Tension measuring device and experimental method thereof

Abstract

The invention discloses a tension measuring device and an experimental method thereof.The tension measuring device comprises a tension base, limiting mechanisms are fixedly installed on the two sides of the tension base, each limiting mechanism comprises a limiting base and a self-locking telescopic rod, and the top ends of the limiting bases are fixedly connected with the fixed ends of the self-locking telescopic rods; according to the invention, real-time measurement of the tension of the rope is realized through the force sensor, visual experimental data is provided for students, and the students are helped to better understand the Newton's second law; through the self-made tension measuring device, the tension borne by the trolley is accurately measured, the influence of weight loss on an experiment result is avoided, and the accuracy and reliability of an experiment are improved; the Newton's second law is combined with a parallelogram rule in a concurrent force balance chapter, and the relationship that the pressure of a rope with an included angle of 120 degrees on a fixed pulley is equal to the tension of the rope is verified through experiments.

Description

Technical Field

[0001] This invention relates to the field of tension measuring device technology, specifically to a tension measuring device and its experimental method. Background Technology

[0002] Newton's second law is one of the core principles in physics, revealing the fundamental relationship between an object's mass, acceleration, and the force acting on it. To help students understand this principle more deeply, people generally use the DIS experiment to assist them in understanding and memorizing it.

[0003] However, traditional DIS experiments have the following drawbacks:

[0004] While existing DIS experiments can automatically measure acceleration in teaching Newton's second law, they have significant limitations when measuring the tension force on a cart. When the cart accelerates horizontally, the weight accelerates downwards, causing weightlessness, resulting in a tension force significantly less than the weight of the weight. For example, when the measured acceleration of the cart is 1.49 m / s², the weight accelerates downwards at the same acceleration, resulting in weightlessness. The actual tension force would be 14.9% less than the weight of the weight, which should be 0.21 N. This cannot be fitted as a straight line. Therefore, the experimental conclusions in online classes are "embellished." After balancing friction, the actual measurement results for a cart with the same mass of 0.127 kg show a significantly smaller acceleration data, which is not proportional to the "tension force." This systematic error significantly affects the experimental results, making it difficult for students to accurately understand Newton's second law. Summary of the Invention

[0005] The purpose of this invention is to provide a tension measuring device and its experimental method to address the limitations of existing DIS experiments mentioned in the background art. While these experiments can automatically measure acceleration in teaching Newton's second law, they have significant limitations when measuring the tension force on a cart. When the cart accelerates horizontally, the weight accelerates downwards, causing weightlessness, resulting in a tension force significantly less than the weight of the weight. For example, when the measured acceleration of the cart is 1.49 m / s², the weight accelerates downwards at the same acceleration, resulting in a weightless state. The actual tension force would be 14.9% less than the weight of the weight, which should be 0.21 N. This cannot be fitted as a straight line. Therefore, the experimental conclusions in online classes are "embellished." After balancing friction, the actual measurement results for a cart with the same mass of 0.127 kg show a significantly smaller acceleration data, which is not proportional to the "tension force." This systematic error significantly affects the experimental results, making it difficult for students to accurately understand Newton's second law.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a tension measuring device, comprising a tension base, with limiting mechanisms fixedly installed on both sides of the tension base. Each limiting mechanism includes a limiting base and a self-locking telescopic rod. The top end of the limiting base is fixedly connected to the fixed end of the self-locking telescopic rod. A limiting shell is fixedly installed on the movable end of the self-locking telescopic rod. Two pressure plates are provided inside the limiting shell. Height plates are fixedly installed on both sides of the top end of the tension base. A mounting bracket is fixedly installed on the middle of opposite sides of the two height plates by screws. A connecting plate is fixedly installed between the two mounting brackets by screws. A tension mechanism is fixedly installed in the middle of the connecting plate. The bottom end of the tension mechanism is provided with... The tension frame has two vertical plates fixedly mounted on the bottom ends of opposite sides of the two height plates by screws. Two displacement plates are slidably connected between the two vertical plates. Two length plates are fixedly mounted on the top ends of opposite sides of the two height plates by screws. Two assembly plates are fixedly mounted between the two length plates by screws. Each of the two assembly plates has multiple equidistantly distributed positioning holes. The tension mechanism includes a tension housing and a push housing. A fixing plate is fixedly mounted inside the tension housing. A lead screw is rotatably connected to the middle of the fixing plate. The bottom end of the lead screw is threadedly connected to the top end of the push housing. A push rod is slidably connected to the tension housing at the bottom end of the push housing. A tension sensor is fixedly mounted on the surface of the push rod.

[0007] As a preferred embodiment of the present invention, pressure shells are fixedly installed on both sides of the inner wall of the limiting shell, and support springs are fixedly installed on one side of the inner wall of each of the two pressure shells. An extension rod that is slidably connected to the pressure shell is fixedly installed on the end of each of the two support springs away from the pressure shell. The opposite sides of the two extension rods are respectively fixedly connected to the opposite sides of the two pressure plates. Several threading grooves are opened on the surface of each of the two pressure plates. The rope is limited by the two opposite threading grooves, and the rope squeezes the pressure plate from one side. The pressure plate drives the extension rod to slide along the pressure shell, and the extension rod squeezes the support spring from one side. The support spring is elastic, and the elastic deformation of the support spring converts the squeezing force.

[0008] As a preferred embodiment of the present invention, one side of each of the two limiting bases is fixedly connected to both sides of the tension base, and the limiting mechanism is installed on the tension base through the limiting base.

[0009] As a preferred embodiment of the present invention, the surface of the tension frame is provided with a plurality of first fixing holes, and the surfaces of the two displacement plates are provided with a plurality of second fixing holes. Tension wheels are installed inside one of the first fixing holes and two of the second fixing holes. The user can adjust the positions of the three tension wheels according to actual needs so that the included angle of the tension wheels meets the experimental requirements.

[0010] As a preferred embodiment of the present invention, the two mounting brackets are respectively fixedly connected to the bottom ends of the opposite sides of the two length plates by screws on their opposite sides. The connection between the mounting brackets and the length plates increases the reliability of the length plate installation.

[0011] As a preferred embodiment of the present invention, a driven umbrella-shaped helical tooth is fixedly installed at the connection between the lead screw and the fixed plate. A handle is rotatably connected to one side of the tension machine housing. An active umbrella-shaped helical tooth located inside the tension machine housing is fixedly installed at one end of the handle. The outer side of the active umbrella-shaped helical tooth meshes with the outer side of the driven umbrella-shaped helical tooth. When the user rotates the handle, the handle drives the active umbrella-shaped helical tooth to rotate. The active umbrella-shaped helical tooth contacts the driven umbrella-shaped helical tooth, and the driven umbrella-shaped helical tooth rotates. The driven umbrella-shaped helical tooth drives the lead screw to rotate. The thread on the surface of the lead screw matches the thread on the inner wall of the push housing. The push housing pushes the push rod to slide along the tension machine housing, thereby adjusting the height of the tension frame.

[0012] As a preferred embodiment of the present invention, the middle part of the tension machine housing is fixedly connected to the connecting plate, the bottom end of the push rod is fixedly connected to the side of the tension frame facing it, the tension mechanism is mounted on the connecting plate through the tension machine housing, and the push rod pushes the tension frame from the top to adjust the height of the tension frame.

[0013] The present invention discloses an experimental method for a tension measuring device, comprising the following steps:

[0014] Step 1: Introduction to the Principle: Introduce the basic concepts and principles of Newton's second law, as well as the parallelogram rule in the chapter on equilibrium of concurrent forces;

[0015] Step 2, Device Usage Instructions: A detailed explanation of how to use the homemade tension measuring device. Pass the rope through the three tension wheels in sequence. The tension sensor on the tension mechanism senses the tension of the rope and is assembled with the 3D printed bracket. The bracket is marked with the central axis and center point.

[0016] Step 3: Verify the included angle: Adjust the position of the tension wheel on the first fixed hole and the position of the tension wheel on the second fixed hole, adjust the rope to be centered and the left and right parts of the rope to be horizontal, and verify the relationship between the pressure of the rope on the tension wheel and the rope tension when the included angle is 120° through experiments;

[0017] Step 4: Record and Observe: Perform the experimental operations and record the data. Pay special attention to observing and analyzing the phenomena of weightlessness and hypergravity caused by vertical acceleration.

[0018] Step 5: Discussion and Exchange: Conduct group discussions and share experimental results and insights, and explore the application of Newton's second law in daily life.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. By using a force sensor to measure the tension of the rope in real time, students are provided with intuitive experimental data to help them better understand Newton's second law;

[0021] 2. By using a self-made tension measuring device, the magnitude of the tension force on the trolley can be accurately measured, avoiding the influence of the weightlessness of the heavy object on the experimental results and improving the accuracy and reliability of the experiment.

[0022] 3. By combining Newton's second law with the parallelogram law in the chapter on equilibrium of concurrent forces, and verifying through experiments that the pressure of a rope with an included angle of 120° on a fixed pulley is equal to the tension of the rope, students can build a complete knowledge system.

[0023] 4. Due to its simple structure, low cost, clear principle, ability to solve practical problems, and completely open source nature, it is easy for teachers in other schools to imitate and reprocess it, which helps to improve the practical and innovative abilities of a wider range of students. Attached Figure Description

[0024] Figure 1 This is a side view of the present invention;

[0025] Figure 2 This is a schematic diagram of the limiting mechanism of the present invention;

[0026] Figure 3 This is a schematic diagram of the tension mechanism of the present invention;

[0027] Figure 4 This is a partial schematic diagram of the present invention;

[0028] Figure 5 This is a flowchart of the present invention;

[0029] Figure 6 This is a graph showing the fluctuations in the force sensor readings of the present invention;

[0030] Figure 7 The figure shows the experimental results of the improved Newton's second law according to the present invention.

[0031] In the diagram: 1. Tension base; 2. Limiting mechanism; 21. Limiting base; 22. Self-locking telescopic rod; 23. Limiting shell; 24. Pressure shell; 25. Support spring; 26. Pressure plate; 27. Wire groove; 28. Extension rod; 3. Height plate; 4. Mounting bracket; 5. Length plate; 6. Assembly plate; 7. Positioning hole; 8. Connecting plate; 9. Tension mechanism; 91. Tension housing; 92. Push shell; 93. Push rod; 94. Tension sensor; 95. Handle; 96. Active umbrella-shaped helical tooth; 97. Fixing plate; 98. Driven umbrella-shaped helical tooth; 99. Lead screw; 10. Tension frame; 11. First fixing hole; 12. Vertical plate; 13. Tension wheel; 14. Second fixing hole; 15. Displacement plate. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] Please see Figure 1-7 This invention provides a tension measuring device, including a tension base 1. Limiting mechanisms 2 are fixedly installed on both sides of the tension base 1. Each limiting mechanism 2 includes a limiting base 21 and a self-locking telescopic rod 22. The top end of the limiting base 21 is fixedly connected to the fixed end of the self-locking telescopic rod 22. A limiting shell 23 is fixedly installed on the movable end of the self-locking telescopic rod 22. Two pressure plates 26 are provided inside the limiting shell 23. Height plates 3 are fixedly installed on both sides of the top of the tension base 1. Mounting brackets 4 are fixedly installed on the middle of opposite sides of the two height plates 3 by screws. A connecting plate 8 is fixedly installed between the two mounting brackets 4 by screws. A tension mechanism 9 is fixedly installed in the middle of the connecting plate 8. A tension frame 10 is provided at the bottom end of the tension mechanism 9. Each of the two vertical plates 12 is fixedly installed on the bottom of the opposite side by screws. Two displacement plates 15 are slidably connected between the two vertical plates 12. Each of the two height plates 3 is fixedly installed on the top of the opposite side by screws by length plates 5. Two assembly plates 6 are fixedly installed between the two length plates 5 by screws. Multiple equidistant positioning holes 7 are opened on the two assembly plates 6. The tension mechanism 9 includes a tension housing 91 and a push housing 92. A fixing plate 97 is fixedly installed inside the tension housing 91. A lead screw 99 is rotatably connected to the middle of the fixing plate 97. The bottom end of the lead screw 99 is threadedly connected to the top end of the push housing 92. A push rod 93 is installed at the bottom end of the push housing 92 and is slidably connected to the tension housing 91. A tension sensor 94 is fixedly installed on the surface of the push rod 93.

[0034] Both sides of the inner wall of the limiting shell 23 are fixedly installed with pressure shells 24. One side of the inner wall of each pressure shell 24 is fixedly installed with a support spring 25. The end of each support spring 25 away from the pressure shell 24 is fixedly installed with an extension rod 28 that is slidably connected to the pressure shell 24. The opposite side of each extension rod 28 is fixedly connected to the opposite side of each pressure plate 26. Several wire grooves 27 are opened on the surface of each pressure plate 26. The rope is limited by the two opposite wire grooves 27, and the rope squeezes the pressure plate 26 from one side. The pressure plate 26 drives the extension rod 28 to slide along the pressure shell 24, and the extension rod 28 squeezes the support spring 25 from one side. The support spring 25 is elastic and the elastic deformation of the support spring 25 converts the squeezing force.

[0035] One side of each of the two limiting bases 21 is fixedly connected to both sides of the tension base 1. The limiting mechanism 2 is installed on the tension base 1 through the limiting bases 21.

[0036] The surface of the tension frame 10 is provided with several first fixing holes 11, and the surfaces of the two displacement plates 15 are provided with several second fixing holes 14. Tension wheels 13 are installed inside one of the first fixing holes 11 and two of the second fixing holes 14. The user can adjust the position of the three tension wheels 13 according to actual needs so that the included angle of the tension wheels 13 meets the experimental requirements.

[0037] The two mounting brackets 4 are fixedly connected to the bottom ends of the two length plates 5 on opposite sides by screws. The connection between the mounting brackets 4 and the length plates 5 increases the reliability of the installation of the length plates 5.

[0038] A driven umbrella-shaped helical tooth 98 is fixedly installed at the connection between the lead screw 99 and the fixed plate 97. A handle 95 is rotatably connected to one side of the tension machine housing 91. An active umbrella-shaped helical tooth 96 located inside the tension machine housing 91 is fixedly installed at one end of the handle 95. The outer side of the active umbrella-shaped helical tooth 96 meshes with the outer side of the driven umbrella-shaped helical tooth 98. When the user rotates the handle 95, the handle 95 drives the active umbrella-shaped helical tooth 96 to rotate. The active umbrella-shaped helical tooth 96 contacts the driven umbrella-shaped helical tooth 98, and the driven umbrella-shaped helical tooth 98 rotates. The driven umbrella-shaped helical tooth 98 drives the lead screw 99 to rotate. The thread on the surface of the lead screw 99 matches the thread on the inner wall of the push housing 92. The push housing 92 pushes the push rod 93 to slide along the tension machine housing 91 to adjust the height of the tension frame 10.

[0039] The middle part of the tension housing 91 is fixedly connected to the connecting plate 8, and the bottom end of the push rod 93 is fixedly connected to the side of the tension frame 10 facing each other. The tension mechanism 9 is mounted on the connecting plate 8 through the tension housing 91, and the push rod 93 pushes the tension frame 10 from the top to adjust the height of the tension frame 10.

[0040] The present invention discloses an experimental method for a tension measuring device, comprising the following steps:

[0041] Step 1: Introduction to the Principle: Introduce the basic concepts and principles of Newton's second law, as well as the parallelogram rule in the chapter on equilibrium of concurrent forces;

[0042] Step 2, Explanation of Device Usage: A detailed explanation of how to use the self-made tension measuring device. Pass the rope through the three tension wheels 13 in sequence. The tension sensor 94 on the tension mechanism 9 senses the tension of the rope and is assembled with the 3D printed bracket. The bracket is marked with the central axis and center point.

[0043] Step 3: Verify the included angle: Adjust the position of the tension wheel 13 on the first fixing hole 11 and the position of the tension wheel 13 on the second fixing hole 14, adjust the rope to be centered and the left and right parts of the rope to be horizontal, and verify the relationship between the pressure of the rope on the tension wheel 13 and the rope tension through experiments when the included angle is 120°.

[0044] Step 4: Record and Observe: Perform the experimental operations and record the data. Pay special attention to observing and analyzing the phenomena of weightlessness and hypergravity caused by vertical acceleration.

[0045] Step 5: Discussion and Exchange: Conduct group discussions and share experimental results and insights, and explore the application of Newton's second law in daily life.

[0046] This invention introduces the basic concepts and principles of Newton's second law and the parallelogram law in the chapter on the equilibrium of concurrent forces. It details the use of a self-made tension measuring device, demonstrating how to pass a rope sequentially through three tension wheels 13. Tension sensors 94 on the tension mechanism 9 sense the rope tension and are assembled with a 3D-printed bracket marked with a central axis and center point. The positions of the tension wheels 13 on the first fixing hole 11 and the second fixing hole 14 are adjusted to center the rope and level its left and right sides. Experiments verify that the pressure exerted by the rope at a 120° angle on the tension wheels 13 is equal to the rope tension. Pay special attention to observing and analyzing the phenomena of weightlessness and hypergravity caused by vertical acceleration during experimentation and data recording. Engage in group discussions and share experimental results and insights, exploring the application of Newton's Second Law in daily life. Evaluate student learning outcomes through classroom performance, experimental procedures, and data analysis. Provide timely and positive feedback and guidance to help students identify and improve their weaknesses. Encourage students to engage in independent learning and further research after class to deepen their understanding and mastery of physical principles. Pay particular attention to students' understanding and analysis of weightlessness and hypergravity phenomena, as well as their awareness and reflection on the application of Newton's Second Law in daily life, referring to the instructions attached. Figure 5 and 6 By improving the experimental setup for Newton's second law, the systematic errors of existing DIS experiments were successfully overcome. Combined with experimental teaching design, this method cultivated students' experimental skills and scientific inquiry abilities. The experimental results proved the accuracy and feasibility of the method, providing students with a more intuitive and accurate experimental experience. At the same time, this method also provides students with a platform for personalized research, encouraging them to explore other areas of physics in depth. Future research will also focus on how to combine the self-made tension measuring device with other physics experiments to expand its application scope and improve students' comprehensive practical abilities. It is hoped that by continuously improving and promoting the application of self-made teaching aids, the innovation and development of physics education can be promoted, and more outstanding talents with scientific literacy and practical abilities can be cultivated.

[0047] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A tension measuring device, comprising a tension base (1), characterized in that: Limiting mechanisms (2) are fixedly installed on both sides of the tension base (1). Each limiting mechanism (2) includes a limiting base (21) and a self-locking telescopic rod (22). The top of the limiting base (21) is fixedly connected to the fixed end of the self-locking telescopic rod (22). A limiting shell (23) is fixedly installed on the movable end of the self-locking telescopic rod (22). Two pressure plates (26) are provided inside the limiting shell (23). Height plates (3) are fixedly installed on both sides of the top of the tension base (1). A mounting bracket (4) is fixedly installed on the middle of the opposite side of the two height plates (3) by screws. A connecting plate (8) is fixedly installed between the two mounting brackets (4) by screws. A tension mechanism (9) is fixedly installed in the middle of the connecting plate (8). A tension frame (10) is provided at the bottom of the tension mechanism (9). A tension frame (10) is provided at the bottom of the opposite side of the two height plates (3). A vertical plate (12) is fixedly installed. Two displacement plates (15) are slidably connected between the two vertical plates (12). Length plates (5) are fixedly installed on the top of the opposite side of the two height plates (3) by screws. Two assembly plates (6) are fixedly installed between the two length plates (5) by screws. Multiple equidistant positioning holes (7) are opened on the two assembly plates (6). The tension mechanism (9) includes a tension housing (91) and a push housing (92). A fixing plate (97) is fixedly installed inside the tension housing (91). A lead screw (99) is rotatably connected to the middle of the fixing plate (97). The bottom end of the lead screw (99) is threadedly connected to the top end of the push housing (92). A push rod (93) is slidably connected to the tension housing (91) at the bottom end of the push housing (92). A tension sensor (94) is fixedly installed on the surface of the push rod (93).

2. The tension measuring device according to claim 1, characterized in that: Both sides of the inner wall of the limiting shell (23) are fixedly installed with pressure shells (24). One side of the inner wall of each of the two pressure shells (24) is fixedly installed with a support spring (25). The end of each of the two support springs (25) away from the pressure shell (24) is fixedly installed with an extension rod (28) that is slidably connected to the pressure shell (24). The opposite side of each of the two extension rods (28) is fixedly connected to the side of each of the two pressure plates (26). Several wire grooves (27) are opened on the surface of each of the two pressure plates (26).

3. The tension measuring device according to claim 1, characterized in that: One side of each of the two limiting bases (21) is fixedly connected to both sides of the tension base (1).

4. The tension measuring device according to claim 1, characterized in that: The tension frame (10) has several first fixing holes (11) on its surface, and the two displacement plates (15) each have several second fixing holes (14) on their surfaces. Tension wheels (13) are installed inside one of the first fixing holes (11) and two of the second fixing holes (14).

5. A tension measuring device according to claim 1, characterized in that: The two mounting brackets (4) are fixedly connected to the bottom ends of the two length plates (5) on opposite sides by screws.

6. A tension measuring device according to claim 1, characterized in that: A driven umbrella-shaped helical tooth (98) is fixedly installed at the connection between the lead screw (99) and the fixed plate (97). A handle (95) is rotatably connected to one side of the tension housing (91). An active umbrella-shaped helical tooth (96) located inside the tension housing (91) is fixedly installed at one end of the handle (95). The outer side of the active umbrella-shaped helical tooth (96) meshes with the outer side of the driven umbrella-shaped helical tooth (98).

7. A tension measuring device according to claim 1, characterized in that: The middle part of the tension machine housing (91) is fixedly connected to the connecting plate (8), and the bottom end of the push rod (93) is fixedly connected to the side of the tension frame (10) facing each other.

8. The experimental method for a tension measuring device according to any one of claims 1-7, characterized in that, Includes the following steps: Step 1: Introduction to the Principle: Introduce the basic concepts and principles of Newton's second law, as well as the parallelogram rule in the chapter on equilibrium of concurrent forces; Step 2, Explanation of device usage: A detailed explanation of how to use the self-made tension measuring device. Pass the rope through the three tension wheels (13) in sequence. The tension sensor (94) on the tension mechanism (9) senses the tension of the rope and is assembled with the 3D printed bracket. The bracket is marked with the central axis and center point. Step 3: Verify the included angle: Adjust the position of the tension wheel (13) on the first fixed hole (11) and the position of the tension wheel (13) on the second fixed hole (14), adjust the rope to be centered and the left and right parts of the rope to be horizontal, and verify the relationship between the pressure of the rope on the tension wheel (13) with an included angle of 120° and the rope tension through experiments; Step 4: Record and Observe: Perform the experimental operations and record the data. Pay special attention to observing and analyzing the phenomena of weightlessness and hypergravity caused by vertical acceleration. Step 5: Discussion and Exchange: Conduct group discussions and share experimental results and insights, and explore the application of Newton's second law in daily life.

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