CN219392828U - Digital friction force experimental device - Google Patents

Abstract

Digital frictional force experimental apparatus relates to teaching aid technical field for solve student to the cognitive error district problem of sliding friction. The device comprises a track, a traction assembly, a speed sensor and an experiment column body, wherein the pressure sensor is arranged on the upper surface of the track, sliding blocks are arranged on the left side and the right side of the pressure sensor and are in sliding connection with the track, and the traction assembly is arranged at one end of the track; the experimental column is in a hexagonal prism shape, an elastic piece is arranged between the experimental column and the sliding block, the experimental column and the sliding block synchronously move, bristles are arranged on the first side face of the six side faces of the experimental column, the areas of the first side face, the second side face and the third side face are the same but the roughness is different, the roughness of the third side face, the fourth side face and the fifth side face is the same but the surface area is different, and rolling bodies are arranged on the sixth side face; the traction assembly is used for traction of the experimental column body to move along the track, and the speed sensor is arranged on the track. The utility model can effectively solve the problem of the cognition error area of the sliding friction force of students.

Description

Digital friction force experimental device

Technical Field

The utility model relates to the technical field of teaching aids, in particular to a digital friction force experimental device.

Background

The course content of the "obligation education physical course standard (2022 edition)" is analyzed by research, and the second theme "2.2 mechanical movements and forces" of the first theme "movements and interactions" is required: "2.2.3 by common examples or experiments, understand the gravity, spring force and friction … … to explore and understand the factors with which the magnitude of sliding friction is related. In the second-level theme "4.2 study class students of the first-level theme" experiment study "the requirement is that: "4.2.2 explores which factors the magnitude of sliding friction is related to. "example 2 suggests" to use a spring force gauge, a plate, a string, a rectangular block, cotton cloth, a towel, etc., to investigate which factors the magnitude of the sliding friction force is related to. "

The "interaction and law of motion" theme of must be revised 1 is required to analyze the course content of the "ordinary high school physical course standard (revised in 2017 edition 2020): "1.2.1 knows gravity, elasticity and friction … … knows the phenomenon of sliding friction and static friction, and can calculate the sliding friction by using the dynamic friction factor. Examples of using or minimizing friction in production and life are investigated by "suggesting in" event advice ". "

Analysis and comparison are carried out, the magnitude of the sliding friction force is qualitatively explored, the factors are related to the magnitude of the sliding friction force, the magnitude of the sliding friction force is quantitatively calculated by the high school, and the phenomenon of static friction is recognized. Therefore, the requirements of the junior middle school and the junior middle school on the content have the advanced property and the linking property, the comprehensive analysis can be carried out during the design and teaching, and the knowledge of students on the concept of friction force is gradually deepened. Therefore, the design of the friction experimental instrument which can be used for linking the primary high school teaching, strengthening the key points of all school segments, breaking through the cognitive difficulties of the school segments and serving the primary teaching becomes the primary challenge of the primary physical teacher.

In combination with the practice of first-line teaching, the conventional friction force traditional or digital instrument for assisting demonstration or grouping of students in the market is analyzed, so that the problem of measuring the sliding friction force of the first-class and the high-class is effectively solved, and the functions of solving other friction force problems are still to be perfected. The following problems mainly exist:

first, demonstration of the first and high school sections on the direction of friction force comes from self-selected materials of teachers

At present, the existing traditional teaching aids and digitizer devices in the market have important breakthroughs in the problem of measuring the friction force, and the existing traditional teaching aids and digitizer devices are completely based on-site material selection of a first-line teacher in the problem of friction force direction.

First-line teachers generally select tools with soft bristles, which are common in life, for demonstration during teaching. The method can clearly show the direction problem of the sliding friction force or the static friction force, but is separated from the help of the friction force demonstration instrument, and the burden of preparing equipment or carrying instruments on lessons is increased for teachers.

The students in the middle school stage have misareas in the knowledge of pressure and gravity in the experiment

According to the cognitive characteristics of students in junior middle school and long-term first-line investigation, when the problem of ' the magnitude of sliding friction force is related to which factors ' is explored by utilizing the traditional wood boards and wood blocks ', a considerable part of students are easily influenced by the operation of increasing and decreasing the hook codes, and the total weight force of the object blocks and the hook codes is considered to influence the magnitude of the sliding friction force. Pen-holder sightedness "scientific research: the public lesson example of friction force "found that the teacher had the following way in the handling of this problem: in the guessing link, students are guided to guess that the sliding friction force is influenced by pressure through language; the student puts forward the gravity, and the teacher directly informs the student not to be gravity, but to be pressure; because students are pre-learned in time, some teachers do not encounter the students' answers about gravity in the class, ignoring the design of the question. The above processing method can solve the confusion of students, and can only obtain the experience of infusion, but can not completely solve the cognitive difficulty of students.

(III) the first and middle school stages lack effective measures for exploring the influence of speed and area on the sliding friction force

Investigation market current tradition teaching aid and digitizer ware, tradition teaching aid have operation difficulty in the aspect of controlling the billet to do uniform velocity rectilinear motion, and the digitizer ware is convenient to carry out the speed governing, but the size of the speed of both being inconvenient for demonstration. Meanwhile, the wood block is generally made into a cuboid or a cylinder, and the operation is difficult in terms of changing the area, so that the experimental operation for more than three times can not be realized.

The problems of influence of exploration speed and area on sliding friction force are generally not explored and solved in class due to the consideration of the capacity of the first line and the instrument effect in class.

Fourth, the primary and middle school stages generally do not measure the magnitude of sliding, rolling and static friction forces

In first-line teaching and high-school teaching, the application problem of sliding, rolling and static friction force is required to be solved in the teaching of 'friction force' in class. In particular, in the problem of "changing sliding friction to rolling friction can reduce friction", a first-line teacher generally explains by way of example, and does not perform quantitative measurement. After examining the existing traditional teaching aids and digitizers in the market, no instrument has been found to explain the problem. Student feedback indicates that quantitative measurement demonstrations are expected to be seen.

Disclosure of Invention

The utility model aims to provide a digital friction force experiment device which is used for solving the problems in teaching described by the patent of the utility model, including the influence of gravity and pressure on the magnitude of sliding friction force, the influence of contact area and moving speed on the magnitude of sliding friction force and the teaching difficulty of sliding and rolling friction force measurement.

The technical scheme adopted for solving the technical problems is as follows: the digital friction force tester comprises a track, a traction assembly, a speed sensor and an experiment column body, wherein the pressure sensor is arranged on the upper surface of the track, sliding blocks are arranged on the left side and the right side of the pressure sensor, the sliding blocks are in sliding connection with the track, and the traction assembly is arranged at one end of the track; the experimental column body is in a hexagonal prism shape, an elastic piece is arranged between the experimental column body and the sliding block, the experimental column body and the sliding block synchronously move, the six side surfaces of the experimental column body are used for being in contact with the upper surface of the pressure sensor, the first side surface is provided with bristles, the areas of the first side surface, the second side surface and the third side surface are the same but the surface roughness is different, the surface roughness of the third side surface, the fourth side surface and the fifth side surface is the same but the surface area is different, and the sixth side surface is provided with rolling bodies; the rolling body is contacted with the upper surface of the pressure sensor, the traction assembly is used for traction of the experimental column body to move along the track, and the speed sensor is arranged on the track and used for detecting the moving speed of the experimental column body.

Further, the top and the bottom of the experimental column body are provided with main body hooks, the top of the sliding block is provided with sliding block hooks, and the elastic piece is arranged between the main body hooks and the sliding block hooks.

Further, the elastic piece is a rubber band and is sleeved on the main body hook and the sliding block hook.

Further, the traction assembly comprises a motor, a winding wheel is arranged at the output end of the motor, a pull rope is wound on the winding wheel, and the tail end of the pull rope is connected with the experimental column body.

Further, the speed sensors are uniformly arranged along the length direction of the pressure sensor.

Further, the upper part of the sliding block hook and the cylinder hook are both in a horizontal state, the upper part of the sliding block hook and the side wall of the cylinder hook are both provided with annular grooves, and the elastic piece is contacted with the inner walls of the annular grooves.

Further, the rolling bodies are rollers, a bracket is arranged on the sixth side surface of the experimental column, and the rolling bodies are rotatably arranged on the bracket.

Further, the rolling bodies are balls, and the balls are installed in the sixth side surface of the experimental cylinder in a 360-degree rotation mode.

Further, the experimental column body is of a hollow structure.

Further, the first side of the experimental column is of a detachable structure.

The beneficial effects of the utility model are as follows:

(1) According to the utility model, through the arrangement of the experimental column body with six side surfaces, the influence of different contact areas and different surface roughness on the sliding friction force can be studied;

(2) According to the utility model, the rolling bodies are arranged on the sixth side surface of the experimental column body, so that the friction force of rolling friction and sliding friction is studied;

(3) According to the utility model, through the arrangement of the speed sensor, the speed measurement of the experimental column body is realized, so that the influence of the moving speed of the experimental column body on the sliding friction force is studied;

(4) The experimental column provided by the utility model has a simple structure, is universal, does not need to additionally prepare teaching materials by teachers, and can be used for teaching friction force of primary, middle and high-grade materials.

Drawings

FIG. 1 is a three-dimensional view of the present utility model;

FIG. 2 is a front view of the present utility model;

FIG. 3 is a top view of the present utility model;

FIG. 4 is a left side view of the present utility model;

FIG. 5 is one of the three-dimensional views of the experimental column;

FIG. 6 is a second three-dimensional view of the experimental column;

FIG. 7 is a front view of the experimental column;

FIG. 8 is a left side view of the experimental column;

FIG. 9 is a schematic illustration of the installation of a pull cord between a winding wheel and an experimental cylinder and the installation of an elastic member between a slider hook and a body hook;

FIG. 10 is a schematic view of the mounting of the elastic member between the slider hook and the body hook;

in the figure: 1 track, 11 chute, 2 pressure sensor, 3 motor, 31 winding wheel, 32 stay cord, 4 speed sensor, 5 slider, 51 slider couple, 52 annular, 6 experimental cylinder, 61 first side, 62 second side, 63 third side, 64 fourth side, 65 fifth side, 66 sixth side, 67 cylinder couple, 7 rolling body, 71 support, 8 elastic component.

Detailed Description

As shown in fig. 1 to 10, the present utility model comprises a track 1, a pressure sensor 2, a traction assembly, a speed sensor 4 and an experimental column 6, and is an improvement on the langerhans friction tester, and the improvement is mainly based on the design of the experimental column 6, and the present utility model will be described in detail with reference to the accompanying drawings.

As shown in fig. 1 to 4, the digital friction tester comprises a rail 1, a traction assembly, a speed sensor 4 and a test cylinder 6, wherein the upper surface of the rail 1 is provided with a pressure sensor 2 with the length of 80-120cm, and the pressure sensor 2 is embedded into the upper surface of the rail 1, namely, the upper surface of the pressure sensor 2 is flush with the upper surface of the rail 1. The left and right sides of pressure sensor 2 all are provided with slider 5, slider 5 and track 1 sliding connection. In order to realize the sliding connection of the sliding block 5 and the track 1, two sliding grooves 11 which are arranged in parallel are arranged on the track 1, the sliding block 5 is in sliding connection with the sliding grooves 11, and the pressure sensor 4 is positioned between the two sliding grooves 11.

As shown in fig. 5 to 7, the experimental column 6 has a hexagonal prism structure, and as shown in fig. 10, an elastic member 8 is provided between the experimental column 6 and the sliding block 5, and the experimental column 6 and the sliding block 5 move synchronously. In order to realize synchronous movement of the experimental column 6 and the sliding block 5, main body hooks 67 are arranged at the top and the bottom of the experimental column 6, the main body hooks 67 are short axes, and the outer wall of the main body hooks 67 is provided with a ring groove 52. The top of slider 5 has slider couple 51, and slider couple 51 is "L" shape structure, and slider couple 51 lower part and slider 5 upper surface contact are fixed, and slider couple 51 upper portion is the horizontality, and slider couple 51 upper portion's outer wall also has annular 52, and annular 52's setting is used for spacing to elastic component 8. After the experimental column 6 is placed on the upper surface of the rail 1, the main body hook 67 is parallel to the upper portion of the slider hook 51. The elastic member 8 is provided between the main body hook 67 and the upper portion of the slider hook 51. Specifically, the elastic element 8 is an elastic band, the elastic element 8 is sleeved on the main body hook 67 and the slider hook 51, the elastic element 8 is in a stretching state, the experimental column 6 and the pressure sensor 4 are kept in contact and pressed under the action of the elastic element 8, and then a certain positive pressure is arranged between the experimental column 6 and the pressure sensor 4. When in use, the elastic piece 8 is sleeved between the main body hook 67 and the upper part of the sliding block hook 51, at the moment, the elastic piece 8 is contacted with the inner wall of the ring groove 52, and the positive pressure between the experimental column 6 and the pressure sensor 4 is changed by increasing or decreasing the number of the elastic pieces 8. The pressure of the experimental column 6 to the pressure sensor 4 is changed without changing the total gravity of the experimental column, so that the sliding friction force and the pressure can be synchronously displayed, and when other conditions are the same, the relation between the sliding friction force and the positive pressure is explored, the students are helped to go out of a misunderstanding area, and the cognitive difficulty is broken through.

As shown in fig. 5 to 7, of the six sides of the experimental column 6, the first to fifth sides are used for contacting with the upper surface of the pressure sensor 4, and the first side 61 is provided with bristles, and the first, second and third sides have the same area but different surface roughness to investigate the influence of the surface roughness of the contact surface on the magnitude of sliding friction; the third, fourth and fifth sides have the same surface roughness but different surface areas to investigate the effect of contact area on the magnitude of sliding friction. To achieve different surface roughness of the first, second and third sides, the first, second and third sides may be designed to be of different materials, the first side 61 being provided with bristles, the second side 62 being provided with cotton, the third side 63 being a wooden board surface. The first side 61 is provided with bristles which can be used to indicate the direction of sliding or static friction. The surface area of the fourth side 64 is larger than the surface area of the third side 63, the surface area of the third side 63 is larger than the surface area of the fifth side 65, the rolling bodies 7 are arranged on the sixth side 66, the rolling bodies 7 are in contact with the upper surface of the pressure sensor 4, when the traction assembly pulls the experimental column 6 to move along the track 1, sliding friction force is generated between the experimental column 6 and the pressure sensor 4 on the track 1, and positive pressure is formed between the experimental column 6 and the pressure sensor 4. The track 1 is provided with a speed sensor 5 for detecting the moving speed of the experimental column 6, and the speed sensor 5 is a plurality of speed sensors uniformly arranged along the length direction of the pressure sensor 4.

As shown in fig. 5 and 7, the rolling element 7 is a roller, the sixth side of the experimental column 6 is provided with four brackets 71, the four brackets 71 are located at four vertexes of a rectangle, and the rolling element 7 is rotatably mounted on the brackets 71. The experimental column 6 is placed on the pressure sensor 4, the rolling body 7 is in contact with the pressure sensor 4, and rolling friction is formed between the experimental column 6 and the pressure sensor 4 when the experimental column 6 is pulled to move along the pressure sensor 4. The rolling bodies 7 may have other structures, as shown in fig. 8, and the rolling bodies 7 are balls which are installed in the sixth side of the experimental column 6 in 360-degree rotation. The traction assembly is arranged at one end of the track 1, as shown in fig. 1 and 3, and comprises a motor 3, the output end of the motor 3 is provided with a winding wheel 31, as shown in fig. 9, a pull rope 32 is wound on the winding wheel 31, and the tail end of the pull rope 32 is connected with the experimental column 6. The motor 3 is a speed regulating motor, and the winding wheel 31 is driven to rotate after the motor 3 is started, so that the pull rope 32 is wound on the winding wheel 31, and the experimental column 6 is pulled to move. In addition, the experimental column 6 is designed to be a hollow structure so as to weaken the recognition error area of the sliding friction force and the gravity related to the student. The first side 61 of the experimental column 6 is designed to be a detachable structure, and after the first side 61 is opened, a weight can be placed on the inner side of the experimental column 6 to ensure that the sliding friction force can be accurately measured. The friction sensor and the pressure sensor 4 are connected with a computer to digitally display the friction force and the positive pressure on the computer.

(1) According to the utility model, through the arrangement of the experimental column body with six side surfaces, the design of different surface roughness and the design of different surface areas, the influence of different contact areas and different surface roughness on the sliding friction force can be studied;

(2) According to the utility model, the rolling body is arranged on the sixth side surface of the experimental column body, so that the friction force relation between rolling friction and sliding friction is studied;

(3) According to the utility model, the speed of the experimental column body is measured by setting the speed sensor, so that the influence of the moving speed of the experimental column body on the sliding friction force is studied;

(4) The experimental column provided by the utility model has a simple structure, is universal, does not need to additionally prepare teaching materials by teachers, and can be used for teaching friction force of primary, middle and high-grade materials.

Claims (10)

1. The digital friction force tester is characterized by comprising a track, a traction assembly, a speed sensor and an experiment column body, wherein the pressure sensor is arranged on the upper surface of the track, sliding blocks are arranged on the left side and the right side of the pressure sensor, the sliding blocks are in sliding connection with the track, and the traction assembly is arranged at one end of the track; the experimental column body is in a hexagonal prism shape, an elastic piece is arranged between the experimental column body and the sliding block, the experimental column body and the sliding block synchronously move, the six side surfaces of the experimental column body are used for being in contact with the upper surface of the pressure sensor, the first side surface is provided with bristles, the areas of the first side surface, the second side surface and the third side surface are the same but the surface roughness is different, the surface roughness of the third side surface, the fourth side surface and the fifth side surface is the same but the surface area is different, and the sixth side surface is provided with rolling bodies; the rolling body is contacted with the upper surface of the pressure sensor, the traction assembly is used for traction of the experimental column body to move along the track, and the speed sensor is arranged on the track and used for detecting the moving speed of the experimental column body.

2. The digital friction tester according to claim 1, wherein the top and bottom of the test cylinder have a main body hook, the slider top has a slider hook, and the elastic member is disposed between the main body hook and the slider hook.

3. The digital friction force tester according to claim 2, wherein the elastic member is a rubber band, and the elastic member is sleeved on the main body hook and the sliding block hook.

4. The digital friction tester according to claim 1, wherein the traction assembly comprises a motor, the output end of the motor is provided with a winding wheel, a pull rope is wound on the winding wheel, and the tail end of the pull rope is connected with the test cylinder.

5. The digitized friction force tester of claim 1 wherein the speed sensor is a plurality of speed sensors uniformly disposed along the length of the pressure sensor.

6. The digital friction force tester according to claim 3, wherein the upper part of the slider hook and the cylinder hook are both in a horizontal state, the upper part of the slider hook and the side wall of the cylinder hook are both provided with annular grooves, and the elastic piece is in contact with the inner walls of the annular grooves.

7. The digital friction tester according to claim 1, wherein the rolling body is a roller, a sixth side of the test cylinder is provided with a bracket, and the rolling body is rotatably mounted on the bracket.

8. The digital friction tester according to claim 1, wherein the rolling bodies are balls, and the balls are mounted in the sixth side of the test cylinder in 360 degrees of rotation.

9. The digital friction tester according to claim 1, wherein the test cylinder is a hollow structure.

10. The digital friction tester according to claim 1, wherein the first side of the test cylinder is a removable structure.