CN215526146U - Rotating liquid gravity acceleration measuring experimental instrument - Google Patents

Abstract

The utility model provides a rotating liquid gravity acceleration measurement experimental instrument which comprises a rotating device, a vertical lifting device and a rotating speed measurement device, wherein the rotating device comprises a T-shaped base, a T-shaped bottom support frame is arranged at the upper end of the T-shaped base, three ends of the T-shaped bottom support frame are respectively in threaded connection with a first adjusting nut, the lower end of the first adjusting nut is in rotating connection with the T-shaped base, a permanent magnet direct current motor is arranged at the upper end of the T-shaped bottom support frame, the output end of the permanent magnet direct current motor is connected with a wood support frame, a second adjusting nut is arranged on the wood support frame, and a rotary table is arranged at the upper end of the second adjusting nut; vertical elevating gear includes mounting bracket and support, and mounting bracket upper end both sides are equipped with the pulley respectively, and it has or not stretch cord to slide on two pulleys, and no stretch cord is connected with the laser instrument towards T shape base one side, and the laser instrument lower extreme is connected with plumbous piece through no stretch cord, and the no stretch cord other end also is connected with plumbous piece. The experimental device has the advantages of simple structure, simple experimental process and reliable experimental result.

Description

Rotating liquid gravity acceleration measuring experimental instrument

Technical Field

The utility model mainly relates to the technical field of measuring gravitational acceleration, in particular to a gravitational acceleration experimental instrument for measuring gravitational acceleration by rotating liquid.

Background

The gravitational acceleration is a physical quantity that is widely used in production and life, and since the value of the gravitational acceleration slightly varies from place to place on the earth, various experiments have been designed to measure the local gravitational acceleration. The currently common measurement method is a single pendulum method, and the application of the method is mature, and is not described herein again. Other universities have used the traditional rotary liquid method. The requirement of the test method on the experimental equipment is very high, and the rotating liquid is always completely static relative to the container, but the fact that the test method is difficult to achieve is due to various factors. Therefore, an experimental instrument with simple structure, convenient measurement of gravitational acceleration and reliable measurement result is needed.

SUMMERY OF THE UTILITY MODEL

The utility model mainly provides a rotating liquid gravity acceleration measurement experimental instrument which is used for solving the technical problems in the background technology.

The technical scheme adopted by the utility model for solving the technical problems is as follows:

the rotating liquid gravity and acceleration measuring experimental instrument comprises a rotating device, a vertical lifting device and a rotating speed measuring device, wherein the rotating device comprises a T-shaped base, a T-shaped bottom supporting frame is arranged at the upper end of the T-shaped base, three ends of the T-shaped bottom supporting frame are respectively in threaded connection with a first adjusting nut, the lower end of the first adjusting nut is in rotating connection with the T-shaped base, a permanent magnet direct current motor is installed at the upper end of the T-shaped bottom supporting frame, the output end of the permanent magnet direct current motor is connected with a wood supporting frame, a second adjusting nut is in threaded connection with the wood supporting frame, and a rotary disc is arranged at the upper end of the second adjusting nut; vertical elevating gear includes mounting bracket and support, mounting bracket and support are located T shape base both sides respectively, mounting bracket upper end both sides are equipped with the pulley respectively, two it has nos stretch cord to slide on the pulley, no stretch cord is connected with the laser instrument towards T shape base one side, the laser instrument lower extreme is connected with plumbous piece through no stretch cord, the no stretch cord other end also is connected with plumbous piece that hangs down, the mounting bracket upper end is equipped with slide caliper and slider, the slider slides on the mounting bracket, slider lower extreme one side is connected with the sawtooth saw blade, the meshing of sawtooth saw blade lower extreme has drive gear, drive gear one side is rotated with the mounting bracket and is connected, just drive gear opposite side axle center is connected with the adjustment disk.

Preferably, the wood support frame comprises a fixed connecting sleeve, three sides of the fixed connecting sleeve are respectively provided with a dispersing connecting sleeve in threaded connection with the second adjusting nut, and the dispersing connecting sleeves are connected with the fixed connecting sleeve.

Preferably, a rectification circuit and a speed regulator are installed on the T-shaped bottom support frame, and the rectification circuit and the speed regulator are electrically connected with the permanent magnet direct current motor.

Preferably, a connecting rod slides on the bracket, and the other side of the connecting rod is connected with a laser receiving screen.

Preferably, the rotating speed measuring device comprises a fixed frame, a photoelectric door is slidably mounted on the fixed frame, and the photoelectric door is electrically connected with a digital millisecond counter.

Preferably, a protruding small wood piece is connected to one side of the rotating disc, and when the rotating disc rotates, the protruding small wood piece passes through the photoelectric door.

Preferably, a container circle center fixing device is arranged on one side of the rotating device and comprises a container support frame and a circle center fixing frame, and a painting brush is fixed at the upper end of the circle center fixing frame.

Compared with the prior art, the utility model has the beneficial effects that:

the level of the rotary table is adjusted by adopting a secondary adjustment method, so that the rotary table always rotates in the same horizontal plane, the absolute position is replaced by the relative position, the lowest point of the liquid level is determined, the accuracy of experimental data is ensured, the traditional rotary liquid method is improved, the requirement on the precision of equipment is reduced by improving the measurement method, the gravitational acceleration can be measured without installing too many precise instruments, and the device has a simple structure and is convenient to produce; when the experiment is carried out, only the rotating speed of the permanent magnet direct current motor needs to be continuously adjusted, and corresponding data are recorded, so that the experiment process is simple, the use is convenient, and the practicability is improved.

The present invention will be explained in detail below with reference to the drawings and specific embodiments.

Drawings

FIG. 1 is a perspective view of the present invention;

FIG. 2 is a partial perspective view of the present invention;

FIG. 3 is a schematic view of a partial structure of the mounting bracket of the present invention;

FIG. 4 is a schematic perspective view of a circle center device of the constant volume device according to the present invention;

FIG. 5 is an analysis diagram of the experimental principle of the present invention;

FIG. 6 is an analysis chart of the experimental principle of the present invention;

FIG. 7 is a graph showing the results of the test according to the present invention.

In the figure: 1. a rotating device; 11. a T-shaped base; 12. a T-shaped bottom support frame; 13. a first adjusting nut; 14. a permanent magnet DC motor; 15. a wooden support frame; 151. fixing the connecting sleeve; 152. dispersing the connecting sleeves; 16. a second adjusting nut; 17. a turntable; 18. a rectifying circuit; 19. a speed regulator; 2. a vertical lifting device; 21. a mounting frame; 22. a pulley; 23. no elastic cord; 24. a laser instrument; 25. a plumb block; 26. a support; 27. a connecting rod; 28. a laser receiving screen; 3. a vernier caliper; 31. a slider; 32. a saw blade; 33. a drive gear; 34. an adjusting disk; 4. a device for measuring the rotating speed; 41. a fixed mount; 42. a photogate; 43. a digital millisecond counter; 44. extruding small wood chips; 5. a device for determining the circle center of the container; 51. a container support frame; 52. a circle center fixing frame; 53. a painting brush.

Detailed Description

In order to facilitate an understanding of the utility model, the utility model will now be described more fully hereinafter with reference to the accompanying drawings, in which several embodiments of the utility model are shown, but which may be embodied in different forms and not limited to the embodiments described herein, but which are provided so as to provide a more thorough and complete disclosure of the utility model.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may be present, and when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present, as the terms "vertical", "horizontal", "left", "right" and the like are used herein for descriptive purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, and the knowledge of the terms used herein in the specification of the present invention is for the purpose of describing particular embodiments and is not intended to limit the present invention, and the term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 and 2, the present invention provides a technical solution: the rotating liquid gravity acceleration measurement experiment instrument comprises a rotating device 1, a vertical lifting device 2 and a rotating speed measurement device 4, wherein the rotating device 1 comprises a T-shaped base 11, a T-shaped bottom support frame 12 is arranged at the upper end of the T-shaped base 11, three ends of the T-shaped bottom support frame 12 are respectively in threaded connection with a first adjusting nut 13, the lower end of the first adjusting nut 13 is rotatably connected with the T-shaped base 11, a permanent magnet direct current motor 14 is arranged at the upper end of the T-shaped bottom support frame 12, the output end of the permanent magnet direct current motor 14 is connected with a wooden support frame 15, a second adjusting nut 16 is in threaded connection with the wooden support frame 15, the wooden support frame 15 comprises a fixed connecting sleeve 151, three sides of the fixed connecting sleeve 151 are respectively provided with a dispersing connecting sleeve 152 in threaded connection with the second adjusting nut 16, and the three dispersing connecting sleeves 152 are connected with the fixed connecting sleeve 151, the upper end of the second adjusting nut 16 is provided with a turntable 17, the T-shaped bottom support frame 12 is provided with a rectifying circuit 18 and a speed regulator 19, and the rectifying circuit 18 and the speed regulator 19 are both electrically connected with the permanent magnet direct current motor 14. Firstly, a universal level meter is placed in the center of a rotary table 17, a first adjusting nut 13 is adjusted to enable a rotating shaft of a permanent magnet direct current motor 14 to be in a vertical state, when the rotary table 17 is rotated, bubbles in the level meter are static relative to the level meter, the rotating shaft can be considered to be adjusted to be vertical, then a second adjusting nut 16 is adjusted to enable the bubbles to be located in the center of the universal level meter, the rotary table 17 can rotate in the same horizontal plane all the time, the level of the rotary table is adjusted by adopting a secondary adjusting method, the adjusting effect is good, and the accuracy is guaranteed.

Referring again to fig. 1 and 3, the vertical lift device 2 includes a mounting bracket 21 and a support bracket 26, the mounting rack 21 and the support 26 are respectively positioned at two sides of the T-shaped base 11, pulleys 22 are respectively arranged at two sides of the upper end of the mounting rack 21, a non-elastic rope 23 slides on the two pulleys 22, one side of the non-elastic rope 23 facing the T-shaped base 11 is connected with a laser instrument 24, the lower end of the laser instrument 24 is connected with a plumb block 25 through the non-elastic rope 23, the other end of the non-elastic rope 23 is also connected with a plumb block 25, the upper end of the mounting rack 21 is provided with a vernier caliper 3 and a slide block 31, the sliding block 31 slides on the mounting frame 21, one side of the lower end of the sliding block 31 is connected with a saw tooth blade 32, the lower end of the tooth saw blade 32 is engaged with a driving gear 33, one side of the driving gear 33 is rotatably connected with the mounting rack 21, and the other side of the driving gear 33 is connected with an adjusting disc 34 in axle center. Through plumb block 25 for laser instrument 24 remains the vertical condition throughout, rotates adjustment disk 34, drives drive gear 33 and rotates, drives tooth saw blade 32 and removes, makes slider 31 drive nos stretch cord 23 and removes, makes laser instrument 24 round trip movement in vertical direction, and slide caliper 3 just can record the relative change of laser instrument 24 position in vertical direction. A connecting rod 27 is arranged on the support 26 in a sliding mode, the other side of the connecting rod 27 is connected with a laser receiving screen 28, and when a horizontal light beam emitted by the laser instrument 24 is below the lowest point of the liquid level, the light beam can display a bright line on the light screen through rotating liquid; when the light beam just hits the lowest point of the liquid level, the light beam at the lowest point is influenced by the concave liquid level at the lowest point of the liquid level, and the originally complete light beam can generate a small gap, so that the position of the laser instrument 24 can be adjusted through the picture displayed on the laser receiving screen 28.

Referring to fig. 1 again, the device 4 for measuring the rotation speed includes a fixed frame 41, a photoelectric gate 42 is slidably mounted on the fixed frame 41, the photoelectric gate 42 is electrically connected to a digital millisecond counter 43, a protruding small wood piece 44 is connected to one side of the rotary table 17, and when the rotary table 17 rotates, the protruding small wood piece 44 passes through the photoelectric gate 42. By adjusting the light gate 42 to a suitable position, the time taken by the turntable 17 to make each two revolutions can be measured in conjunction with the digital millisecond counter 43, and the angular velocity of the rotating liquid can be obtained.

Please refer to fig. 5 again, one side of the rotating device 1 is provided with a container center fixing device 5, the container center fixing device 5 includes a container supporting frame 51 and a center fixing frame 52, and a painting brush 53 is fixed at the upper end of the center fixing frame 52. The container is placed on the container support frame 51, the circle centering frame 52 is close to the container support frame 51, the painting brush 53 can draw lines at the bottom of the container, the container is rotated, the pen point of the painting brush 53 can draw a concentric circle concentric with the circular container at the bottom of the container, and when the container is placed, the container can be considered to be placed in the center of the turntable 17 only by enabling the circle to coincide with the circle on the turntable 17.

The experimental principle that this device adopted does:

when a container containing liquid rotates around the symmetry axis of the cylindrical surface at a constant speed of an angular speed omega, the container drives the liquid to rotate, the liquid level sinks, when the rotating speed of the liquid is the same as that of the container, the liquid level does not sink any more, and at the moment, a coordinate system shown in the figure is established to analyze the stress of a certain element in the liquid level, as shown in the following figure 5.

mg tanθ＝mω²x

And because tan theta ═ d_y/d_x

Therefore, it is not only easy to use

It can thus be seen that the surface of the revolution is a paraboloid. Let x be R (R is the radius of the container), the above formula becomes

Y is the lowest liquid levelEnd to topmost vertical distance. Therefore, theoretically, the gravity acceleration can be calculated by only measuring the rotation speed omega, the radius R of the container and the vertical distance y from the bottommost end to the topmost end of the liquid level. However, this height difference y cannot be directly measured due to the liquid immersion. However, from the knowledge of mathematical integration and analysis by the isometric method, the following relationship y is 2y (y is the vertical distance between the lowermost end of the rotating liquid surface and the initial liquid surface), as shown in fig. 6 below.

The above equation becomes

Is finished to obtain

Because g and R are both constant values, the sinking depth h of the liquid surface and the square omega of the angular velocity can be seen²Proportional relation, and making omega by measuring the corresponding liquid level falling depth h at different rotation speeds²The slope of the plot of-h is used to obtain the g value.

The specific operation mode of the utility model is as follows:

when the universal level meter is used by a worker, the universal level meter is placed in the center of the turntable 17, the first adjusting nut 13 is adjusted to enable the rotating shaft of the permanent magnet direct current motor 14 to be in a vertical state, when the turntable 17 is rotated, bubbles in the level meter are static relative to the level meter, the rotating shaft can be considered to be adjusted to be vertical, then the second adjusting nut 16 is adjusted to enable the bubbles to be located in the center of the universal level meter, the turntable 17 rotates in the same horizontal plane all the time, the level of the turntable is adjusted by adopting a secondary adjusting method, a container is placed on the container supporting frame 51, then the circle centering frame 52 is close to the container supporting frame 51, the painting brush 53 can draw a line at the bottom of the container, the container is rotated, the pen point of the painting brush 53 can draw a concentric circle concentric with the circular container at the bottom of the container, when the container is placed, the circle coincides with the circle on the turntable 17, then a proper amount of castor oil is added into the container, starting the permanent magnet DC motor 14 to rotate the container, and after the liquid rotation speed is stabilized, using numbersThe millisecond counter 43 measures the rotation speed of the liquid, simultaneously rotates the adjusting disc 34 to drive the driving gear 33 to rotate and drive the saw tooth blade 32 to move, so that the slide block 31 drives the non-elastic rope 23 to move, the laser instrument 24 moves back and forth in the vertical direction, the lowest position of the concave liquid level is determined, the corresponding reading of the vernier caliper 3 is recorded, the rotation speed of the permanent magnet direct current motor 14 is changed, the steps are repeated, multiple groups of data are measured, and origin software is used for fitting to obtain omega²-h relation curve, calculating the gravity acceleration according to the slope;

the measurement data are as follows:

circular container

Rotating liquid

The measured data were input into origin software, and the fitting results are shown in fig. 7, where the red boxed portion in the following figure is the slope of the image, and its value is: 37556.8365.

the gravity acceleration measured by the experiment is 9.79566m/s by combining the related data²。

The utility model is described above with reference to the accompanying drawings, it is obvious that the utility model is not limited to the above-described embodiments, and it is within the scope of the utility model to adopt such insubstantial modifications of the inventive method concept and solution, or to apply the inventive concept and solution directly to other applications without modification.

Claims (7)

1. Rotatory liquid surveys gravitational acceleration experiment appearance, including rotating device (1), vertical elevating gear (2), measurement rotational speed device (4), its characterized in that: the rotating device (1) comprises a T-shaped base (11), a T-shaped bottom supporting frame (12) is arranged at the upper end of the T-shaped base (11), first adjusting nuts (13) are respectively in threaded connection with three ends of the T-shaped bottom supporting frame (12), the lower end of each first adjusting nut (13) is rotatably connected with the T-shaped base (11), a permanent magnet direct current motor (14) is installed at the upper end of the T-shaped bottom supporting frame (12), the output end of the permanent magnet direct current motor (14) is connected with a wood supporting frame (15), a second adjusting nut (16) is in threaded connection with the wood supporting frame (15), and a rotating disc (17) is arranged at the upper end of the second adjusting nut (16);

vertical elevating gear (2) includes mounting bracket (21) and support (26), mounting bracket (21) and support (26) are located T shape base (11) both sides respectively, mounting bracket (21) upper end both sides are equipped with pulley (22) respectively, two it has stretch cord (23) to slide on pulley (22), stretch cord (23) are connected with laser instrument (24) towards T shape base (11) one side, laser instrument (24) lower extreme is connected with plumbous pendant (25) through stretch cord (23), stretch cord (23) other end also is connected with plumbous pendant (25), mounting bracket (21) upper end is equipped with slide caliper (3) and slider (31), slider (31) slide on mounting bracket (21), slider (31) lower extreme one side is connected with tooth saw blade (32), tooth saw blade (32) lower extreme meshing has drive gear (33), one side of the driving gear (33) is rotatably connected with the mounting rack (21), and the axis of the other side of the driving gear (33) is connected with an adjusting disc (34).

2. The rotary liquid gravitational acceleration test instrument according to claim 1, characterized in that: the wood support frame (15) comprises a fixed connecting sleeve (151), three sides of the fixed connecting sleeve (151) are respectively provided with a dispersed connecting sleeve (152) which is in threaded connection with a second adjusting nut (16), and the dispersed connecting sleeves (152) are connected with the fixed connecting sleeve (151).

3. The rotary liquid gravitational acceleration test instrument according to claim 1, characterized in that: a rectifying circuit (18) and a speed regulator (19) are installed on the T-shaped bottom support frame (12), and the rectifying circuit (18) and the speed regulator (19) are electrically connected with the permanent magnet direct current motor (14).

4. The rotary liquid gravitational acceleration test instrument according to claim 1, characterized in that: the support (26) is provided with a connecting rod (27) in a sliding mode, and the other side of the connecting rod (27) is connected with a laser receiving screen (28).

5. The rotary liquid gravitational acceleration test instrument according to claim 1, characterized in that: the rotating speed measuring device (4) comprises a fixed frame (41), a photoelectric door (42) is arranged on the fixed frame (41) in a sliding mode, and the photoelectric door (42) is electrically connected with a digital millisecond counter (43).

6. The rotary liquid gravitational acceleration test instrument according to claim 5, characterized in that: the rotary disc (17) is connected with a small protruding wood chip (44) on one side, and when the rotary disc (17) rotates, the small protruding wood chip (44) passes through the photoelectric door (42).

7. The rotary liquid gravitational acceleration test instrument according to claim 1, characterized in that: a container circle center fixing device (5) is arranged on one side of the rotating device (1), the container circle center fixing device (5) comprises a container supporting frame (51) and a circle center fixing frame (52), and a painting brush (53) is fixed at the upper end of the circle center fixing frame (52).

Images