CN110794470B

CN110794470B - Experimental device for measuring gravitational acceleration

Info

Publication number: CN110794470B
Application number: CN201911017801.8A
Authority: CN
Inventors: 文灵华; 王庆波
Original assignee: Yanshan University; Tangshan Normal University
Current assignee: Yanshan University; Tangshan Normal University
Priority date: 2019-10-24
Filing date: 2019-10-24
Publication date: 2021-05-18
Anticipated expiration: 2039-10-24
Also published as: CN110794470A

Abstract

The utility model provides a measure acceleration of gravity's experimental apparatus, including top surface open-ended box, the box is transparent material, the bottom surface inner wall middle part fixed mounting supporting shoe of box, first blind hole has been seted up respectively to the both sides face of supporting shoe, the inside of first blind hole is equipped with the first slide bar of sliding fit with it respectively, two first slide bars one end in opposite directions correspond the inner wall of first blind hole through first spring coupling respectively, the one end that two first slide bars carried on the back mutually is inclined plane wedge face up, the top surface fixed mounting backup pad of supporting shoe, the preceding first recess of two vertical and cross-sections for T shapes of seting up of backup pad, the inside of first recess is equipped with the first slider that the cross-section is T shape respectively. The invention can be used as a simple balance for roughly measuring the quality of an experiment substance during the experiment, improves the utilization rate of a teaching instrument, reduces the waste of teaching resources, has simple operation, economical practicability, is suitable for teaching in various forms, and has good applicability.

Description

Experimental device for measuring gravitational acceleration

Technical Field

The invention belongs to the field of measuring instruments, and particularly relates to an experimental device for measuring gravitational acceleration.

Background

The gravity acceleration is also called as the acceleration of the free falling body, and occupies an important position in the teaching of physical experiments, the measuring method is to measure the distance and the time of the movement of the free falling body and calculate the gravity acceleration according to the formula of h & ltv & gt 0t + gt2/2, while the measuring device for the current experiment teaching usually adopts a dotting timer, a photoelectric door timing or a manual timing on the time measurement, the timing precision of the manual timing is low, the dotting timer timing needs to convert the time by points punched on a paper tape, the calculation is complicated, the paper tape is used twice at most, the resource is wasted, the teaching cost is high, although a photoelectric door instrument has high detection precision, the equipment is expensive, the economic practicability is poor, the traditional gravity acceleration experimental device has single performance, only can measure the gravity acceleration of one experimental falling body at a time, and can not carry out comparison experiments on a plurality of experimental falling bodies at the same time, the teaching intuition nature of contrast experiment is poor, and experimental apparatus can only measure the acceleration most and can only use at the teaching stage of acceleration promptly, and long-time idle has caused the waste of teaching resource to a great extent.

Disclosure of Invention

The invention provides an experimental device for measuring gravitational acceleration, which is used for overcoming the defects in the prior art.

The invention is realized by the following technical scheme:

an experimental device for measuring gravitational acceleration comprises a box body with an opening on the top surface, the box body is made of transparent materials, a supporting block is fixedly installed in the middle of the inner wall of the bottom surface of the box body, first blind holes are respectively formed in two side surfaces of the supporting block, first slide rods in sliding fit with the first blind holes are respectively arranged in the first blind holes, opposite ends of the two first slide rods are respectively connected with the inner wall of the corresponding first blind holes through first springs, opposite ends of the two first slide rods are wedge-shaped surfaces with upward inclined surfaces, a supporting plate is fixedly installed on the top surface of the supporting block, two vertical first grooves with T-shaped cross sections are formed in the front of the supporting plate, first slide blocks with T-shaped cross sections are respectively arranged in the first grooves, the top surfaces of the first slide blocks are respectively connected with the top surfaces of the inner walls of the corresponding first grooves through second springs, the bottom surfaces of the first slide blocks are respectively connected with the peripheries of the adjacent first slide, the opposite side surfaces of the two press plates are wedge-shaped surfaces with upward inclined surfaces, a timing device and a clamping device are respectively arranged below the two press plates, the bottom surfaces of the two press plates are respectively in contact fit with a timing switch knob of the timing device, the clamping device is respectively in contact fit with the periphery of the corresponding timing device, second grooves with T-shaped sections are respectively arranged on the inner walls of the opposite sides of the two first grooves, the interiors of the second grooves are communicated with the front space of the support plate, second sliders with T-shaped sections are respectively arranged inside the second grooves, the opposite ends of the two second sliders are respectively connected with the inner walls of the corresponding second grooves through third springs, the peripheries of the press rods are respectively and fixedly connected with the front surfaces of the two second sliders, the bottom surfaces of the two press rods are inclined surfaces and are in contact fit with the wedge-shaped surfaces of the adjacent press plates, vertical through grooves are arranged on the front surfaces of the support plate, and first, the front of the first screw is fixedly connected with the periphery of a sleeve, the periphery of the sleeve is in contact fit with the front of a support plate, the periphery of the bottom of the sleeve is provided with two through grooves, two second slide bars in sliding fit with the sleeve are arranged in the sleeve, the opposite side surfaces of the two second slide bars are connected through a fourth spring, the peripheries of the two second slide bars are respectively and fixedly connected with the fixed end of a telescopic rod, the movable end of the telescopic rod is respectively and movably connected with the top surfaces of corresponding press bars, the opposite side surfaces of the two second slide bars are respectively provided with a clamping hand, the back of the first screw is provided with a third blind hole along the axial direction of the first screw, a power rod in sliding fit with the third blind hole is arranged in the third blind hole, the front of the power rod is connected with the front of the inner wall of the third blind hole through a fifth spring, the front of the power rod is respectively connected with the opposite side surfaces of the two, the front surface of the first thread sleeve is in contact fit with the rear surface of the support plate.

The experimental device for measuring the gravitational acceleration is a digital stopwatch with the accuracy of 0.01 second, a timing switch key of the digital stopwatch is in contact fit with the bottom surface of the corresponding pressing plate, and the side periphery of the digital stopwatch is in contact fit with the corresponding clamping device.

According to the experimental device for measuring the gravitational acceleration, the clamping device is respectively composed of two coaxial second threaded sleeves and two third screws, the peripheries of the second threaded sleeves are respectively and fixedly connected with the front of the supporting plate, the second threaded sleeves are located between the supporting block and the corresponding pressing plate, the interiors of the two second threaded sleeves are respectively in threaded fit with one third screw, and the opposite side surfaces of the third screws are in contact fit with the periphery of the timing device.

As above, the top surface of the pressure lever is respectively provided with the second blind holes, the movable ends of the telescopic rods can respectively slide in the corresponding second blind holes, the side peripheries of the second blind holes are respectively provided with the penetrating second screw holes, the inner parts of the second screw holes are respectively provided with the bolts in threaded fit, and one ends of the bolts are respectively in contact fit with the peripheries of the movable ends of the corresponding telescopic rods.

According to the experimental device for measuring the gravitational acceleration, the inner wall of the box body and the wedge-shaped surfaces of the two first sliding rods are respectively provided with the soft rubber protective layers.

The experimental device for measuring the gravitational acceleration comprises two horizontal clamping plates and two limiting rods, wherein one end of each clamping plate is hinged to one end of the middle part of the sleeve in the back direction of the adjacent second sliding rod, the two sides of the clamping plates in the back direction are hinged to one ends of the corresponding limiting rods respectively, the other ends of the limiting rods are hinged to the side surfaces of the adjacent sleeves respectively, the two clamping plates and the two limiting rods are symmetrically distributed on two sides of the transverse central line of the sleeve, arc grooves are formed in the opposite side surfaces of the two clamping plates respectively, and rubber protective layers are arranged in the arc grooves.

According to the experimental device for measuring the gravitational acceleration, the front of the supporting block and the front of the supporting plate are respectively provided with the height measuring scale marks.

According to the experimental device for measuring the gravitational acceleration, the inner walls of the two sides of the box body are respectively hinged with the bottom ends of the supporting rods, the top ends of the supporting rods are respectively and fixedly connected with the middle part of the bottom surface of the horizontal plate, the periphery of the supporting rods is respectively hinged with the top end of the push rod, the bottom ends of the push rods are respectively hinged with one end, away from the middle part of the box body, of the adjacent first slide rod, and the top surfaces of the two horizontal plates are respectively provided with the rubber layer.

The invention has the advantages that: the invention aims to overcome the defects in the prior art and provides a gravity acceleration experimental device with detachable components, wherein before use, an operator movably connects two telescopic rods with corresponding pressure rods, then rotates a first screw sleeve to separate the front of the first screw sleeve from the back of a supporting plate, then moves a first screw rod to enable the first screw rod to vertically slide to a required experimental position along a through groove, then reversely rotates the first screw sleeve again to enable the front of the first screw sleeve to be in contact fit with the back of the supporting plate again, namely the position of a sleeve is fixed, in the process, the two telescopic rods limit the swinging of the sleeve and enable the axis of the sleeve to be horizontal, the operator respectively slides a pressure plate upwards and places a timing device on the top surface of a supporting table, at the moment, the bottom surfaces of the pressure plates are respectively in contact with the top surfaces of timing switches of the corresponding timing devices, and the operator respectively controls corresponding clamping and fastening the timing devices, then the operator controls the clamping hands to clamp the corresponding experimental falling body, when the experimental falling body clamp is used, the operator presses the power rod forwards, the fifth spring compresses and stores energy, at the moment, the fourth spring releases and stores energy to drive the two second sliding rods to move backwards, the two second sliding rods respectively drive the corresponding clamping hands to open, the experimental falling body loses binding force and starts to move freely, meanwhile, the two second sliding rods respectively drive the corresponding telescopic rods to move backwards, the two telescopic rods respectively drive the corresponding pressure rods to move away from the vertical central line of the supporting plate, the two pressure rods respectively drive the pressure plates matched with the pressure rods to move downwards, the pressure plates press the timing switches of the corresponding timing devices to start timing, when the experimental falling body is contacted with the wedge-shaped surfaces of the corresponding first sliding rods, the experimental falling body drives the corresponding first sliding rods to move towards one side of the vertical central line of the supporting plate, the first slide bar pulls the corresponding first slide block to slide downwards through the cord, the first slide block drives the corresponding press plate to move downwards, the press plate presses the timing switch of the corresponding timing device again to stop timing, at the moment, the first spring corresponding to the first slide bar contracts to store energy, the second spring corresponding to the first slide block extends to store energy, after an operator takes away an experimental falling body, the first spring and the second spring release the energy to respectively drive the corresponding first slide bar and the first slide block to recover the initial state, the operator measures the displacement of the experimental falling body and reads the time of the timing device, the gravitational acceleration of the experimental falling body can be obtained through simple calculation, and similarly, the operator can realize the gravitational acceleration measurement of the experimental falling bodies with different heights by adjusting the height of the sleeve from the top surface of the supporting block, and the invention can also carry out simultaneous experiments on the two experimental falling bodies, the comparison experiment of two different experimental falling bodies has strong intuition, the same experimental falling body adopts two simultaneous experiments, which is beneficial to improving the experiment precision and efficiency, and the experiment persuasion is strong, the invention only needs one person to carry out the whole experiment process without the assistance of other people, saves manpower, avoids the influence of the reflection error on the experiment when two persons cooperate, and is beneficial to improving the experiment precision, when the invention is not used as a gravity acceleration detection device, an operator can remove a timing device, for example, the timing device can be used for daily teaching of a teacher, the operator can retract a telescopic rod to an initial state, the operator loosens a screw sleeve to enable a first screw rod to be positioned at the bottom of a through groove, and when the first screw rod can rotate in the through groove, the invention can be used as a simple balance for rough measurement of the experimental substance quantity during the experiment, and improves the utilization rate of teaching instruments, the invention reduces the waste of teaching resources, has simple operation, economical practicability, is suitable for teaching in various forms, and has good applicability.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic view showing the structure of the present invention, fig. 2 is a view taken along direction a of fig. 1, fig. 3 is a partially enlarged view of fig. 1, and fig. 4 is a partially enlarged view of fig. 1, ii.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

An experimental device for measuring gravitational acceleration comprises a box body 1 with an opening on the top surface, as shown in the figure, the box body 1 is made of transparent materials, a supporting block 2 is fixedly installed in the middle of the inner wall of the bottom surface of the box body 1, first blind holes 4 are respectively formed in two side surfaces of the supporting block 2, the two first blind holes 4 share a horizontal central line, first slide bars 5 in sliding fit with the first blind holes 4 are respectively arranged in the first blind holes 4, opposite ends of the two first slide bars 5 are respectively connected with the inner wall corresponding to the first blind holes 4 through first springs, opposite ends of the two first slide bars 5 are wedge-shaped surfaces with upward inclined surfaces, a supporting plate 3 is fixedly installed on the top surface of the supporting block 2, two first vertical grooves 6 with T-shaped cross sections are formed in the front surface of the supporting plate 3, first slide blocks 7 with T-shaped cross sections are respectively arranged in the first grooves 6, the first slide blocks 7 can slide along the corresponding first grooves 6, the top surfaces of the first slide blocks 7 are respectively, the bottom surfaces of the first sliding blocks 7 are respectively connected with the peripheries of adjacent first sliding rods 5 through ropes, the inner walls of the two first blind holes 4 are respectively provided with first line holes, the first line holes enable the interiors of the corresponding first blind holes 4 to be communicated with the interiors of the adjacent grooves 6, the top ends of the ropes are respectively fixedly connected with the bottom surfaces of the corresponding first sliding blocks 7, the other ends of the ropes respectively penetrate through the corresponding first line holes and are fixedly connected with the peripheries of the corresponding first sliding rods 5, the first ropes are always in a tightening state, the front surfaces of the two first sliding blocks 7 are respectively fixedly connected with the back surfaces of the pressing plates 8, the opposite side surfaces of the two pressing plates 8 are wedge-shaped surfaces with upward inclined surfaces, timing devices 22 and clamping devices are respectively arranged below the two pressing plates 8, the clamping devices are used for clamping and fixing the timing devices, the bottom surfaces of the two pressing plates 8 are respectively in contact fit with timing switch knobs of the timing devices 22, and the clamping devices are, the inner walls of the opposite sides of the two first grooves 6 are respectively provided with a second groove 9 with a T-shaped cross section, the two second grooves 9 share a horizontal central line, the inner parts of the second grooves 9 are communicated with the front space of the support plate 3, the inner parts of the second grooves 9 are respectively provided with a second slider 10 with a T-shaped cross section, the second sliders 10 can slide along the corresponding second grooves 9, the opposite ends of the two second sliders 10 are respectively connected with the inner walls of the corresponding second grooves 9 through a third spring, the third spring is in a stretching state, the front surfaces of the two second sliders 10 are respectively and fixedly connected with the periphery of a compression bar 11, the bottom surfaces of the two compression bars 11 are inclined surfaces and are in contact fit with the wedge-shaped surface of the adjacent compression plate 8, the front surface of the support plate 3 is provided with a vertical through groove 12, the through groove 12 is positioned between the two second grooves 9, the inside of the through groove 12 is provided with a first screw 13, the front surface of the first screw 13, the periphery of the sleeve 14 is in contact fit with the front surface of the support plate 3, the periphery of the bottom of the sleeve 14 is provided with two through grooves 16, two second slide bars 15 in sliding fit with the sleeve 14 are arranged in the sleeve 14, the opposite side surfaces of the two second slide bars 15 are connected through a fourth spring, the fourth spring is in a compressed state, the peripheries of the two second slide bars 15 are respectively and fixedly connected with the fixed end of a telescopic rod 17, the movable end of the telescopic rod 17 is respectively and movably connected with the top surface of a corresponding press rod 11, the opposite side surfaces of the two second slide bars 15 are respectively provided with a clamping hand, the clamping hands are used for clamping and releasing an experimental falling body for the free falling body time, the rear surface of the first screw rod 13 is provided with a third blind hole 19 along the axial direction of the first screw rod, a power rod 20 in sliding fit with the third blind hole 19 is arranged in the third blind hole 19, the front surface of the power rod 20 is connected with the front surface of the inner wall of the third, the front of the power rod 20 is respectively connected with the opposite side surfaces of the two second slide bars 15 through a thread rope, the front of the inner wall of the third blind hole 19 is provided with a transverse second thread hole, the inside of the second thread hole is communicated with the inside of the sleeve 14, the front of the second screw rod 20 is connected with one end of the second thread rope, the other end of the second thread rope is respectively and fixedly connected with the opposite side surfaces of the two second slide bars 15, the second thread rope is always in a tightened state, the periphery of the rear end of the first screw rod 13 is provided with a first thread sleeve 21 in threaded fit with the first thread sleeve, and the front of the first thread sleeve 21 is in contact fit with the rear surface of the support plate. The invention aims to overcome the defects in the prior art, and provides a gravity acceleration experimental device with detachable components, before the device is used, an operator movably connects two telescopic rods 17 with corresponding pressure rods 11, then the operator rotates a first screw sleeve 21 to separate the front of the first screw sleeve from the back of a supporting plate 3, then the operator moves a first screw rod 13 to slide to a required experimental position along a through groove in the vertical direction, then the operator rotates the first screw sleeve 21 reversely again to enable the front of the first screw sleeve to be in contact fit with the back of the supporting plate 3 again, namely the position of a sleeve 14 is fixed, in the process, the two telescopic rods 17 limit the swinging of the sleeve 14 and enable the axis of the sleeve 14 to be horizontal, the operator respectively slides a pressure plate 8 upwards and places a timing device 22 on the top surface of a supporting table 2, at the moment, the bottom surfaces of the pressure plates 8 are respectively in contact with the top surfaces of timing switches of the corresponding timing, an operator respectively controls the corresponding clamping, clamping and fastening fixed timing devices 22, then the operator controls the clamping hands to clamp the corresponding experimental falling body, when in use, the operator forwards presses the power rod 20, the fifth spring compresses and stores energy, at the moment, the fourth spring releases and stores energy to drive the two second sliding rods 15 to move backwards, the two second sliding rods 15 respectively drive the corresponding clamping hands to open, the experimental falling body loses the binding force and starts to move freely, meanwhile, the two second sliding rods 15 respectively drive the corresponding telescopic rods 17 to move backwards, the two telescopic rods 17 respectively drive the corresponding pressure rods 11 to move away from the vertical central line of the supporting plate 3, the two pressure rods 11 respectively drive the pressure plates 8 in contact fit with the pressure rods to move downwards, the pressure plates 8 press the timing switches of the corresponding timing devices 22 to start timing, when the experimental falling body is in contact with the corresponding wedge-shaped surfaces of the first sliding rods 5, the experimental falling body drives the corresponding first slide bar 5 to move towards one side of the vertical center line of the supporting plate 3, the first slide bar 5 pulls the corresponding first slide block 7 to slide downwards through a cord, the first slide block 7 drives the corresponding press plate 8 to move downwards, the press plate 8 presses the timing switch of the corresponding timing device 22 again to stop timing, at the moment, the first spring corresponding to the first slide bar 5 contracts to store energy, the second spring corresponding to the first slide block 7 extends, after an operator takes away the experimental falling body, the first spring and the second spring release the energy to drive the corresponding first slide bar 5 and the corresponding first slide block 7 to return to the initial state respectively, the operator measures the displacement of the experimental falling body and reads the time of the timing device 22, the gravity acceleration of the experimental falling body can be obtained through simple calculation, and similarly, the operator can realize the gravity acceleration measurement of the experimental falling bodies with different heights by adjusting the height from the top surface of the sleeve 14 to the supporting block 2, the invention can also carry out the simultaneous experiment on two experimental falling bodies, the comparative experiment of the two different experimental falling bodies has strong intuition, the same experimental falling body adopts two simultaneous experiments, which is favorable for improving the accuracy and the efficiency of the experiment, and the experimental persuasiveness is strong, the invention only needs one person to carry out the whole experimental process without the assistance of other people, saves the manpower, avoids the influence of the reflection error on the experiment when two persons cooperate, and is favorable for improving the experimental accuracy, when the invention is not used as a gravity acceleration detection device, an operator can remove the timing device 22, for example, the timing device 22 can be used for the daily teaching of a teacher, the operator retracts the telescopic rod 17 to the initial state, the operator loosens the screw sleeve 21 to ensure that the first screw rod 13 is positioned at the bottom of the through groove 12 and the first screw rod 13 can rotate in the through groove 12, the invention can be used as the simple balance for the rough measurement of the experimental substance amount during the experiment, the invention has the advantages of simple operation, economical and practical performance, suitability for teaching in various forms and good applicability.

Specifically, as shown in fig. 1, the timer 22 according to the present embodiment is a digital stopwatch with an accuracy of 0.01 second, a time switch of the digital stopwatch is in contact with the bottom surface of the corresponding pressing plate 8, and a side circumference of the digital stopwatch is in contact with the corresponding holding device. Compared with a stopwatch with scales, the digital stopwatch avoids the influence of human subjective factors on the read value when the falling time is read, and is favorable for improving the experiment precision.

Specifically, as shown in fig. 1, the clamping device according to the present embodiment is respectively composed of two coaxial second threaded sleeves 24 and two third threaded rods 25, the peripheries of the second threaded sleeves 24 are respectively and fixedly connected to the front of the supporting plate 3, the second threaded sleeves 24 are located between the supporting block 2 and the corresponding pressing plate 8, the insides of the two second threaded sleeves 24 are respectively in threaded fit with one third threaded rod 25, and the opposite side surfaces of the third threaded rods 25 are in contact fit with the periphery of the timing device 22. An operator places the timing device 22 on the bottom surface of the supporting block 2, and after the timing switch key is contacted with the bottom surface of the corresponding pressing block 8, the back surface of the timing device 22 is contacted and matched with the front surface of the supporting plate 3, the operator rotates the two corresponding third screw rods 25 to move oppositely to clamp the periphery of the timing device 22, and the two contact points of the two third screw rods 25 and the timing device 22 and the contact points of the timing device 22 and the supporting block 2 form a stable clamping triangle, so that the timing precision error caused by the stress swing of the timing device 22 in the experimental process is avoided, the time precision is ensured, when the timing device is not used, the operator can detach the timing device for other purposes, and the use efficiency of the equipment is improved.

Further, as shown in fig. 4, the top surface of the pressing rod 11 according to this embodiment is respectively provided with second blind holes 26, the movable ends of the telescopic rods 17 can slide in the corresponding second blind holes 26, the lateral peripheries of the second blind holes 26 are respectively provided with through second screw holes 27, the inside of the second screw holes 27 is respectively provided with a bolt 28 in threaded fit, and one end of the bolt 28 is respectively in contact fit with the periphery of the movable end of the corresponding telescopic rod 17. During the use, operating personnel inserts in corresponding second blind hole 26 through the expansion end of telescopic link 17, twists corresponding bolt 28 afterwards and makes it compress tightly the expansion end of corresponding telescopic link 17, makes telescopic link 17 and corresponding depression bar 11 fixed in position to realized that telescopic link 17 drives corresponding depression bar 11 lateral motion, depression bar 11 drives the purpose that corresponding clamp plate 8 pressed timing device 22 and timed.

Furthermore, the experimental falling body is in hard contact with the surfaces of the corresponding first sliding rods 5 and the box body 1, and the experimental device is easily damaged due to hard contact for many times. The soft protective layer has avoided the experiment to fall the body and has caused the probability of establishing other damage with the wedge face of the first slide bar 5 that corresponds, the inner wall hard contact of box 1, is favorable to improve equipment's life.

Furthermore, as shown in fig. 2, the clamping hand according to this embodiment is respectively composed of two horizontal clamping plates 29 and two limiting rods 30, one end of each clamping plate 29 is hinged to one end of the adjacent second slide rod 15 opposite to the middle of the sleeve 14, the opposite sides of the two clamping plates 29 are hinged to one end of the corresponding limiting rod 30, the other end of each limiting rod 30 is hinged to the corresponding side of the adjacent sleeve 14, the two clamping plates 29 and the two limiting rods 30 are symmetrically distributed on two sides of the transverse center line of the sleeve 14, arc-shaped grooves are respectively formed in the opposite sides of the two clamping plates 29, and rubber protection layers are arranged in the arc-shaped grooves. When the device is used, an operator presses the power rod 20 forwards, the fifth spring compresses for energy storage, at the moment, the fourth spring releases energy storage to drive the two second sliding rods 15 to move backwards, the two second sliding rods 15 respectively drive the two corresponding tightening plates 29 to move towards the direction away from the middle part of the sleeve 14, the two tightening plates 29 on the same side are respectively opened backwards under the limiting action of the corresponding limiting rods 30, the operator puts an experimental falling body between the two tightening plates 29 on the same side and then loosens the power rod 20, the fifth spring releases energy storage to drive the power rod 20 to move backwards, the power rod 20 drives the two second sliding rods 15 to move towards each other through a cotton rope, the second sliding rods 15 drive the two corresponding tightening plates 29 to move towards the middle part of the sleeve 14, the tightening plates 29 move towards each other under the limiting action of the corresponding limiting rods 30 to clamp the experimental falling body, so that the clamping of the experimental falling body is realized, during the experiment, the above-mentioned process of operating personnel repetition, two experiments fall and are losing the centre gripping back free fall that corresponds step-up plate 29, whole mechanical transmission, and the contrast experiment of different experiments fall can alone be accomplished to one person, compares in artifical manual release and needs many people to cooperate, has saved the manpower, has avoided a plurality of operating personnel to cause experimental error because of release and timing are different simultaneously, has improved the experiment precision.

Furthermore, the front surface of the supporting block 2 and the front surface of the supporting plate 3 are respectively provided with height measuring scale marks. The displacement of the experimental falling body can be read by an operator through the scale marks, the operation is simple, and the realization efficiency is improved.

Furthermore, as shown in fig. 1, the inner walls of the two sides of the box body 1 according to the embodiment are respectively hinged to the bottom ends of a supporting rod 18, the top ends of the supporting rods 18 are respectively and fixedly connected to the middle of the bottom surface of the horizontal plate 31, the periphery of the supporting rod 18 is respectively hinged to the top end of a push rod 32, the bottom ends of the push rods 32 are respectively hinged to one ends of the adjacent first sliding rods 5 departing from the middle of the box body 1, and the top surfaces of the two horizontal plates 31 are both provided with rubber layers. The structure enables an experiment falling body to contact with the horizontal plate 31 and drive the horizontal plate 31 to generate a downward movement trend when falling, the horizontal plate 31 drives the corresponding support rod 18 to rotate towards the middle of the box body 1 along the hinged point under the limiting action of the corresponding support rod 18, the support rod 18 drives the corresponding push rod 32 to move towards the middle of the box body 1, the push rod 32 drives the corresponding first slide rod 5 to move towards the middle of the box body 1, the first slide rod 5 drives the corresponding press plate 8 to press the switch knob of the timing device 22 through a cotton rope, thereby realizing the timing closing of the timing device 22, the structure converts the gravity of the experiment body into the thrust of the corresponding first slide rod 5, compared with the experiment falling body which directly contacts with the wedge-shaped surface of the first slide rod 5, the transverse thrust of the first slide rod 5 is increased, the transverse displacement speed of the first slide block 5 is favorably improved, and further the timing device 22 can rapidly stop timing, is favorable for improving the experimental accuracy.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. The utility model provides a measure acceleration of gravity's experimental apparatus which characterized in that: the box comprises a box body (1) with an opening on the top surface, the box body (1) is made of transparent materials, a supporting block (2) is fixedly installed in the middle of the inner wall of the bottom surface of the box body (1), two side surfaces of the supporting block (2) are respectively provided with a first blind hole (4), a first sliding rod (5) in sliding fit with the first blind hole (4) is respectively arranged in the first blind hole (4), one opposite end of the two first sliding rods (5) is respectively connected with the inner wall corresponding to the first blind hole (4) through a first spring, one end opposite to the other end of the two first sliding rods (5) is a wedge-shaped surface with an upward inclined surface, a supporting plate (3) is fixedly installed on the top surface of the supporting block (2), two vertical first grooves (6) with T-shaped cross sections are formed in the front surface of the supporting plate (3), first sliding blocks (7) with T-shaped cross sections are respectively arranged in the first grooves (6), the top surfaces, the bottom surfaces of the first sliding blocks (7) are respectively connected with the peripheries of the adjacent first sliding rods (5) through ropes, the front surfaces of the two first sliding blocks (7) are respectively fixedly connected with the back surfaces of the pressing plates (8), the opposite side surfaces of the two pressing plates (8) are wedge-shaped surfaces with upward inclined surfaces, a timing device (22) and a clamping device are respectively arranged below the two pressing plates (8), the bottom surfaces of the two pressing plates (8) are respectively in contact fit with a timing switch knob of the timing device (22), the clamping device is respectively in contact fit with the peripheries of the corresponding timing devices (22), second grooves (9) with T-shaped sections are respectively formed in the inner walls of the opposite sides of the two first grooves (6), the interiors of the second grooves (9) are respectively communicated with the front space of the supporting plate (3), second sliding blocks (10) with T-shaped sections are respectively arranged in the interiors of the second grooves (9), and the opposite ends of the two second sliding blocks (10) are respectively connected with the inner walls of the corresponding second grooves (9) through third springs, the front surfaces of the two second sliding blocks (10) are respectively fixedly connected with the peripheries of the pressing rods (11), the bottom surfaces of the two pressing rods (11) are inclined planes and are in contact fit with the wedge-shaped surfaces of the adjacent pressing plates (8), the front surface of the supporting plate (3) is provided with a vertical through groove (12), a first screw (13) is arranged inside the through groove (12), the front surface of the first screw (13) is fixedly connected with the periphery of a sleeve (14), the periphery of the sleeve (14) is in contact fit with the front surface of the supporting plate (3), the periphery of the bottom of the sleeve (14) is provided with two through grooves (16), the inside of the sleeve (14) is provided with two second sliding rods (15) in sliding fit with the sleeve, the opposite side surfaces of the two second sliding rods (15) are connected through fourth springs, the periphery of the two second sliding rods (15) is respectively and fixedly connected with the fixed ends of the telescopic rods (17), and the movable ends of the telescopic rods (17) are, the opposite sides of the two second sliding rods (15) are respectively provided with a clamping hand, the back of the first screw (13) is provided with a third blind hole (19) along the axial direction of the first screw, a power rod (20) in sliding fit with the third blind hole is arranged inside the third blind hole (19), the front of the power rod (20) is connected with the front of the inner wall of the third blind hole (19) through a fifth spring, the front of the power rod (20) is respectively connected with the opposite sides of the two second sliding rods (15) through a thread rope, the periphery of the rear end of the first screw (13) is provided with a first thread sleeve (21) in threaded fit with the first screw sleeve, and the front of the first thread sleeve (21) is in contact fit with the back of the supporting plate (3).

2. The experimental apparatus for measuring gravitational acceleration according to claim 1, wherein: the timing device (22) is a digital stopwatch with the accuracy of 0.01 second, a timing switch key of the digital stopwatch is in contact fit with the bottom surface of the corresponding pressing plate (8), and the side periphery of the digital stopwatch is in contact fit with the corresponding clamping device.

3. The experimental apparatus for measuring gravitational acceleration according to claim 1, wherein: the clamping device is composed of two coaxial second threaded sleeves (24) and two third screw rods (25), the peripheries of the second threaded sleeves (24) are fixedly connected with the front of the supporting plate (3) respectively, the second threaded sleeves (24) are located between the supporting block (2) and the corresponding pressing plate (8), the insides of the two second threaded sleeves (24) are in threaded fit with the third screw rods (25) respectively, and the opposite side faces of the third screw rods (25) are in contact fit with the periphery of the timing device (22).

4. The experimental apparatus for measuring gravitational acceleration according to claim 1, wherein: second blind hole (26) have been seted up respectively to the top surface of depression bar (11), the expansion end of telescopic link (17) can slide in second blind hole (26) that correspond respectively, penetrating second screw (27) have been seted up respectively to the side week of second blind hole (26), the inside of second screw (27) is equipped with screw-thread fit's bolt (28) respectively, the one end of bolt (28) respectively with correspond the expansion end periphery contact cooperation of telescopic link (17).

5. The experimental apparatus for measuring gravitational acceleration according to claim 1, wherein: the inner wall of the box body (1) and the wedge-shaped surfaces of the two first slide bars (5) are respectively provided with a soft rubber protective layer.

6. The experimental apparatus for measuring gravitational acceleration according to claim 1, wherein: the tight hand of clamp respectively by two horizontally step up board (29), two gag lever post (30) are constituteed, the one end of step up board (29) articulates the one end at adjacent second slide bar (15) middle part dorsad respectively, the side of two step up board (29) back of the body articulates the one end of corresponding gag lever post (30) respectively, the other end of gag lever post (30) articulates the side of adjacent sleeve (14) respectively, two step up board (29), the distribution of two gag lever post (30) symmetry is in the both sides of sleeve (14) horizontal central line, the arc wall has been seted up respectively to two step up board (29) side in opposite directions, be equipped with the rubber protection layer in the arc wall.

7. The experimental apparatus for measuring gravitational acceleration according to claim 1, wherein: the front of the supporting block (2) and the front of the supporting plate (3) are respectively provided with height measuring scale marks.

8. The experimental apparatus for measuring gravitational acceleration according to claim 1, wherein: the bottom of a supporting rod (18) is hinged to the inner walls of the two sides of the box body (1) respectively, the top ends of the supporting rods (18) are fixedly connected to the middle of the bottom surface of the horizontal plate (31) respectively, the periphery of each supporting rod (18) is hinged to the top end of a push rod (32) respectively, the bottom ends of the push rods (32) are hinged to one ends, close to the first slide rods (5), of the first slide rods (5) and deviated from the middle of the box body (1) respectively, and rubber layers are arranged on the top surfaces of the two horizontal plates.