JPWO2015186239A1 - Electronic horn - Google Patents

Abstract

The present invention provides an electronic sounding device having an improved timbre capable of making the overall shape sufficiently compact and realizing a significant cost reduction. In an electronic sounding device that vibrates a diaphragm 4 with a piezoelectric body 6 and outputs an alarm sound, a circuit 85A for generating a high-frequency first basic rectangular wave and a low-frequency second basic rectangle A circuit 85B for generating a wave, a circuit 84 for generating a modulated rectangular wave, the first fundamental rectangular wave and the second fundamental rectangular wave are modulated with the modulated rectangular wave, and the frequency deviation during the modulation of the first fundamental rectangular wave The circuit 83 for setting the frequency shifts at the time of modulation of the shift and the second basic rectangular wave within a predetermined range, and the modulated first basic rectangular wave and the modulated second basic rectangular wave alternately in a predetermined cycle And a circuit 81 that generates the drive signal and drives the piezoelectric body 6 with the drive signal. [Selection] Figure 2

Description

  The present invention relates to an electronic horn, and more particularly, to realize an electronic horn that is capable of simultaneously producing high and low tones and improving the timbre by using a consonant sound in a compact and low-cost manner.

  In order to improve the timbre of the horn, it has traditionally been possible to generate two sets of electromagnetic flat horns for high and low sounds to generate a consonant sound. There was a problem that it required space and increased costs. Therefore, Patent Document 1 proposes a structure in which a small horn having an outer diameter smaller than this is provided in front of a flat horn.

JP 58-162994

  However, even with the structure described in Patent Document 1, the size in the front-rear direction is not particularly compact, and there is a problem in that it is unavoidable to increase the cost because there is no change in providing two alarming devices. .

  Therefore, the present invention solves such a problem, and provides an electronic sounding device having an improved tone that can significantly reduce the overall shape including the front-rear direction and can achieve a significant cost reduction. Objective.

  In order to achieve the above object, according to the first aspect of the present invention, in the electronic sounding device that vibrates the diaphragm (4) by the piezoelectric body (6) and outputs an alarm sound, the first basic rectangular wave on the high sound side Generating means (85A), means for generating a second basic rectangular wave on the low sound side (85B), means for generating a modulated rectangular wave (84), the first basic rectangular wave and the second basic rectangular wave Means (83) for modulating a wave with the modulation rectangular wave, and a frequency shift at the time of modulation of the first basic rectangular wave and a frequency shift at the time of modulation of the second basic rectangular wave are set in predetermined ranges, respectively. Means (83) for generating a drive signal in which the modulated first basic rectangular wave and the modulated second basic rectangular wave are alternately continued at a predetermined period, and using the drive signal, the piezoelectric body (6) Means (81) for driving.

  According to the first aspect of the present invention, the piezoelectric body is driven by the drive signal in which the modulated first basic rectangular wave and the modulated second basic rectangular wave are alternately continued at a predetermined period, so that the piezoelectric body generates vibration. The alarm sound emitted from the diaphragm is a concerto sound of high and low sounds, and the tone is greatly improved. In the first aspect of the invention, a single diaphragm generates a high-pitched sound and a low-pitched sound, so that the entire alarm device becomes sufficiently compact and a significant cost reduction is realized.

  According to the second aspect of the present invention, in the electronic sounding device that vibrates the diaphragm (4) by the piezoelectric body (6) and outputs a warning sound, the means (85A) for generating the first fundamental rectangular wave on the high sound side; Means for generating a second basic rectangular wave on the low sound side (85B), means for generating a first modulated rectangular wave (84A), means for generating a second modulated rectangular wave (84B), and the first basic wave Means (86) for modulating a rectangular wave with the first modulated rectangular wave, means (86) for modulating the second basic rectangular wave with the second modulated rectangular wave, and frequency at the time of modulating the first basic rectangular wave Means (86) for setting the deviation within a predetermined range, means (86) for setting the frequency deviation at the time of modulation of the second basic rectangular wave, and the modulated first basic rectangular wave A drive signal in which the modulated second basic rectangular wave is alternately continued with a predetermined period is generated and the drive signal is generated. And means (81) for driving the piezoelectric element (6).

  Also in the second aspect of the invention, a high-frequency and low-frequency sound is generated by one diaphragm, so that the entire alarm device is sufficiently compact and a significant cost reduction is realized.

  The frequency of the fundamental rectangular wave is set between 1800 and 3550 Hz, preferably between 2000 and 3150 Hz, the frequency of the modulated rectangular wave is set between 290 and 580 Hz, preferably between 310 and 440 Hz, and the frequency deviation is set. The shift may be set between -11 and -25 dB, preferably between -15 and -21 dB with respect to the frequency of the fundamental rectangular wave.

  The reference numerals in the parentheses indicate the correspondence with specific means described in the embodiments described later.

  As described above, according to the electronic audible alarm of the present invention, the overall shape including the front-rear direction can be made sufficiently compact and a significant cost reduction can be realized.

1 is an overall cross-sectional view of an electronic audible alarm in a first embodiment of the present invention. It is a block diagram which shows the structure of the warning circuit in 1st Embodiment of this invention. It is a figure which shows the frequency spectrum of the warning sound of the conventional bass side electromagnetic flat horn. It is a figure which shows the frequency spectrum of an alarm sound of the conventional electromagnetic flat type alarm device for high sounds. It is a figure which shows the frequency spectrum of the warning sound at the time of making the conventional low sound and the high sound flat alarm device sound simultaneously. It is a wave form diagram of a drive voltage signal applied to a piezoelectric material in a 1st embodiment of the present invention. It is a wave form diagram of a drive voltage signal applied to a piezoelectric material in a 2nd embodiment of the present invention. It is a block diagram which shows the structure of the warning circuit in 3rd Embodiment of this invention. It is a wave form diagram of a drive voltage signal applied to a piezoelectric material in a 3rd embodiment of the present invention.

  The embodiment described below is merely an example, and various design improvements made by those skilled in the art without departing from the gist of the present invention are also included in the scope of the present invention.

(First embodiment)
FIG. 1 is an overall cross-sectional view of the electronic sound alarm of the present invention. The electronic sound alarm includes a metal plate housing 1 having a circular open container shape, and a mounting stay 11 is bolted to the center of the bottom wall of the housing 1. An open container-like resin holder 2 is inserted in the housing 1 along this, and a circuit board 3 is disposed on the bottom wall of the holder 2 in parallel therewith. The circuit board 3 is fitted and supported by a pin portion 21 erected on the bottom wall of the holder 2, and a warning circuit described later is provided on the circuit board 3. Note that the circuit components and the like of the alarm circuit are not shown.

  A metal diaphragm plate 4 as a diaphragm is stretched in parallel with the circuit board 3 with the opening of the holder 2 closed, and the outer peripheral edge of the diaphragm plate 4 is the opening edge of the holder 2 and the opening of the holder 2. Between the outer periphery of the resin resonator 5 covered with the The resonator 5 is provided with sound output ports 51 at a plurality of locations on the outer peripheral portion (in this embodiment, four locations at regular intervals in the circumferential direction). A circular piezoelectric body 6 is joined to the diaphragm plate 4 at the center of the back surface (the lower surface in FIG. 1). Output lines 31 and 32 extend from the circuit board 3 to one electrode (not shown) of the piezoelectric body 6 and to the diaphragm plate 4 leading to the other electrode (not shown) of the piezoelectric body 6. In addition, one end of a power supply connector 33 extending to the outside of the housing 1 is connected to one end of the circuit board 3. The outer side of the resonator 5 is covered with a metal cover body 7 in which a long hole-like sound emission port 71 is formed.

  FIG. 2 shows the configuration of the alarm circuit 8 provided on the circuit board 3. Both electrodes of the piezoelectric body 6 are connected to a drive circuit 81, and a drive voltage is supplied to the drive circuit 81 from a voltage generation circuit 82. A frequency modulation / shift circuit 83 is connected to the drive circuit 81. The frequency modulation / shift circuit 83 has a modulation rectangular wave generation circuit 84 and a first basic rectangle that generates a first fundamental rectangular wave on the high sound side. The wave generating circuit 85A and the second basic rectangular wave generating circuit 85B that generates the second basic rectangular wave on the low sound side are connected. The first and second basic rectangular waves generated by the first and second basic rectangular wave generating circuits 85A and 85B are described later in the frequency modulation / shift circuit 83 by the modulating rectangular wave output from the modulating rectangular wave generating circuit 84. Thus, frequency modulation is performed with a predetermined frequency shift, and a drive voltage signal corresponding to the modulated wave is applied to the piezoelectric body 6 via the drive circuit 81, and the piezoelectric body 6 is vibrated. The frequency modulation / shift circuit 83, the modulation rectangular wave generation circuit 84, and the basic rectangular wave generation circuits 85A and 85B may be realized by software instead of hardware.

  Here, FIG. 3 shows an example of the frequency spectrum of the alarm sound of the conventional low-frequency electromagnetic flat sound alarm. In the example shown in FIG. 3, the fundamental frequency of the alarm sound is 350 Hz, and the resonance plate resonates at the 8th harmonic (2800 Hz) of a plurality of harmonics having a frequency that is an integral multiple of the fundamental frequency. The pressure became the largest, and the sound pressure was in the range of 105 to 118 dB.

  FIG. 4 shows an example of the frequency spectrum of the alarm sound of a conventional high-frequency electromagnetic flat alarm. In the example shown in FIG. 4, the fundamental frequency of the alarm sound is 400 Hz, and the resonance plate resonates at the 8th harmonic (3200 Hz) of a plurality of harmonics having a frequency that is an integral multiple of the fundamental frequency. The pressure became the largest, and the sound pressure was in the range of 105 to 118 dB.

  As shown in FIG. 5, the frequency spectrum of the alarm sound when the low-pitched sound and the high-pitched sound alarm are simultaneously blown is as shown in FIG. It is the sum of the frequency spectrum of the alarm sound of the high-pitched flat horn.

  Therefore, the frequency of the first fundamental rectangular wave to be modulated is set to 3200 Hz, the frequency of the modulating rectangular wave is set to 350 Hz, and the frequency shift is set to 400 Hz (absolute value). When this frequency shift is expressed in dB, 20 log (frequency shift / basic rectangular wave frequency) = 20 log (400/3200) = − 18 dB. The reason why the frequency shift is set to -18 dB is that the timbre of the alarm sound can be improved as will be described later.

  The frequency of the second fundamental rectangular wave to be modulated is set to 2800 Hz, the frequency of the modulating rectangular wave is set to 350 Hz, and the frequency shift is set to 400 Hz (absolute value). When this frequency shift is expressed in dB, 20 log (frequency shift / basic rectangular wave frequency) = 20 log (400/2800) = − 17 dB. The reason why the frequency shift is set to -17 dB is that the tone color of the alarm sound can be improved as will be described later.

  When the frequency of the first basic rectangular wave is 3200 Hz, the frequency of the second basic rectangular wave is 2800 Hz, the frequency of the modulated rectangular wave is 350 Hz, and the frequency deviation is set to 400 Hz (absolute value) as described above, the driving circuit The waveform of the drive voltage signal output to the piezoelectric body 6 via 81 is as shown in FIG. That is, in FIG. 6, the waveform is a square wave that changes positively and negatively, with a frequency of 3200 Hz of the first basic rectangular wave as a center, a 3600 Hz region X1 and a 2800 Hz region Y1 up and down by 400 Hz, and a second basic rectangular wave A region X2 of 3200 Hz and a region Y2 of 2400 Hz, which are up and down by 400 Hz around a frequency of 2800 Hz, are alternately repeated with a period of 2.9 ms (= 1/350 (Hz)).

  The frequency spectrum of the alarm sound generated by the diaphragm plate 4 oscillated by the piezoelectric body 6 to which such a drive voltage is applied is output from a conventional high-frequency electromagnetic flat sound alarm shown as an example. It becomes the same as the frequency spectrum (refer to FIG. 5) obtained by adding the frequency spectrum of the alarm sound (see FIG. 3) and the frequency spectrum of the alarm sound (see FIG. 4) output from the low-frequency electromagnetic alarm. The sound of the horn is greatly improved.

  As for the sound pressure, for example, the diaphragm plate 4 is composed of a SUS plate having a plate thickness of 0.3 mm and φ64, and a piezoelectric member 6 having a plate thickness of 0.3 mm and φ40 is used as the vibration plate. If the drive voltage that changes positively and negatively at an absolute value of 62.5 V is applied, a sufficient sound pressure of about 110 dB can be obtained when the drive frequency is close to the resonance frequency of the diaphragm plate 4. The resonance frequency of the diaphragm plate 4 can be changed by changing the plate thickness or outer diameter.

  Here, according to the sensory test by five subjects, as shown in Table 1, when the frequency of the basic rectangular wave is set in a range of 1800 to 3550 Hz (a range with a single circle in Table 1), an electromagnetic flat type A timbre close to the timbre of the alarm sound output from the horn is obtained, and the range of 2000 to 3350 Hz is particularly preferable (the range with the double circle in Table 1). At 1600 Hz, it may deviate from the tone color of the electromagnetic flat horn, and at 1400 Hz or less, sufficient sound pressure cannot be obtained. At 3750 Hz, the sound is slightly higher than that of the electromagnetic flat horn, and above 3950 Hz, the sound is high.

  As shown in Table 2, the frequency of the modulated rectangular wave is close to the timbre of the alarm sound output from the electromagnetic flat horn when set in the range of 290 to 580 Hz (the range with a single circle in Table 2). A timbre is obtained, and the range of 310 to 440 Hz is particularly preferable (the range with a double circle in Table 2). At 270 Hz, a slight beat may be felt, and at 250 Hz or less, a beat can be felt. At 600 Hz, the sound is somewhat monotonous with respect to the electromagnetic flat horn, and at 620 Hz or more, it is completely monotonous.

  As shown in Table 3, when the frequency deviation is set in the range of -11 to -25 dB, a tone close to the tone of the alarm tone output from the electromagnetic flat horn is obtained (single circles in Table 3 are attached). The range of −15 to −21 dB is particularly preferable (the range with a double circle in Table 3). At -7 dB, the sound is slightly broken, and at -3 dB or less, the sound is broken. At -29 dB, the sound is slightly monotonous with respect to the electromagnetic flat horn, and at -33 dB or more, it is close to a single sound.

(Second Embodiment)
In the present embodiment, as in the first embodiment, the frequency of the first basic rectangular wave is 3200 Hz, the frequency of the second basic rectangular wave is 2800 Hz, and the frequency shift is set to 400 Hz (absolute value). The frequency of the modulated rectangular wave is set to 700 Hz, which is twice the 350 Hz in the first embodiment. In this case, the waveform of the drive voltage signal generated by the frequency modulation / shift circuit 83 and output to the piezoelectric body 6 via the drive circuit 81 is as shown in FIG. That is, in FIG. 7, the waveform is a square wave that changes positively and negatively, with a frequency of 3200 Hz of the first basic rectangular wave as a center, a 3600 Hz region X3 and a 2600 Hz region Y3 that are up and down by 400 Hz, and a second basic rectangular wave A 3200 Hz region X4 and a 2400 Hz region Y4, which are 400 Hz higher and lower than the center at a frequency of 2800 Hz, are alternately repeated with a period of 1.4 ms (= 1 / (350 × 2) (Hz)), respectively. It is assumed that the basic rectangular wave and the modulated second basic rectangular wave are alternately repeated at a cycle of 2.9 ms (= 1/350 (Hz)). Other configurations are the same as those of the first embodiment. According to such a configuration, in addition to the effects of the first embodiment, it is possible to generate a timbre that emphasizes the midrange between the low range of 350 Hz to 400 Hz and the high range of 2800 Hz to 3200 Hz.

(Third embodiment)
FIG. 8 shows the configuration of the warning circuit in the present embodiment. The difference between the alarm circuit in the present embodiment and that in the first embodiment is that a pair of first and second modulation rectangular wave generation circuits are provided, and the frequency modulation / shift circuit 86 is the first in the first embodiment. Both the basic rectangular wave and the second basic rectangular wave are modulated, and an output signal as described later is output to the piezoelectric body 6 via the drive circuit 81. In the present embodiment, the frequency of the first basic rectangular wave is 3200 Hz, the frequency of the second basic rectangular wave is 2800 Hz, and the frequency shift of the first basic rectangular wave in the frequency modulation / shift circuit 86 is 400 Hz (absolute value), The frequency shift of the second basic rectangular wave is set to 350 Hz (absolute value).

  Further, the frequency of the modulated rectangular wave output from the first modulated rectangular wave generating circuit 84A is 400 Hz, and the frequency of the modulated rectangular wave output from the second modulated rectangular wave generating circuit 84B is 350 Hz. In the alarm circuit having such a configuration, the waveform of the drive voltage signal output to the piezoelectric body 6 via the drive circuit 81 is as shown in FIG. That is, in FIG. 9, the waveform is a square wave that changes positively and negatively, with a frequency of 3200 Hz of the first basic rectangular wave as a center, a 3600 Hz region X5 and a 2800 Hz region Y5 up and down by 400 Hz, and a second basic rectangular wave A 3150 Hz region X6 and a 2450 Hz region Y6, which are up and down by 350 Hz from the center at a frequency of 2800 Hz, have a period of 2.5 ms (= 1/400 (Hz)) and 2.9 ms (= 1/350 (Hz)), respectively. It shall be repeated alternately. According to such a configuration, in addition to the effects of the first embodiment, it is possible to generate many chords and generate a favorite timbre.

  DESCRIPTION OF SYMBOLS 1 ... Housing, 2 ... Holder, 3 ... Circuit board, 4 ... Diaphragm board (diaphragm), 6 ... Piezoelectric body, 8 ... Warning sound circuit, 81 ... Drive circuit, 83 ... Frequency modulation / shift circuit, 84 ... Modulation Rectangular wave generation circuit, 84A ... first modulation rectangular wave generation circuit, 85B ... second modulation rectangular wave generation circuit, 85A ... first basic rectangular wave generation circuit, 85B ... second basic rectangular wave generation circuit, 86 ... frequency modulation Shift circuit.

Claims (3)

In an electronic horn that vibrates a diaphragm with a piezoelectric body and outputs an alarm sound, means for generating a first basic rectangular wave on the high frequency side, means for generating a second basic rectangular wave on the low frequency side, Means for generating a modulated rectangular wave; means for modulating the first fundamental rectangular wave and the second fundamental rectangular wave with the modulating rectangular wave; a frequency shift during the modulation of the first fundamental rectangular wave; and the second Means for setting the frequency shift at the time of modulation of the basic rectangular wave to a predetermined range, and driving in which the modulated first basic rectangular wave and the modulated second basic rectangular wave are alternately continued in a predetermined cycle Means for generating a signal and driving the piezoelectric body with the drive signal. In an electronic horn that vibrates a diaphragm with a piezoelectric body and outputs an alarm sound, means for generating a first basic rectangular wave on the high frequency side, means for generating a second basic rectangular wave on the low frequency side, Means for generating a first modulated rectangular wave; means for generating a second modulated rectangular wave; means for modulating the first fundamental rectangular wave with the first modulated rectangular wave; and Means for modulating with two modulated rectangular waves, means for setting a frequency shift at the time of modulation of the first basic rectangular wave, and a frequency shift at the time of modulation of the second basic rectangular wave within a predetermined range Means for generating a drive signal in which the modulated first fundamental rectangular wave and the modulated second fundamental rectangular wave are alternately continued at a predetermined period, and driving the piezoelectric body with the drive signal; Electronic horn equipped with. The frequency of the fundamental rectangular wave is set between 1800 and 3550 Hz, preferably between 2000 and 3150 Hz, the frequency of the modulated rectangular wave is set between 290 and 580 Hz, preferably between 310 and 440 Hz, and the frequency shift is The electronic sounding device according to claim 1 or 2, which is set between -11 and -25 dB, preferably -15 to -21 dB with respect to the frequency of the fundamental rectangular wave.

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