CN215495593U - Force composition and decomposition demonstration device - Google Patents

Abstract

The utility model discloses a force composition and decomposition demonstration device, which comprises a first marker post ruler, a second marker post ruler, a third marker post ruler, a fourth marker post ruler and a fifth scale ruler, wherein the first marker post ruler, the second marker post ruler, the third marker post ruler, the fourth marker post ruler and the fifth scale ruler are strip-shaped plates with grooves in the middle, indication arrows and metric scales which are positioned on two sides of the grooves are respectively arranged, positioning holes are symmetrically arranged at the head end and the tail end of each of the strip-shaped plates, the five marker post ruler consists of a semicircular angle plate and a strip-shaped plate with grooves in the middle, the angle plate is provided with 0-180-degree scale marks, the positioning holes at the front ends of the first scale rod ruler and the fourth scale rod ruler are movably connected through a first pin shaft, the positioning holes at the front ends of the second scale rod ruler and the third scale rod ruler are respectively movably connected with a second pin shaft and a fourth pin shaft which are positioned in grooves of the first scale rod ruler and the fourth scale rod ruler, the grooves of the second scale rod ruler and the third scale rod ruler are simultaneously sleeved on the third pin shaft, the elastic pull rope comprises three branch ropes, and the end parts of the branch ropes are connected with a spring dynamometer; the utility model can demonstrate the synthesis and the decomposition of force through a parallelogram rule, can demonstrate the infinite possibility of force change, dynamically demonstrates, and is convenient and visual.

Description

Force composition and decomposition demonstration device

Technical Field

The utility model belongs to physical teaching equipment, and particularly relates to a demonstration device for force synthesis and decomposition.

Background

Most of current high school physics experimental apparatus are obsolete, for example Newton's first law demonstration appearance, few ready-made instruments exist, and teachers make teaching aids simple and crude and rough, so that teaching experiments are stopped at the head of mouth or on test questions.

In addition, in the teaching that relates to mechanics, current experiment is more single, and a lot of experiments are difficult to embody through the teaching aid moreover, and a lot of teachers are suspected to be experimental troublesome, therefore single experiment also does very seldom, leads to student's learning inefficiency.

SUMMERY OF THE UTILITY MODEL

In order to reduce the experiment workload of teachers, strengthen the comprehensive exploration experiment capacity of students, strengthen the innovative cultivation of students and embody the interest of the experiment, the utility model provides a force synthesis and decomposition demonstration device.

The technical scheme adopted by the utility model for solving the technical problems is as follows: a force composition and decomposition demonstration device comprises a first marker rod ruler, a second marker rod ruler, a third marker rod ruler, a fourth marker rod ruler, a fifth marker rod ruler and an elastic pull rope, wherein the first marker rod ruler, the second marker rod ruler, the third marker rod ruler and the fourth marker rod ruler are strip plates with grooves in the middle, the strip plates are respectively provided with an indicating arrow head and a metric scale which are positioned at two sides of the grooves, positioning holes are symmetrically arranged at the head end and the tail end of the strip plates, the fifth marker rod ruler is composed of a semicircular angle plate and a strip plate with grooves in the middle, the angle plate is provided with 0-180-degree scale marks, the positioning holes at the front ends of the first marker rod ruler and the fourth marker rod ruler are movably connected through a first pin shaft, the positioning holes at the front ends of the second marker rod ruler and the third marker rod ruler are respectively movably connected with a second pin shaft and a fourth pin shaft which are positioned in the grooves of the first marker rod ruler and the fourth marker rod ruler, the second marker rod ruler and the third marker rod ruler are sleeved on the third pin shaft, the elastic pull rope is composed of a nut, a first branch rope, a second branch rope and a third branch rope, wherein the first branch rope, the second branch rope and the third branch rope are led out from the nut, and the end part of each branch rope is connected with a spring dynamometer.

The force composition and decomposition demonstration device is characterized in that a first branch rope, a second branch rope and a third branch rope are graduated pull rulers which are wound in nuts through coil springs.

According to the force composition and decomposition demonstration device, the strip-shaped plate of the fifth staff gauge is provided with indicating arrows and metric scales which are positioned at two sides of the groove.

The force composition and decomposition demonstration device is characterized in that a strip-shaped plate is a transparent plate.

The force composition and decomposition demonstration device is characterized in that the pin shafts of the device are composed of screw rods and nuts.

The force composition and decomposition demonstration device is characterized in that a magnet is arranged on a pin shaft.

The force composition and decomposition demonstration device is characterized in that a gasket is arranged on a pin shaft.

The utility model can realize the synthesis and the decomposition of the demonstration force of the parallelogram rule through four marker post rulers, can show the infinite possibility of force change, can dynamically show conveniently and visually, can standardize and help students and teachers to make drawings, can visually show dynamic transformation, is convenient for students to understand various problems of learning vectors, has simple structure, very strong variability and one function, can be used for making polygonal patterns by matching with a fifth marker post ruler with the function of a protractor, can make circles and the like by fixing the radius of the circle center.

Drawings

FIG. 1 is a schematic of the structure of the present invention;

FIG. 2 is a schematic diagram of a parallelogram rule demonstrating forces of the present invention;

FIG. 3 is a schematic diagram of the composition and resolution of the demonstration force of the present invention after the fifth staff gauge is placed thereon.

The figures are numbered: 1-first mark pole chi, 2-second mark pole chi, 3-third mark pole chi, 4-fourth mark pole chi, 5-fifth mark pole chi, 6-first spring dynamometer, 7-second spring dynamometer, 8-elasticity stay cord, 81-first branch rope, 82-second branch rope, 83-third branch rope, 11-first round pin axle, 12-second round pin axle, 13-third round pin axle, 14-fourth round pin axle.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Referring to fig. 1 and 2, the utility model discloses a force synthesis and decomposition demonstration device, which comprises an elastic pull rope 8, and a first scale bar 1, a second scale bar 2, a third scale bar 3, a fourth scale bar 4 and a fifth scale bar 5 which have the same size and specification and are strip plates with grooves in the middle, wherein the first scale bar 1, the second scale bar 2, the third scale bar 3 and the fourth scale bar 4 are respectively provided with an indicating arrow and a metric scale which are positioned at two sides of the grooves, the head end and the tail end of each strip plate are symmetrically provided with positioning holes, the aperture of each positioning hole is the same as the groove width, the positioning holes at the front ends of the first scale bar 1 and the fourth scale bar 4 are movably connected through a first pin shaft 11, the positioning holes at the front ends of the second scale bar 2 and the third scale bar 3 are respectively movably connected with a second pin shaft 12 and a fourth pin shaft 14 which are positioned in the grooves of the first scale bar 1 and the fourth scale bar 4, the grooves of the second scale rod 2 and the third scale rod 3 are simultaneously sleeved on the third pin shaft 13, so that four scale rod rulers with indicating arrows and metric scales form a parallelogram through four pins, the elastic pull rope 8 consists of a nut and a first branch rope 81, a second branch rope 82 and a third branch rope 83 led out from the nut, when the first branch rope 81 is fixed, the end parts of the second branch rope 82 and the third branch rope 83 are respectively connected with the first spring dynamometer 6 and the second spring dynamometer 7, and the second branch rope 82 is attached to the grooves, and the tail ends of the second branch rope 82 reach the pin shaft, the tension values displayed by the first side and the fourth side of the parallelogram and the corresponding spring dynamometer are two component forces F1 and F2 which form an angle with each other in the parallelogram rule.

The utility model changes the parallelogram rule of the verification force from the mapping verification to the dynamic demonstration verification, has convenient display and obvious effect, dynamically displays the dynamic change part which is difficult to be understood by students in the teaching, is very intuitive, is convenient for the students to understand and learn and can solve the practical problem.

Referring to fig. 3, the same fifth measuring stick 5 is placed on the first pin 11, and since the fifth measuring stick 5 is also provided with an indication arrow and metric scales on two sides of the groove, when the third pin 13 falls into the groove of the fifth measuring stick 5, the second branch rope 82 is attached to the groove and the end reaches the pin, the fifth measuring stick 5 can be represented as a diagonal line of a parallelogram, and the tension value displayed by the corresponding spring dynamometer is the measured resultant force F. The resultant forces of F1 and F2 are obtained by using a parallelogram rule, the magnitude of the resultant forces of F, F1 and F2 is judged to be equal by comparing the two, and the direction of the force is checked to be the same according to an indication arrow on a scale bar. The magnitude of the force displayed by the fifth scale bar 5 is equal to the magnitude of the theoretical resultant force within the error tolerance range, which indicates that the parallelogram rule of the force is correct.

The force component and the resultant force change when the included angle changes can be dynamically demonstrated: the included angle of the two divided forces becomes small, and the resultant force becomes large; the included angle of the two divided forces becomes larger, and the resultant force becomes smaller.

Further, set up the fifth scale rod chi 5 that the strip board of a semi-circular angle board and middle trough of belt is constituteed, the angle board is provided with 0 ~ 180 scale mark, and be provided with the instruction arrow point and the metric system scale that are located the groove both sides on its strip board, fifth scale rod chi 5 has possessed the function of protractor and ruler simultaneously promptly, because the strip board is the transparent plate, and the round pin axle comprises screw rod and nut, can be at will through the position of adjusting pin axle and then adjust and record the big or small numerical value in parallelogram interior angle, further demonstrate the synthesis and the decomposition of power. By this equivalent method in the parallelogram rule of can the complete demonstration power, through reducing or increasing the quantity of sighting rod chi, for example eight sighting rod chi add a longer fifth sighting rod chi 5 (in plane geometry at most to octagon), can also further demonstrate the vector operation rule of power according to the actual size that the scale shows and the actual pulling force that the spring dynamometer shows to and the composition and the decomposition of vector: the three constant forces act on the same point of the object at the same time, when the stressed object is in a static state or a uniform linear motion state, the three forces are balanced, wherein the resultant force of any two forces is equal to the third force in magnitude and opposite in direction. If any two forces are taken as component forces, the magnitude of the third force represents the magnitude of the resultant force of the first two forces, and the opposite direction of the third force represents the direction of the resultant force.

The two-force resultant range can also be verified by the vector triangle rule: the resultant force is the greatest when the arrows point in the same direction, i.e., the two force components are in the same direction, and the resultant force is the least when the arrows point in the opposite direction, i.e., the two force components are in the opposite direction.

Three force composition demonstrations may also be performed: when the three rulers are connected end to form a triangle, the minimum value can be zero when the three forces are combined, and the maximum value of the resultant force is the sum of the three forces.

In addition, can be with first branch rope 81, second branch rope 82 and third branch rope 83 for the scale that takes through the coil spring rolling in the nut, pull out the slide bar during the use, the back slide bar that finishes using is folded in the nut under the coil spring effect, has improved the convenience of using greatly.

In addition, still can set up magnet on the round pin axle, can adsorb whole presentation device on the blackboard like this, can be better to student's demonstration in the classroom.

When the three-force balance demonstration instrument is used as a three-force balance demonstration instrument, the first pin shaft 11 represents gravity fixation, two end point forces connected with the gravity are connected through the movable shaft, and the rest superposed end points are placed in the clamping grooves capable of being moved back and forth.

The utility model is flexible and changeable, can show infinite possibility of force change, is dynamic in display, is convenient and intuitive, and can standardize and help students and teachers to draw (can be used as a common ruler, can also be used for vector synthesis and decomposition, and is additionally provided with almost all plane figures, such as parallel lines, triangles, quadrangles, circles, ellipses, parabolas and even hyperbolas); secondly, dynamic transformation can be visually displayed, so that students can conveniently understand various problems of learning vectors (such as three-force balance, two-force synthesis range, multiple solutions of decomposition force, and extreme value of synthesis or decomposition); thirdly, simple structure, the variability is very powerful, and a special multipotency can be done, can do polygon pattern according to the protractor function of fifth scale 5, and the radius of fixed centre of a circle (add the sucking disc, the blank also can be used) can be done the circle etc..

The utility model can also demonstrate the extreme problem in the resolution of forces: the included angle of two sighting rod chi is unchangeable, and when the fixed one end of third sighting rod chi one end removed, the third power was minimum when can verifying to constitute right triangle-shaped.

In addition, one or more gaskets with the same thickness as the ruler can be arranged on the pin shaft, so that the ruler is convenient to adjust to be parallel to the supporting surface.

The demonstration device is flexible and changeable in use, can adapt to various problems by slight modification, solves various problems, and really achieves one function and multiple functions, such as demonstration of a two-force synthesis range (two component forces are unchanged in magnitude, one component force is unchanged in direction, and the other component force is unchanged in magnitude and direction), a three-force synthesis range (minimum and maximum analysis), vector understanding of multi-force synthesis, dynamic balance of three forces, extreme value analysis in dynamic change of resultant force or component force (such as only changing the magnitude of a certain force), observation of a unique solution in force decomposition and the like.

The above-described embodiments are merely illustrative of the principles and effects of the present invention, and some embodiments may be applied, and it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the inventive concept of the present invention, and these embodiments are within the scope of the present invention.

Claims (7)

1. A force composition and decomposition demonstration device is characterized in that: including first mark pole chi (1), second mark pole chi (2), third mark pole chi (3), fourth mark pole chi (4), fifth mark pole chi (5) and elasticity stay cord (8), first mark pole chi (1), second mark pole chi (2), third mark pole chi (3) and fourth mark pole chi (4) be middle grooved strip board, strip board on be provided with instruction arrow head and metric system scale that is located the groove both sides, strip board head and the tail both ends symmetry are provided with the locating hole, fifth mark pole chi (5) constitute by semi-circular angle board and middle grooved strip board, the angle board be provided with 0 ~ 180 scale mark, wherein the locating hole of first mark pole chi (1) and fourth mark pole chi (4) front end passes through first round pin axle (11) swing joint, the locating hole of second mark pole chi (2) and third mark pole chi (3) front end respectively with be located first mark pole chi (1) and fourth mark pole chi (4) round pin axle (12) and second round pin axle (12) and fourth mark pole inslot (4) 12) of second mark pole chi (4) and middle grooved strip board Four round pin axles (14) swing joint, the groove of second mark pole chi (2) and third mark pole chi (3) overlaps simultaneously on third round pin axle (13), elasticity stay cord (8) constitute by nut and first branch rope (81), second branch rope (82) and third branch rope (83) of drawing forth from the nut, branch rope tip be connected with the spring dynamometer.

2. A force composition and decomposition demonstrating device according to claim 1, wherein said first branch rope (81), second branch rope (82) and third branch rope (83) are graduated pull-tapes wound in nuts by coil springs.

3. A force composition and resolution demonstration device according to claim 1 characterised in that the strip of the fifth staff gauge (5) is provided with indicating arrows and metric scales on both sides of the groove.

4. A force composition decomposition demonstrating device according to claim 1, 2 or 3, wherein said strip is a transparent plate.

5. A force composition and resolution demonstration device according to claim 1, 2 or 3 wherein said pins are comprised of screws and nuts.

6. A force composition and resolution demonstration device according to claim 1, 2 or 3 wherein said pin is provided with a magnet.

7. A force composition and resolution demonstration device according to claim 1, 2 or 3 wherein said pin is provided with a spacer.

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