JPS623827Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a breath pressure sensor that generates an electric signal for controlling the volume, etc., in accordance with the breath pressure blown from a mouthpiece in an electronic wind instrument.

In recent years, various electronic wind instruments have been devised by applying electronic musical instrument technology to wind instruments.

The pitch of such electronic wind instruments is selected by a push-button key switch installed in the tube body, but when you hold the mouthpiece in your mouth and blow into it, the sound is produced at a volume that corresponds to the pressure of your breath. Without it, you won't be able to perform like a wind instrument.

This invention is capable of sensitively detecting the breath pressure blown into the mouthpiece and generating electrical signals for controlling the volume, etc. in the electronic wind instrument as described above, and has a simple structure and can be manufactured at low cost. The purpose is to provide a breath pressure sensor.

Therefore, the breath pressure sensor for electronic wind instruments according to this invention has an elastic membrane arranged in a cylindrical case to receive breath pressure and can be deformed according to the breath pressure, and an elastic membrane arranged close to the elastic membrane. a plate-shaped body that can be deflected according to the deformation of the plate-shaped body, and a strain detection element that is fixed to the plate-shaped body and generates an electrical signal change according to the amount of the deflection; It consists of a support part that is fixed to the case, and a deflection part that has a larger area than the support part and is integrally connected to the support part by a narrow constriction part, and the strain detection device is attached to the constriction part. The element is fixed and the strain detection element is used to detect the breath pressure from the elastic membrane side of the case.

The content of this invention will be explained below with reference to embodiments shown in the accompanying drawings.

FIG. 1 is a partially cutaway plan view of an electronic wind instrument to which this invention is applied, and FIG. 2 is a sectional view of the vicinity of the mouthpiece. This electronic wind instrument consists of a tube body 1 having a similar shape to a flute, and a mouthpiece 2 that fits into one end of the tube body 1. The tube body 1 is provided with a power switch 3 and a number of push buttons 4 for pitch selection so that they can be operated from the outside. In addition, a breath pressure sensor 5 of this invention is fitted into the inside of the tube body 1, as shown in FIG. A speaker 6 is attached to the part, and the sound is produced from the opening like a general wind instrument. In addition, although not shown, key switches, circuit boards, batteries, etc. corresponding to each push button are built-in.

3 to 6 show details of the breath pressure sensor according to this invention. This breath pressure sensor 5 is
A stepped portion 10a provided on the inner peripheral surface of the cylindrical case 10
In addition, a circular elastic membrane 11 having a large ventilation resistance as shown in FIG. 6 is arranged so as to receive the breath pressure from the direction of arrow P in FIG. A plate-like body 12 such as a flexible metal plate is provided.

As shown in FIG. 5, this plate-shaped body 12 has a semicircular support portion 12a with a diameter approximately equal to the large inner diameter D ₁ of the case 10, and a semicircular support portion 12a with a diameter somewhat smaller than the small inner diameter D ₂ of the case 10. It consists of a circular biased part 12b and a narrow constricted part 12c that integrally connects the support part 12a and the biased part 12b, and the area of the biased part 12b is larger than the area of the support part 12a. There is.

The support portion 12a of this plate-like body 12 is adhered and fixed to the step portion 10a of the case 10, and the elastic membrane 1
Also fix the area around 1 with adhesive.

A strain detection element 13 is fixed to the back surface of the constricted portion 12c of the plate-shaped body 12 to detect strain caused by the deflection. As this strain detection element, a pressure sensitive resistance element such as a barium titanate element, a piezo element, a semiconductor pressure sensitive element, or a piezoelectric conversion element is used. 14,1 in Figure 3
Reference numeral 5 designates a terminal for taking out output such as resistance value or electromotive voltage from the strain detection element as an electrical signal change, and reference numeral 16 in FIG. 4 represents a protection net.

The breath pressure sensor 5 configured as described above is fitted into the tube body 1 as shown in FIG.
When you breathe in, the elastic membrane 11 deforms in the direction of arrow P in FIG. 4 due to the breath pressure. As a result, the biased portion 12b of the plate-like body 12 becomes the constricted portion 12c.
It deflects while deforming it. Therefore, the strain detection element 13 changes its resistance value or generates an electromotive force in response to a pressure change due to the deformation strain of the constriction part 12c of the plate-shaped body 12, and sends an electric signal corresponding to the breath pressure to the terminal 14.
Output from 15.

FIG. 7 is a diagram showing the circuit configuration of the electronic wind instrument shown in FIGS. 1 and 2. 20 is an oscillator such as a CR oscillator or an astable multivibrator, and 21 is a pitch selection circuit forming a part of the oscillator 20, which includes a number of key switches KS that are closed when each push button 4 in FIG. 1 is pressed, and this key switch. It consists of resistors R ₁ to Rn selectively connected in series as part of the resistors that determine the oscillation frequency of the oscillator 20 by KS. Instead of this resistor, the capacitance of a capacitor that determines the oscillation frequency of the oscillator 20 may be changed by the key switch KS.

22 is a voltage control circuit which controls the output voltage according to the resistance value when the breath pressure sensor 5 outputs a resistance value according to the breath pressure, and controls the output voltage according to the resistance value by the breath pressure sensor 5. When a corresponding electromotive voltage is output, it is voltage amplified, and in any case, a voltage corresponding to the magnitude of the breath pressure is output.

23 is a transistor to which the output of the oscillator 20 is applied to the base via a resistor 24 and drives the speaker 6 at its oscillation frequency; 25 is a battery as a power source.

In the electronic wind instrument configured as described above, when the power switch 3 is turned on, the voltage of the battery 25 is applied to the oscillator 20 and the voltage control circuit 22. When one of the push buttons 4 in FIG.
Joins the base of 3. However, if the voltage control circuit 22 is set not to output voltage at the resistance value (or electromotive force) of the breath pressure sensor 5 when no breath is blown into the mouthpiece 2, the speaker 6 will not be driven at this time. , not pronounced.

Then, when you breathe in through the mouthpiece 2, the strain detection element 13 of the breath pressure sensor 5 changes its resistance value or generates an electromotive force according to the breath pressure, as described above, and the signal causes a voltage to be generated. The control circuit 22 outputs a voltage according to the breath pressure and controls the collector current of the transistor 23. Therefore, the speaker 6 is driven by a current that corresponds to the breath pressure, and emits a tone of the pitch selected by the push button 4 at a volume that corresponds to the breath pressure.

Note that if the elastic membrane 11 of the breath pressure sensor 5 is made of a membrane made of rubber or the like that is neither breathable nor water permeable, the breath pressure can be reduced.
In addition to being 100% deformed, moisture contained in tongue fluid and breath is blocked, so deterioration of the strain detection element 13 can be prevented.

In addition, since the plate-shaped body 12 has the shape shown in FIG. 5, the deflection portion 12b is easily deflected, and the strain is concentrated in the constriction portion 12c, so that one strain detection element 13 fixed thereto is easily deflected. Accordingly, breath pressure can be detected with high sensitivity and responsiveness.

As mentioned above, the breath pressure sensor for electronic wind instruments according to this invention can detect the breath pressure blown in from the mouthpiece with high sensitivity and responsiveness, and is inexpensive because it has a simple structure and requires only one detection element. can be manufactured.

If this breath pressure sensor is incorporated into an electronic wind instrument and the volume is controlled by detecting the breath pressure blown into the mouthpiece, it is possible to create any performance expression using breath pressure, just like with general wind instruments. It can be carried out.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway plan view of an electronic wind instrument to which this invention is applied, Figure 2 is a sectional view taken along line A-A in Figure 1, and Figures 3 to 6 are breath pressure sensors according to this invention. Fig. 3 is a rear view, and Fig. 4 is a rear view.
The figure is a sectional view taken along the line B-B in Figure 3, Figure 5 is a perspective view of the plate-like body, Figure 6 is a perspective view of the elastic membrane, and Figure 7 is a block circuit diagram of the electronic wind instrument in Figure 1. It is. 1... Tube body, 2... Mouthpiece, 3... Power switch, 4... Push button, 5... Breath pressure sensor, 6
... Speaker, 10 ... Case, 11 ... Elastic membrane, 12 ... Plate-shaped body, 12a ... Support part, 13 ...
...Distortion detection element.

Claims (1)

[Claims for Utility Model Registration] 1. An elastic membrane disposed in a cylindrical case to receive breath pressure and deformable according to the breath pressure, and an elastic membrane disposed close to the elastic membrane to be able to deform. a plate-shaped body that can be deflected according to the amount of the deflection, and a strain detection element that is fixed to the plate-shaped body and generates an electrical signal change according to the amount of the deflection, and the plate-shaped body is fixed to the cylindrical case. and a biasing part that has a larger area than the support part and is integrally connected to the support part by a narrow constriction part, and the strain sensing element is fixed to the constriction part. A breath pressure sensor for an electronic wind instrument, characterized in that the strain detection element detects breath pressure from the elastic membrane side of the case. 2. The breath pressure sensor for an electronic wind instrument according to claim 1, wherein the elastic membrane is made of rubber or the like and is neither air permeable nor water permeable.