A sanding device

Abstract

The application discloses a sand paving device, belonging to the technical field of 3D printing, comprising symmetrically arranged mounting seats, a knife edge plate assembly arranged between the two seats, and a central shaft assembly connected to both ends of the knife edge plate assembly. At least one end of the knife edge plate assembly is provided with a containing cavity, and an eccentric assembly is arranged on the mounting seat and extends into the cavity. An active space is formed between the eccentric assembly and the cavity wall, which can contact the cavity wall during rotation and drive the knife edge plate to make high-frequency micro-amplitude swing around the central shaft. The design integrates eccentric drive into the end of the knife edge plate, and the exciting force is uniformly transmitted along the length direction of the knife edge through swing, effectively overcoming the problems of different power synchronization and intermediate attenuation that may occur in traditional double-sided drive. The vibration of the knife edge plate effectively improves the flow flatness and filling density of the sand particles, and makes the sand layer more flat and dense. At the same time, the swing action of the knife edge plate when leaving the sand paving area can reduce the adhesion of sand particles, significantly inhibit the "sand dragging" or "sand sticking" phenomenon, and ensure the sand paving quality and the continuity of the printing operation.

Description

Technical Field

[0001] This invention belongs to the field of 3D printing technology, and particularly relates to a sand-laying device. Background Technology

[0002] In the 3D printing industry, especially in binder-jet based 3D printing technology, the precision and stability of the sand-laying device directly determine the layer thickness uniformity and final quality of the formed part. Existing sand-laying devices typically employ a single-piece beam-based blade structure. This long, one-piece blade, due to its large span, is prone to deformation under long-term workloads, making it difficult to guarantee the flatness of the sand-laying surface and affecting printing accuracy. Simultaneously, the excessive blade length also presents significant machining challenges, resulting in high manufacturing costs and low yield rates. Regarding sand-laying power transmission, it generally relies on dual-sided external vibrators. The excitation force is attenuated and asynchronous during transmission from both ends to the middle, leading to uneven sand particle distribution along the blade length and unsatisfactory sand-laying effect. Furthermore, this structure frequently exhibits "sand dragging" or "sand sticking" phenomena during sand-laying, meaning that some sand particles are abnormally carried away when the blade leaves the sand-laying surface, damaging the integrity of the already leveled sand surface and severely affecting the continuity of the printing process and the reliability of the formed part. These defects collectively restrict the production efficiency and forming quality of 3D printing equipment. Summary of the Invention

[0003] (a) Purpose of the invention

[0004] In order to overcome the above shortcomings, the purpose of this invention is to provide a sand-laying device to solve the technical problems of uneven sand laying and frequent sand dragging caused by the use of easily deformable one-piece long blades and inefficient external vibrators in existing sand-laying devices, which seriously affect the accuracy and stability of 3D printing.

[0005] (II) Technical Solution

[0006] To achieve the above objectives, the technical solution provided in this application is as follows:

[0007] A sand-laying device includes: two symmetrically arranged mounting seats, a blade plate assembly disposed between the two mounting seats, the blade plate assembly having a receiving cavity at at least one end, two central shaft assemblies respectively disposed on the two mounting seats and rotatably connected to the two ends of the blade plate assembly, and an eccentric assembly disposed on at least one mounting seat and extending into the receiving cavity at the corresponding end, the eccentric assembly forming a movable space with the receiving cavity and being tangential to the inner wall of the receiving cavity when rotating, so as to drive the blade plate assembly to swing around the central shaft assembly.

[0008] By directly integrating the eccentric drive mechanism into the end of the blade assembly and utilizing its oscillating principle, the excitation force is transmitted more directly and uniformly along the blade length, effectively avoiding the power asynchrony and intermediate attenuation problems that may occur with traditional external double-sided drives. This drive method, combined with the oscillating motion of the blade, can generate continuous and uniform high-frequency micro-vibrations on the sand particles during the sand-laying process, significantly improving the leveling and filling density of the sand particles, thereby obtaining a smoother and denser sand layer. At the same time, the oscillating motion of the blade when leaving the sand-laying surface helps reduce the adhesion of sand particles to the blade, fundamentally suppressing the occurrence of "sand dragging" or "sand sticking" phenomena, ensuring the integrity of the sand-laying surface and the continuity of the printing process.

[0009] In some embodiments, the blade plate assembly includes: an elongated support beam, a blade plate disposed on the support beam, and two guide seats disposed at both ends of the support beam, wherein the guide seats have the receiving cavity.

[0010] By adopting a separate assembly structure for the blade plate and guide seat, the blade plate can focus on its scraping function, simplifying its structural form and reducing the manufacturing difficulty and cost of long, narrow blade plates. The guide seat can be a standard part or a more easily machined component, specifically optimized to accommodate the drive components and achieve oscillation guidance, improving the rationality and manufacturability of the structure. This modular design not only facilitates independent machining and precision control of each component but also simplifies subsequent maintenance and replacement. If the blade plate wears out, only that part needs to be replaced, effectively reducing maintenance costs.

[0011] In some embodiments, the central shaft assembly includes: a central shaft with one end fixed to two mounting bases and a first bearing disposed at the other end of the central shaft, the first bearing being rotatably connected to the end of the blade plate assembly.

[0012] The combination of the central shaft and the first bearing provides a stable, low-friction, and precise center of rotation for the cutterhead assembly. This fulcrum design ensures that the cutterhead assembly can smoothly and reliably reciprocate around a fixed axis, with a stable and controllable oscillation trajectory, avoiding unnecessary shaking or deviation, thus guaranteeing the consistency of the cutterhead's movement trajectory during sand spreading. The stable oscillation center combined with the eccentric drive results in higher efficiency in the transmission of driving force and higher conversion into oscillating kinetic energy, contributing to enhanced vibration sand spreading effects. Simultaneously, the bearing connection reduces wear during long-term operation, extending the device's service life and ensuring the durability of motion accuracy.

[0013] In some embodiments, the eccentric component includes: a motor fixed on a mounting base, a second bearing disposed on the mounting base corresponding to the position of the motor, a connecting shaft with one end passing through the second bearing and connected to the motor, and an eccentric wheel connected to the other end of the connecting shaft and extending into a receiving cavity, wherein the connecting shaft is connected to the non-central position of the eccentric wheel.

[0014] The motor, acting as the power source, directly transmits torque to the eccentric wheel via a connecting shaft, resulting in a short power transmission path and minimal energy loss. The rotation of the eccentric wheel within the receiving cavity generates periodic centrifugal force, which is converted into a tangential force driving the knife-edge plate assembly to swing through its contact with the cavity's inner wall. This built-in excitation method concentrates vibration energy more directly onto the knife-edge plate, significantly improving vibration efficiency and uniformity, ensuring that sand particles along the entire length of the knife-edge plate are effectively excited and fully leveled. Compared to external vibrators, this structure effectively solves the problems of asynchronous and attenuated excitation force transmission, resulting in a more uniform sand density. Simultaneously, the motor's speed and torque are easily controlled, facilitating adjustments to the vibration intensity and frequency according to different sand materials and layer thickness requirements, enhancing the device's adaptability and intelligence.

[0015] In some embodiments, the blade plate includes multiple interconnected blade plate segments.

[0016] The multi-segment connected cutterhead design is an effective way to solve the problem of easy deformation in long-span structures. It breaks down the originally monolithic, easily bent cutterhead into multiple shorter segments. The rigidity and straightness of each segment are more easily guaranteed, thus significantly reducing the risk of structural deformation due to self-weight or working stress. This ensures higher flatness and straightness of the cutterhead along its entire length, providing a fundamental guarantee for the smoothness of the sand-laying. Furthermore, the segmented structure greatly reduces the machining difficulty of individual parts and the risk of deformation during heat treatment, improving the yield and accuracy of finished products. During on-site maintenance, if a local cutterhead segment is damaged, it is not necessary to replace the entire cutterhead; only the damaged segment needs to be replaced, greatly reducing maintenance complexity and cost, and improving the economic efficiency of the equipment. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the sand-laying device of the present invention;

[0018] Figure 2 This is the invention Figure 1 Cross-sectional view of the sand-laying device along direction AA;

[0019] Figure 3 This is the invention Figure 1 Cross-sectional view of the sand-laying device in the BB direction.

[0020] Figure label:

[0021] 1. Mounting base; 2. Blade plate assembly; 201. Blade plate; 2011. Blade plate segment; 202. Guide seat; 2021. Receiving cavity; 203. Support beam; 3. Central shaft assembly; 301. Central shaft; 302. First bearing; 4. Eccentric assembly; 401. Motor; 402. Second bearing; 403. Connecting shaft; 404. Eccentric wheel. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0023] This invention provides a sand-laying device, comprising two symmetrically arranged mounting seats 1, which are typically fixed to the base frame of the sand-laying equipment by bolts or welding to ensure overall stability. Further, a blade plate assembly 2 is provided between the two mounting seats 1, with at least one end of the blade plate assembly 2 designed with a receiving cavity 2021, i.e., its end portion forming a hollow structure. Specifically, two central shaft assemblies 3, respectively mounted on the two mounting seats 1, are rotatably connected to the two ends of the blade plate assembly 2, allowing the blade plate assembly 2 to swing around the central shaft assembly 3. In addition, an eccentric assembly 4 is mounted on at least one mounting seat 1, extending into the corresponding receiving cavity 2021. A certain clearance is maintained between the eccentric assembly 4 and the receiving cavity 2021, and when the eccentric assembly 4 rotates, its outer edge can periodically tangent to the inner wall of the receiving cavity 2021, thereby driving the blade plate assembly 2 to swing at a high frequency around the central shaft assembly 3. Preferably, the mounting base 1 is made of a metal plate with a thickness of about 10mm to enhance rigidity, while the blade plate assembly 2 can be made of wear-resistant alloy steel. This design not only ensures structural strength, but also effectively improves the uniformity of sand spreading through the built-in swing mechanism.

[0024] Furthermore, the blade plate assembly 2 includes: a long strip-shaped support beam 203, a blade plate 201 disposed below the support beam 203, and two guide seats 202 respectively fixed at both ends of the blade plate 201. The guide seats 202 have internal accommodating cavities 2021 for accommodating a portion of the eccentric assembly 4. Preferably, the blade plate 201 and the guide seats 202 are assembled by bolt connection or plug-in connection, facilitating disassembly and maintenance. In particular, the blade plate 201 can be manufactured as an integral or modular structure according to actual needs; for example, a segmented design can be used in long-span applications to reduce the risk of deformation. This modular layout simplifies the manufacturing process and improves assembly flexibility and maintainability.

[0025] Specifically, the segmented design of the blade plate in 2011 is as follows:

[0026] The blade plate 201 comprises multiple interconnected blade plate segments 2011. These segments are sequentially mounted on the support beam 203 using connectors such as bolts or snap-fit ​​structures, forming a long strip. Preferably, the blade plate segments 2011 are made of the same material, such as tool steel, and the length of each segment can be customized according to processing conditions, for example, approximately 500mm per segment, to reduce processing deformation. Specifically, alignment grooves or locating pins are provided at the segment joints to ensure flatness after assembly. It is worth noting that this segmented design not only reduces the manufacturing difficulty and cost of long blades but also facilitates partial replacement and maintenance, thereby extending the service life of the device and improving economic efficiency.

[0027] Based on this, the central shaft assembly 3 includes a central shaft 301 fixed at one end to two mounting seats 1 and a first bearing 302 disposed at the other end of the central shaft 301. The first bearing 302 is rotatably connected to the end of the blade plate assembly 2, allowing the blade plate assembly 2 to swing smoothly around the central shaft 301 as a fulcrum. Preferably, the central shaft 301 is made of high-strength steel, and the first bearing 302 is a deep groove ball bearing or a sliding bearing to reduce friction loss. Furthermore, the central shaft 301 is fixed to the mounting seat 1 by threaded fastening or press-fitting to ensure reliable connection. It is worth noting that this rotating support structure provides a stable swing axis for the blade plate assembly 2, thereby ensuring the accuracy and consistency of the sand-spreading action.

[0028] Specifically, the eccentric assembly 4 includes a motor 401 fixed on the mounting base 1, a second bearing 402 positioned on the mounting base 1 corresponding to the motor 401, a connecting shaft 403 with one end passing through the second bearing 402 and connected to the output shaft of the motor 401, and an eccentric wheel 404 connected to the other end of the connecting shaft 403 and extending into the receiving cavity 2021. The connecting shaft 403 is connected to the off-center position of the eccentric wheel 404, meaning the eccentric wheel 404 is designed with a center of gravity offset, thereby generating centrifugal force during rotation. Preferably, the motor 401 is a stepper motor 401 or a DC servo motor 401 to control the speed and torque; the second bearing 402 can be a rolling bearing or an oil-impregnated bearing to support the rotational movement of the connecting shaft 403. Furthermore, the connecting shaft 403 is coupled to the motor 401 via a keyway or coupling to ensure efficient power transmission. When the motor 401 starts, the connecting shaft 403 drives the eccentric wheel 404 to rotate within the receiving cavity 2021. Due to the eccentric effect, the eccentric wheel 404 periodically contacts the inner wall of the receiving cavity 2021 and applies a tangential force, pushing the blade plate assembly 2 to swing. In this way, this built-in drive method applies the excitation force directly to the vicinity of the swing center, avoiding the attenuation problem of traditional external power and significantly improving the uniformity of sand particle distribution.

[0029] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A sand-laying device, characterized in that, include: Two symmetrically arranged mounting seats (1), a blade plate assembly (2) disposed between the two mounting seats (1), the blade plate assembly (2) having a receiving cavity (2021) at least one end, two central shaft assemblies (3) respectively disposed on the two mounting seats (1) and rotatably connected to the two ends of the blade plate assembly (2), and an eccentric assembly (4) disposed on at least one mounting seat (1) and extending into the corresponding end of the receiving cavity (2021), the eccentric assembly (4) forming a movable space with the receiving cavity (2021) and being able to be tangent to the inner wall of the receiving cavity (2021) when rotating, so as to drive the blade plate assembly (2) to swing around the central shaft assembly (3).

2. The sand-laying device according to claim 1, characterized in that, The blade plate assembly (2) includes: a long strip-shaped support beam (203), a blade plate (201) disposed on the support beam (203), and two guide seats (202) respectively disposed at both ends of the support beam (203), wherein the guide seats (202) have the receiving cavity (2021).

3. The sand-laying device according to claim 1, characterized in that, The central shaft assembly (3) includes: a central shaft (301) with one end fixed on the two mounting seats (1) and a first bearing (302) disposed at the other end of the central shaft (301), the first bearing (302) being rotatably connected to the end of the blade plate assembly (2).

4. The sand-laying device according to claim 1, characterized in that, The eccentric assembly (4) includes: a motor (401) fixed on the mounting base (1), a second bearing (402) disposed on the mounting base (1) corresponding to the position of the motor (401), a connecting shaft (403) with one end passing through the second bearing (402) and connected to the motor (401), and an eccentric wheel (404) connected to the other end of the connecting shaft (403) and extending into the receiving cavity (2021), wherein the connecting shaft (403) is connected to the non-central position of the eccentric wheel (404).

5. The sand-laying device according to claim 2, characterized in that, The blade plate (201) includes: multiple interconnected blade plate segments (2011).

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