Preschool education teaching demonstration device

Abstract

The present invention belongs to the technical field of teaching equipment, and specifically discloses a preschool education teaching demonstration device, comprising a plurality of hanging posts arranged on the upper part of a placement slot, a function board suspended on the hanging posts and located in front of a television, and four long board boxes arranged on the periphery of the placement slot, with rotating parts provided at both ends of the long board boxes, a first rotating shaft provided on the rotating part being rotatably connected to an axis support provided at both ends of each side of the placement slot, a power assembly provided on the first rotating shaft, an opening being provided on the side wall facing the function board when the long board boxes are tightened, a liquid storage tank being provided at the edge of the opening inside the long board boxes, a long board electromagnet being provided slidingly provided in the liquid storage tank, and adaptive cooperative locking assemblies being symmetrically provided at both ends of the long board boxes. The present invention drives a clamping component filled with magnetic fluid through an automatic tightening structure to achieve flexible wrapping and precise fitting of the edge of the function board, and achieves adaptive locking with the function board through solidification of the magnetic fluid, significantly improving the stability of the fixation and the versatility for various function boards.

Description

Technical Field

[0001] The present invention belongs to the technical field of teaching equipment, and in particular relates to a preschool education teaching demonstration device. Background Art

[0002] In current preschool education, a variety of teaching media and tools are often used at the center of the classroom to stimulate children's learning interest and cultivate their multiple intelligences. For example, large-screen televisions are used to play instructional videos, display images, and animations; traditional blackboard writing tools (blackboards with chalk) are used to explain concepts; and drawing and graffiti tools (specialized teaching drawing boards with colored markers), various magnetic teaching aids (magnetic boards with letters, numbers, and patterns), and physical manipulative teaching aids (plug-in boards with interlocking building blocks) also play an indispensable role in cultivating children's hands-on skills and artistic qualities.

[0003] In recent years, large LCD screens have become the core display device in preschool classrooms, often placed prominently in the center of the podium. These large displays themselves occupy a significant visual focal point and physical space, so adding other types of teaching boards around or in front of them often faces spatial conflicts or integration difficulties. To address these issues, several solutions have emerged in the prior art.

[0004] A common solution is to use a push-pull or sliding integrated structure, where one or more teaching boards are mounted on rails via pulleys, allowing them to be pushed or pulled in front of the display device or moved away. This approach often suffers from the following drawbacks: First, this structure can only integrate teaching boards with relatively single functions, making it difficult to accommodate a variety of different types of teaching boards; second, the overall structure can be bulky, occupying a large amount of horizontal or vertical space; and finally, its mechanical stability and durability may be insufficient, making it prone to shaking, getting stuck, or even derailing after prolonged use.

[0005] Another solution is to use independent, movable teaching units, such as mounting different teaching boards on a base frame with wheels. These boards can then be rolled to the podium area when in use. While this solution offers a certain degree of flexibility in switching between functions, it also has significant drawbacks: multiple independent teaching units take up a significant amount of storage and access space; and these mobile units are difficult to ensure stability during rollout, positioning, and use, posing safety risks.

[0006] Based on the above shortcomings, some technologies have attempted to install clamping fixtures on the sides or frames of display devices to temporarily hang and secure teaching boards with different functions in front of the display device. Although the planar dimensions of these teaching boards can be designed to roughly match the fixtures, due to the different functions they carry (for example, writing boards are generally thin, while building blocks or drawing boards with special coatings may have a certain thickness), these functional display boards inevitably have different thickness dimensions. This makes it difficult to use a single-size fixture to achieve a tight, stable and reliable fixation for all functional boards of different thicknesses, and they are prone to shaking or even falling off. Summary of the Invention

[0007] In response to the above situation, the present invention provides a preschool education teaching demonstration device, which drives a clamping component filled with magnetic fluid through an automatic tightening structure to achieve flexible wrapping and precise fitting of the edge of the functional board. Through the solidification of the magnetic fluid, adaptive locking that perfectly matches the thickness and contour of the board is achieved, solving the problems of traditional fixing methods being sensitive to the thickness of the board and loose fixing, and significantly improving the stability of the fixation and the versatility for a variety of functional boards.

[0008] The technical solution adopted by the present invention is as follows: The present invention proposes a preschool education teaching demonstration device, including a placement slot and a TV, the bottom of the placement slot is fixedly arranged close to the wall, the TV is fixed in the placement slot, and also includes a plurality of hanging columns arranged on the upper part of the placement slot, a function board suspended on the hanging columns and located in front of the TV, and four long board boxes arranged on the periphery of the placement slot, the two ends of the long board box are provided with rotating parts, the first rotating shaft arranged on the rotating part is rotatably connected to the shaft support arranged at both ends of each side of the placement slot, the first rotating shaft is provided with a power component for synchronously driving all the long board boxes to expand and tighten in a petal-like manner, the long board box surrounds the function board when tightened, and the side wall facing the function board when tightened is provided with an opening, the edge of the opening is provided with a liquid storage tank inside the long board box, and a long board electromagnet is slidingly provided in the liquid storage tank.

[0009] Furthermore, adaptive cooperative locking components are symmetrically provided at both ends of the long board box, and the adaptive cooperative locking components include multiple support members. The support members on the placement groove and the support members on the outside of the long board box are linked by a gear group, the support members on the outside of the long board box and the support members inside the long board box are linked by a sprocket group, and the support members inside the long board box and the long board electromagnet are linked by a rack group.

[0010] Furthermore, the gear set includes a first gear, a second rotating shaft and a second gear. The first gear is fixed on the support member of the placement slot, the first gear is coaxially arranged with the first rotating shaft on the rotating member, the second rotating shaft is engaged and rotated on the support member outside the long board box, the second gear is coaxially arranged on the second rotating shaft, and the second gear performs planetary meshing motion around the first gear.

[0011] Furthermore, the sprocket group includes a first sprocket, a second sprocket and a chain. The first sprocket is coaxially arranged on the second rotating shaft and rotates synchronously with the second gear. The second sprocket is engaged and rotated on a support member inside the long board box. The chain is cooperated with the first sprocket and the second sprocket.

[0012] Furthermore, the rack group includes a third gear and a linkage rack, the third gear is coaxially fixedly connected to the second sprocket, the linkage rack is arranged on the side of the long plate electromagnet facing away from the opening, the linkage rack is meshed with the third gear, and the third gear is located between the linkage rack and the second gear.

[0013] Furthermore, the power assembly includes bevel teeth, which are coaxially arranged on the first rotating shaft. The bevel teeth on two adjacent first rotating shafts located at a corner of the placement groove are vertically meshed and connected. Protective covers are provided on two adjacent shaft supports to cover the bevel teeth. One of the protective covers is provided with a self-locking motor, and the output end of the self-locking motor is coaxially fixedly connected to one of the bevel teeth.

[0014] Furthermore, an elastic membrane is provided on the opening to close the opening, and the closed space formed by the elastic membrane, the liquid storage tank and the long plate electromagnet is filled with magnetic fluid.

[0015] Furthermore, a limiting plate is provided on the side wall of the placement slot. When the long board box is fully unfolded, it is parallel to the wall and blocked by the limiting plate. When the long board box is fully tightened, it is perpendicular to the wall and blocked by the side wall of the placement slot.

[0016] Furthermore, a power adapter is provided inside the long board box, and the power adapter is electrically connected to the long board electromagnet.

[0017] Furthermore, when the long board box is fully unfolded, the elastic membrane is in an initial unexpanded state. When the long board box is fully tightened, the elastic membrane is expanded by the outwardly extending long board electromagnet and magnetic fluid to wrap both sides of the edge of the functional board.

[0018] The beneficial effects achieved by the present invention using the above structure are as follows:

[0019] (1) In order to solve the problem that the fixing device in the prior art is sensitive to the thickness of the functional board and it is difficult to achieve a stable fixation of all functional boards of different thicknesses, the present invention drives the long board electromagnet through the adaptive cooperative locking component inside the long board box when it is tightened, so that the elastic membrane connected to the magnetic fluid can flexibly wrap and accurately fit the edge of the functional board of any thickness. Then the long board electromagnet is energized to solidify the magnetic fluid, forming a customized lock that perfectly matches the edge contour of the functional board, thereby ensuring that functional boards of different thicknesses can be fixed tightly and extremely firmly, effectively avoiding shaking or falling off, and is suitable for diversified teaching in preschool education.

[0020] (2) In order to solve the problems of the existing push-pull structure, such as the overall structure being bulky, occupying a lot of space, and the independent mobile units occupying a large amount of storage and passage space, the four long board boxes of the present invention can be fully unfolded to be parallel to the wall when the functional board is not in use, thereby minimizing the occupation of the teaching space. The petal-shaped tightening movement is also more compact than the traditional linear push-pull. More importantly, the locking is achieved through the solid-liquid conversion of the magnetic fluid, rather than relying solely on traditional mechanical push-pull or clamping, thereby improving the long-term stability and durability of the device.

[0021] (3) In the present invention, teachers only need to control it through simple start and stop operations. The initial placement of the function board only needs to be hung on the hanging column. The subsequent clamping and fixing are automatically completed by the adaptive collaborative locking component linking the long board electromagnet and magnetic fluid. There is no need for manual complex alignment or locking operations. Similarly, to release the function board, it is only necessary to turn off the long board electromagnet and reversely start the self-locking motor. The whole process has a high degree of automation, which greatly simplifies the teacher's operating steps and improves the efficiency of teaching preparation and switching. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the three-dimensional structure of a preschool education teaching demonstration device proposed by the present invention.

[0023] Figure 2 This is a schematic diagram of the exploded structure of a preschool education teaching demonstration device proposed by the present invention.

[0024] Figure 3 This is a front view of a preschool education teaching demonstration device proposed by the present invention.

[0025] Figure 4 The present invention provides a side view of a preschool education teaching demonstration device.

[0026] Figure 5 This is a structural schematic diagram of a placement slot for a preschool education teaching demonstration device proposed by the present invention.

[0027] Figure 6This is a schematic diagram of the exploded structure of the positional relationship between the power assembly and the protective cover of a preschool education and teaching demonstration device proposed by the present invention.

[0028] Figure 7 for Figure 6 Middle AA section view.

[0029] Figure 8 This is a structural schematic diagram of the adaptive cooperative locking component of a preschool education teaching demonstration device proposed by the present invention.

[0030] Figure 9 for Figure 8 Enlarged view of part B.

[0031] Figure 10 This is a motion trajectory diagram of a long board box of a preschool education teaching demonstration device proposed by the present invention.

[0032] Among them, 1. placement slot, 11. shaft support, 12. limit plate, 13. hanging column, 2. TV, 3. function board, 4. long board box, 41. rotating part, 42. first rotating shaft, 43. opening, 44. liquid storage tank, 45. power adapter, 46. elastic membrane, 5. adaptive cooperative locking component, 51. support part, 52. first gear, 53. second gear, 531. second rotating shaft, 54. first sprocket, 55. chain, 56. second sprocket, 57. third gear, 58. linkage rack, 59. long board electromagnet, 6. power component, 61. bevel gear, 62. protective cover, 63. self-locking motor.

[0033] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0035] In the description of the present invention, it should be understood that terms such as "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0036] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 As shown, the present invention proposes a preschool education teaching demonstration device, which includes a placement slot 1, a TV 2, a function board 3, four long board boxes 4, an adaptive cooperative locking component 5 and a power component 6.

[0037] The bottom of the placement slot 1 is designed to be fixedly attached to the wall to ensure the stability of the entire device. The TV 2 is fixedly installed in the placement slot 1 as the main teaching display device. In order to facilitate the hanging of different types of function boards 3, at least two hanging columns 13 are provided on the upper part of the placement slot 1. The function board 3 (such as a blackboard, a whiteboard, a magnetic board, a building block board, etc.) is hung on the hanging column 13 through the opening or hook on its upper edge, so that the function board 3 is located in front of the TV 2 and maintains a certain distance from the TV 2 to avoid direct contact.

[0038] The four long board boxes 4 are arranged on the periphery of the placement groove 1. Specifically, a rotating part 41 is provided at both ends of each long board box 4. The first rotating shaft 42 provided on the rotating part 41 is rotatably connected to the shaft support 11 provided at both ends of each side of the placement groove 1. This arrangement enables the four long board boxes 4 to be flipped with the first rotating shaft 42 as the axis. A power component 6 is provided on the first rotating shaft 42, which is used to synchronously drive all four long board boxes 4 to rotate around their respective first rotating shafts 42, realizing a petal-like inward tightening or outward expanding action. When the long board boxes 4 are tightened, they surround the edge parts of the functional board 3 from all sides.

[0039] In order to clamp and fix the edge of the functional board 3, each long board box 4 is provided with an opening 43 on the side wall facing the functional board 3 when tightened. The edge of the opening 43 is connected to a liquid storage tank 44 inside the long board box 4, and a long board electromagnet 59 is slidingly provided in the liquid storage tank 44.

[0040] In order to achieve precise movement of the long board electromagnet 59 and adaptive locking of the functional board 3, adaptive cooperative locking components 5 are symmetrically provided at both ends of the long board box 4. The adaptive cooperative locking components 5 include multiple support members 51. Specifically, the support member 51 on the placement slot 1 and the support member 51 on the outside of the long board box 4 are linked through a gear group; the support member 51 on the outside of the long board box 4 and the support member 51 inside the long board box 4 are linked through a sprocket group; the support member 51 inside the long board box 4 and the long board electromagnet 59 are linked through a rack group.

[0041] The gear set includes a first gear 52, a second rotating shaft 531 and a second gear 53. The first gear 52 is fixed on the support 51 of the placement slot 1, and the first gear 52 is coaxially arranged with the first rotating shaft 42 on the rotating member 41 of the corresponding long board box 4. The second rotating shaft 531 is engaged and rotated on the support 51 outside the long board box 4, and the second gear 53 is coaxially fixed on the second rotating shaft 531. When the long board box 4 rotates around the first rotating shaft 42, since the first gear 52 is fixed and the relative position of the second gear 53 and the long board box 4 remains unchanged through the support 51, the second gear 53 will perform planetary meshing motion around the fixed first gear 52, and the second gear 53 itself will also rotate.

[0042] The sprocket group includes a first sprocket 54, a second sprocket 56 and a chain 55. The first sprocket 54 is coaxially fixed on the second rotating shaft 531, so it will rotate synchronously with the second gear 53. The second sprocket 56 is engaged and rotated on the support member 51 inside the long board box 4. The chain 55 is tensioned and fitted on the first sprocket 54 and the second sprocket 56 to transmit the rotation of the first sprocket 54 to the second sprocket 56.

[0043] The rack group includes a third gear 57 and a linkage rack 58. The third gear 57 is coaxially fixedly connected to the second sprocket 56, so it will rotate synchronously with the second sprocket 56. The linkage rack 58 is arranged on the side of the long board electromagnet 59 facing away from the opening 43. The linkage rack 58 is meshed with the third gear 57. In particular, the third gear 57 is located between the linkage rack 58 and the second gear 53. This setting logic ensures that during the tightening of the long board box 4, the planetary motion and rotation of the second gear 53 are transmitted to the third gear 57 through the sprocket group. The rotation of the third gear 57 then drives the linkage rack 58 to move linearly, thereby pushing the long board electromagnet 59 to move toward the opening 43.

[0044] The power assembly 6 is used to drive the synchronous opening and closing of the long board box 4. Specifically, the power assembly 6 includes a plurality of bevel gears 61, each bevel gear 61 is coaxially arranged on the first rotating shaft 42 of the corresponding long board box 4, and the bevel gears 61 on the two adjacent first rotating shafts 42 located at a corner of the placement slot 1 are set to be vertically meshed and connected with each other. In this way, when one first rotating shaft 42 rotates, the engagement of the bevel gears 61 can drive the adjacent first rotating shaft 42 to rotate, thereby realizing the synchronous movement of the four long board boxes 4. For safety and aesthetics, protective covers 62 are provided on the two adjacent shaft supports 11 to cover the meshing bevel gears 61, and a self-locking motor 63 is provided on one of the protective covers 62. The output end of the self-locking motor 63 is coaxially fixedly connected to one of the bevel gears 61. As a practice of existing conventional technology, the self-locking motor 63 enables its output shaft to be automatically and firmly locked when it stops, preventing the long board box 4 from accidentally shaking, thereby ensuring the stability of state switching.

[0045] In order to achieve flexible wrapping of the edge of the functional board 3 and solidification and locking of the magnetic fluid, an elastic membrane 46 is provided on the opening 43 of the long board box 4. The elastic membrane 46 seals the opening 43. The elastic membrane 46 is usually preferably made of highly elastic, chemically resistant and wear-resistant materials, such as silicone rubber or special polyurethane elastomer, which is used to seal the magnetic fluid and achieve flexible wrapping of the edge of the functional board 3. The elastic membrane 46, the liquid storage tank 44 and the long board electromagnet 59 together form a closed space, which is pre-filled with magnetic fluid. Magnetic fluid is an intelligent material that can change its rheological properties under the action of a magnetic field.

[0046] In order to regulate the movement range of the long board box 4, a limit plate 12 is provided on the side wall of the placement slot 1. When the long board box 4 is fully unfolded, it will be parallel to the wall and blocked by the limit plate 12 to prevent excessive unfolding. When the long board box 4 is fully tightened, it will be perpendicular to the wall and blocked by the side wall of the placement slot 1 to ensure that it reaches the closed position accurately.

[0047] In order to power the long board electromagnet 59 , a power adapter 45 is provided inside the long board box 4 . The power adapter 45 is electrically connected to the long board electromagnet 59 and is used to convert external power into a voltage and current suitable for the operation of the long board electromagnet 59 .

[0048] When the long board box 4 is fully unfolded, the elastic membrane 46 is in its initial, unstretched state. When the long board box 4 is tightened and the adaptive cooperative locking assembly 5 drives the long board electromagnet 59 to move toward the opening 43, the long board electromagnet 59 will squeeze the magnetic fluid in the enclosed space, so that the magnetic fluid pushes the elastic membrane 46 to bulge outward. Since the elastic membrane 46 is elastic, its bulging part can flexibly adapt to and wrap the front and rear sides of the edge of the functional board 3, achieving precise fit, and is not affected by the slight differences in the thickness and edge contour of the functional board 3.

[0049] The working process of this device is as follows:

[0050] First, fix the placement slot 1 on the wall in the center of the podium, and fix the TV 2 in the placement slot 1. When the teacher needs to use the TV 2 for teaching, the four long board boxes 4 are in a fully expanded state, parallel to the wall, and blocked by the limit plate 12. At this time, the screen of the TV 2 will not be blocked. When the function board 3 needs to be used, the teacher first hangs the selected function board 3 on the hanging column 13 on the upper part of the placement slot 1 to complete the initial placement of the function board 3. At this time, the function board 3 is located directly in front of the TV 2 and maintains a certain distance from the TV 2. Then the self-locking motor 63 is turned on, and the output shaft of the self-locking motor 63 rotates to drive the bevel gear 61 coaxially connected to it to rotate. The rotation of the bevel gear 61 drives the first rotating shaft 42 of the adjacent long board box 4 to rotate through another bevel gear 61 vertically meshing, and so on, so that all four long board boxes 4 are synchronously flipped toward the direction of the function board 3, presenting a motion trajectory similar to the tightening of petals.

[0051] When the gear 52 is in the gear 52 position, the second gear 53 is rotated around the first gear 52 and the second gear 53 is rotated.

[0052] When the four long board boxes 4 are fully tightened and blocked by the side walls of the placement slot 1 and no longer move further, the self-locking motor 63 can be controlled to automatically stop rotation and self-lock by detecting the resistance change through a preset stroke constraint (such as a limit switch) or a torque sensor. At this time, the elastic membrane 46 raised by the magnetic fluid has tightly and adaptively wrapped the front and back sides of all edges of the functional board 3, achieving a perfect fit with the edge contour of the functional board 3. Turn on the power, and the power adapter 45 supplies power to the long board electromagnet 59 to generate a magnetic field. Under the action of the magnetic field, the magnetic fluid surrounding the edge of the functional board 3 quickly solidifies. The magnetic fluid is also called magnetorheological fluid. Under the action of the magnetic field, the internal magnetic particles will quickly arrange into a chain structure, causing the liquid viscosity to increase dramatically, and change from a flow-like state to a solid-like state, thereby firmly locking the functional board 3 in the current position. Due to the flexible wrapping and solidification characteristics of the magnetic fluid, even functional boards 3 with different thicknesses or imperfect edges can be stably and reliably fixed.

[0053] When the function board 3 needs to be removed, first turn off the power supply of the long board electromagnet 59 to demagnetize it, and the magnetic fluid will restore its fluid state after losing the magnetic field. Then turn on the self-locking motor 63 in the reverse direction, and the self-locking motor 63 drives the bevel gear 61 to rotate in the reverse direction, so that the four long board boxes 4 are synchronously expanded outward. During the expansion of the long board boxes 4, the linkage mechanism of the adaptive cooperative locking assembly 5 also moves in the reverse direction, so that the long board electromagnet 59 retracts into the inside of the long board box 4. The elastic membrane 46 gradually returns to its initial unexpanded state under the action of its own elasticity and the reflux of the magnetic fluid. Finally, when the four long board boxes 4 are fully expanded and blocked by their respective limit plates 12, the self-locking motor 63 automatically stops and self-locks. At this time, the teacher can easily remove the function board 3 from the hanging column 13.

[0054] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0055] While the embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that various changes, modifications, substitutions, and alterations can be made to the embodiments without departing from the principles and spirit of the invention.

[0056] The present invention and its embodiments are described above. This description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs structures and embodiments similar to this technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. A preschool education teaching demonstration device, comprising a placement slot (1) and a television (2), wherein the bottom of the placement slot (1) is fixedly arranged close to a wall surface, and the television (2) is fixed in the placement slot (1), characterized in that: The device further comprises a plurality of hanging posts (13) provided on the upper portion of the placement slot (1), a function board (3) suspended on the hanging posts (13) and located in front of the television (2), and four long board boxes (4) provided on the periphery of the placement slot (1), wherein rotating members (41) are provided at both ends of the long board boxes (4), a first rotating shaft (42) provided on the rotating member (41) is rotatably connected to an axis support (11) provided at both ends of each side of the placement slot (1), a power assembly (6) is provided on the first rotating shaft (42) for synchronously driving all the long board boxes (4) to expand and tighten in a petal-like manner, the long board boxes (4) surround the function board (3) when tightened, an opening (43) is provided on the side wall of the long board box (4) facing the function board (3) when tightened, a liquid storage tank (44) is provided at the edge of the opening (43) inside the long board box (4), and a long board electromagnet (59) is slidably provided in the liquid storage tank (44); The two ends of the long board box (4) are symmetrically provided with adaptive cooperative locking components (5), and the adaptive cooperative locking components (5) include a plurality of support members (51), the support members (51) on the placement slot (1) and the support members (51) outside the long board box (4) are linked via a gear group, the support members (51) outside the long board box (4) and the support members (51) inside the long board box (4) are linked via a sprocket group, and the support members (51) inside the long board box (4) and the long board electromagnet (59) are linked via a rack group; An elastic membrane (46) is provided on the opening (43) to seal the opening (43), and a closed space formed by the elastic membrane (46), the liquid storage tank (44) and the long plate electromagnet (59) is filled with magnetic fluid; When the long plate box (4) is fully unfolded, the elastic membrane (46) is in an initial unstretched state. When the long plate box (4) is fully retracted, the elastic membrane (46) is stretched open by the outwardly extending long plate electromagnet (59) and the magnetic fluid to wrap around both sides of the edge of the functional plate (3).

2. A preschool education teaching demonstration device according to claim 1, characterized in that: The gear set comprises a first gear (52), a second rotating shaft (531) and a second gear (53), wherein the first gear (52) is fixedly arranged on the support member (51) of the placement slot (1), the first gear (52) is coaxially arranged with the first rotating shaft (42) on the rotating member (41), the second rotating shaft (531) is engaged and rotatably arranged on the support member (51) outside the long board box (4), the second gear (53) is coaxially arranged on the second rotating shaft (531), and the second gear (53) performs planetary meshing motion around the first gear (52).

3. A preschool education teaching demonstration device according to claim 2, characterized in that: The sprocket assembly comprises a first sprocket (54), a second sprocket (56) and a chain (55); the first sprocket (54) is coaxially arranged on the second rotating shaft (531) and rotates synchronously with the second gear (53); the second sprocket (56) is engaged and rotated on a support member (51) inside the long board box (4); and the chain (55) is cooperatively arranged on the first sprocket (54) and the second sprocket (56).

4. A preschool education teaching demonstration device according to claim 3, characterized in that: The rack assembly comprises a third gear (57) and a linkage rack (58), wherein the third gear (57) is coaxially fixedly connected to the second sprocket (56), and the linkage rack (58) is arranged on the side of the long plate electromagnet (59) facing away from the opening (43). The linkage rack (58) is meshedly connected with the third gear (57), and the third gear (57) is located between the linkage rack (58) and the second gear (53).

5. A preschool education teaching demonstration device according to claim 4, characterized in that: The power assembly (6) includes a bevel gear (61) coaxially arranged on the first rotating shaft (42), and the bevel gears (61) on two adjacent first rotating shafts (42) located at a corner of the placement slot (1) are vertically meshed and connected, and protective covers (62) are provided on two adjacent shaft supports (11) to cover the bevel gears (61), and a self-locking motor (63) is provided on one of the protective covers (62), and the output end of the self-locking motor (63) is coaxially fixedly connected to one of the bevel gears (61).

6. A preschool education teaching demonstration device according to claim 5, characterized in that: A limiting plate (12) is provided on the side wall of the placement slot (1); when the long board box (4) is fully unfolded, it is parallel to the wall and blocked by the limiting plate (12); when the long board box (4) is fully retracted, it is perpendicular to the wall and blocked by the side wall of the placement slot (1).

7. A preschool education teaching demonstration device according to claim 6, characterized in that: A power adapter (45) is provided inside the long board box (4), and the power adapter (45) is electrically connected to the long board electromagnet (59).

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