Measuring tape
By introducing a rotation angle sensor and main control board into the tape measure, accurate readings are achieved in environments with insufficient light, solving the problem of traditional tape measure relying on line of sight and light, and improving scene adaptability.
Patent Information
- Application Number
- CN202510937792.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-08
- Publication Date
- 2025-09-05
AI Technical Summary
Traditional tape measure reads inaccurately in environments with insufficient light and poor scene adaptability, which depends on the user's line of sight and ambient light.
The rotation angle sensor and main control board are introduced into the tape measure. By detecting the rotation angle of the ruler core reel, the pull-out length of the ruler is calculated and played, and the electronic player is used to provide reading assistance in an environment with insufficient light.
It improves the accuracy of readings, reduces dependence on ambient light, and enhances the adaptability of the tape measure in different lighting conditions.
Smart Images
Figure CN120593582A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of measuring tools, in particular to a measuring tape. Background Art
[0002] A tape measure is a commonly used measuring tool. Comprising core components like a ruler, housing, and locking mechanism, it allows for quick measurement of the dimensions of an object. A tape measure is a portable measuring tool based on a spring-loaded mechanism, enabling it to measure lengths of several meters within confined spaces and offering repeated use without failure.
[0003] Traditional tape measures require users to observe with the naked eye to determine the measured size value. Although convenient, when reading, it is easy for the user's line of sight to be not perpendicular to the tape surface, resulting in reading offset. In addition, it is difficult to read clearly in low-light environments. It is highly dependent on the environment and lacks scene adaptability, and its use has great limitations. Summary of the Invention
[0004] The purpose of the present invention is to provide a tape measure to solve the problems existing in the above-mentioned prior art, improve the accuracy of readings, effectively get rid of dependence on the environment, and improve scene adaptability.
[0005] To achieve the above object, the present invention provides the following solutions: The present invention provides a tape measure, comprising a ruler box, a ruler core reel, a ruler strip, a rotation angle sensor and a main control board, the top end of the ruler box being a top plate, and the bottom end of the ruler box being a bottom plate; the ruler core reel is placed between the top plate and the bottom plate, the ruler core reel being able to rotate, a first mounting groove being provided on the top surface of the ruler core reel, a mounting post being fixedly provided in the first mounting groove; the inner end of the ruler strip is fixed on the ruler core reel, the ruler strip is wound on the ruler core reel, and the outer end of the ruler strip is provided outside the ruler box; the rotation angle sensor comprises a rotation module and a detection module, the rotation module being fixed on the mounting post, the rotation module being able to rotate following the ruler core reel, the detection module being fixed on the bottom surface of the main control board, and the detection module being able to detect the rotation angle of the rotation module; the main control board being fixed on the top surface of the top plate, the main control board being communicatively connected with the detection module, and an electronic player being fixed on the main control board.
[0006] Preferably, a support spring is further included, wherein the support spring is sleeved on the mounting column, and the top end of the support spring can press the rotation module onto the top plate or the main control board.
[0007] Preferably, a second mounting groove is provided on the bottom surface of the ruler core reel, a third mounting groove is provided on the top surface of the second mounting groove, a positioning column is fixed on the bottom plate, and the top end of the positioning column extends into the third mounting groove.
[0008] Preferably, it also includes a ruler spring, the inner end of the ruler spring is fixed on the positioning column, and the outer end of the ruler spring is fixed on the ruler core reel; the bottom end of the mounting column is fixed with a supporting tray, and the supporting tray can support the bottom end of the supporting spring, and the center of the top surface of the supporting tray has a first protrusion, and the outer side surface of the first protrusion can contact the inner side surface of the bottom end of the supporting spring; a plurality of first positioning grooves are opened on the outer surface of the supporting tray, and a plurality of first positioning protrusions are opened on the inner side surface of the first mounting groove, and the first positioning protrusions correspond to the first positioning grooves one by one, and the first positioning protrusions can be embedded in the first positioning groove; a second protrusion is provided on the bottom surface of the first mounting groove, and the second protrusion is coaxially arranged with the third mounting groove, and a fourth mounting groove is opened at the center of the bottom surface of the supporting tray, and the fourth mounting groove is sleeved on the second protrusion.
[0009] Preferably, the outer surface of the mounting column is provided with a plurality of second positioning protrusions, the rotating module is provided with a plurality of second positioning grooves, the second positioning protrusions correspond to the second positioning grooves one by one, and the second positioning protrusions can be embedded in the second positioning grooves.
[0010] Preferably, a circular hole is provided on the main control board, and the top of the mounting column has a cylindrical head, which extends into the circular hole and can rotate along the inner surface of the circular hole; the rotation module is fixedly mounted on the mounting column, and the rotation module is placed below the cylindrical head.
[0011] Preferably, the bottom surface of the top plate is provided with an annular rib, the rotation module is fixedly sleeved on the top end of the mounting column, and the rotation module can rotate along the inner side surface of the annular rib.
[0012] Preferably, the rotation angle sensor is a circular capacitive grating angle sensor, the rotation module is a moving grating disc, and the detection module is a circular capacitive grating fixed grating.
[0013] Preferably, the rotation angle sensor is a grating encoding sensor, the rotation module is a grating code disk, and the detection module is a slot-type optical coupler.
[0014] Preferably, the rotation angle sensor is a magnetic rotary encoding sensor, the rotation module includes a circular magnet and a magnet tray, and the detection module is a magnetic rotary encoder; the magnet tray is fixed on the mounting column, and a receiving groove is provided on the top surface of the magnet tray, and the circular magnet is fixed in the receiving groove.
[0015] Compared with the prior art, the present invention has achieved the following technical effects: The tape measure provided by the present invention provides an installation base for the rotation module of the rotation angle sensor by arranging a first installation groove on the top surface of the tape core reel and arranging a installation column in the first installation groove, detects the rotation angle of the rotation module by the detection module, and calculates the pull-out length of the tape based on the rotation angle of the rotation module by arranging a main control board with computing capability, and plays the calculation result of the pull-out length of the tape by arranging an electronic player, thereby effectively assisting the user's naked eye observation of the reading and improving the accuracy of the reading. In addition, the result playback of the electronic player can be suitable for environments with insufficient light, effectively getting rid of dependence on the environment and improving scene adaptability. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0017] Figure 1 This is a schematic diagram of the tape measure structure in Example 1; Figure 2 This is a schematic diagram of the circular capacity grid fixed grid in Example 1; Figure 3 Schematic diagram of the movable gate plate in Example 1; Figure 4 This is a schematic diagram of the tape measure structure in Example 2; Figure 5 Schematic diagram of the slot-type optical coupler in Example 2; Figure 6 Schematic diagram of the grating code disk in Example 2; Figure 7 This is a schematic diagram of the tape measure structure in Example 3; Figure 8 Schematic diagram of the circular magnet in Example 3; Figure 9 This is a schematic diagram of the magnet tray in Example 3; Figure 10 for Figure 9 Schematic diagram of the magnet tray in another direction; Figure 11 A schematic diagram of the mounting post and support tray in the tape measure provided by the present invention; Figure 12 for Figure 11 Schematic diagram of the mounting column and the supporting tray in another direction; In the figure: 1-ruler box, 2-ruler core reel, 3-ruler strip, 4-main control board, 5-top plate, 6-bottom plate, 7-first mounting slot, 8-mounting column, 9-rotation module, 10-detection module, 11-support spring, 12-second mounting slot, 13-third mounting slot, 14-positioning column, 15-ruler spring, 16-support tray, 17-first protrusion, 18-first positioning slot, 19-second protrusion, 20-fourth mounting slot, 21-second positioning protrusion, 22-cylindrical head, 23-annular rib, 24-circular magnet, 25-magnet tray. DETAILED DESCRIPTION
[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0019] The purpose of the present invention is to provide a tape measure to solve the problems existing in the above-mentioned prior art, improve the accuracy of readings, effectively get rid of dependence on the environment, and improve scene adaptability.
[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0021] Example 1 like Figure 1 、 Figure 2 、 Figure 3 、 Figure 11 and Figure 12 As shown, this embodiment provides a tape measure, including a ruler box 1, a ruler core reel 2, a ruler strip 3, a rotation angle sensor and a main control board 4, the top of the ruler box 1 is a top plate 5, and the bottom end of the ruler box 1 is a bottom plate 6; the ruler core reel 2 is placed between the top plate 5 and the bottom plate 6, the ruler core reel 2 can rotate, and a first mounting groove 7 is opened on the top surface of the ruler core reel 2, and a mounting column 8 is fixed in the first mounting groove 7; the inner end of the ruler strip 3 is fixed on the ruler core reel 2, the ruler strip 3 is wound on the ruler core reel 2, and the outer end of the ruler strip 3 is arranged outside the ruler box 1; the rotation angle sensor includes a rotation module 9 and a detection module 10, the rotation module 9 is fixed on the mounting column 8, the rotation module 9 can rotate with the ruler core reel 2, the detection module 10 is fixed on the bottom surface of the main control board 4, and the detection module 10 can detect the rotation angle of the rotation module 9; the main control board 4 is fixed on the top surface of the top plate 5, the main control board 4 is communicated with the detection module 10, and an electronic player is fixed on the main control board 4.
[0022] The tape measure provided in this embodiment provides an installation base for the rotation module 9 of the rotation angle sensor by setting a first installation groove 7 on the top surface of the ruler core reel 2 and setting a installation column 8 in the first installation groove 7. The rotation angle of the rotation module 9 is detected by the detection module 10. The main control board 4 with computing capability is provided to calculate the pull-out length of the ruler 3 based on the rotation angle of the rotation module 9. The calculation result of the pull-out length of the ruler 3 is played by providing an electronic player, thereby effectively assisting the user's naked eye observation of the reading and improving the accuracy of the reading. In addition, the result playback of the electronic player can be suitable for environments with insufficient light, effectively getting rid of dependence on the environment and improving scene adaptability.
[0023] The electronic player may specifically use an electronic display screen for screen display, may also use a voice player for voice broadcasting, and may also use an electronic display screen and a voice player at the same time.
[0024] The main control board 4 can be equipped with auxiliary units such as a microcontroller chip, a power supply circuit, and a drive circuit according to actual use requirements.
[0025] In this embodiment, the main control board 4 is locked on the top surface of the top plate 5 by screws, which is convenient for installation or disassembly; the inner end of the ruler 3 is snapped into the clamping groove on the ruler core reel 2, which is convenient for installation or disassembly, and the outer end of the ruler 3 is fixed with a hook, which is used to fix the object to be measured to ensure that the starting point of the measurement is accurate.
[0026] The specific principle of the main control board 4 calculating the pull-out length of the ruler 3 based on the rotation angle of the rotation module 9 is as follows: the rotation angle of the ruler core reel 2 is detected by using the rotation module 9 and the detection module 10, and the original signal of the detection module 10 is input into the microcontroller chip on the main control board 4. After being processed by the preset calculation program or software in the microcontroller chip, the rotation angle value of the ruler core reel 2 is obtained, and then combined with the diameter change of the ruler 3 wound on the ruler core reel 2, it is finally converted into the pull-out length value of the ruler 3, thereby obtaining the digital value of the measured length, which is convenient for other functional expansion applications such as digital recording, uploading, calculation and display.
[0027] Specifically, the formula for calculating the circumference of a circle is: 2πR; based on the differential principle, within a short period of time t, the angle value of the ruler core reel 2 rotated due to the pulling of the ruler bar 3 is recorded as θ t , converted into the pull-out length L of the ruler 3 t , then L t =2πR t (θ t / 360), R t is the radius of the circle where the three segments of the ruler are currently drawn, θ tThe rotation angle is detected by the rotation angle sensor and processed by the microcontroller chip; as the length of the ruler 3 is gradually increased, R t The value gradually decreases. By combining the diameter change of the strip 3 winding roll caused by the thickness of the strip 3 itself, it is easy to obtain the real-time radius R of the circle where the strip 3 is pulled out in each time period t. t Therefore, by accumulating the length L of the ruler 3 pulled out in each period of time t t , and then we get the total length L of the ruler 3 pulled out, then L=L0+L1+L2+L3+……+L t Similarly, when the ruler 3 has been pulled out to a length of L, when it is retracted, it is the reverse of the above process, and the length of the ruler 3 currently retracted is L. t By constantly subtracting the length L of the recycling ruler 3 t , thus obtaining the remaining length value L' of the ruler 3 that has been pulled out, then L'=L-L0-L1-L2-..., until the result is zero, which means that the ruler 3 is completely retracted.
[0028] As a more preferred implementation of this embodiment, the tape measure provided in this embodiment also includes a support spring 11, which is sleeved on the mounting column 8. The top of the support spring 11 can press the rotation module 9 onto the top plate 5 or the main control board 4. Since the mounting column 8 and the rotation module 9 rotate synchronously, the support spring 11 will not be twisted during the movement. The support spring 11 can provide a stable axial thrust, so that the rotation module 9 is close to the top plate 5 or the main control board 4 during the movement, thereby providing a relatively stable detection space structure for the rotation angle sensor, that is, the distance between the detection module 10 and the rotation module 9 remains basically stable, making the test signal more stable.
[0029] As a more preferred implementation of this embodiment, a second mounting groove 12 is provided on the bottom surface of the ruler core reel 2, a third mounting groove 13 is provided on the top surface of the second mounting groove 12, and a positioning column 14 is fixed on the bottom plate 6. The top end of the positioning column 14 extends into the third mounting groove 13 to facilitate the rotation of the ruler core reel 2 around the positioning column 14.
[0030] As a more preferred implementation of this embodiment, the tape measure provided in this embodiment also includes a ruler spring 15, the inner end of the ruler spring 15 is fixed on the positioning column 14, and the outer end of the ruler spring 15 is fixed on the ruler core reel 2. It should be noted here that the fixing and connection structure between the ruler spring 15, the ruler core reel 2 and the ruler strip 3 can adopt a conventional structure; the bottom end of the mounting column 8 is fixedly provided with a supporting tray 16, which can support the bottom end of the support spring 11, and a first protrusion 17 is provided at the center of the top surface of the supporting tray 16. The outer side surface of the first protrusion 17 can contact the inner side surface of the bottom end of the support spring 11, which can effectively limit the support spring 11, prevent the support spring 11 from radial displacement, and avoid uneven force on the rotating module 9; the outer surface of the supporting tray 16 is opened There are several first positioning grooves 18, and the inner side surface of the first mounting groove 7 is provided with several first positioning protrusions, the first positioning protrusions correspond to the first positioning grooves 18 one by one, and the first positioning protrusions can be embedded in the first positioning grooves 18 so that the supporting tray 16 and the mounting column 8 rotate synchronously with the ruler core reel 2; as an optional implementation method of this embodiment, the supporting tray 16, the mounting column 8 and the ruler core reel 2 can also be integrally molded during injection molding to make a complete component; a second protrusion 19 is provided on the bottom surface of the first mounting groove 7, and the second protrusion 19 is coaxially arranged with the third mounting groove 13. A fourth mounting groove 20 is opened at the center of the bottom surface of the supporting tray 16, and the fourth mounting groove 20 is sleeved on the second protrusion 19, which can effectively cooperate with the rotation positioning, improve the rotation stability and reduce shaking.
[0031] As a more preferred implementation of this embodiment, the outer surface of the mounting column 8 is provided with a plurality of second positioning protrusions 21, and the rotating module 9 is provided with a plurality of second positioning grooves. The second positioning protrusions 21 correspond one-to-one to the second positioning grooves, and the second positioning protrusions 21 can be embedded in the second positioning grooves to facilitate the synchronous rotation of the mounting column 8 and the rotating module 9.
[0032] As a more preferred implementation scheme of this embodiment, a circular hole is opened on the main control board 4, and the top of the mounting column 8 has a cylindrical head 22, which extends into the circular hole and can rotate along the inner surface of the circular hole; the rotation module 9 is fixedly mounted on the mounting column 8, and the rotation module 9 is placed below the cylindrical head 22, which can effectively cooperate with the rotation positioning, improve the rotation stability, and reduce shaking.
[0033] As a more preferred implementation manner of this embodiment, the rotation angle sensor is a circular capacitive grid angle sensor, the rotation module 9 is a moving grid disk, a mounting hole is provided in the middle of the moving grid disk, and a plurality of second positioning grooves are provided on the inner side surface of the mounting hole. The moving grid disk is in the shape of a circular disk as a whole, and the moving grid disk itself has no electrical characteristics. It has a specific signal reflection electrode, which reflects the signal from the signal emitter of the circular capacitive grid fixed grid back to the signal receiving electrode on the circular capacitive grid fixed grid according to a specific path. The detection module 10 is a circular capacitive grid fixed grid, which is in the shape of a circular disk as a whole, with signal emitters distributed in an umbrella rib shape, and a circular ring-shaped signal receiving electrode in the middle. The signal emitter emits a signal, and the signal is returned to the signal receiving electrode through the signal reflector of the moving grid disk, and the rotation angle signal is output after decoding inside the capacitive grid chip; an avoidance hole is provided on the top plate 5 to avoid the moving grid disk, facilitate the rotation of the moving grid disk, and facilitate the signal transmission between the moving grid disk and the circular capacitive grid fixed grid; the circular capacitive grid fixed grid is embedded in the main control board 4, and the moving grid disk needs to be close to the main control board 4.
[0034] Example 2 like Figure 4 、 Figure 5 and Figure 6 As shown, this embodiment provides a tape measure. Compared with the tape measure in Example 1, the main difference is that the type of rotation angle sensor is different. In this embodiment, the rotation angle sensor is a grating encoding sensor, and the rotation module 9 is a grating code disk. A mounting hole is provided in the middle of the grating code disk, and a plurality of second positioning grooves are provided on the inner side surface of the mounting hole. Windows are regularly opened or not opened around the mounting hole to form a specific grating structure. When rotating, the light emitted by the slot-type optical coupler is regularly blocked (or passed through). The detection module 10 is a slot-type optical coupler. The slot-type optical coupler has a transmitting tube and a receiving tube. The transmitting tube can emit light, and the receiving tube can collect light. As the grating code disk rotates, a pulse signal with a specific pattern is formed, which can be converted into a rotation angle; an avoidance hole is provided on the top plate 5 to avoid the slot-type optical coupler, so that the slot-type optical coupler can be easily extended into the ruler box 1; the grating code disk needs to be tightly attached to the top plate 5, and the position of the grating code disk is restricted by the top plate 5 to ensure that the relative position of the grating code disk and the slot-type optical coupler is stable.
[0035] Example 3 like Figure 7 、 Figure 8 、 Figure 9 and Figure 10 As shown, this embodiment provides a tape measure. Compared with the tape measure in Example 1, the main difference is the installation position and type of the rotation angle sensor. In this embodiment, an annular rib 23 is provided on the bottom surface of the top plate 5, and the rotation module 9 is fixedly mounted on the top of the mounting column 8. The rotation module 9 can rotate along the inner surface of the annular rib 23, can effectively cooperate with the rotation positioning, improve the rotation stability, and reduce shaking.
[0036] In this embodiment, the rotation angle sensor is a magnetic rotary encoding sensor, and the rotation module 9 includes a circular magnet 24 and a magnet tray 25. The circular magnet 24 is circular and radially magnetized, and can generate a specific magnetic field, which is convenient for the magnetic rotary encoder to detect; the detection module 10 is a magnetic rotary encoder, which can receive the magnetic field changes after the circular magnet 24 rotates, and decode and output the processed rotation angle signal; the magnet tray 25 is fixed on the mounting column 8, and a mounting groove is provided at the bottom end of the magnet tray 25, and a plurality of second positioning grooves are provided on the inner side surface of the mounting groove. A receiving groove is provided on the top surface of the magnet tray 25, and the circular magnet 24 is fixed in the receiving groove. Preferably, the circular magnet 24 is bonded to the receiving groove; an avoidance hole is provided on the top plate 5 to avoid the circular magnet 24 and the magnetic rotary encoder; the magnet tray 25 needs to be tightly attached to the top plate 5, and the position of the magnet tray 25 and the circular magnet 24 is limited by the top plate 5 to make the relative position of the circular magnet 24 and the magnetic rotary encoder stable.
[0037] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.
Claims
1. A tape measure, characterized by: The ruler box comprises a ruler box, a ruler core reel, a ruler strip, a rotation angle sensor and a main control board, the top of the ruler box is a top plate, and the bottom end of the ruler box is a bottom plate; the ruler core reel is placed between the top plate and the bottom plate, the ruler core reel can rotate, a first mounting groove is opened on the top surface of the ruler core reel, and a mounting post is fixed in the first mounting groove; the inner end of the ruler strip is fixed on the ruler core reel, the ruler strip is wound on the ruler core reel, and the outer end of the ruler strip is arranged outside the ruler box; the rotation angle sensor comprises a rotation module and a detection module, the rotation module is fixed on the mounting post, the rotation module can rotate with the ruler core reel, the detection module is fixed on the bottom surface of the main control board, and the detection module can detect the rotation angle of the rotation module; the main control board is fixed on the top surface of the top plate, the main control board is communicatively connected with the detection module, and an electronic player is fixed on the main control board.
2. The tape measure according to claim 1, wherein: It also includes a support spring, which is sleeved on the mounting column, and the top end of the support spring can press the rotation module onto the top plate or the main control board.
3. The tape measure according to claim 2, wherein: A second mounting groove is provided on the bottom surface of the ruler core reel, a third mounting groove is provided on the top surface of the second mounting groove, a positioning column is fixed on the bottom plate, and the top end of the positioning column extends into the third mounting groove.
4. The tape measure according to claim 3, wherein: The cam is fixedly provided with a support plate at the bottom end of the mounting column, and the support plate is capable of supporting the bottom end of the supporting spring, and a first protrusion is provided at the center of the top surface of the support plate, and the outer side surface of the first protrusion can contact the inner side surface of the bottom end of the supporting spring; a plurality of first positioning grooves are provided on the outer surface of the support plate, and a plurality of first positioning protrusions are provided on the inner side surface of the first mounting groove, and the first positioning protrusions correspond to the first positioning grooves one by one, and the first positioning protrusions can be embedded in the first positioning groove; a second protrusion is provided on the bottom surface of the first mounting groove, and the second protrusion is coaxially arranged with the third mounting groove, and a fourth mounting groove is provided at the center of the bottom surface of the support plate, and the fourth mounting groove is sleeved on the second protrusion.
5. The tape measure according to claim 4, wherein: The outer surface of the mounting column is provided with a plurality of second positioning protrusions, and the rotating module is provided with a plurality of second positioning grooves. The second positioning protrusions correspond to the second positioning grooves one by one, and the second positioning protrusions can be embedded in the second positioning grooves.
6. The tape measure according to claim 3, wherein: A circular hole is provided on the main control board, and a cylindrical head is provided on the top of the mounting column. The cylindrical head extends into the circular hole and can rotate along the inner surface of the circular hole; the rotation module is fixedly mounted on the mounting column, and the rotation module is placed below the cylindrical head.
7. The tape measure according to claim 3, wherein: An annular rib is provided on the bottom surface of the top plate, and the rotating module is fixedly sleeved on the top end of the mounting column. The rotating module can rotate along the inner side surface of the annular rib.
8. The tape measure according to claim 1, wherein: The rotation angle sensor is a circular capacitive grating angle sensor, the rotation module is a moving grating disc, and the detection module is a circular capacitive grating fixed grating.
9. The tape measure according to claim 1, wherein: The rotation angle sensor is a grating encoding sensor, the rotation module is a grating code disk, and the detection module is a slot-type optical coupler.
10. The tape measure according to claim 1, wherein: The rotation angle sensor is a magnetic rotary encoding sensor, the rotation module includes a circular magnet and a magnet tray, and the detection module is a magnetic rotary encoder; the magnet tray is fixed on the mounting column, and a receiving groove is provided on the top surface of the magnet tray, and the circular magnet is fixed in the receiving groove.