of the slurry, and thus effectively improve the density and mechanical properties of the printed finished product.

[0013] Further preferably, an opening and closing mechanism is provided on one side or both sides of the bottom of the slurry scraping plate. The setting of the opening and closing mechanism can control and adjust the opening of the slurry scraping plate.

[0014] The leveling process of the piezoelectric sensor in the present invention is as follows: Set the initial position of each piezoelectric sensor to 0, and the initial value of the pressure borne by the piezoelectric sensor is g i , where i = 1, 2, 3... N; the actual force value of the piezoelectric sensor is g m ; If the self-weights of the forming platform at several positions of the piezoelectric sensor are g1, g2, g3, g4... g N , g1, g2, g3, g4... g N serve as the input signals corresponding to the piezoelectric sensors; When the self-weight received by each piezoelectric sensor changes, that is, g m≠ g i时， If the actual force g of the piezoelectric sensor at the compressed end of the forming platformm > g i , the piezoelectric sensor automatically outputs to execute the expansion action to automatically zero the forming platform, that is, g m = g i ; If the actual force g on the piezoelectric sensor at the non-pressed end of the forming platform m < g i , the piezoelectric sensor automatically executes the contraction action to achieve the leveling effect.

[0015] From the above technical solutions, the present invention has the following beneficial effects: 1. In the present invention, an optical curing forming platform, through reasonable design of the structure of the forming platform, and through the setting of the piezoelectric sensor, enables the piezoelectric sensor to act as a driving member, enabling it to level the forming platform in a timely manner according to the weight carried, thus well solving the problem of local density difference in the formed product caused by the unevenness of the forming platform, and further improving the forming quality of the product and enhancing the printing accuracy.

[0016] 2. The release film device includes a release film and a tensioning mechanism. The tensioning mechanism is arranged below or above the release film, and the tension of the release film is adjusted through the tensioning mechanism. The setting of the tensioning mechanism can adjust the tension of the release film, preventing the release film located on the forming platform from being too loose and affecting the forming quality of the lower part of the product.

[0017] 3. The use of the negative pressure adsorption type scraper facilitates the uniform spreading of the slurry on the finished product platform. Through negative pressure adsorption fixation, it prevents the slurry from splashing or moving, and at the same time can also improve the formability of the slurry, avoiding slurry accumulation, thereby effectively improving the density and mechanical properties of the printed finished product. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of the forming platform in the present invention; Figure 2 is a schematic cross-sectional view of the bottom structure of the multi-array scraper in the present invention; Figure 3 is a schematic cross-sectional view of the hollow type scraper structure; Figure 4 is a schematic side view of the hollow type scraper structure In the figure: forming platform 1, release film device 2, release film 21, tensioning mechanism 22. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The present invention will be further clarified below with reference to the drawings and specific embodiments.

[0020] Embodiment 1 This embodiment discloses a method for controlling the accuracy of a stereolithography forming platform, including a forming platform 1. At least one group of piezoelectric sensors is provided below the forming platform 1, and the piezoelectric sensors are connected to a power supply to form an automatic leveling mechanism for the forming platform 1. During the operation of the forming platform 1, the self-weight of the forming platform 1 itself is used as the input signal of the piezoelectric sensor, that is, the initial value of the pressure borne by the piezoelectric sensor is g. i When the self-weight received by each piezoelectric sensor changes, the piezoelectric sensor serves as a driving member. The piezoelectric sensor at the compressed end will automatically output and perform an expansion action to make the forming platform 1 automatically return to zero, or the non-compressed end will perform a contraction action to achieve the leveling effect.

[0021] In this embodiment, at least four piezoelectric sensors are provided below the forming platform 1. The specific leveling process is as follows: Let the initial position of each piezoelectric sensor be 0, and the initial value of the pressure borne by the piezoelectric sensor be g, where i = 1, 2, 3... N; the actual force value of the piezoelectric sensor is g. i ; m ; If the self-weights of the forming platform 1 at several positions of the piezoelectric sensors are g1, g2, g3, g4... g respectively, N g1, g2, g3, g4... g N serve as the input signals for the corresponding piezoelectric sensors. When the self-weight received by each piezoelectric sensor changes, that is, g m≠ g i时， If the actual force g of the piezoelectric sensor at the compressed end of the forming platform 1 m > g i , then the piezoelectric sensor automatically outputs and performs an expansion action to make the forming platform 1 automatically return to zero, that is, g m = g i ; If the actual force g of the piezoelectric sensor at the non-compressed end of the forming platform is m < g i , then the piezoelectric sensor automatically performs a contraction action to achieve the leveling effect.

[0022] The forming platform 1 is made of glass or a compound eye lens. It should be noted that the forming platform 1 can select a platform made of other materials according to the actual needs of processing, as long as it can meet the production needs.

[0023] The glass is quartz microcrystalline glass, and the compound eye lens is made of a scintillator material or an up / down conversion material. It can be imagined that appropriate material components can be selected according to actual needs, not limited to the above two materials.

[0024] Embodiment 2 The precision control method of the stereolithography platform described in this embodiment is the same as that in Embodiment 1. Further, as Figure 1 shown, a release film device 2 is provided above the stereolithography platform.

[0025] The release film device 2 includes a release film 21 and a tensioning mechanism 22. The tensioning mechanism 22 is arranged below or above the release film 21. By adjusting the tension of the release film 21 through the tensioning mechanism 22, the release film 21 located above the forming platform 1 can be in a straightened state. During the working process, the tensioning degree of the release film 21 can be adjusted through the tensioning mechanism 22 to better meet the needs of production and processing.

[0026] The tensioning mechanism 22 includes a main driving mechanism, a set of driven transmission mechanisms and a motor. The output end of the motor is in transmission connection with the main driving mechanism, and the main driving mechanism is in transmission connection with the driven transmission mechanisms.

[0027] The main transmission mechanism and the driven transmission mechanisms can select appropriate combinations according to actual needs. For example, the main driving mechanism includes a main driving roller, one end of the main driving roller is provided with a double-row driving wheel, and the other end is provided with a driven wheel. The driven transmission mechanism includes a driven roller, and both ends of the driven roller are provided with driven wheels. The driving wheel at the output end of the motor is in transmission connection with the double-row driving wheel on the main driving roller through a synchronous belt, and the double-row driving wheel and the driven wheel on the main driving roller are respectively in transmission connection with the driven wheels at both ends of the corresponding driven roller through synchronous belts. It should be noted that the structure of the tensioning mechanism 22 can select other adjustment mechanisms that can meet the adjustment of the release film tension according to needs.

[0028] Embodiment 3 The precision control method of the stereolithography platform described in this embodiment is the same as that in Embodiment 2. Further still, it further includes a slurry scraping device, and the slurry scraping plate in the slurry scraping device is located above the release film device 2.

[0029] The slurry scraping plate adopts a negative pressure adsorption type scraping plate, which is connected with a slurry adjustment control mechanism for adjusting the slurry uniformity. The slurry adjustment control mechanism includes a vacuum pump, a pressure pump and a feeding pump. During actual use, the slurry scraping plate can be connected with the corresponding mechanism according to needs.

[0030] Preferably, the slurry scraping plate can select a hollow type scraping plate or a multi-array scraping plate or a combination thereof according to actual needs, so as to better meet the needs of the actual processing and printing process.

[0031] One side or both sides of the bottom of the slurry scraper are provided with an opening and closing mechanism. The opening and closing mechanism includes an opening and closing plate and an opening and closing control device. The opening and closing plate is hinged to the slurry scraper, and the opening and closing control device is connected to the opening and closing plate.

[0032] The opening and closing control device includes an opening and closing driving mechanism, a ratchet mechanism and a driving rod. The opening and closing driving mechanism is connected to the ratchet mechanism, the driving rod is connected to the ratchet mechanism, and one end of the driving rod away from the ratchet mechanism is connected to the opening and closing plate. It should be noted that other structures capable of meeting this function can also be selected for the opening and closing mechanism.

[0033] The side plate on at least one side of the opening and closing mechanism is movable. It can be in the form of the movement of a guide rail and a slider, or in the form of a roller and a guide rail, as long as it can meet the function of the side plate for sealed movement, which is beneficial to disassembly and cleaning after additive printing.

[0034] A spacing of 1 um - 1000 um is provided at the bottom of the slurry scraper. It should be noted that the spacing at the bottom of the slurry scraper can be adjusted according to the actual situation and is not limited to the current range.

[0035] In this embodiment, the slurry scraper can adopt a hollow flow channel structure made of metal, ceramic, organic matter, composite material or a combination thereof. It should be noted that during actual use, different materials of slurry scrapers can be selected according to specific actual situations as long as they can meet specific requirements and are not limited to the current materials.

[0036] The above is only the preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, several improvements can be made without departing from the principle of the present invention, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. A method for controlling the precision of a photo-stereolithography platform, characterized in that: include: A molding platform (1), wherein at least one group of piezoelectric sensors is provided below the molding platform (1), and the piezoelectric sensors are connected to a power source to form an automatic leveling mechanism for the molding platform (1); During the operation of the molding platform (1), the weight of the molding platform (1) itself is used as the input signal of the piezoelectric sensor, that is, the initial value of the pressure on the piezoelectric sensor is g. i When the deadweight received by each piezoelectric sensor changes, the piezoelectric sensor acts as a driving component, and the piezoelectric sensor at the pressure end will automatically output an expansion action to make the molding platform (1) automatically return to zero or perform a contraction action at the non-pressure end, thereby achieving a leveling effect on the molding platform.

2. The method for controlling the precision of a photo-stereolithography platform according to claim 1, characterized in that: At least four piezoelectric sensors are provided below the molding platform (1).

3. The method for controlling the precision of a photo-stereolithography platform according to claim 1, characterized in that: The molding platform (1) is made of glass or a compound eye lens.

4. The method for controlling the precision of a photo-stereolithography platform according to claim 3, characterized in that: The glass is quartz microcrystalline glass, and the fly-eye lens is made of scintillator material or up / down conversion material.

5. The method for controlling the precision of a photo-stereolithography platform according to claim 1, characterized in that: A release film device (2) is arranged above the molding platform (1).

6. The method for controlling the precision of a photo-stereolithography platform according to claim 5, characterized in that: The release film device (2) comprises a release film (21) and a tensioning mechanism (22); the tensioning mechanism (22) is arranged below or above the release film (21); and the tension of the release film (21) is adjusted by the tensioning mechanism (22).

7. The method for controlling the precision of a photo-stereolithography platform according to claim 5, characterized in that: It also comprises a slurry scraping device, wherein a slurry scraping plate in the slurry scraping device is located above the release film device (2).

8. The method for controlling the precision of a photo-stereolithography platform according to claim 7, characterized in that: The slurry scraper adopts a negative pressure adsorption type scraper.

9. The method for controlling the precision of a photo-stereolithography platform according to claim 7, characterized in that: An opening and closing mechanism is provided on one or both sides of the bottom of the slurry scraper. The slurry scraper is a hollow scraper or a multi-array scraper or a combination thereof. The slurry scraper adopts a hollow flow channel structure made of metal, ceramic, organic matter, composite material or a combination thereof.

10. A method for controlling the precision of a photo-stereolithography platform according to any one of claims 1 to 9, characterized in that: The leveling process of the piezoelectric sensor is as follows: Assume that the initial position of each piezoelectric sensor is 0, and the initial pressure value of the piezoelectric sensor is g i , where i=1, 2, 3, ... N; The actual force value of the piezoelectric sensor is g m ; If the weight of the molding platform (1) at several positions of the piezoelectric sensor is g1, g2, g3, g4, ... g N , g1, g2, g3, g4...g N As the input signal of the corresponding piezoelectric sensor; When the weight received by each piezoelectric sensor changes, that is, g m≠ g i时， If the actual force g on the piezoelectric sensor at the pressurized end of the molding platform (1) m >g i , the piezoelectric sensor automatically outputs an expansion action to make the molding platform (1) automatically return to zero, that is, g m =g i ; If the actual force on the piezoelectric sensor at the non-pressure end of the forming platform is g m <g i , the piezoelectric sensor automatically performs a contraction action to achieve a leveling effect.

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