CN1010515B - Multifunctional wave demonstrator - Google Patents

Abstract

The present invention relates to a multifunctional wave demonstrator which is an instrument. The present invention uses a plurality of columns of waves to demonstrate the rules of vibration synthesis and wave propagation, and is composed of a plurality of vibration synthesizers (in an attached figure), a transmission wheel and cranking bars, wherein the vibration synthesizers are combined together; cams in the same group use axial trough transmission; the transmission of each group of the cams is controlled by the cranking bar at the end of a cam group; the speed ratio of each group of the cams is controlled by a speed variator between the cranking bars. The present invention can demonstrate the rules of the vibration synthesis, wave superposition and interference, and wave propagation in different media. Besides, the present invention can demonstrate the rule that waves with various frequencies group velocity propagation in the same phase velocity and different phase velocities, etc.

Description

Multifunctional wave demonstrator

The present invention relates to a kind of instrument that in physics teaching, is used for demonstrating synthetic and ripple propagation law in medium of vibration.

In present technology, generally the instruments used for education wave demonstrator of Shi Yonging (middle school teaching instrument numbering 2203) is in order to demonstrate the propagation of ripple in medium, its formation is made up of 16 oscillators (Figure 27), and weak point is can only be with the itemize propagation of ripple in a kind of medium of a frequency of train wave demonstration one; U.S. Pat-3,518,780(LONGITUDINAL WAVE PROPAGATION DEMONSTRATORS) disclosed in is a kind of device of demonstrating the rule of compressional wave, its formation is the rotation promotion slide block vibration with disk, and drive the vibrating mass vibration, by the effect of the spring between the vibrating mass, the vibrating mass of back is vibrated successively, the vibration of vibrating mass touches microswitch again, makes miniature bulb luminous with the vibration of vibrating mass.It is to demonstrate the propagation of compressional wave and the reflection wave and the incident wave interference of compressional wave with the vibration of vibrating mass and miniature bulb luminous.Weak point is the wave interference rule that can not demonstrate under other situation.And because the oscillator that vibrating mass in the device and spring are formed has natural frequency, its amplitude is not only determined by the amplitude of vibration source, also the frequency with it changes, there is friction force again between vibrating mass and its track, vibration is decayed in the air, and this has all influenced its demonstration effect.

The objective of the invention is to avoid above-mentioned weak point of the prior art, and the synthesising law that provides a kind of energy demonstration to vibrate, can demonstrate the general stack of ripple and interfere rule, the propagation law of ripple in different mediums can be demonstrated, ripple that row contain several frequencies a kind of product can be demonstrated with the propagation law of identical and different phase velocity group velocitys.

Product of the present invention by a plurality of vibration compositors combine add power wheel, crank is formed; Wherein each vibration compositor all is by the vibrating arm that is in the same vertical plane, promote the cam of vibrating arm vibration, the connection vibrating arm makes it to form at the groove of vertical direction motion in order to the connecting rod and the axle on the limiting rod of transmitting vibrations, the rotation of each cam all can promote a contacted with it vibrating arm vibration, transmission by connecting rod, each is subjected to the vibrating arm that cam promotes all can be their vibration transfer to another vibrating arm, makes this vibrating arm end points be the close vibration of other vibrating arm end points in the vibration of vertical direction in the vibration of vertical direction; A plurality of vibration compositors fit together, same group of cam covers on the same axle, adopt the axial trough transmission between the adjacent cams, on an end points of every group of cam set, all cover the crank of a belt wheel, crank and the combination of end points cam are fixed together, the rotation crank can drive the end points cam and rotate together, by the axial trough transmission between the cam, this group cam is rotated successively, under the promotion of each cam, each vibrating arm vibrates successively, the vibration of vibrating arm end points forms ripple, all by the crank control of cam set end points, each rotating ratio of organizing cam is by the control of the speed change gear between the crank in the rotation of every group of cam, is the synthetic and ripple rule in the air of demonstrating vibration with the multiple row ripple.

Vibration compositor in the product of the present invention: the vibration compositor that a plurality of branches vibrate is formed, contained to the vibration compositor that wherein contains the vibration of two kinds of branches by three vibrating arms and two cams, connecting rod, grooves is to add vibrating arm, connecting rod between its vibrating arm again, and cam and groove are formed.

A plurality of vibration compositors are combined, transmitting the method for rotating between same group the adjacent cams is to allow a side of each cam stay driving groove, moving axis is handed down to posterity in the another side, transmission shaft can stretch in the driving groove of adjacent cam, and in groove, can rotate the φ angle, the promotion of transmission cell wall is driven the rotation of next cam by transmission shaft.Wherein the φ angle has determined the wavelength of formed ripple, and its relation is λ=360 °/φ.Change the wavelength of formed ripple by the big I that changes the φ angle, changing the method for wavelength a kind of with change φ angle is the cam of selecting for use the φ angle different.Another kind method is the movable slider device of packing in the driving groove of cam and can change the φ angle.

What cam rotation was respectively organized in promotion is the crank that is added in the belt wheel of cam set end points.Add power wheel or belt between the wheel on the crank, corresponding gearing such as chain is respectively organized the rotating ratio of cam with regard to may command, changes the ratio of the frequency of each train wave on the panel, and the ratio of the rotating speed of each cam set just equals the ratio of formed wave frequency.

Combine with the vibration compositor that includes only two branch vibrations, it two groups of cams about two different end points be respectively charged into crank, just can form can demonstrate from about two wave sources send two the row stack of the ripple of propagation and the instrument of interference rule in opposite directions, and be respectively charged into crank at its same end points of two groups of cams, just can form and to demonstrate wave propagation rule and the synthetic instrument of propagating to same direction of vibration, and be can demonstrate a plurality of vibrations synthetic with the instrument of the vibration compositor assembling that contains the vibration of a plurality of branches, the stack of multiple row ripple and contain the instrument of the wave propagation rule of a plurality of frequencies.

For preventing cam being free to slide on its axle, between cam and its axle, also should add a clamp that can increase the friction force between cam and the axle.

The transmission shaft of flank of cam is stressed excessive when preventing with the assembling of more a plurality of vibration compositors, also can adopt the cam of twin shaft double flute.

The drawing of accompanying drawing is described as follows:

Fig. 1 is the structural representation that contains the vibration compositor of two branch vibrations.

Fig. 2 is the structural representation that contains the vibration compositor of three branch vibrations.

Fig. 3 is the organigram of Fig. 1 king-rod (1).

Fig. 4 is the organigram of Fig. 1 king-rod (2), and its middle part is to be formed by shaft (44) and end cap (45) two parts group.

Fig. 5 is the organigram of Fig. 1 king-rod (3).

Fig. 6 is the organigram of Fig. 1 king-rod (4).

Fig. 7 is the organigram of Fig. 1 king-rod (5).

Fig. 8 is the organigram of groove among Fig. 1 (8).

Fig. 9 is the organigram of Fig. 1 axis (11), (12), (14).

Figure 10 is the organigram of Fig. 1 cam (6).

Figure 11, Figure 12 are the organigrams of Fig. 1 cam (7).

Figure 13 is the organigram of Fig. 1 cam (6).

Figure 14 is the organigram of the slide block in the driving groove of Figure 13 cam (6) and the slide block synoptic diagram during diverse location in groove.

Figure 15 is the synoptic diagram of the interior slide block diverse location in groove of the driving groove of Fig. 1 cam (7).

Figure 16, Figure 17 are the organigram of the crank of band gear.

The assembling synoptic diagram that Figure 18 combines for the vibration compositor shown in some picture groups 1, two vibration compositors only draw among the figure.

Figure 19 is the transmission structures synoptic diagram between two cranks among embodiment one embodiment two.

Figure 20 is the variable speed drive structural representation between two cranks among the embodiment three.

Figure 21 is the variable speed drive structural representation between two cranks among embodiment four embodiment five.

Figure 22 is the structural representation of Figure 21 middle gear (37).

Figure 23 is the synoptic diagram of waveform shown on panel among the embodiment one, two, three and the panel.

Figure 24 is the synoptic diagram of waveform shown on panel among the embodiment four, five, six and the panel.

Figure 25 is the variable speed drive structural representation between two cranks in embodiment six, the example seven.

Figure 26 is the cam configuration synoptic diagram that two driving grooves and twopiece drive shaft are arranged.

Figure 27 is the oscillator structural representation in the prior art wave demonstrator.

Describe concrete structure of the present invention and working condition in detail below in conjunction with accompanying drawing.

Keep cam (7) motionless among Fig. 1, uniform rotation cam (6) rotates around axle (16), bar (1) is vibrated around axle (13) around axle (10), bar (2), identical simple harmonic oscillation is done at vertical direction in end points (18), (19), and amplitude is A1, keeps cam (6) motionless, uniform rotation cam (7) rotates around axle (17), can make bar (3) around axle (15) vibration, end points (20) is done simple harmonic oscillation at vertical direction, and amplitude is that A2(removes A1=among the embodiment seven $\sqrt{2}$ Outside the A2, A1=A2 among all the other embodiment), and impeller-hub (13) slides up and down in the vertical slots of " worker " font groove (8), compares hour at amplitude A 2 and pole length, and end points (19) is identical in the vibration of vertical direction with end points (20).Rotating cam (6) and cam (7), end points (18) are done forced vibration with the rotation of cam (6) simultaneously, end points (20) is done forced vibration with the rotation of cam (7), the vibration of in the vertical direction end points (19) be end points (18) and end points (20) vibration close vibration.Member among the figure (1), (2), (3), (4), (5), (6), (7), (8) even available rigid plastic or other light hard material constitute.(9) be the line of rabbet joint on the panel.

Structure in the empty frame among Fig. 2 is the part that is increased between Fig. 1 king-rod (1) and bar (2), wherein at vertical direction, the vibration of end points (19) be other vibrating arm end points vibration close vibration.Between bar (1) and bar (2), construct part in empty frame of every increase, just can increase a branch vibration.Can make the vibration compositor that contains a plurality of branch vibrations with increasing the method for dividing vibration.

Fig. 3 is the bar 1 among Fig. 1, and axis hole 40 is left in its centre, and front end is spherical end points, and axis hole 41 is left in the rear end, and (purpose is when making cam rotation to the center of gravity of whole bar, and bar contacts together with cam under action of gravity all the time in the rear end of bar partially.Fix magnetic flat thin magnet and iron plate respectively in bar and the cam outer rim part that contacts, also can reach this purpose) with magnetic force.

Fig. 4 is the bar 2 among Fig. 1, and its centre is to be combined by shaft 44 and end cap 45, in axle 46 patchholes 47, and 44 and 45 capable of being combined being fixed together; 42 is the axis hole in the middle of the bar, and 43 is the axis hole of rod rear end, and the bar front end is spherical end points.

Fig. 5 is Fig. 1 king-rod 3, and axis hole 48 is left in its centre, and axis hole 49 is left in the rear end, and forward terminal is spherical end points.

Fig. 6 is the connecting rod 4 among Fig. 1, its upper and lower axis hole 50 and 51 respectively left, and it and bar 1 bar 2 ends link together with axle 11 and axle 12 respectively, can rotate flexibly around axle.

Fig. 7 is the connecting rod 5 among Fig. 1, be fixed with axle 13 on its two sides, upper end, there is axis hole 52 lower end, it and bar 2, bar 3 middle linking together, mode is that axle 13 passes respectively in the vertical slots 56 of the groove 8 that is stuck in both sides behind the hole 42 of bar 2 again, and axis hole 52 and 48 is to link together with spools 14.

Fig. 8 is the groove 8 among Fig. 1, and vertical slots 56 is left in its two sides, and a plurality of grooves 8 are combined, and mode is that axle 53 inserts in the hole 54 of adjacent slot 8, passes hole 56 with major axis 21 and is fixed, and all grooves 56 all are fixed in the same vertical plane.

Fig. 9 is axle 11, axle 12, the axle 14 among Fig. 1, and it adopts transition fit with the hole of bar 1, bar 2, bar 5, with the hole employing clearance fit (can be analogs such as pinning, screw) of bar 4, bar 3.

Figure 10 is the cam 6 among Fig. 1, and Figure 11 is the cam 7 of Fig. 1 axis 58 towards a left side, and Figure 12 is axle 58 cams 7 towards the right side.Driving groove 57 is left in side of cam, transmission shaft 58 is stretched out in the another side, when a plurality of cam set lump together, axis hole 59 all overlaps and is through on the same major axis, axle 58 can stretch in the groove 57 of adjacent cams, axle 58 can rotate the φ angle in groove 57, promote the cell wall of groove 57 by axle 58, can drive next cam rotation, rectify to rotating first cam from one, the cam of this group is rotated successively, and each cam all falls behind previous cam φ angle first cam of backward rotation, and this group cam is all synchronously rotated, and the size of the axle 58 angle φ that can rotate in groove 57 has determined the end points of the vibrating arm that cam promoted to vibrate the wavelength of formed ripple, its relation is λ=360 °/φ, changes the wavelength that the φ angle can change formed ripple.At cam outer shaft 60 places leaving certain gaps uncovered by the economic plan groove, resilient clip 61 on 60 places card is used for increasing the friction force between cam and the axle, can prevent that cam from arbitrarily sliding on axle.

Figure 13 is the cam 6 of band movable slider among Fig. 1, and Figure 14 is the organigram of the slide block in the driving groove of Figure 13 cam (6) and the slide block synoptic diagram during diverse location in groove.Figure 15 is the synoptic diagram of the interior slide block diverse location in groove of the driving groove of Fig. 1 cam (7).62 is the resilient clip of being fixed on the flank of cam, and 63 is its bayonet socket, and 64 and 65 is the axle on the slide block, makes 65 to be stuck in the different bayonet socket 63 by 64 moving sliders, can change the position of slide block in groove, the φ angle is is different values.

Figure 16, Figure 17 are the crank of band gear, wheel side leaves two axle 66(or hole 67) when it being contained in an end of cam set, 66 groove 57 interior (or hole 67 covers are through on the axle 58 of end points cam) that can stretch into the end points cam can drive the end points cam and rotate with crank.

The assembling synoptic diagram that Figure 18 combines for a plurality of vibration compositors shown in Figure 1.The hole 40 of the bar 1 of wherein all vibration compositors is all overlapped and is through on the major axis 10, and the hole 49 of bar 3 is all overlapped and is through on the major axis 15, and the hole 59 of cam 6 is all overlapped and is through on the major axis 16, and the hole 59 of cam 7 is all overlapped and is through on the major axis 17, and groove 8 is combined cover and is through on the major axis 21.

Figure 19 is embodiment one, gear drive synoptic diagram among the embodiment two between two cranks, gear 28 and 29 is fixed on the axle 32, as shown in FIG., crank 22 and 23 can rotate respectively, as cushion block 33 is taken out from right-hand member, Zola's axle 32, allow 33 to be placed on left end, can make gear 24～26～28～29～30 engaged transmission, 34 is crust of the device.

Figure 20 is the gear drive synoptic diagram between two cranks among the embodiment three, as shown in FIG., 22 and 23 can rotate respectively, take out 33 from right-hand member, a left side pushes away 32, allow 33 to be placed on left end entirely, can make gear 24～26～28～29～30 engaged transmission, gear 24 is identical with 30 rotating speeds, all take out from left end 33, the right side pushes away 32 allows 33 all to be placed on right-hand member, can make gear 25～27～28～29～31 engaged transmission, and crank 22 and 23 will rotate with the 3:4 rotating ratio.

Figure 21 is embodiment four, gear drive synoptic diagram among the embodiment five between two cranks, 35 and 36 for being fixed on the step cone on the crank among the figure, 37 is the power wheel of the energy adjusted position between two step conies, adjustment by 37 can make 22 and 23 with 1:1,3:4,2:3, four rotating ratios of 1:2 rotate.

Figure 22 is the organigram of the gear 37 among Figure 21, gear 37 can rotate on axle 39, axle 39 is put in the elongated slot 69 of tooth rest 68, go up and link to each other with pull bar 70, link to each other with extension spring 71 down, extension spring 71 other ends are fixed on the tooth rest, and by pull bar 70 and extension spring 71 positions of adjustable axle 39 in groove 69, tooth rest 68 can and sway along axle 38 move left and right.

Figure 23 is the panel among the embodiment one, two, three, Figure 24 is the panel among the embodiment four, five, six, leave some the vertical lines of rabbet joint on the panel, the vibrating arm of each vibration compositor is up-down vibration in a line of rabbet joint all, mark some the equally spaced horizontal lines of level on the panel and represent respectively to arrange the equilibrium position and the vibration displacement of particle respectively, put on the numeral that the high wave source distance in equilibrium position of particle is respectively vibrated in expression successively by direction of wave travel respectively at the upper and lower of each line of rabbet joint.

Figure 25 is the gearing synoptic diagram between two cranks among the embodiment six, seven, and gear 72 can be gone up to move and rotate and can make gear (24) and (30) rotate and mesh rotation respectively at axle (38).

Figure 26 is the cam that two driving grooves and twopiece drive shaft are arranged, two disks in its two sides, two driving grooves are left in its side, two transmission shafts are left in the another side, when a plurality of cam set lump together, two transmission shafts insert respectively in two driving grooves of a back cam, promote cell wall jointly and make a back cam rotation, use this kind cam can reduce transmission shaft stressed of flank of cam.

Figure 27 is an oscillator.The uniform rotation cam can make the vibrating arm end points do simple harmonic oscillation at vertical direction.

Embodiment one: 33 vibration compositors are combined, wherein 33 bars (1) cover is through on the major axis (10), 33 bars (3) cover is through on the major axis (15), 33 cams (6) cover is through on the major axis (16), 33 cams (7) cover is through on the major axis (17), the cam that its cam (6) selects for use Figure 10 to construct, the cam that cam (7) selects for use Figure 11 to construct, the φ angle all is 30 °, 34 grooves (8) are combined cover and are through on the major axis (21), put on crank (22) at axle (16) left end point cover, put on crank (23) at axle (17) right-hand member cover, gearing such as Figure 19 between two cranks.

Under situation shown in Figure 19:

1, forward rotation crank (22), can make on the panel occur, in the wavelength propagated from left to right of two rows be the identical ripple of 12 units.

2, forward rotation crank (23), the wavelength of can make in occurring on the panel, following two rows propagating from right to left are the identical ripple of 12 units.

3, backward rotation crank (22) and (23) can make the particle of respectively arranging on the panel all get back to the equilibrium position, and this is to use the set-up procedure that at first will do before this device.

4, transfer gear (28), (29) to make gear (24)-(26)-(28)-(29)-(30) engaged transmission, forward rotation crank (22) or (23), gear (24) is rotated with identical speed with (30), can make on the panel occur, in the ripple propagated from left to right of two rows, in, the following ripple propagated from right to left of two rows, the wave source frequency at two ends, the left and right sides is all identical with phase, after middle row's two train waves meet, and the stack that can produce ripple.(as Figure 23) can demonstrate the stack and the interference of the two wave source frequencies ripple all identical with phase, and the difference △ γ=K λ place vibration that can observe from two wave sources distance is the strongest, and △ γ=K λ+λ/2 places vibration is the most weak.

5, earlier crank (22) forward rotation one angle (for example 60 °) is adjusted gear (28) and (29) again, make gear (24)-(26)-(28)-(29)-(30) engaged transmission, and then forward rotation crank (22) or (23), it is identical just can to demonstrate two wave source frequencies, the wave interference that first phase is different.

6, earlier 180 ° of crank (22) backward rotation, forward rotation again, make shownly on the panel go up, in two row's ripples when just propagating into low order end, adjust gear (28) and (29) and make gear (24)-(26)-(28)-(29)-(30) engaged transmission, rotate crank (22) or (23) again, just can demonstrate a ripple that is listed as propagation from left to right and run into reverberation, produce half-wave loss and reflect the interference of reflection wave and incident wave again.

Embodiment two: whole device is identical with embodiment one, it is 22.5 ° cam that its cam 6 changes the φ angle into, cam (7) is constant, and during gear (24)-(26)-(28)-(29)-(30) engaged transmission, the rotating ratio of crank (22) and (23) is 3: 4.The formed wavelength of propagating from left to right will become 16 units on the panel, frequency be propagation from right to left wave frequency 3/4, can demonstrate the stack of two frequencies, two train waves that wave source sent inequality.

Embodiment three, as embodiment one and embodiment two, 33 vibration compositors are fitted together, cam (6) changes the cam that Figure 13 φ angle shown in Figure 14 can be adjusted into, wherein the φ angle can be adjusted to 22.5 ° from 30 °, cam (7) is constant, the variable speed drive of device such as Figure 20.Transferring the φ angle of cam (6) is 30 °, gear (24)-(26)-(28)-(29)-(30) engaged transmission, and device becomes embodiment one; Transferring the φ angle of cam (6) is 22.5 °, gear (25)-(27)-(28)-(29)-(31) engaged transmission, and device becomes embodiment two.

Among the above embodiment, vibration compositor number can suitably increase and decrease, but is advisable with odd number (as 21).(as in above embodiment, cut the cam 6 of several vibration compositors of left end, bar 1 bar 4 is also fixing their axle 12, or several vibrate cam 7 bars 3, the bar 5 of compositors to cut right-hand member, and it is fixing their axle 13, device can also be demonstrated the non-interfering character of ripple except that the stack that can demonstrate ripple and interference rule.）

Embodiment four, with above embodiment is the same the vibration compositor is fitted together, cam (6) adopts the cam of Figure 10 structure, the φ angle is 30 °, cam (7) adopts cam shown in Figure 12, and the φ angle is 45 °, and the driving groove of flank of cam all faces a left side, load onto the crank of being with step cone respectively at two groups of cam set left ends, the gear (or adopting modes such as belt, chain) that adds position adjustable between two step conies carries out transmission.Adopt gear-driven device such as Figure 21.Concrete operating position is:

1, transfer gear (37) to make gear (35) and (36) with 1: 1 rotational speed, forward rotation crank (22) or (23), be 12 units with the row's of formation one train wave length on the panel, arrange wavelength down and be 8 units and the identical ripple of propagating from left to right of wave source vibration (screening go in the vibration of row's particle), can demonstrate the propagation of ripple in different mediums, change panel line of rabbet joint bottom and represent that row's particle is 0 from the numeral of wave source distance down, 1.5,3,4.5 ... (it is 0 that middle row's particle is respectively from two wave source wave path-differences from left to right also can to demonstrate the wave interference rule, 0.5,1,1.5 ... particle).

2, transfer gear (37) that gear (35) and (36) are rotated with 2: 3 speed, forward rotation crank (23) or (23), to occur row's wavelength on the panel is 12 ripples that cell frequency is 2f, arranging wavelength down is 8 ripples that cell frequency is 3f, and middle row's ripple is the ripple of upper and lower two row's ripple stacks.Can demonstrate the synthetic of vibration, phenomenon is clapped in the stack of ripple, the ripple that contains two kinds of frequencies in d ν/d λ=0 o'clock with the propagation of identical phase velocity and group velocity.

3, transfer gear (37) that gear (35) and (36) are rotated with 3: 4 speed, forward rotation crank (22) or (23), to occur row's wavelength on the panel is 12 ripples that cell frequency is 3f, and following row's wavelength is 8 ripples that cell frequency is 4f, and middle row is the ripple of upper and lower two row's ripple stacks.Can demonstrate contain two kinds of frequencies ripple in d ν/d λ＞0 o'clock with the propagation of different phase velocity group velocitys.

4, transfer gear (37) that gear (35) and (36) are rotated with 1: 2 speed, forward rotation crank (22) or (23), to occur row's wavelength on the panel is 12 ripples that cell frequency is f, and following wave-wave length is 8 ripples that cell frequency is 2f, and middle row's ripple is the ripple of upper and lower two row's ripple stacks.Can demonstrate contain two kinds of frequencies ripple in d ν/d λ＞0 o'clock with the propagation of different phase velocity group velocitys.

Embodiment five, device as enforcement four change cam (6) into cam that the φ angle can be adjusted to 22.5 °, 30 °, 45 °, and cam (7) changes the cam that the φ angle can be adjusted to 30 °, 36 °, 45 ° into, the various phenomenons of device in can demonstrating embodiment four, all right:

1, transferring down, cam (7) φ angle all is 30 °, overhead cam (6) left half cam φ angle is 30 °, right half cam φ angle is 45 °, transfer gear (37) that gear (35) and (36) are rotated with same rotational speed, forward rotation crank (22) or (23), the wave source vibration that will occur upper and lower two row's ripples on the panel is identical, under to arrange wavelength be 12 units, on to arrange the left half wavelength be that 12 unit right half wavelength are that the ripple of propagating from left to right (screening go in the vibration of row's particle) of 8 units can be demonstrated ripple enters another kind of medium from a kind of medium propagation law.

2, transferring down, cam (7) φ angle all is 30 °, overhead cam (6) two end portions cam φ angle is that 30 ° of center section cam φ angles are 45 °, transfer gear (37) that gear (35) and (36) are rotated with same rotational speed, forward rotation crank (22) or (23), the wave source vibration that will occur upper and lower two row's ripples on the panel is identical, and following row's wavelength is 12 units.Last row two ends wavelength is that wavelength is that the ripple of propagating from left to right (screening go in the vibration of row's particle) of 8 units can be demonstrated ripple continue propagation law this medium again after a kind of medium passes another kind of medium in the middle of 12 units.

3, transfer gear (37) to make gear (35) and (36) rotate to demonstrate and contain ripple propagation in medium under d ν/d λ=0, d ν/d λ＞0, d ν/d λ＜0 three kind of situation that frequency is 3f and 4f with 3: 4 speed, wherein:

A, to transfer cam (6) φ angle be 22.5 °, and cam (7) φ angle is 30 °, can demonstrate the situation of d ν/d λ=0 o'clock.

B, to transfer cam (6) φ angle be 30 °, and cam (7) φ angle is 45 °, can demonstrate the situation of d ν/d λ＞0 o'clock.

C, to transfer cam (6) φ angle be 30 °, and cam (7) φ angle is 36 °, can demonstrate the situation of d ν/d λ＜0 o'clock.

Implement six, for avoiding in use transferring among the embodiment five trouble at cam φ angle, useful φ angle is that the cam of different sizes is made the device of function singleness, wherein the gearing between the crank can adopt the better simply gearing of structure (Figure 25), also can adopt the corresponding kind of drive such as belt gear or chain drive between the power wheel on two cranks, wherein available three devices are used a that finishes among 3 among the embodiment five, b, three kinds of situation wave propagations of c, and the vibration compositor in the device of the propagation of demonstration ripple in different mediums can replace with two groups of oscillators (Figure 27).

Embodiment seven, and device is as embodiment six, and its middle gear (35) is identical with (36) number of teeth, and the φ angle of all cams all is 30 °, and the vibration amplitude of cam (6) row of making particle is for arranging 3 times of particle vibration amplitudes down.Earlier 150 ° or 210 ° of crank (22) forward rotation, transfer gear 72 that gear (35) can be rotated with identical speed with (36) engagement then, forward rotation crank (22) or (23) again, the three row's waveforms that occurred on the panel can reflect the image relation of three-phase alternating current neutral voltage line current and phase-voltage phase-current.

Embodiment eight: with the vibration compositor among the vibration compositor replacement embodiment four that contains a plurality of branch vibrations, be respectively charged into the crank of belt wheel with end at each group cam, and between each is taken turns, adding gearing, the ripple that just can make the stack of the synthetic and ripple that can demonstrate several vibrations and contain several frequencies is with a kind of instrument of the propagation law of identical and different phase velocity group velocitys.

Among the above embodiment, vibration compositor number all can suitably increase and decrease.

The present invention has following advantage compared to existing technology:

1, function is many, applied range. It can use in the teaching of the subject fluctuations such as sound, light, electricity.

2, easy to operate. Phenomenon during the observable ripple is propagated continuously when rotating crank, the moment of each train wave of observable concerns when stopping operating crank.

3, experimental phenomena is obviously directly perceived, and effect is lively, and teaching efficiency is good.

4, remedied the deficiency of existing physics teaching demonstration test apparatus. In " in university and normal colleges and schools' General Physics, lecture experiment and the instrument reference list (first draft) of establishment on May 21st, 1988, (printing the fourth phase in 1988 " Physical Experiment ") ripple propagation in different mediums is for need improving or instrument to be developed, the ripple that contains several frequencies in medium take the propagation of identical with different phase velocity group velocitys then as undeveloped blank project.

Claims (6)

1, a kind of rotation become vibration, with the propagation law and the stack of ripple in medium of the propagation of vibration and the composition demonstrating ripple of vibration, interfere the instrument of rule, it is characterized in that by a plurality of vibration compositors combine add power wheel, crank is formed; Wherein each vibration compositor is all made it to be formed at the groove of vertical direction motion in order to the connecting rod and the axle on the limiting rod of transmitting vibrations by the vibrating arm, the cam of promotion vibrating arm vibration, the connection vibrating arm that are in the same vertical plane, the rotation of each cam all can promote a contacted with it vibrating arm vibration, transmission by connecting rod, each is subjected to the vibrating arm that cam promotes all can be their vibration transfer to another vibrating arm, makes this vibrating arm end points be the close vibration of other vibrating arm end points in the vibration of vertical direction in the vibration of vertical direction; A plurality of vibration compositors fit together, same group of cam covers on the same axle, adopt the axial trough transmission between the adjacent cams, on an end points of every group of cam set, all cover the crank of a belt wheel, crank and the combination of end points cam are fixed together, the rotation crank can drive the end points cam and rotate together, by the axial trough transmission between the cam, this group cam is rotated successively, under the promotion of each cam, each vibrating arm vibrates successively, the vibration of vibrating arm end points forms ripple, all by the crank control of cam set end points, each rotating ratio of organizing cam is by the control of the speed change gear between the crank in the rotation of every group of cam, thereby can demonstrate the synthetic and ripple rule in the air of vibration with the multiple row ripple.

2, by the instrument described in the claim 1, it is characterized in that the vibration compositor that contains two kinds of branch vibrations wherein is made up of three vibrating arms and two cams, connecting rod, grooves, the vibration compositor that contains a plurality of branch vibrations is to add vibrating arm, connecting rod, cam and groove again to form between its vibrating arm.

3, by the instrument described in the claim 1, it is characterized in that the axial trough kind of drive that is adopted between the same group of cam wherein is to allow a side of each cam stay driving groove, transmission shaft is stretched out in another side, when combining, the axle that stretches out can insert in the adjacent cams lateral groove, axle can rotate the φ angle in groove, promote cell wall by axle and drive next cam rotation, φ angle size has determined the wavelength of formed ripple, its relation is λ=360 °/φ, changes the wavelength of formed ripple by the big I that changes the φ angle.

4, by the instrument described in the claim 3, the mode that it is characterized in that change φ angle wherein is to select the cam at different φ angle for use, or the movable slider of packing in the flank of cam groove changes the size at φ angle.

5, by the instrument described in the claim 1, it is characterized in that the crank of control cam set rotation wherein is divided in the two ends, the left and right sides of upper and lower two cam set, thereby two row that two wave sources send about demonstrating are the stack and the interference rule of the ripple of propagation in opposite directions, can demonstrate the transfer law of the ripple of the synthetic and co-propagate of vibrating when crank is contained in same end.

6, by the instrument described in the claim 1, it is characterized in that the speed change gear of rotating ratio that wherein control respectively organizes cam set by transmission gear that can the shift position and the gear drive that other gear is formed, or between crank, adopt the similarly gearing of transmission such as belt, chain.

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