Rotary angle measurement teaching aid

Abstract

The utility model discloses a rotary angle measurement teaching aid which comprises a main frame body and an angle measurement assembly. The connecting assembly is used for connecting the first semicircular ruler and the second semicircular ruler, so that the main frame body has an unfolded state and a folded state; in the unfolded state, the first semicircular ruler and the second semicircular ruler are arranged in an overlapping manner, so that the projection area of the main frame body is reduced; the angle measuring assembly comprises an angle mark which is used for being matched with the main frame body to observe a numerical value corresponding to the measured angle. According to the utility model, the main frame body adopts the folding structure design, so that the technical problems of overlarge axial projection area and inconvenience in carrying of the traditional angle measurement teaching aid are effectively solved. The device is simple in structure, easy to manufacture and use and suitable for large-scale production and popularization.

Description

TECHNICAL FIELD

[0001] The utility model relates to writing or drawing technical field, especially, relate to a rotary angle measurement teaching aid. BACKGROUND

[0002] Angle measurement teaching aid is the tool commonly used in mathematics teaching and learning, is widely used in teacher's teaching, student homework and geometry drawing scene etc.. Traditional angle measurement teaching aid usually adopts half circle or full circle protractor structure, is made of transparent plastic or metal material, has angle scale on the surface, is directly observed and measured angle for user. However, the existing product has the insufficient that overall size is too big, and the portability is poor in design and function, and the traditional protractor usually adopts the half circle or circular structure of fixed size, and the overall size is big, causes the problem of inconvenient carrying. Aiming at the above problem, a compact structure, function optimized angle measurement teaching aid is needed to improve its portability. SUMMARY

[0003] In order to overcome the insufficient of prior art, the utility model discloses a rotary angle measurement teaching aid, solves the problem that the measurement teaching aid is poor in portability.

[0004] The utility model discloses the purpose is realized by the following technical scheme:

[0005] A rotary angle measurement teaching aid, characterized in that, comprising:

[0006] A main frame, the main frame includes a first semicircular ruler, a second semicircular ruler and a connecting assembly, the connecting assembly is used for connecting the first semicircular ruler and the second semicircular ruler, so that the main frame has an unfolded state and a folded state, the projection area of the main frame along the axial direction is a first area when the main frame is in the unfolded state, the projection area of the main frame along the axial direction is a second area when the main frame is in the folded state, the first area is greater than the second area, the first semicircular ruler and the second semicircular ruler are arranged in an overlapping manner when the main frame is in the folded state, and the first semicircular ruler and the second semicircular ruler have angle scale values respectively.

[0007] An angle measuring assembly, the angle measuring assembly includes an angle scale, and the angle scale is used to cooperate with the main frame to observe the value corresponding to the measured angle.

[0008] Further, the first semicircular ruler and the second semicircular ruler are arranged in a coplanar manner when the main frame is in the unfolded state.

[0009] Further, the connecting assembly is a hinge structure, and the angle scale is movably connected to the main frame.

[0010] Further, the angle measuring assembly further comprises a rotating connecting structure, the angle marker is movably connected with the rotating connecting structure, the angle marker is rotatably connected with the central shaft of the main frame through the rotating connecting structure, and the pointing end of the angle marker is matched with the scale of the circular ruler to read the angle value.

[0011] Further, the rotating connecting structure comprises a fixed column and an axial limiting assembly, the fixed column is embedded in the central shaft of the main frame, the axial limiting assembly is arranged at one end of the fixed column, the opposite sides of the pivoted end of the angle marker are respectively abutted against the axial limiting assembly and the main frame, and the limiting hole of the pivoted end of the angle marker is movably matched with the fixed column.

[0012] Further, the first label and the second label are connected through a third easy-tear structure, so that the first label and the second label can be separated.

[0013] Further, the angle marker is provided with a linear scale along the direction of the central shaft of the main frame, and the linear scale is used for measuring the length or radius value of the measured person.

[0014] Further, the buckle structure or the magnetic interface is movably matched with the edge of the main frame, so that the angle marker can cross the junction of the first half circular ruler and the second half circular ruler when the main frame is in the unfolded state.

[0015] Further, the angle marker is movably connected with the main frame.

[0016] Further, the first half circular ruler and the second half circular ruler of the main frame are provided with magnetic attraction matching structures at corresponding edges, and when the main frame is in the folded state, the corresponding magnetic structures of the first half circular ruler and the second half circular ruler are attracted to each other.

[0017] Further, the rotating angle measuring teaching aid further comprises a timing display module or a time dial, and the timing display module or the time dial is connected at the central shaft of the main frame through the buckle structure.

[0018] Compared with the prior art, the angle measuring teaching aid has the beneficial effects that:

[0019] 1. The first half circular ruler and the second half circular ruler are used in cooperation to expand the angle measurement range, and the first half circular ruler and the second half circular ruler are close to each other and overlap, so that the size of the main frame 1 can be reduced for storage.

[0020] 2. Adopting folding structure design: connecting the first semicircular ruler and the second semicircular ruler through the connecting assembly, so that the main frame has two states of unfolding and folding, in the folded state, the two semicircular rulers are overlapped, and the projection area is reduced by about 50% after folding, effectively solving the technical problems of the overall size of the traditional angle measurement teaching aid being too large and inconvenient to carry. The design greatly improves the portability and storage convenience of the product while ensuring complete measurement function. The design not only retains the function of the traditional protractor, but also optimizes the portability and use efficiency through the foldable structure.

[0021] 3. Adopting magnetic attraction structure design: complementary magnetic attraction structures are arranged on the corresponding edges of the first semicircular ruler and the second semicircular ruler, when the main frame is in the folded state, the stable locking of the teaching aid is realized through the mutual attraction of the magnets. The design not only avoids the defects of the traditional angle measurement teaching aid, such as easy wear and tear and inconvenient operation, but also effectively prevents accidental unfolding during transportation or carrying, significantly improving the use reliability of the product.

[0022] 4. Multifunctional modular integration: integrating a detachable timing display module at the center shaft through a standardized buckle structure, including two implementation modes of an electronic timer and a mechanical time scale, realizing the organic integration of angle measurement and time management functions, and the modular design enables the teaching aid to adapt to various teaching scene requirements. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a structure schematic view of a rotating angle measurement teaching aid of the first embodiment of the utility model, at this time, the rotating angle measurement teaching aid is in a folded state;

[0024] Figure 2 is a structure schematic view of a rotating angle measurement teaching aid of the first embodiment of the utility model, at this time, the rotating angle measurement teaching aid is in an unfolded state.

[0025] In the figure: 1, main frame; 2, angle mark; 3, hinge structure; 4, magnetic attraction structure; 5, time scale. DETAILED DESCRIPTION

[0026] In the following, the utility model is further described in combination with the drawings and specific embodiments, and it should be noted that the following described embodiments or technical features can be combined to form new embodiments without conflict.

[0027] It should be noted that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. Where, when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements can also be present. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0029] First embodiment:

[0030] Referring to Figure 1 , Figure 2 , a kind of rotary angle measurement teaching aid of a preferred embodiment of the application is shown, the rotary angle measurement teaching aid includes main frame body 1 and angle measuring assembly;The main frame body 1 includes first semicircular ruler, second semicircular ruler and connecting assembly;The connecting assembly is used to connect the first semicircular ruler and second semicircular ruler, so that the main frame body 1 has unfolded state and folding state;The projection area of the main frame body 1 along the axial direction of the main frame body 1 is first area when the main frame body 1 is in unfolded state, the projection area of the main frame body 1 along the axial direction of the main frame body 1 is second area when the main frame body 1 is in folding state, and the first area is greater than the second area;When the main frame body 1 is in folding state, the first semicircular ruler and the second semicircular ruler are arranged in overlap;The first semicircular ruler and second semicircular ruler have angle scale values respectively;The angle measuring assembly includes angle mark 2, and the angle mark 2 is used to cooperate with main frame body 1 to observe the numerical value corresponding to the measured angle.

[0031] Obviously, based on the cooperation of the first semicircular ruler and the second semicircular ruler, the measurement range of the angle is expanded, and after the first semicircular ruler and the second semicircular ruler are closed and overlapped, the size of the main frame body 1 can be reduced for storage. Based on the folding structure design: the first semicircular ruler and the second semicircular ruler are connected by the connecting assembly, so that the main frame body 1 has two states of unfolding and folding, and in the folding state, the two semicircular rulers are arranged in overlap, and the projection area is reduced by about 50% after folding, effectively solving the technical problems of the overall size of the traditional angle measurement teaching aid being too large and being inconvenient to carry. The design greatly improves the portability and storage convenience of the product while ensuring complete measurement function. The design not only retains the function of the traditional protractor, but also optimizes the portability and use efficiency through the foldable structure.

[0032] The connecting assembly adopts a certain connecting structure to connect the first semicircular ruler and the second semicircular ruler, so that the first semicircular ruler and the second semicircular ruler can rotate relative to each other, thereby realizing the two use states of the unfolded and folded main frame body 1. When the main frame body 1 is unfolded, the two semicircular rulers are in a 180° flat state, and the axial projection forms a complete circle with a first area. At this time, 0°-360° full range angle measurement and drawing can be performed. When folded, the two semicircular rulers are overlapped by rotating to form a second area, so that the overall size is reduced by about 50%, facilitating carrying and storage. In a specific implementation, the first semicircular ruler and the second semicircular ruler are both made of transparent wear-resistant material, and the surfaces are respectively marked with complementary angle scales, such as 0°-180° for the first semicircular ruler and 180°-360° for the second semicircular ruler. When unfolded, the scales are continuously aligned to ensure measurement accuracy.

[0033] Preferably, the connecting assembly is a hinge structure 3. The above-mentioned method plays a core role in realizing stable rotational connection of the first semicircular ruler and the second semicircular ruler, while ensuring the angle measurement accuracy in the unfolded state and the compact storage in the folded state. The connecting assembly adopts a precision hinge structure 3. In a specific implementation, the hinge adopts a zinc alloy material shell matched with a stainless steel shaft core, and a wear-resistant nylon gasket is provided at the shaft to ensure smooth rotation and prolong the service life. The hinge is fixed on both sides of the semicircular ruler through embedded screws, and a reinforcing rib is designed at the connection to withstand repeated mechanical stress. In addition, a soft rubber protective sleeve is wrapped outside the hinge to prevent bumping and improve grip comfort, so that the teaching aid meets the dual needs of teaching demonstration and daily use by students. As an alternative setting method, the connecting assembly is a circular arc groove and a circular arc protrusion, which are respectively provided on the first semicircular ruler and the second semicircular ruler. The circular arc groove and the circular arc protrusion are in sliding cooperation to enable the main frame body 1 to switch between the unfolded state and the folded state.

[0034] Preferably, the angle scale 2 is movably connected to the main frame body 1. The angle scale 2 is movably connected to the main frame body 1, and its core role is to realize dynamic adjustment of the angle scale and multifunctional measurement. This design can adopt a sliding rail type connecting structure or a mechanical rotary connecting structure. Specifically, the angle scale 2 is installed on the main frame body 1 in a hinged manner. As an alternative setting method, the angle scale 2 can be a ruler or a rope. In another embodiment, as an alternative to movable connection, the angle scale 2 can be used together with the main frame body 1, but they are separated from each other for independent storage when stored.

[0035] Preferably, the angle measuring assembly further comprises a rotating connection structure, the angle marker 2 is movably connected with the rotating connection structure, the angle marker 2 is rotatably connected with the central axis of the main frame 1 through the rotating connection structure, and the pointing end of the angle marker 2 is matched with the scale of the circular ruler to read the angle value. The rotating connection structure is designed in a precise bearing or pivoting manner to ensure that the angle marker 2 remains stable and does not shake during rotation, thereby ensuring the accuracy of angle measurement. The pointing end of the angle marker 2 is accurately matched with the scale of the circular ruler, and the user can quickly position the target angle by rotating the angle marker 2 and directly read the scale value, realizing intuitive and efficient angle measurement. In principle, the rotating connection structure is fixedly connected with the main frame 1 through the central axis, and the angle marker 2 is rotatable by 360 degrees through the bearing or low-friction rotating shaft. When the angle marker 2 rotates, its pointing end always points to the corresponding scale on the circular ruler, and the user only needs to rotate the angle marker 2 to the side line of the angle to be measured to directly read the scale value, which is simple to operate and has small error. In addition, a damping device can be provided in the rotating connection structure, so that the angle marker 2 can stop at any position during rotation, avoiding deviation caused by accidental touch and improving measurement stability.

[0036] In specific implementation, the rotating connection structure can be made of metal or high-strength plastic to ensure durability and light weight. The angle marker 2 and the rotating connection structure are fixed by buckles or screws, which is convenient for disassembly, maintenance or replacement. The pointing end of the angle marker 2 is designed to be sharp or with a magnifying function, which further improves the reading accuracy. In addition, the rotating connection structure can integrate an angle locking button, which can be pressed by the user to fix the current angle, facilitating recording or drawing. The overall design takes into account functionality, durability and user experience, and is suitable for teaching, engineering drawing and other scenarios.

[0037] Preferably, the rotating connection structure comprises a fixed column and an axial limiting component, the fixed column is embedded in the central axis of the main frame 1, the axial limiting component is arranged at one end of the fixed column, the opposite sides of the pivoting end of the angle marker 2 abut against the axial limiting component and the main frame 1 respectively, and the limiting hole of the pivoting end of the angle marker 2 movably matches with the fixed column. The core function of the above-mentioned mode is to ensure that the fixed column is embedded in the central axis of the main frame 1 to form a stable rotating reference. The axial limiting component is arranged at one end of the fixed column and cooperates with the main frame 1 to form an axial clamping structure, so that the pivoting end of the angle marker 2 is accurately constrained on the fixed column, which can freely rotate and avoid axial movement. The pivoting end of the angle marker 2 is provided with a limiting hole to keep coaxial during rotation, and its two sides abut against the axial limiting component and the surface of the main frame 1 respectively to form a three-positioning mechanism.

[0038] The core principle of the structure is to realize the function that the angle table can rotate but not deviate through modular axial constraint, that is, the fixed column is used as the rotating center axis and is pressed into the center hole of the main frame 1 by interference fit; the axial limiting assembly includes a limiting baffle which is fixed at the top end of the fixed column by a screw to form an adjustable axial pre-tightening force. When the angle scale 2 rotates, the limiting hole at the pivotal end thereof slides along the outer wall of the fixed column, and the contact surfaces on both sides are coated with a special material to reduce the friction coefficient and ensure smooth rotation. The axial limiting assembly provides constant pressure, which eliminates the assembly gap and avoids over-tightening.

[0039] In implementation, the fixed column is made of stainless steel, and the diameter tolerance is controlled within a certain range; the limiting hole at the pivotal end of the angle scale 2 is embedded with a copper alloy bushing, and an oil storage groove is formed in the inner wall to realize self-lubrication. The axial limiting assembly realizes fine adjustment of the pre-tightening force through threaded connection, and a lock nut is used to ensure that it does not loosen during long-term use. This structure is particularly suitable for teaching scenarios that require repeated and accurate measurement.

[0040] Preferably, the angle scale 2 is provided with a linear scale along the direction of the center axis of the main frame 1, which is used to measure the length or radius value of the measured object. The angle scale 2 is provided with a linear scale along the direction of the center axis of the main frame 1, which realizes the integration of angle measurement and length measurement. Its core function is to simultaneously complete angle calculation and size measurement through a single teaching aid, which is particularly suitable for geometric drawing scenarios that require simultaneous acquisition of angle value and line length, such as fan radius measurement and triangle side length determination. The introduction of the linear scale upgrades the teaching aid from a single angle measurement tool to a multifunctional plotter, significantly improving teaching efficiency.

[0041] In terms of structural principle, the linear scale is laser engraved with double-scale marks in millimeters or centimeters as units along the length direction of the angle scale 2 with the center axis of the main frame 1 as the zero reference point. When the angle scale 2 is rotated and expanded, the extended part forms a movable measuring arm, and the reading is taken through the cooperation of the scale and the indicating mark on the edge of the main frame 1. In addition, a sliding vernier design can also be innovatively used, that is, a transparent slide is embedded on the side of the angle scale 2, and the indicating line on the slide forms a vernier caliper type measurement structure with the linear scale, which has a certain accuracy in length measurement accuracy. At the same time, a zero reset mechanism is provided at the center axis to ensure that each measurement starts from the reference point.

[0042] In specific implementation, the linear scale is made of wear-resistant ABS material, with a scratch-resistant coating on the surface and UV printing process to ensure clear and durable scale. The angle scale 2 is embedded with metal reinforcing ribs to maintain rigidity and prevent deformation during extension measurement. Three modes are developed to support the use: basic mode for direct reading of scale value; precise mode for sliding cursor for subdivided reading; and teaching demonstration mode for quick fixing of commonly used length through the magnetic attraction positioning point at the center axis. When measuring the radius, the angle scale 2 is rotated to the desired position, and the value at the intersection of the linear scale and the main frame 1 is read, which is intuitive and convenient. The integrated design adds at least multiple geometric measurement application scenarios while maintaining the original angle measurement function.

[0043] Preferably, the first and second semicircular scales of the main frame 1 are provided with magnetic attraction structures 4 corresponding to the edges, and when the main frame 1 is in a folded state, the corresponding magnetic structures of the first and second semicircular scales are attracted to each other. The further optimized magnetic attraction structure 4 design enables the teaching aid to automatically and accurately align and firmly lock when folded. This design not only avoids the defects of traditional angle measurement teaching aids such as wear and inconvenience of operation, but also effectively prevents accidental unfolding during transportation or carrying, significantly improving the use reliability of the product. The magnetic attraction system uses a magnet array with polar symmetry, and when the semicircular scales are folded and overlapped, the N-pole magnetic block at the edge of the first semicircular scale will automatically attract and position with the S-pole magnetic block at the edge of the second semicircular scale, generating a certain holding force to ensure that the teaching aid does not accidentally unfold when carried in a backpack or pencil case. The magnetic attraction structure also has a guiding function, and through the tapered magnetic pole design, the two semicircular scales can automatically correct positional deviation when a certain distance apart, achieving millimeter-level self-alignment folding.

[0044] In an embodiment, the magnetic attraction assembly adopts an embedded modular design: each semicircular scale edge is provided with 5 groups of magnetic steel with a diameter of 3mm, the adjacent magnetic steels are spaced apart by 10mm, and the outside is covered with a 0.5mm thick anti-collision rubber layer. The magnetic steels of the first semicircular scale are arranged in N-S-N-S staggered order for polarity arrangement, and the second semicircular scale adopts a completely complementary S-N-S-N arrangement to ensure maximum attraction efficiency. The magnetic steels and the scale body are fixed with epoxy resin glue, and the structure strength is enhanced by laser welding stainless steel edge covering. Actual tests show that this design can achieve a certain magnetic force required for more than several folding cycles, and the overall thickness in the folded state is reduced by 20% compared with the traditional buckle type structure. When teaching, the teacher can demonstrate the principle of magnetic attraction, and when the two semicircular scales are close to a certain distance, they will automatically fold.

[0045] Preferably, the rotating angle measurement teaching aid further comprises a timing display module or time dial 5 connected to the center axis of the main frame 1 through a buckle structure.

[0046] The utility model further innovates the integrated design of timing display module, and makes the traditional angle measuring tool upgrade to the teaching instrument with time management function. The module adopts the modular quick release structure, is connected through the positioning buckle at the central shaft and the main frame body 1 or the rotary connection structure, can keep integrity and can be replaced independently. Its core function is to cultivate the time concept of students when measuring angle, and it is especially suitable for limited time classroom practice scene. In specific implementation, the timing module shell adopts the same material as the main frame body 1, such as translucent PC alloy or ABS alloy, and the diameter is controlled to be the same as the diameter of the central shaft cover plate. The electronic version is equipped with three key controls, such as mode, setting and start, and has a certain waterproof level; the mechanical version can observe the internal gear operation through the transparent dial. When installing, it can be locked by aligning the buckle position and rotating 45 DEG, and when disassembling, it can be released by pressing the bottom. The design has shown unique advantages in actual teaching. In geometry examination, teachers can set the countdown function uniformly. Through testing, the additional module only increases about 18g weight, but greatly improves the functional value of the teaching aid.

[0047] Second embodiment:

[0048] The second embodiment of the utility model provides a rotary angle measuring teaching aid with optimized structure, namely, when the main frame body 1 is in the unfolded state, the first semicircular ruler and the second semicircular ruler are arranged in the same plane. The innovation lies in that when the main frame body 1 is in the unfolded state, the first semicircular ruler and the second semicircular ruler are arranged in the same plane through the precise plane calibration mechanism. The core function of the design is to eliminate the seam error of the traditional folding protractor, ensure that the unfolded measurement reference surface meets the industrial plane degree requirement, and the plane degree error is less than a certain value, and it is especially suitable for high-precision geometric drawing and professional drawing. The embodiment effectively solves the technical problems of the traditional angle measuring teaching aid, such as large overall size and inconvenience in carrying. The design greatly improves the portability and storage convenience of the product while ensuring complete measurement function.

[0049] Third embodiment:

[0050] The third embodiment of the utility model provides a rotary angle measuring teaching aid with optimized structure, and the third embodiment further includes the first embodiment, and the difference lies in that the angle mark 2 has a buckle structure or a magnetic interface, and the buckle structure or the magnetic interface is movably matched at the edge of the main frame body 1, so that the angle mark 2 can cross the junction of the first semicircular ruler and the second semicircular ruler when the main frame body 1 is in the unfolded state.

[0051] Preferably, the angle mark 2 is detachably connected with the main frame body 1.

[0052] The core improvement of this embodiment is that the angle mark 2 adopts a different connection design, and is connected with the edge of the main frame 1 through a buckle structure or a magnetic interface. The outstanding advantage of this design is that when the teaching aid is unfolded for use, the angle mark 2 can seamlessly cross the connection joint between the first semicircular ruler and the second semicircular ruler, completely solving the measurement blind area problem caused by the joint of the traditional folding protractor, and realizing 360° continuous measurement without dead angle. The third embodiment of the utility model retains all the functions of the first embodiment, and innovatively improves the structure of the angle mark 2. The core improvement of this embodiment is that the angle mark 2 adopts a modular connection design, and is connected with the edge of the main frame 1 through a buckle structure or a magnetic interface. The outstanding advantage of this design is that when the teaching aid is unfolded for use, the angle mark 2 can seamlessly cross the connection joint between the first semicircular ruler and the second semicircular ruler, completely solving the measurement blind area problem caused by the joint of the traditional folding protractor, and realizing 360° continuous measurement without dead angle.

[0053] The rotating angle measurement teaching aid includes a main frame 1, which adopts a rotatable double-semicircular structure design and can realize seamless angle measurement of 0°-360°, which is not only suitable for angle measurement requirements of conventional mathematical problems, but also can be used for drawing accurate angles, arcs and geometric figures, greatly expanding the functional range of the traditional protractor. The rotating angle measurement teaching aid can be made of materials with the characteristics of lightness, impact resistance and wear resistance, such as environmentally friendly ABS engineering plastic or non-toxic TPU soft rubber material, and the edges are treated with round corner passivation to avoid sharp corners and ensure the safety of teachers and students during use and ensure its applicability to different scenes. In addition, the surface of the teaching aid is engraved with high-precision laser scales and is matched with double-color contrast marks, such as black background and white characters or fluorescent scales, to improve the recognition in different light environments. In order to further enhance the portability and protection, the teaching aid is also provided with a special storage box, the box body is lined with shockproof EVA or a hard PP shell, and the inside is provided with a clamping groove fixing structure, which can stably store the teaching aid and avoid the loosening of the structure connecting the two semicircular rulers or the wear of the scales due to collision and extrusion, especially suitable for students to carry and use frequently in class.

[0054] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the skilled person in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited. The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of various changes or replacements within the technical scope disclosed by the present application, which should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A rotational angle measurement teaching aid, characterized in that , comprising: a main frame (1) comprising a first semicircular ruler, a second semicircular ruler and a connecting assembly; the connecting assembly is used to connect the first semicircular ruler and the second semicircular ruler, so that the main frame (1) has an unfolded state and a folded state; the projection area of the main frame (1) in the axial direction is a first area when the main frame (1) is in the unfolded state, and the projection area of the main frame (1) in the axial direction is a second area when the main frame (1) is in the folded state; the first area is greater than the second area; the first semicircular ruler and the second semicircular ruler are arranged in an overlapping manner when the main frame (1) is in the folded state; the first semicircular ruler and the second semicircular ruler are respectively provided with an angular scale value; an angle measuring assembly comprising an angle scale (2), the angle scale (2) is used to cooperate with the main frame (1) to observe the angular scale value corresponding to the measured angle.

2. A rotational angle measurement teaching aid according to claim 1, wherein , the first semicircular ruler and the second semicircular ruler are arranged in a coplanar manner when the main frame (1) is in the unfolded state.

3. A rotational angle measurement teaching aid according to claim 1, wherein , the connecting assembly is a hinge structure (3); the angle scale (2) is movably connected to the main frame (1).

4. A rotational angle measurement teaching aid according to claim 3, wherein , the angle measuring assembly further comprises a rotary connection structure, the angle scale (2) and the rotary connection structure are movably connected, the angle scale (2) is rotatably connected to the central axis of the main frame (1) through the rotary connection structure, and the pointing end of the angle scale (2) cooperates with the scale of the ruler to read the angle value.

5. A rotational angle measurement teaching aid according to claim 4, wherein , the rotary connection structure comprises a fixed column and an axial limiting assembly, the fixed column is embedded in the central axis of the main frame (1); the axial limiting assembly is arranged at one end of the fixed column, the opposite sides of the pivotal end of the angle scale (2) abut against the axial limiting assembly and the main frame (1) respectively, and the limiting hole of the pivotal end of the angle scale (2) movably cooperates with the fixed column.

6. A rotational angle measurement teaching tool according to claim 3, wherein , the angle scale (2) is provided with a linear scale along the central axis direction of the main frame (1), and the linear scale is used to measure the length or radius value of the measured person.

7. A rotational angle measurement teaching aid according to claim 3, wherein The angle scale (2) has a buckle structure or a magnetic interface, which movably cooperates with the edge of the main frame (1), so that the angle scale (2) can span the junction of the first semicircular ruler and the second semicircular ruler when the main frame (1) is in the unfolded state.

8. A rotational angle measurement teaching aid according to claim 7, wherein , the angle scale (2) and the main frame (1) are detachably connected.

9. A rotational angle measurement teaching tool according to claim 1, wherein , the first semicircular ruler and the second semicircular ruler of the main frame (1) are provided with a magnetic attraction structure (4) corresponding to the edge, and when the main frame (1) is in the folded state, the corresponding magnetic structures of the first semicircular ruler and the second semicircular ruler are attracted to each other.

10. A rotational angle measurement teaching tool according to claim 1, wherein The rotating angle measuring teaching aid further comprises a timing display module or a time dial (5), which is connected at the central axis of the main frame (1) through a buckle structure.

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