JPH0350559Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an electronic whistle using a piezoelectric buzzer.

As is well known, in the conventional whistle, the sound is produced by blowing into the mouth as well as strongly to activate a vibration system, but the following drawbacks can be pointed out. First, blowing continuously for long periods of time limits your lung capacity and is extremely tiring. Furthermore, it is extremely difficult to use the instrument in such a way as to emit the notes at a certain rhythm while exercising, as the breathing of the player becomes disturbed due to the exercise, and requires a considerable amount of practice. Furthermore, saliva accumulates inside the whistle, making it extremely unhygienic. Therefore, for example, Japanese Utility Model Application Publication No. 53-44485 proposes a whistle in which the sound is generated by a push button switch without depending on the person's breathing. However, although the above-mentioned problem was solved in the whistle disclosed in this publication, there was a problem in that it was difficult to change the tone of the pronunciation.

This idea was created in view of the problems with the conventional technology as described above, and its purpose was to hold a piezoelectric buzzer, which is powered by a battery rather than by a person's breath, by holding it in one's mouth or pressing it lightly with one's finger. It is an object of the present invention to provide an electronic whistle which is controlled by a switch section which is operated by a switch section, and whose tone color changes depending on the magnitude of the pressure applied at that time.

Hereinafter, one embodiment of this invention will be described in detail based on the drawings.

FIG. 1 shows the external appearance of the electronic whistle according to this invention, and FIG. 2 is an enlarged sectional view showing its internal structure. This electronic whistle is divided into two parts: a main body case 1 and a switch case 2. The main body case 1 is formed into a cylindrical shape, and a piezoelectric buzzer 4 is built in the end of the main body case 1 on the sounding hole 3 side, and two power batteries 5, 5 are housed on the back side of the piezoelectric buzzer 4. The piezoelectric buzzer 4 includes a piezoelectric sounding body such as PZT and a drive circuit (oscillation circuit) that drives the sounding body.
When a driving voltage from a battery 5 is applied to this, the driving circuit self-oscillates, and the sounding body is driven by the oscillation signal to generate sound. Note that when the drive voltage changes within a certain range, the oscillation frequency of the drive circuit changes, so the piezoelectric buzzer 4
The tone changes.

The switch case 2 is formed into a mouthpiece shape, and has an annular threaded portion 2a screwed into a threaded portion on the outer periphery of the rear end opening of the main body case 1, and a flat operating portion 2c to be described later, which are continuous with each other at a tapered portion 2b. At least the flat operating portion 2c has flexibility. A switch mechanism 6 is housed inside this flat operating section 2c. This switch mechanism 6 includes two flexible electrode plates 6a and 6b, and this electrode plate 6.
It is composed of a pressure-sensitive conductor 6c, such as a pressurized conductive rubber, sandwiched between a and 6b. The switch case 2 also serves as a lid for replacing the battery inside the main case 1, and when the switch case 2 is screwed to the main case 1, it is provided continuously at the end of the electrode plate 6a. A lead plate 9 has a spring contact piece 7 pressed against the back of the battery 5 and is electrically connected thereto, and a contact piece 8 extending from one end of the other electrode plate 6b is connected to the piezoelectric buzzer 4. electrically connected to. As a result, an electrical loop connecting the piezoelectric buzzer 4, battery 5, and switch mechanism 6 is formed.
Note that a neck strap 11 is attached to the locking hole 10 of the main body case 1.

In the electronic whistle configured as described above, the flat operating portion 2c of the switch case 2 is held in the mouth or with fingers, and a certain amount of clamping pressure is applied to the operating portion 2c. Since the operating portion 2c is flexible, the applied pressure is applied to the switch mechanism 6.
acts between the two electrode plates 6a and 6b to compress the pressure-sensitive conductor 6c. Then, the electrical resistance between the electrode plates 6a and 6b suddenly decreases, and the switch mechanism 6
is closed, the output of the power supply battery 5 is applied to the piezoelectric buzzer 4, and the piezoelectric buzzer 4 sounds. Also, remove the pressure applied to the operating section 2c (make it extremely weak)
Then, the switch mechanism 6 returns to its original position by the elastic force of the operating portion 2c, the electrode plates 6a, 6b, and the pressure-sensitive conductor 6c, and the piezoelectric buzzer 4 stops ringing. In addition,
Since the electrical resistance of the pressure-sensitive conductor 6c changes continuously, by appropriately adjusting the pressure applied to the operating section 2c, the voltage applied to the piezoelectric buzzer 4 is changed when the piezoelectric buzzer 4 is ringing. You can change the tone.

As explained in detail above, the electronic whistle according to this invention can produce sounds simply by operating the operation part of the switch case with your mouth or fingers.
It is almost painless to pronounce the words continuously,
It is suitable as an emergency alarm for sick people or as a crime prevention alarm, and it is easy to generate a constant rhythmic sound even when breathing is irregular during exercise.It is also suitable for sports and recreation, and does not collect saliva. Therefore, it has effects such as being hygienic. Furthermore, according to the present invention, the tone color can be easily changed according to the pressure applied to the operating section.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the external appearance of an electronic whistle according to an embodiment of the invention, and FIG. 2 is an enlarged sectional view showing its internal structure. 1...Main case, 2...Switch case, 2
c... Flat operation unit, 3... Sound hole, 4... Piezoelectric buzzer, 5... Power battery, 6... Switch mechanism,
6a, 6b...electrode plate, 6c...pressure sensitive conductor.

Claims (1)

[Scope of utility model registration request] A piezoelectric buzzer consisting of a piezoelectric sounding body and a drive circuit for the sounding body, a main body case housing a power supply battery for driving the piezoelectric buzzer, and a return type switch formed in the shape of a mouthpiece and closed by external operation. An electronic whistle having a switch case provided with a mechanism, the switch case being detachably attached to the main body case, and the piezoelectric buzzer and a power source battery being electrically connected via the switch mechanism, The above-mentioned switch mechanism has a structure in which a pressure-sensitive conductor is sandwiched between two electrodes, and is built in the flat operation part of the above-mentioned switch case. An electronic whistle characterized in that the resistance value changes and the tone of the piezoelectric buzzer changes in accordance with the change.