CN2901474Y

CN2901474Y - Sound propagation demonstrator

Info

Publication number: CN2901474Y
Application number: CN 200620033914
Authority: CN
Inventors: 沈昌生
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-04-24
Filing date: 2006-04-24
Publication date: 2007-05-16
Anticipated expiration: 2016-04-24

Abstract

A device is used to incarnate the sound propagation characters in teaching-sound propagation demonstration instrument which employs the polymethyl-methacrylate cylinder structure, and in which a colatorium, a foam globule and a loudspeaker are provided. After the instrument is connected to the external sound source, user not only can hear the elegant sound from the loudspeaker, but also can see the amplified sound vibration as that the foam globule merrily is bouncing up and down with the sound. Then the instrument is connected to an air-pump, and with air pumping out we can hear the sound gradually diminishing, but we still can see the foam globule merrily bouncing up and down with the sound as before.

Description

The sound transmission demonstration device

Affiliated technical field

The utility model relates to a kind of instrument---the sound transmission demonstration device of the embodiment sound transmission characteristics of using in the teaching.

Background technology

For many years, all demonstrate " vibration of sound and propagation " in the following manner at physics with in imparting knowledge to students naturally, in order to the explanation and the acoustic scientific knowledge of deducing.

Place small alarm clock or small radio receiver in a big glass bell jar, allow its sounding, start air pump again the air in the glass bell jar is discharged, air should not heard sound after extracting out, thereby air has been left in explanation, and the sound wave that acoustical vibration sends just passes to come out.

Though this mode has been continued to use decades, shortcoming is tangible: be not easy to accomplish strict seal (poorly sealed sound can spread out of) 1.; 2. can not arbitrarily control volume (volume is difficult to regulate); 3. too heaviness clashing and breaking easily again of glass bell jar.Even, because the cost height does not dispose the school of remote backwardness, lose the demonstration machine meeting still more so a lot of school has this cover instrument often to demonstrate and unsuccessful.

Summary of the invention

The purpose of this utility model, initiative one cover not only effectively but also very easily the sound transmission demonstration device replace the glass bell jar formula demonstration device of the heaviness of former usefulness.

The utility model addresses this problem the technical scheme that is adopted: select a heavy wall organic glass large cylinder for use, its two ends connect end cap up and down respectively with the blue mode of organic glass weight, realize the impermeability and the transparency in this way, filter screen, foam bead, loudspeaker are established in its inside, the loudspeaker voice coil extension line is sealed among the blue dish of the organic glass weight end cap, and venting ball valve is linked on the airtight container.

The effect of filter screen is that anti-bleeding point is stopped up by the foam bead, and the effect of foam bead is to amplify the effect that shows acoustical vibration, and loudspeaker is converted into the tone currents of outside input the sound of sound film vibration.The experiment note amplifier that the source of tone currents can adopt high-power radio cassette player or laboratory to be equipped with.When volume was very big, we not only can hear the graceful sound that loudspeaker is emitted, also simultaneously can see amplified vibration---the foam bead is beated with the cheerful and light-hearted high and low of sound.Because visibility is big, the demonstration effect greatly improves.Then Open valve, connect pumping with exhaust blower, along with the discharge of air, the sound that we can hear diminishes gradually but the vibration (bob that the foam bead is cheerful and light-hearted) that can see remains unchanged.The conclusion of demonstration is very clear: sound is the propagation of mechanical vibration, has left this medium of air, and vibration is not just propagated in a vacuum.

The beneficial effects of the utility model are: (1) principle is clear, kills two birds with one stone: can hear sound, can see vibration again, the characteristics of vivider distincter understanding sound transmission; (2) visibility is big, and demonstration instrument is not only attractive in appearance but also durable; (3) simple in structure, be easy to produce, be convenient to operation, cost is not high, popularizes easily.

Advance of the present utility model and suitable having benefited from: (1) organic glass is processed easily, and is lighter and handier than glass; (2) the foam bead is light especially, bounces easily; (3) loudspeaker and source of sound split, and have simplified the generation and the adjusting of sound.

Description of drawings

Below in conjunction with drawings and Examples the utility model is further specified.

Fig. 1 is a sound transmission demonstration device structure key diagram.

Among the figure, 1-ball valve, 2-bolt, 3-upper end cover, the 4-matter O-ring seal that softens, the 5-filter screen, 6-heavy wall organic glass tube, 7-foam bead, the 8-loudspeaker, 10-connects lead, 11-flush type binding post.

Embodiment

In Fig. 1, heavy wall organic glass tube 6 two ends connect the blue dish of organic glass weight respectively, and the blue end cap of last weight connects ball valve, and the blue dish of following weight connects lead 10 and binding post 11, bond and fix loudspeaker 8, the filter screen 5 of aperture is opened in the place near to the upper end setting of organic glass tube top, sprinkles an amount of foam bead 7 on loudspeaker, after the well gentle matter O-ring seal 4 of cloth, cover end cap 3, tight a bolt 2, bottom end cover is also handled as method, and so air obtains sealing then in the tube.

During experimental demonstration, connect upward source of sound with lead, connect upward air pump with flexible pipe, we can hear that not only loudspeaker emits graceful sound, also can see simultaneously amplified acoustic vibration---the foam bead is with the cheerful and light-hearted bob of sound, along with the discharge of air, the sound that we can hear diminishes gradually even becomes nothing, but the vibration of seeing remains unchanged.After air enters once more, then can hear sound again.

Claims

Instrument--the sound transmission demonstration device of the embodiment sound transmission characteristics of using in 1 one kinds of teaching, it is characterized in that: adopt a heavy wall organic glass large cylinder, its two ends connect end cap up and down with organic glass respectively in the blue mode of weight, establish filter screen, foam bead, loudspeaker in inside, the loudspeaker voice coil extension line is sealed among the blue dish of the organic glass weight end cap, venting ball valve is linked on the airtight container, external sound source can connect the upper speaker sounding by binding post, and air pump can be extracted air in the tube out by ball valve.