Lever balance principle demonstration instrument

Abstract

The utility model discloses a lever balance principle demonstration instrument, which comprises a support frame, a circular writing display board, a lever, a connecting assembly, a mass block, a force meter and a graduated scale, and is characterized in that the support frame is provided with a vertical column extending upwards, and the vertical column is provided with a rotating shaft; the circular writing display board is rotatably installed on a rotating shaft of the stand column. The lever is rotatably arranged on a rotating shaft of the stand column; the connecting assembly comprises a power arm fulcrum and a resisting arm fulcrum which are arranged on the two sides of the center, in the length direction, of the lever correspondingly, and the power arm fulcrum and the resisting arm fulcrum are suitable for moving in the length direction of the lever correspondingly. The mass block is detachably connected to the resisting arm fulcrum; the force meter is detachably connected to the power arm fulcrum; and the graduated scale is rotatably arranged on the support frame. The lever balance demonstration instrument can visually demonstrate the balance of the lever, and is easy to operate and convenient to use.

Description

Technical Field

[0001] This utility model relates to a lever balance principle demonstration device, belonging to the field of teaching aids technology. Background Technology

[0002] Currently, lever balance demonstrations are widely used in physics teaching, mainly for experimental demonstrations and independent exploration of "lever balance conditions" in middle school physics.

[0003] After searching the existing technology, a Chinese patent with publication number CN221466170U was found to disclose a lever balance condition demonstration device. This patent uses a scaled dial as part of a background panel. However, during use, it was found that the background panel was inconvenient for teachers to write on when drawing diagrams of the lever balance principle during lectures, which could disrupt the flow of the teaching process and increase the complexity and time cost of instruction. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to overcome the defects of the prior art and provide a lever balance principle demonstration device that can intuitively demonstrate the balance of levers, is easy to operate and convenient to use.

[0005] To solve the above-mentioned technical problems, the technical solution of this utility model is: a lever balance principle demonstration device, comprising:

[0006] A support frame, wherein an upwardly extending column is provided on the support frame, and a rotating shaft is provided on the column;

[0007] A circular writing display board, which is rotatably mounted on the rotation axis of the column;

[0008] A lever, which is rotatably mounted on the rotation axis of the column;

[0009] A connecting component, the connecting component including a power application point and a resistance application point respectively disposed on both sides of the center of the lever along the length direction, the power application point and the resistance application point being adapted to move along the length direction of the lever;

[0010] A mass block, which is detachably connected to the point where the resistance force is applied;

[0011] A force measuring instrument, wherein the force measuring instrument is detachably connected to the point of application of the power;

[0012] A scale ruler is rotatably mounted on the support frame, and the scale ruler rotates synchronously with the circular writing display board;

[0013] The lever and the ruler are located on the same side of the circular writing display board.

[0014] Furthermore, a specific structure for a balance adjustment mechanism is provided, wherein each end of the lever is provided with a balance adjustment mechanism, the balance adjustment mechanism comprising:

[0015] A threaded rod, which is fixedly mounted on the lever along the length of the lever;

[0016] A balance nut, which is threaded onto the threaded rod and is adapted to move axially along the threaded rod.

[0017] Furthermore, the mass block includes at least one weight, and each weight has a hook at its bottom;

[0018] The weight can be selectively connected to the point where resistance is applied.

[0019] Furthermore, a specific type of force measuring instrument is provided, wherein the force measuring instrument is a spring force gauge.

[0020] Furthermore, the lever balance principle demonstrator also includes multiple magnetic marking elements, which can be selectively attached to the circular writing display board.

[0021] Furthermore, a specific structure for a connecting component is provided, wherein the lever is provided with a groove extending along the length direction;

[0022] The connection component includes:

[0023] The first hook is slidably disposed on the groove of the lever;

[0024] The point of application of the power is set on the first hook component;

[0025] The second hook is slidably disposed on the groove of the lever;

[0026] The resistance point is located on the second hook component.

[0027] Furthermore, a specific structure of a rotation limiting damping mechanism is provided, wherein the rotation shaft of the column is provided with a threaded section;

[0028] The lever balance principle demonstrator also includes a rotation limit damping mechanism, which comprises:

[0029] A clamping nut, which is threaded onto the threaded section of the rotating shaft, is located on the other side of the circular writing display board relative to the column;

[0030] An elastic washer is disposed between the clamping nut and the circular writing display board;

[0031] The clamping nut is adapted to be actuated to adjust the pressure of the elastic washer on the circular writing display board, so that the circular writing display board abuts against the column, thereby restricting the rotation of the circular writing display board.

[0032] Furthermore, the lever is provided with indicator marks.

[0033] Furthermore, the circular writing display board is provided with force direction guide lines perpendicular to the length direction of the ruler.

[0034] By adopting the above technical solution, this utility model has the following beneficial effects:

[0035] In this invention, the equilibrium of a lever in a horizontal state is first demonstrated. In the experiment, a mass block is suspended at the point of application of resistance on the lever, and the required force is measured at the point of application using a force measuring instrument. Subsequently, by adjusting the lever to demonstrate its equilibrium in a non-horizontal state, the user can understand that lever equilibrium is not limited to a horizontal state; as long as the lever is stationary or rotating at a constant speed, it can be considered in equilibrium. This demonstration helps to intuitively understand the basic principles of a lever.

[0036] In further experiments, the length of the resistance arm and the magnitude of the applied resistance were fixed. Then, the length of the effort arm was varied, and multiple positions were selected. The magnitude and direction of the effort arm force at each position were measured until the lever reached equilibrium. After each equilibrium was achieved, the length of the effort arm, the magnitude and direction of the force at the point of application, and the length of the resistance arm and the magnitude of the resistance were recorded. Similarly, the length of the effort arm was fixed, and the length and force of the resistance arm were adjusted until the lever reached equilibrium again, and the corresponding parameters were recorded. These data allow for a direct verification of the lever's equilibrium condition: the product of the effort arm length and the applied force equals the product of the resistance arm length and the applied force.

[0037] When the lever is horizontal and the forces on both the effort arm and resistance arm are perpendicular to the lever, the lengths of the effort arm and resistance arm can be directly measured. However, when the force is not perpendicular to the lever, the circular writing display board needs to be rotated to align the scale with the direction of the force being measured, and then the length of the effort arm can be read from the scale. This process allows students to measure the effort arm first, followed by the resistance arm. Through these operations, students can clearly observe and verify the conditions for lever balance.

[0038] At the same time, each time the circular writing display board is used, a schematic diagram can be drawn on the circular writing display board, and the necessary information can be recorded.

[0039] In addition, the balance adjustment mechanism can adjust the weight on both sides of the lever to make the lever balanced; the weights in the connecting components can provide different resistance levels; and the magnetic marking element can also facilitate temporary marking of the circular writing display board, making the teaching process more interactive.

[0040] In summary, this invention demonstrates various lever equilibrium states, flexibly showcasing the five elements of a lever. By adjusting variables such as effort, resistance, lever arm length, and direction, it enables students to deeply understand the equilibrium conditions of a lever. Not only is it simple to operate and precisely adjustable, but it also boasts advantages such as structural stability, portability, and excellent demonstration effects. It significantly enhances the effectiveness and practicality of teaching the lever principle and is suitable for quantitative experiments and classroom demonstrations in physics teaching. Attached Figure Description

[0041] Figure 1 This is a front view of the lever balance principle demonstrator of this utility model;

[0042] Figure 2 This is a right view of the lever balance principle demonstrator of this utility model. Detailed Implementation

[0043] To make the contents of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0044] like Figure 1-2 As shown, a lever balance principle demonstration device includes: a support frame 1, an upwardly extending column on the support frame 1, and a rotating shaft on the column;

[0045] A circular writing display board 2 is rotatably mounted on the rotating shaft of the column;

[0046] Lever 3 is rotatably mounted on the rotation axis of the column;

[0047] The connecting component includes a power application point and a resistance application point respectively disposed on both sides of the center of the lever 3 along the length direction, and the power application point and the resistance application point are respectively adapted to move along the length direction of the lever 3;

[0048] Mass block 4 is detachably connected to the resistance application point;

[0049] Force measuring instrument 5, which is detachably connected to the point of application of the power;

[0050] The scale 6 is rotatably mounted on the support frame 1, and the scale 6 rotates synchronously with the circular writing display board 2.

[0051] Lever 3 and ruler 6 are located on the same side of the circular writing display board 2.

[0052] In this embodiment, as Figure 1 As shown, firstly, the equilibrium of lever 3 in a horizontal state is demonstrated. In the experiment, a mass block 4 is suspended from the point of resistance application on lever 3, and the required force is measured at the point of application using a force measuring meter 5. Subsequently, by adjusting the demonstration of the equilibrium of lever 3 in a non-horizontal state, users can understand that lever equilibrium is not limited to a horizontal state; as long as lever 3 is at rest or rotating at a uniform speed, it can be considered in equilibrium. This demonstration helps to intuitively understand the basic principles of levers.

[0053] In further experiments, the length of the resistance arm of lever 3 and the magnitude of the applied resistance were fixed. Then, the length of the effort arm was varied, and multiple positions were selected. The magnitude and direction of the effort arm force at each position were measured until lever 3 reached equilibrium. After each equilibrium was achieved, the length of the effort arm, the magnitude and direction of the force at the point of application, and the length of the resistance arm and the magnitude of the resistance were recorded. Similarly, the length of the effort arm was fixed, and the length and force of the resistance arm were adjusted until lever 3 reached equilibrium again, and the corresponding parameters were recorded. These data can be used to visually verify the equilibrium condition of the lever, namely, that the product of the effort arm length and the applied force is equal to the product of the resistance arm length and the applied force.

[0054] When lever 3 is horizontal and the forces on both the effort arm and resistance arm are perpendicular to lever 3, the lengths of the effort arm and resistance arm can be directly measured. However, when the force is not perpendicular to lever 3, the circular writing display board 2 needs to be rotated so that the scale 6 is perpendicular to the direction of the force being measured, and then the length of the effort arm can be read from the scale 6. This process allows students to measure the effort arm first, followed by the resistance arm. Through these operations, students can clearly observe and verify the conditions for lever balance.

[0055] At the same time, each time the circular writing display board 2 is used, a schematic diagram can be drawn on the circular writing display board 2 and the necessary information can be recorded.

[0056] In this embodiment, the circular writing display board 2 can be an acrylic board with blackboard paper pasted on it. The support frame 1 can specifically be an iron stand.

[0057] Specifically, such as Figure 1 As shown, each end of lever 3 is provided with a balance adjustment mechanism. The balance adjustment mechanism can have the following structure, including:

[0058] A threaded rod is fixedly mounted on lever 3 along the length of lever 3.

[0059] A balance nut is threaded onto a threaded rod and is adapted to move axially along the threaded rod.

[0060] In this embodiment, as Figure 1 As shown, the balance adjustment mechanism at both ends of lever 3 is used to adjust the lever and make it balanced. The threaded rod is fixed to lever 3 and extends along its length, providing a track for the balance nut to move. The balance nut is connected to the threaded rod by threads and can move axially along the threaded rod, thereby changing the position of the center of gravity of lever 3.

[0061] In use, the operator can rotate the balance nut to move it on the threaded rod, thereby fine-tuning the balance of lever 3 and ensuring the accuracy of the experimental results.

[0062] Specifically, such as Figure 1 As shown, mass block 4 includes four weights, each with a hook at the bottom;

[0063] Weights can be selectively attached to the point where resistance is applied.

[0064] In this embodiment, as Figure 1 As shown, the weights can be multiple weights of the same mass, multiple weights of different masses, or a combination of both. Using weights of the same mass allows for a visual demonstration of the linear relationship between weight and torque; while using weights of different masses simulates more complex real-world scenarios, showing the impact of different masses on lever balance. In some embodiments, the number of weights is not limited to four and can be set according to specific needs, and mass block 4 can also use other materials as resistance, not limited to weights.

[0065] Specifically, such as Figure 1 As shown, force measuring instrument 5 is a spring force measuring instrument.

[0066] In this embodiment, as Figure 1 As shown, the force measuring instrument 5 adopts the form of a spring force gauge. The working principle of the spring force gauge is based on Hooke's law. When an external force is applied, the distance the spring extends is proportional to the force applied. Therefore, the magnitude of the force can be read directly through the scale.

[0067] Specifically, such as Figure 1-2 As shown, the lever balance principle demonstrator also includes multiple magnetic marking elements, which can be selectively attached to the circular writing display board 2.

[0068] In this embodiment, magnetic markers can be used to mark important locations, draw auxiliary lines, or highlight key data points, making the demonstration process more intuitive and clear. For example, magnetic markers can be used to mark the resistance point and the point of force application on a lever, or to draw torque diagrams on a circular writing display board. These visual elements help students better understand the principles and calculation methods of lever balance.

[0069] Specifically, such as Figure 1As shown, lever 3 has a groove extending along its length.

[0070] The connection components include:

[0071] The first hook is slidably set on the groove of the lever 3;

[0072] The point of application of the power is set on the first hook component;

[0073] The second hook is slidably set on the groove of the lever 3;

[0074] The resistance point is set on the second hook.

[0075] In this embodiment, as Figure 1-2 As shown, the first hook and the second hook are provided with limiting parts on both sides and are locked in the groove in the middle. The first hook and the second hook are tightly fitted with the lever 3 and have a certain friction force. When force is applied, they will not be driven to deviate from the preset position.

[0076] Specifically, such as Figure 1-2 As shown, the rotating shaft of the column is provided with a threaded section;

[0077] The lever balance principle demonstrator also includes a rotation limit damping mechanism, which includes:

[0078] A clamping nut is threaded onto the threaded section of the rotating shaft and is located on the opposite side of the circular writing display board 2 relative to the column.

[0079] An elastic washer is provided between the clamping nut and the circular writing display board 2.

[0080] The clamping nut is adapted to be actuated to adjust the pressure of the elastic washer on the circular writing display board 2, so that the circular writing display board 2 abuts against the column, thereby restricting the rotation of the circular writing display board 2.

[0081] In this embodiment, as Figure 1-2 As shown, when the circular writing display board 2 needs to be kept in a fixed position, a rotational limiting damping mechanism can be used to firmly abut the circular writing display board 2 against the column; while when the circular writing display board 2 needs to be rotated, the pressure can be appropriately reduced, allowing the circular writing display board 2 to rotate under a certain resistance. This adjustable damping effect not only increases the flexibility of the demonstration but also improves the operational stability.

[0082] Specifically, such as Figure 1 As shown, lever 3 has indicator lines.

[0083] Specifically, such as Figure 1-2As shown, the circular writing display board 2 has a force direction guide line perpendicular to the length direction of the ruler 6.

[0084] In this embodiment, as Figure 1-2 As shown, during use, lever 3 is first adjusted using the balance adjustment mechanism to achieve equilibrium. Simultaneously, the indicator line on lever 3 is adjusted to align with the scale 6 on the circular writing display board 2, ensuring consistent readings. Next, following the experimental steps, the equilibrium of lever 3 in both horizontal and non-horizontal states is demonstrated. The experiment focuses on exploring the equilibrium state of lever 3 under different directional forces.

[0085] In the experiment, the magnitude of the resistance and the point of application of the resistance arm were first fixed. Then, by changing the point of application of the effort arm, the equilibrium state of lever 3 was observed under different application points. Through analysis of the experimental data, the basic condition for lever equilibrium can be derived: the effort multiplied by the length of the effort arm equals the resistance multiplied by the length of the resistance arm. In this way, students can understand the equilibrium of different types of levers, including effort-saving levers, effort-multiplying levers, and equal-arm levers.

[0086] Specifically, when lever 3 is horizontal, both the effort and resistance are perpendicular to lever 3. By fixing the resistance and resistance arm, and adjusting the point of application of the effort, the change in the magnitude of the effort can be observed. By changing the length of the effort arm, students can intuitively understand the following: a lever that saves effort (effort arm is longer than resistance arm), a lever that requires more effort (effort arm is shorter than resistance arm), and a lever with equal arms (effort arm equal to resistance arm). The characteristics of these different types of levers are clearly demonstrated in the experiment.

[0087] After the experiment, tidy up and put away the equipment. Through this series of experimental steps, students can clearly understand the equilibrium condition of lever 3 and the characteristics of different types of levers, thereby deepening their understanding of the lever principle.

[0088] The specific embodiments described above further illustrate the technical problems, technical solutions, and beneficial effects of this utility model. It should be understood that the above descriptions are merely specific embodiments of this utility model and are not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A lever balance principle demonstration instrument, characterized in that, It includes: Support frame (1), the support frame (1) is provided with upwardly extending column, the column is provided with rotating shaft; Circular writing display board (2), the circular writing display board (2) is rotatably installed on the rotating shaft of the column; Lever (3), the lever (3) is rotatably arranged on the rotating shaft of the column; Connecting assembly, the connecting assembly includes power action point and resistance force applying point respectively arranged on the both sides of the center of the lever (3) along the length direction, the power action point and the resistance force applying point are respectively adapted to move along the length direction of the lever (3); Mass block (4), the mass block (4) is detachably connected on the resistance force applying point; Force measuring meter (5), the force measuring meter (5) is detachably connected on the power action point; Scale (6), the scale (6) is rotatably arranged on the support frame (1), and the scale (6) is synchronously rotated with the circular writing display board (2); The lever (3) and the scale (6) are located on the same side of the circular writing display board (2); Wherein, the circular writing display board (2) is provided with force direction guide line perpendicular to the length direction of the scale (6).

2. The lever balance principle demonstration instrument according to claim 1, wherein, the both ends of the lever (3) are respectively provided with balance adjusting mechanism, and the balance adjusting mechanism comprises: threaded rod, the threaded rod is fixedly arranged on the lever (3) along the length direction of the lever (3); Balance nut, the balance nut is threadedly connected on the threaded rod, and the balance nut is adapted to move along the axial direction of the threaded rod.

3. The lever balance principle demonstration instrument according to claim 1, wherein, the mass block (4) comprises at least one weight, and the bottom of each weight is provided with a hook; The weight can be selectively connected to the resistance force applying point.

4. The lever balance principle demonstration instrument according to claim 1, wherein, the force measuring meter (5) is a spring dynamometer.

5. The lever balance principle demonstration instrument according to claim 1, further comprising a plurality of magnetic marking elements, which can be selectively adsorbed on the circular writing display board (2).

6. The lever balance principle demonstration instrument according to claim 1, wherein, the lever (3) is provided with a groove extending along the length direction; The connecting assembly comprises: First hook element, the first hook element is slidably arranged on the groove of the lever (3); The power action point is arranged on the first hook element; Second hook element, the second hook element is slidably arranged on the groove of the lever (3); The resistance force applying point is arranged on the second hook element.

7. The lever balance principle demonstration instrument according to claim 1, wherein, the rotating shaft of the column is provided with a threaded section; Further comprising a rotary limiting damping mechanism, the rotary limiting damping mechanism comprises: Compression nut, the compression nut is threadedly connected on the threaded section of the rotating shaft, and is located on the other side of the circular writing display board (2) relative to the column. ​ ​ ​ ​ ​ ​ ​ ​ An elastic washer is arranged between the compression nut and the circular writing display board (2); The compression nut is adapted to be actuated to adjust the pressure of the elastic washer on the circular writing display board (2), so that the circular writing display board (2) abuts against the stand to limit the rotation of the circular writing display board (2).

8. The lever balance principle demonstration instrument according to claim 1, characterized in that, An indicating scale is arranged on the lever (3).

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