CN100456038C - Ring shaped air-cushion extensible guide used for testing object curvilinear motion physical quantity - Google Patents

Abstract

This invention relates to one ring pad guide rail to test object curve move moment, which comprises guide rail, slide device, photo electricity gate, level device and gas source and force signal integral device, wherein, the said guide rail is of aluminum ring rail with down part set with a I-shape ring tray board with space in between as gas chamber; the gas chamber is set with gas-in valve; the arc guide rail is set with arc slide device with light block slice and mass align device; the ring tray is fixed on base socket with three sets of adjust level bottom leg screw; the ring rail load device is set above ring gas cushion rail.

Description

The ring shaped air-cushion extensible guide that is used for test object curvilinear motion physical quantity

Technical field

The present invention relates to a kind of air track of testing physical quantity, especially a kind of ring shaped air-cushion extensible guide that is used for test object curvilinear motion physical quantity.

Background technology

The linear pattern air track is the experimental apparatus that is used to measure the relevant physical quantity of rectilinear motion and the checking law of conservation of momentum, it comprises linear air track, two photogate, two linear slider that have light barrier, is furnished with source of the gas and mechanical signal general measuring instrument.This air track can only be used to measure straight-line physical quantity, then can't measure for the physical quantity of object curvilinear motion, also can't verify the object relevant law of conservation that moves along a curved path.

Summary of the invention

The objective of the invention is to: can not measure and the practical problems of verifying relevant law of conservation (as law of conservation of moment of momentum etc.) for the physical quantity of curvilinear motion at present linear air track, a kind of ring shaped air-cushion extensible guide that is used for test object curvilinear motion physical quantity is provided.

The object of the present invention is achieved like this: a kind of ring shaped air-cushion extensible guide that is used for test object curvilinear motion physical quantity, comprise the guide rail that is provided with the aperture of giving vent to anger, two gliders that have light barrier, photogate, level meter and source of the gas and mechanical signal general measuring instrument, it is characterized in that: the described aperture guide rail of giving vent to anger that is provided with is an aluminium ring shape guide rail, it is I-shaped annular supporting plate that the ring-shaped guide rail below is provided with corresponding cross section, space between ring-shaped guide rail and the annular supporting plate is an air chamber, air chamber is furnished with the adjustable air intake valve, arc-shaped guide rail is provided with the arc glider, the arc glider is provided with light barrier and barycenter coordination device, the annular supporting plate is fixed on the pedestal, and pedestal has three groups of stone bolts of regulating levelness; The circular orbit charger is located at the top of ring shaped air-cushion extensible guide.

Among the present invention: described ring-shaped guide rail is provided with 1～2 infrared light electric switch, and the infrared light electric switch is fixed on the annular supporting plate by support, and described arc glider is big glider of arc and the little glider of arc.

Among the present invention: described ring-shaped guide rail is provided with both sides elastomeric bidirectional elastic resilience device is housed, and bidirectional elastic resilience device is fixed on the annular supporting plate by support.

Among the present invention: described ring-shaped guide rail cross sectional shape is triangular in shape, and the ring-shaped guide rail upper surface is provided with the aperture of giving vent to anger, the arc contact surface coupling of described arc glider and ring-shaped guide rail, and its xsect is herringbone.

Among the present invention: described ring-shaped guide rail cross sectional shape is triangular in shape, and the ring-shaped guide rail upper surface is provided with the aperture of giving vent to anger, the surface of contact coupling of described arc glider and ring-shaped guide rail, and its xsect is herringbone.

A kind of circular orbit charger that is exclusively used in described ring shaped air-cushion extensible guide, it is characterized in that: the track of annular charger is identical with the radius of aluminium ring shape guide rail, and pass through the supporting plate medial support above aluminium ring shape guide rail, the track of annular charger is provided with horizontal trolley and vertical sliding wheel, and the scale pan hanging wire that has a little hook is hung on the arc glider and is connected with scale pan with vertical sliding wheel by horizontal trolley.

The invention has the advantages that: change the guide rail in the linear pattern air track into annular, the physical quantity physical law relevant that can be used for the test object curvilinear motion with checking, it can directly measure the relation of the angular velocity, angular acceleration, normal acceleration, line amount of rotor and angle amount and acceleration of gravity etc., also can study the object circular motion effectively, the Rigid Body in Rotation With basic law, rotor damped motion basic law, checking law of rotation, principle of moment of momentum and law of conservation of moment of momentum etc.Compact conformation of the present invention, easy to use.

Description of drawings

Fig. 1 is the structural representation of a specific embodiment the present invention relates to;

Fig. 2 is used for a kind of circular orbit charger structural representation of the present invention.

Among the figure: 1, ring-shaped guide rail; 2, anti-dazzling screen; 3, the little glider of arc; 4, level meter; 5, regulate the stone bolt of level; 6, bidirectional elastic resilience device; 7, adjustable air intake valve; 8, infrared light electric switch; 9, the track of annular charger; 10, pedestal; 11, barycenter coordination device; 12, scale pan hanging wire; 13, the big glider of arc; 14, horizontal trolley; 15, infrared light electric switch socket; 16, annular supporting plate; 17, vertical sliding wheel; 18, scale pan.

Embodiment

Accompanying drawing discloses the concrete structure that the present invention relates to embodiment without limitation, below in conjunction with embodiment the present invention is done to describe further.

As seen from Figure 1, the present invention is the same with traditional linear air track, guide rail is also arranged, have two gliders, photogate, source of the gas and the mechanical signal general measuring instrument of light barrier, their difference is: described guide rail is an aluminium ring shape guide rail 1, it is the supporting plate 16 of I-shaped annular that ring-shaped guide rail 1 below is provided with corresponding cross section, space between ring-shaped guide rail 1 and the annular supporting plate 16 is an air chamber, air chamber is furnished with adjustable air intake valve 7, and ring-shaped guide rail 1 is provided with big glider 13 of arc and the little glider 3 of arc that has light barrier 2 and barycenter coordination device 11.In the present embodiment, also be provided with both sides on the ring-shaped guide rail 1 elastomeric bidirectional elastic resilience device 6 and two infrared light electric switches 8 are housed, they all are fixed on the annular supporting plate 16 by support, annular supporting plate 16 is fixed on the pedestal 10, and pedestal 10 has three groups of stone bolts 5 of regulating levelness.Described ring-shaped guide rail 1 cross sectional shape is triangular in shape, and ring-shaped guide rail 1 upper surface is provided with the aperture of giving vent to anger, and the little glider 3 of big glider 13 of arc and arc is an arcwall face with the arc contact surface of ring-shaped guide rail, and its xsect is herringbone.

In the present embodiment: ring-shaped guide rail central diameter: 714mm; Arc footpath, the big glider of arc center: 714mm; The big glider angular length of arc degree: 20 °; Arc footpath, the little glider of arc center: 714mm; The little glider angular length of arc degree: 12 °; Light stopper shield bars subtended angle: 0.057 radian; Glider limiting mode: two-sided spring steel wire limit ereisma.

Matching used in the present embodiment mechanical signal general measuring instrument is: LXC-2 type mechanical signal general measuring instrument, this instrument can real rich Industrial Co., Ltd. be bought from Shanghai.

In the use, air chamber is linked up by adjustable air intake valve 7 and source of the gas, and the signal of infrared light electric switch 8 is connected with the signal I/O end of mechanical signal general measuring instrument by signal wire by infrared light electric switch socket 15.

During concrete enforcement, a ring-shaped guide rail formula charger can also be set on the ring-shaped guide rail 1, the track 9 of annular charger is identical with the radius R of aluminium ring shape guide rail 1, and be supported on the top of aluminium ring shape guide rail 1 by pole by the supporting plate inboard, as seen from Figure 2, the track 9 of annular charger is provided with horizontal trolley 14 and vertical sliding wheel 17, and the scale pan hanging wire 12 that has little hook is hung on the arc glider and passes through horizontal trolley 14 and is connected with scale pan 18 with vertical sliding wheel 17.

Be equipped with barycenter coordination device on big glider of arc and the little glider of arc, barycenter coordination device can adopt and add the quality mass in the blind hole, make the barycenter of glider be in the wherein centre of footpath (identical) arc length with footpath in the ring shaped air-cushion track, generally can not change after the adjustment, do not need to adjust, can periodic check and coordination in the use, must relocation bit when unbalance (as falling damage).

Illustrate several application of the present invention below, they are not the concrete restrictions to range of application of the present invention.

1, measures the angular velocity of uniform rotation

Configuration on the ring-shaped guide rail: an infrared light electric switch 8 of configuration and an arc glider on the ring-shaped guide rail 1.

Open source of the gas before the test earlier, after utilizing the stone bolt 5 of level meter 4 and adjusting level that ring-shaped guide rail 1 is transferred to level, give and infrared light electric switch 8 angular velocity at the beginning of one of the arc glider of θ (angular distance), make subtended angle on the arc glider be the light barrier 2 of Δ θ by infrared light electric switch 8, the light barrier 2 of noting subtended angle Δ θ with mechanics signal parameter measuring instrument passes through infrared light electric switch 8 needed time Δ t.Because ring-shaped guide rail 1 is in horizontality, under the prerequisite of opening source of the gas, exist air layer between arc glider and the ring-shaped guide rail 1, owing to have air cushion between the glider of motion and the ring-shaped guide rail 1, the I that rubs is ignored very much, can think that then the rotation of arc glider is uniform rotation, so the angular velocity of the uniform rotation that records thus is:

$\mathrm{\ω}=\frac{\mathrm{\Δ\θ}}{\mathrm{\Δt}}$

2, measure the angular velocity omega and the angular acceleration β of uniform rotation

Configuration on the ring-shaped guide rail: two infrared light electric switches 8, arc glider, ring-shaped guide rail formula charger and a bidirectional elastic resilience device 6 are set on the ring-shaped guide rail 1.

Open source of the gas before the test, utilize the stone bolt 5 of level meter 4 and adjusting level that ring-shaped guide rail 1 is transferred to horizontality, reed with the arc glider leans against on the steel wire of bidirectional elastic resilience device 6 then, and on the scale pan of the ring-shaped guide rail formula charger of arc glider, add an amount of counterweight (heavy G=mg), under the prerequisite of opening source of the gas, make the arc glider under the effect of counterweight drag torque, do even the acceleration and rotate.Noting subtended angle on the arc glider with mechanics signal measurement instrument is that the light barrier 2 of Δ θ is by two time of being in the light Δ t at a distance of two infrared light electric switches 8 of θ angular distance ₁, Δ t ₂And cross two time t between the infrared light electric switch 8, then just can utilize following formula to calculate the angular acceleration of glider, promptly

$\mathrm{\β}=\frac{{{\mathrm{\ω}}_2}^2-{{\mathrm{\ω}}_1}^2}{2\mathrm{\θ}}$

Or $a=\frac{{\mathrm{\ω}}_2-{\mathrm{\ω}}_1}{t}$

Wherein ${\mathrm{\&omega;}}_1=\frac{\mathrm{\&Delta;\&theta;}}{\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="C20071002117900101.png"\; state="\{\{state\}\}">t</figure-callout>}}_1}$ ${\mathrm{\&omega;}}_2=\frac{\mathrm{\&Delta;\&theta;}}{\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="C20071002117900101.png"\; state="\{\{state\}\}">t</figure-callout>}}_2}$

3, survey the moment of inertia of object

Configuration on the ring-shaped guide rail: two infrared light electric switches 8, arc glider, ring-shaped guide rail formula charger and a bidirectional elastic resilience device 6 are set on the ring-shaped guide rail 1.

Open source of the gas before the test, utilize the stone bolt 5 of level meter 4 and adjusting level that ring-shaped guide rail 1 is transferred to horizontality after, two infrared light electric switches 8 are placed on the annular air guide rail 1 with certain angular distance theta.The arc glider places the suitable angular distance of two infrared light electric switch 8 fronts, and lean against on the steel wire of bidirectional elastic resilience device 6, pin the arc glider, on the scale pan of the ring-shaped guide rail formula charger of arc glider, add suitable counterweight (heavy G=mg).Under the prerequisite of opening source of the gas, discharge glider, then big (little) glider of arc is done even the acceleration and is rotated under the effect of load, and noting subtended angle on big (little) glider of arc with mechanics signal measurement instrument is the time Δ t that the light barrier 2 of Δ θ passes through two infrared light electric switches 8 ₁, Δ t ₂, then can measure the moment of inertia J of big (little) glider of arc around the air track central shaft,

Promptly $J_0=\frac{m(g-\mathrm{R\&beta;})}{\mathrm{\&beta;}+\mathrm{K\&omega;}}$

M is the quality of glider in the formula, and R is the center radius that slides guide rail, and β is the angular acceleration of glider, and K is an attenuation constant, and ω is the angular velocity of glider.If an object under test is placed on the circular glove platform of glider (its center is at the center radius place of guide rail), measure the angular acceleration β ' of glider after the loading again, then can calculate the moment of inertia J of contained object, promptly

Utilize parallel axis theorem again, just can calculate the moment of inertia of object under test around its central shaft.M ' is the quality of closing of testee and glider in the formula.

If do not consider air-damped influence, i.e. K=0, then following formula becomes

$J=R[\frac{m^{\&prime;}(g-R{\mathrm{\&beta;}}^{\&prime;})}{{\mathrm{\&beta;}}^{\&prime;}}-\frac{m(g-\mathrm{R\&beta;})}{\mathrm{\&beta;}}]$

The frictional influence between if the lanyard of consideration loader and loader rail are led, then available following formula calculates the moment of inertia of testee:

$J=J^{\&prime;}-J_0=R[\frac{m^{\&prime;}(g-R{\mathrm{\&beta;}}^{\&prime;})-f}{{\mathrm{\&beta;}}^{\&prime;}+K{\mathrm{\&omega;}}^{\&prime;}}-\frac{m(g-\mathrm{R\&beta;})-f}{\mathrm{\&beta;}+\mathrm{K\&omega;}}]$

F is the friction force between loader lanyard and loader rail are led in the formula.

If two gliders are coupled together with sheet metal along circular air cushion guide rail diametric(al), establish an article carrying platform in the centre of this device (being the center of ring shaped air-cushion extensible guide), testee is placed on this platform, then can directly measure the moment of inertia of object along its central shaft.

4, survey the ring shaped air-cushion extensible guide air damping

Configuration on the ring-shaped guide rail: an infrared light electric switch 8 and an arc glider are set on the ring-shaped guide rail 1.

Open source of the gas before the test, an arc glider is placed on the guide rail, utilize the stone bolt 5 of level meter 4 and adjusting level that ring-shaped guide rail 1 is transferred to horizontality, the arc glider is placed on the correct position of ring-shaped guide rail 1.Under the prerequisite of opening source of the gas, trigger glider with hand, it is moved along ring-shaped guide rail 1, when light barrier 2 repeatedly by same infrared light electric switch 8, utilize the mechanical signal general measuring instrument to note that subtended angle is more than 2 time Δ t by this infrared light electric switch 8 of light barrier of Δ θ on the glider ₁, Δ t ₂Δ t _n(light barrier 2 per pass infrared light electric switches 8 should be at once reset the timer of mechanical signal general measuring instrument).Calculate corresponding to θ=0,2 π 4 π .6 π, 8 π ... the angular velocity omega of the light barrier 2 of angular displacement ₁, ω ₂, ω ₃ω _nMake ω-θ figure.Just can obtain decay coefficient K from the slope of this figure line.Can try to achieve ratio of damping b=kJ thus ₀J wherein ₀Be the moment of inertia of glider, the method for the angular velocity of available measurement uniform rotation records.

5, checking law of conservation of moment of momentum

Configuration on the ring-shaped guide rail: two each and every one infrared light electric switches 8, the big glider 13 of arc and the little glider 3 of arc are set on the ring-shaped guide rail 1.

Open source of the gas before the test, utilize the stone bolt 5 of level meter 4 and adjusting level that ring-shaped guide rail 1 is transferred to level, with this understanding, the windage power that glider is subjected to when rotating on air track is very small, can ignore.The alternate angular distance theta of big or small glider is positioned on the air track.The big glider 13 of arc places the previous suitable angular distance of first photogate.The little glider 3 of arc is placed in the middle of two infrared light electric switches 8 still.Under the prerequisite of opening source of the gas, trigger big glider 13 motions with hand.When it by behind first infrared light electric switch 8, just and occupy two little gliders 3 collisions of the arc between the photogate.After the collision, big or small glider rotates with certain angular velocity separately, and successively by second infrared light electric switch 8.With mechanics signal measurement instrument, measuring subtended angle on the big glider 13 of arc respectively is the time Δ t of the light barrier 2 of Δ θ by first infrared light electric switch 8 ₁, subtended angle all is that the time of light barrier 2 by second photogate of Δ θ is Δ t ' on the big or small glider ₁With Δ t ₂, the angular velocity that then can obtain them respectively is

${\mathrm{\&omega;}}_1=\frac{\mathrm{\&Delta;\&theta;}}{\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="C20071002117900101.png"\; state="\{\{state\}\}">t</figure-callout>}}_1}$ ${\mathrm{\&omega;}}_1^{\&prime;}=\frac{\mathrm{\&Delta;\&theta;}}{\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="C20071002117900101.png"\; state="\{\{state\}\}">t</figure-callout>}}_1^{\&prime;}}$ ω ₂=0 ${\mathrm{\&omega;}}_2^{\&prime;}=\frac{\mathrm{\&Delta;\&theta;}}{\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="C20071002117900101.png"\; state="\{\{state\}\}">t</figure-callout>}}_2},$ The moment of inertia J of size glider ₁, J ₂The method of available the 3rd joint is measured.Then can find

J ₁ω ₁+J ₂ω ₂＝J ₁ω′ ₁+J ₂ω′ ₂

It is conservation of angular momentum.

Claims (6)

1, a kind of ring shaped air-cushion extensible guide that is used for test object curvilinear motion physical quantity, comprise the guide rail that is provided with the aperture of giving vent to anger, two gliders that have light barrier, photogate, level meter and source of the gas and mechanical signal general measuring instrument, it is characterized in that: the described guide rail that is provided with the aperture of giving vent to anger is an aluminium ring shape guide rail, described glider is the arc glider, it is I-shaped annular supporting plate that the ring-shaped guide rail below is provided with corresponding cross section, space between ring-shaped guide rail and the annular supporting plate is an air chamber, air chamber is furnished with the adjustable air intake valve, arc-shaped guide rail is provided with the arc glider, the arc glider is provided with light barrier and barycenter coordination device, the annular supporting plate is fixed on the pedestal, and pedestal has three groups of stone bolts of regulating levelness; The circular orbit charger is located at the top of ring shaped air-cushion extensible guide.

2, the ring shaped air-cushion extensible guide that is used for test object curvilinear motion physical quantity according to claim 1, it is characterized in that: described photogate is the infrared light electric switch, described ring-shaped guide rail is provided with 1～2 infrared light electric switch, the infrared light electric switch is fixed on the annular supporting plate by support, and described arc glider is big glider of arc and the little glider of arc.

3, the ring shaped air-cushion extensible guide that is used for test object curvilinear motion physical quantity according to claim 1 and 2, it is characterized in that: described ring-shaped guide rail is provided with both sides elastomeric bidirectional elastic resilience device is housed, and bidirectional elastic resilience device is fixed on the annular supporting plate by support.

4, the ring shaped air-cushion extensible guide that is used for test object curvilinear motion physical quantity according to claim 1 and 2, it is characterized in that: described ring-shaped guide rail cross sectional shape is triangular in shape, the ring-shaped guide rail upper surface is provided with the aperture of giving vent to anger, the arc contact surface coupling of described arc glider and ring-shaped guide rail, its xsect is herringbone.

5, the ring shaped air-cushion extensible guide that is used for test object curvilinear motion physical quantity according to claim 3, it is characterized in that: described ring-shaped guide rail cross sectional shape is triangular in shape, the ring-shaped guide rail upper surface is provided with the aperture of giving vent to anger, the surface of contact coupling of described arc glider and ring-shaped guide rail, its xsect is herringbone.

6, a kind of circular orbit charger that is exclusively used in the described ring shaped air-cushion extensible guide of claim 1, it is characterized in that: the track of annular charger is identical with the radius of aluminium ring shape guide rail, and be supported on the top of aluminium ring shape guide rail by pole by the supporting plate inboard, the track of annular charger is provided with horizontal trolley and vertical sliding wheel, and the scale pan hanging wire that has a little hook is hung on the arc glider and is connected with scale pan with vertical sliding wheel by horizontal trolley.

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