A writing friction detection device for improving accuracy

Abstract

This utility model discloses a writing friction force detection device with improved accuracy, belonging to the field of detection devices. It includes a detection platform with a detection mechanism on its top surface. The dynamic angle adjustment mechanism uses a third cylinder to drive a rack and pinion gear, which in turn drives a concave frame to rotate around a rotating rod, allowing for arbitrary angle adjustment of the writing platform within the range of 0-90°. This precisely adapts to the personalized writing needs of left-handed users tilting to the left and right-handed users tilting to the right, while also accommodating the 25°-35° tilt angle required for English writing and the 10°-25° tilt angle commonly used for Chinese character writing. This precise angle adjustment capability ensures that the pen tip and paper make contact in a realistic writing state, avoiding uneven force distribution caused by angle deviations. This ensures that the friction and pressure distribution matches actual writing conditions, thereby eliminating detection misjudgments caused by angle mismatches and significantly improving the accuracy of the detection data.

Description

Technical Field

[0001] This utility model relates to the field of testing devices, and in particular to a writing friction testing device that improves accuracy. Background Technology

[0002] To test the smoothness of writing, pen manufacturers need to conduct corresponding tests on the pens they produce. The smoothness of writing can be quantitatively determined by measuring the amount of friction under specified writing angles, speeds, and pressures using a specialized writing scribing instrument.

[0003] In the prior art, Chinese utility model patent with publication number "CN221100055U" and patent name "A Writing Pen Writing Detection Clamping Structure and Writing Pen Writing Detection Device" discloses a detection device. This patent describes a technical solution including "a support rod and a sensor installed at the end of the support rod; a positioning sleeve is positioned at the end of the sensor away from the support rod; a vertically mounted linear bearing is positioned on the positioning sleeve; a guide sleeve is slidably mounted on the inner ring of the linear bearing on the pen barrel; a guide sleeve flange with an inwardly folded edge is provided along the upper edge of the guide sleeve; the guide sleeve flange is positioned and pressed between the pen shell and the pen barrel." However, when this detection device detects writing pens, differences in writing habits among different groups lead to variations in the angle, pressure, and other mechanical parameters between the pen and paper. For example, when left-handed people write, the paper usually needs to be tilted to the left to avoid the hand obscuring the writing; the contact angle and friction distribution between the pen and paper also differ significantly from those of right-handed people. The fixed wedge support block can only provide a single tilt angle. If the paper angle during testing does not match the actual writing habit, the friction and pressure distribution between the pen tip and the paper will change. At an incorrect tilt angle, a normally smooth writing pen may experience uneven pressure on the pen tip, leading to an abnormally high measured friction value and thus being misjudged as having poor writing fluency. Furthermore, the diversity of writing habits is not only reflected in left- or right-handed differences but also in angle preferences when writing different languages. When writing English, the paper tilt angle is typically 25°-35° to facilitate cursive writing; when writing Chinese characters, due to the characteristics of the stroke structure, the tilt angle may be between 10°-25°. Fixed-angle detection devices can only simulate limited scenarios and cannot cover these differences, resulting in a lack of comprehensiveness in the test samples. For writing pens that only demonstrate performance at specific angles, testing at mismatched angles cannot reflect their true performance, and the resulting test data cannot accurately reflect the product's performance in actual use, reducing the reliability and accuracy of the test results. Therefore, to solve the above technical problems, this utility model proposes a writing friction detection device with improved accuracy. Utility Model Content

[0004] The main objective of this invention is to provide a writing friction detection device that improves accuracy and can effectively solve the problems in the background art.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a writing friction force detection device with improved accuracy, comprising a detection platform, a detection mechanism on the top surface of the detection platform, and the detection mechanism including a support rod, a detection sensor, a linear bearing, and a writing pen. The detection sensor is fixedly connected to the other end of the support rod, and the linear bearing is fixedly connected to a mounting bracket on one side of the detection sensor. The writing pen is fixedly connected in the linear bearing. A dynamic angle adjustment mechanism is also provided on the right side of the top surface of the detection platform, and the dynamic angle adjustment mechanism includes a concave frame, a gear, a third cylinder, a rack, a rotating seat, and a writing platform. The concave frame is movably connected to a fixed plate on the top surface of the detection platform through rotating rods on both sides of its inner wall, and the gear is fixedly connected to the rotating rod. The third cylinder is fixedly connected to the side wall of the second mounting bracket on the top surface of the detection platform, and racks meshing with the gear are fixedly connected to both ends of the connecting rod at the output end of the third cylinder. A first motor is fixedly connected to the bottom surface of the concave frame, and the writing platform is fixedly connected to the output end of the first motor through the rotating seat on the top surface.

[0006] In a preferred embodiment of this invention, a set of symmetrical support plates are fixedly installed on the top surface of the testing platform, and guide openings are provided on the side walls of the support plates. A horizontal plate is also fixedly installed between the support plates.

[0007] In a preferred embodiment of this invention, a first cylinder is fixedly mounted on the bottom surface of the horizontal plate, and an adjustment platform is fixedly mounted on the output end of the first cylinder. Guide blocks are fixedly mounted on both sides of the adjustment platform, and the guide blocks are movably mounted in the guide opening. A first mounting seat is fixedly mounted on the top surface of the adjustment platform, and a first guide rail is also fixedly mounted on the top surface of the adjustment platform. The second cylinder is fixedly mounted on the side wall of the first mounting seat, and a support rod is fixedly mounted on the output end of the second cylinder. A first slider is fixedly mounted on the bottom surface of the support rod, and the first slider is slidably mounted together with the first guide rail.

[0008] In a preferred embodiment of this utility model, a set of symmetrical fixing plates are fixedly installed on the top surface of the testing platform, and rotating holes are provided on the side walls of the fixing plates. A second mounting base is fixedly installed on the right side of the top surface of the testing platform, and a set of symmetrical second guide rails are also fixedly installed on the top surface of the testing platform between the fixing plates.

[0009] In a preferred embodiment of this invention, the concave frame is in an inverted state, the rotating rod is movably installed in the rotating hole, a set of symmetrical second sliders is fixedly installed on the bottom surface of the rack, and the second sliders are slidably installed together with the second guide rail. An angle tilt sensor is also fixedly installed on the side wall of the concave frame.

[0010] In a preferred embodiment of this utility model, the first motor is fixedly installed on the bottom surface of the concave frame, and a rotating seat is fixedly installed on the output end of the first motor. A writing table is fixedly installed on the top surface of the rotating seat. Guide rollers are movably installed on both sides of the writing table, and an unwinding frame and a winding frame are fixedly installed on the bottom surface of the writing table. An unwinding roller is movably installed on the unwinding frame, and a winding roller is movably installed on the winding frame. A second motor is also fixedly installed on one side of the winding frame, and the output end of the second motor is fixedly installed together with the roller shaft at one end of the winding roller through a coupling.

[0011] Compared with existing technologies, this utility model has the following advantages: The dynamic angle adjustment mechanism in this utility model uses a third cylinder to drive a rack and pinion gear, which in turn drives a concave frame to rotate around a rotating rod, allowing for arbitrary angle adjustment of the writing surface within the range of 0-90°. This precisely adapts to the personalized writing needs of left-handed users tilting to the left and right-handed users tilting to the right, while also accommodating the 25°-35° tilt angle required for English writing and the 10°-25° tilt angle commonly used for Chinese character writing. This precise angle adjustment capability ensures that the pen tip contacts the paper in a realistic writing state, avoiding uneven force distribution caused by angle deviations. This ensures that the friction and pressure distribution conforms to actual writing conditions, thereby eliminating misjudgments caused by angle mismatches and significantly improving the accuracy of the detection data. The first and second cylinders in the detection mechanism work together to achieve precise displacement adjustment of the writing pen in both the vertical and horizontal directions. The first cylinder drives the adjustment platform to move up and down along the guide opening on the side wall of the support plate. The second cylinder, through the first slider at the bottom of the support rod, cooperates with the first guide rail on the top surface of the adjustment platform to fine-tune the horizontal position of the writing pen. Combined with the linear bearing, this reduces the vertical friction of the writing pen, ensuring that the writing pen maintains a stable and accurate position during the testing process, further improving testing accuracy. Simultaneously, the first motor drives the rotating seat to rotate the writing platform, enabling the writing pen to write on the paper. At the same time, the second motor drives the take-up roller to rotate through the coupling, cooperating with the unwind roller and guide roller to automatically complete the paper take-up and unwinding process. This eliminates the need for frequent manual paper changes, greatly improving testing efficiency and meeting the rapid testing needs of large-scale pen manufacturing plants. The automated operation mode not only reduces manual intervention and labor intensity but also avoids errors caused by human operation, ensuring the stability and consistency of test results. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0013] Figure 2 This is a front view schematic diagram of the overall structure of this utility model;

[0014] Figure 3 This is a structural breakdown diagram of the testing mechanism of this utility model;

[0015] Figure 4 This is a schematic diagram of the overall structure of the dynamic angle adjustment mechanism of this utility model;

[0016] Figure 5 For the present utility model Figure 4 A schematic diagram of the structural breakdown at point A.

[0017] In the diagram: 1. Detection table; 2. Detection mechanism; 3. Dynamic angle adjustment mechanism; 4. Support plate; 5. Guide port; 6. Horizontal plate; 7. First cylinder; 8. Adjustment table; 9. Guide block; 10. First mounting base; 11. First guide rail; 12. Second cylinder; 13. Support rod; 14. First slider; 15. Detection sensor; 16. Mounting bracket; 17. Linear bearing; 18. Writing pen; 19. Fixing plate; 20. Rotation hole; 1. Second mounting base; 22. Second guide rail; 23. Concave frame; 24. Rotating rod; 25. Gear; 26. Third cylinder; 27. Connecting rod; 28. Rack; 29. ​​Second slider; 30. First motor; 31. Rotating seat; 32. Writing table; 33. Guide roller; 34. Unwinding frame; 35. Rewinding frame; 36. Unwinding roller; 37. Rewinding roller; 38. Second motor; 39. Coupling; 40. Angle tilt sensor. Detailed Implementation

[0018] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0019] like Figure 1 - Figure 5 As shown, a writing friction detection device for improving accuracy includes a detection platform 1. A detection mechanism 2 is provided on the top surface of the detection platform 1. The detection mechanism 2 includes a support rod 13, a detection sensor 15, a linear bearing 17, and a writing pen 18. The detection sensor 15 is fixedly connected to the other end of the support rod 13, and the linear bearing 17 is fixedly connected to a mounting bracket 16 on one side of the detection sensor 15. The writing pen 18 is fixedly connected in the linear bearing 17. A dynamic angle adjustment mechanism 3 is also provided on the right side of the top surface of the detection platform 1. The dynamic angle adjustment mechanism 3 includes a concave frame 23, a gear 25, and a third air... The system includes a cylinder 26, a rack 28, a rotating seat 31, and a writing table 32. The concave frame 23 is movably connected to the fixed plate 19 on the top surface of the testing platform 1 via rotating rods 24 on both sides of the inner wall, and the gear 25 is fixedly connected to the rotating rods 24. The third cylinder 26 is fixedly connected to the side wall of the second mounting seat 21 on the top surface of the testing platform 1, and the two ends of the connecting rod 27 at the output end of the third cylinder 26 are respectively fixedly connected to the second slider 29 that meshes with the gear 25. The bottom surface of the concave frame 23 is fixedly connected to the first motor 30, and the writing table 32 is fixedly connected to the output end of the first motor 30 via the rotating seat 31 on the top surface.

[0020] like Figure 3 As shown, a set of symmetrical support plates 4 are fixedly installed on the top surface of the testing platform 1, and guide openings 5 ​​are provided on the side walls of the support plates 4. A horizontal plate 6 is also fixedly installed between the support plates 4. The symmetrical support plates 4, guide openings 5, and horizontal plate 6 on the top surface of the testing platform 1 constitute the basic frame. The support plates 4 and the horizontal plate 6 are welded or bolted together to form a stable triangular structure. The guide openings 5 ​​slide with the guide blocks 9 on both sides of the adjusting platform 8, restricting the adjusting platform 8 to move only in the vertical direction. This design provides stable support for the subsequent testing mechanism 2, ensuring that the adjusting platform 8 does not shift laterally when raised or lowered, laying the foundation for precise adjustment of the writing pen 18 position; Figure 3 As shown, the first cylinder 7 is fixedly installed on the bottom surface of the horizontal plate 6, and an adjusting platform 8 is fixedly installed on the output end of the first cylinder 7. Guide blocks 9 are fixedly installed on both sides of the adjusting platform 8, and the guide blocks 9 are movably installed in the guide port 5. The first mounting base 10 is fixedly installed on the top surface of the adjusting platform 8, and a first guide rail 11 is also fixedly installed on the top surface of the adjusting platform 8. The second cylinder 12 is fixedly installed on the side wall of the first mounting base 10, and a support rod 13 is fixedly installed on the output end of the second cylinder 12. A first slider 14 is fixedly installed on the bottom surface of the support rod 13, and the first slider 14 is slidably installed together with the first guide rail 11. The detection sensor 15 is fixedly installed between the support rod 13 and the mounting bracket 16, and a detection sensor 15 is also fixedly installed inside the mounting bracket 16. A linear bearing 17 is used, and a writing pen 18 is fixedly installed together with the linear bearing 17. A first cylinder 7 is fixed to the bottom surface of the horizontal plate 6 and drives the adjustment platform 8 to rise and fall vertically through the output shaft. A second cylinder 12 is installed on the first mounting seat 10 on the top surface of the adjustment platform 8, and its output end drives the support rod 13. Horizontal displacement is achieved through the sliding cooperation between the first slider 14 and the first guide rail 11. This mechanism uses cylinders to provide power, and the slider guide rail ensures high-precision guidance. The linear bearing 17 converts the vertical sliding of the writing pen 18 into low-friction rolling. The effect is that the height and horizontal position of the writing pen 18 can be accurately adjusted so that it contacts the paper with a set pressure and angle, while eliminating the interference of gravity-directed friction on the detection and improving the accuracy of friction detection. Figure 4 and Figure 5 As shown, a set of symmetrical fixing plates 19 are fixedly installed on the top surface of the testing platform 1, and rotating holes 20 are provided on the side walls of the fixing plates 19. A second mounting base 21 is fixedly installed on the right side of the top surface of the testing platform 1, and a set of symmetrical second guide rails 22 are also fixedly installed on the top surface of the testing platform 1 between the fixing plates 19. The rotating holes 20 of the fixing plates 19 are used to install the rotating rod 24 of the concave frame 23, forming a rotation fulcrum. The second guide rails 22 cooperate with the second slider 29 at the bottom of the subsequent rack 28 to constrain the rack 28 to make horizontal linear motion. This structure ensures that the axis of the concave frame 23 is stable when it rotates, and the rack 28 moves smoothly, avoiding shaking that affects the angle adjustment accuracy; Figure 4 and Figure 5As shown, the concave frame 23 is in an inverted state, and rotating rods 24 are fixedly installed on both sides of the inner wall of the concave frame 23. Gears 25 are fixedly installed on the inner end of the rotating rods 24. The third cylinder 26 is fixedly installed on the side wall of the second mounting base 21, and a connecting rod 27 is fixedly installed on the output end of the third cylinder 26. Racks 28 are fixedly installed on both ends of the connecting rod 27, and the racks 28 and gears 25 mesh together. A set of symmetrical second sliders 29 are also fixedly installed on the bottom surface of the racks 28. The second slider 29 is slidably mounted with the second guide rail 22. An angle tilt sensor 40 is also fixedly mounted on the side wall of the concave frame 23. The third cylinder 26 drives the connecting rod 27 to drive the rack 28 in linear motion. The rack 28 meshes with the gear 25 inside the rotating rod 24, converting the linear motion into the rotational motion of the concave frame 23, thus achieving angle adjustment. The second slider 29 cooperates with the second guide rail 22 to guide and ensure the stable movement of the rack 28, thereby flexibly adjusting the tilt angle of the writing table 32 to adapt to different writing habits and improve detection accuracy. Figure 4 and Figure 5 As shown, a first motor 30 is fixedly installed on the bottom surface of a concave frame 23, and a rotating seat 31 is fixedly installed on the output end of the first motor 30. A writing table 32 is fixedly installed on the top surface of the rotating seat 31. Guide rollers 33 are movably installed on both sides of the writing table 32, and an unwinding frame 34 and a winding frame 35 are fixedly installed on the bottom surface of the writing table 32. An unwinding roller 36 is movably installed on the unwinding frame 34, and a winding roller 37 is movably installed on the winding frame 35. A second motor 38 is also fixedly installed on one side of the winding frame 35, and the output end of the second motor 38 is fixedly installed with the roller shaft at one end of the winding roller 37 through a coupling 39. The first motor 30 drives the rotating seat 31 to rotate the writing table 32 to realize the writing action. The guide rollers 33 stabilize the paper, and the unwinding frame 34 and the unwinding roller 36 supply paper. The second motor 38 drives the winding roller 37 to wind up the paper through the coupling 39, thereby realizing the automated and continuous writing process, improving detection efficiency and quality, and making the detection process more orderly.

[0021] The process and principle of testing the writing friction of the writing pen 18 using the testing platform 1 and testing mechanism 2 are as follows: After the writing paper roll is fitted onto the unwinding roller 36, the unwinding roller 36 is placed on the unwinding frame 34. The writing paper on the roll is pulled so that it passes through the guide rollers 33 on both sides of the writing platform 32 and is fixed together with the winding roller 37 on the winding frame 35. This paper installation method uses the guide rollers 33 to limit and guide the paper, ensuring that the paper is flat and wrinkle-free during the conveying process, avoiding friction detection errors caused by uneven paper, and laying the foundation for accurate testing. Subsequently, the writing pen 18 is interlocked with the linear bearing 17 installed in the mounting frame 16. The linear bearing 17 can convert the vertical sliding friction of the writing pen 18 into rolling friction, greatly reducing vertical friction, effectively eliminating the interference of gravity on the test results, and significantly improving the accuracy of the test.

[0022] After installation, the third cylinder 26 installed on the side wall of the second mounting base 21 is activated. The third cylinder 26 drives the output end to retract, causing the connecting rod 27 to move to the right. The connecting rod 27 drives the rack 28 to slide to the right along the second guide rail 22 via the second slider 29. During the sliding process, the rack 28 meshes with the gear 25, causing the gear 25 to rotate, which in turn causes the rotating rod 24 to rotate in the rotating hole 20 on the side wall of the fixed plate 19, ultimately driving the concave frame 23 to rotate. The angle tilt sensor 40 monitors the tilt angle of the concave frame 23 in real time. When the preset value is reached, such as 20° left tilt for simulating left-handed writing, or 30° right tilt for English writing, the third cylinder 26 stops running. This dynamic angle adjustment process can achieve precise angle adjustment of the writing table 32 within the range of 0-90°. It can highly reproduce the real writing angle required for different writing habits, such as left-handed writing and different languages, avoiding uneven pen tip force caused by angle mismatch, effectively eliminating detection misjudgment caused by angle problems, and greatly improving the accuracy of detection data.

[0023] After the angle adjustment is completed, the first cylinder 7 installed on the top surface of the horizontal plate 6 is activated, and its output end pushes the adjustment platform 8 upward. The adjustment platform 8 moves between the support plates 4, and the guide blocks 9 on both sides slide in the guide openings 5 ​​on the side walls of the support plates 4 to adjust the height of the writing pen 18, ensuring that the pen tip maintains a suitable initial contact pressure with the paper. Next, the second cylinder 12 on the side wall of the first mounting base 10 is activated, and its output end pushes the support rod 13. The support rod 13 moves to the right along the first guide rail 11 via the first slider 14, precisely adjusting the horizontal position of the writing pen 18. Through the dual precise adjustment of height and horizontal position, the writing pen 18 can be kept in stable and precise contact with the writing paper on the top surface of the writing table 32, so that the pen tip is in the optimal detection position, further improving the accuracy and reliability of the detection.

[0024] At this time, the first motor 30, installed on the bottom surface of the unwinding frame 34, is activated. Its output end drives the writing table 32 to rotate via the rotating seat 31, simulating the writing trajectory. Simultaneously, the second motor 38, located on the side wall of the winding frame 35, is activated. Its output end drives the winding roller 37 to rotate on the winding frame 35 via the coupling 39, winding the paper. During the winding process, the unwinding roller 36 rotates on the unwinding frame 34 to unwind the paper, achieving automatic and continuous paper supply. When the writing pen 18 simulates writing on the paper, the detection sensor 15 collects the frictional force data between the pen tip and the paper in real time. The detection sensor 15 converts the mechanical force into an electrical signal, which is then amplified, filtered, and transmitted to the data acquisition system. The system analyzes the data according to a preset standard range, judges the writing smoothness of the writing pen 18, and generates a test report. The automated writing simulation and paper delivery process eliminates the need for frequent manual intervention, greatly improving detection efficiency and avoiding errors caused by manual operation, ensuring the stability and consistency of the test results, and achieving efficient and accurate evaluation of the writing pen's performance.

[0025] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A writing friction detection device for improving accuracy, comprising a detection table (1), characterized in that: The top surface of the testing platform (1) is provided with a testing mechanism (2), and the testing mechanism (2) includes a support rod (13), a testing sensor (15), a linear bearing (17), and a writing pen (18). The testing sensor (15) is fixedly connected to the other end of the support rod (13), and the linear bearing (17) is fixedly connected to the mounting bracket (16) on one side of the testing sensor (15). The writing pen (18) is fixedly connected in the linear bearing (17). The right side of the top surface of the testing platform (1) is also provided with a dynamic angle adjustment mechanism (3), and the dynamic angle adjustment mechanism (3) includes a concave frame (23), a gear (25), a third cylinder (26), a rack (28), and a rotating... The concave frame (23) is movably connected to the fixed plate (19) on the top surface of the test table (1) via rotating rods (24) on both sides of the inner wall, and the gear (25) is fixedly connected to the rotating rods (24). The third cylinder (26) is fixedly connected to the side wall of the second mounting seat (21) on the top surface of the test table (1), and racks (28) that mesh with the gear (25) are fixedly connected to both ends of the connecting rod (27) at the output end of the third cylinder (26). The bottom surface of the concave frame (23) is fixedly connected to the first motor (30), and the writing table (32) is fixedly connected to the output end of the first motor (30) via the rotating seat (31) on the top surface.

2. The device for detecting the writing friction force for improving the precision according to claim 1, wherein: A set of symmetrical support plates (4) are fixedly installed on the top surface of the testing platform (1), and guide openings (5) are provided on the side walls of the support plates (4). A horizontal plate (6) is also fixedly installed between the support plates (4).

3. A device for detecting the writing friction force for improving the accuracy according to claim 2, characterized in that: A first cylinder (7) is fixedly installed on the bottom surface of the horizontal plate (6), and an adjustment platform (8) is fixedly installed on the output end of the first cylinder (7). Guide blocks (9) are fixedly installed on both sides of the adjustment platform (8), and the guide blocks (9) are movably installed in the guide opening (5). A first mounting seat (10) is fixedly installed on the top surface of the adjustment platform (8), and a first guide rail (11) is also fixedly installed on the top surface of the adjustment platform (8). A second cylinder (12) is fixedly installed on the side wall of the first mounting seat (10), and a support rod (13) is fixedly installed on the output end of the second cylinder (12). A first slider (14) is fixedly installed on the bottom surface of the support rod (13), and the first slider (14) is slidably installed together with the first guide rail (11).

4. The device for detecting the writing friction force for improving the precision according to claim 3, wherein: A set of symmetrical fixing plates (19) are fixedly installed on the top surface of the testing platform (1), and a rotating hole (20) is opened on the side wall of the fixing plate (19). A second mounting seat (21) is fixedly installed on the right side of the top surface of the testing platform (1), and a set of symmetrical second guide rails (22) are also fixedly installed on the top surface of the testing platform (1) between the fixing plates (19).

5. A device for detecting the writing friction force for improving the accuracy according to claim 4, characterized in that: The concave frame (23) presents an inverted state, the rotating rod (24) is movably installed in the rotating hole (20), the bottom surface of the rack (28) is further fixedly installed with a set of symmetrical second sliding blocks (29), and the second sliding blocks (29) are slidably installed with the second guide rails (22), and an angle inclination sensor (40) is further fixedly installed on the side wall of the concave frame (23).

6. A device for detecting the writing friction force for improving the accuracy according to claim 5, characterized in that: The first motor (30) is fixedly installed on the bottom surface of the concave frame (23), a rotating base (31) is fixedly installed on the output end of the first motor (30), a writing table (32) is fixedly installed on the top surface of the rotating base (31), guide rollers (33) are movably installed on the two sides of the writing table (32) respectively, unwinding frames (34) and winding frames (35) are fixedly installed on the bottom surface of the writing table (32) respectively, unwinding rollers (36) are movably installed on the unwinding frames (34), winding rollers (37) are movably installed on the winding frames (35), a second motor (38) is further fixedly installed on one side of the winding frame (35), and the output end of the second motor (38) and the shaft of one end of the winding roller (37) are fixedly installed together through a shaft coupling (39).

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