JPS6044000A - Loudspeaker device - Google Patents

Abstract

PURPOSE:To execute easily the inflexion vibration of a piezoelectric element, and to prevent the drop of a sound pressure level in a low register by coupling the center part of the piezoelectric element to a part of a cabinet by keeping an interval by a spacer to support it. CONSTITUTION:A base board 4 and the piezoelectric element 2 are provided in a radio set cabinet body 1. The piezoelectric element 2 is a bimorph type formed by sticking the piezoelectric elements 11, 12 to both upper and lower faces of a metallic intermediate electrode 10. A spacer 7 consisting of a high rigidity material such as a metal or a polymer, etc. is provided on the center part of this piezoelectric element, and this part is stuck firmly by keeping the gap (d) to the cabinet body 1. The gap (d) is provided to enable the piezoelectric element 2 to perform the inflexion motion. Accordingly, its vibration modes I , II and III are not suppressed to realize a loudspeaker device extending over a wide band.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a speaker device 1'4i for audio equipment such as a radio or a cassette tape recorder with a radio.

Conventional If configurations and their problems In recent years, heating equipment such as radios and cassette coaters with ratios have been constantly becoming smaller and more compact. Among these, the shape of the speaker is one of the factors that hinders miniaturization.

The current speaker has a cone-shaped diaphragm and a magnetic circuit.
Electrodynamic speakers are the mainstream, and have become one of the largest of the ten soto parts. To solve this problem, a reproduction method has been developed in which a piezoelectric element is directly attached to a part of the cabinet that makes up the rack set, and the cabinet 1 is used as a diaphragm.The following is a conventional speaker using this method. I will explain about it.

The first is 1. Figure 2 shows radio sensors 1 to 1 with a conventional speaker device installed, and Figure 1 shows an external view.
21j shows a structural cross-sectional view. In the same figure, 1 is -1
1)) A cabinet main body, 3 a dial part, and 41 electrical components 6 are arranged. il (Piezoelectric element-I' 21171: Directly and firmly adhered to the cabinet body 1. Glue-1 wire for sending the γL electric signal to the 5-digit piezoelectric element 2.

The operation of the conventional speaker device configured as described above will be explained below.

In the speaker device i'l shown in structure 11, the pressure element 11L is bent and extracted from the gear body of the set, and this pressure rK element vibrates the speaker body to reproduce sound. This is what we aim to do. That is, when an electric voltage is applied to the pressure gauge element 2 through the lead PA5, a driving force such as flexural vibration ('F) is generated in the piezoelectric element 2, and this driving force causes the gear groove main body to vibrate. Σ.Gabineso 1-Kiyū 1 are the parts that constitute the array shape of the set, so 1 motion is f
11 wide, pressure "Aζ"<
-11? It is possible to convert it into an acoustic output.

1. The piezoelectric element is significantly thinner than conventional electrodynamic speakers, and can be made into a compact compact speaker.

However, in the above-mentioned arrangement, since one entire surface of the piezoelectric element 2 is bonded to the cabinet body 1, the surface vibration (plane vibration 11) of the piezoelectric element 2 that applies the driving force to the gear vignette body 1 is suppressed, and the amplitude is particularly large. In the bass range, there is a significant drop in sound pressure level, resulting in extremely poor playback with insufficient bass.
1. It was a speaker device with a narrow range.

OBJECTS OF THE INVENTION The present invention solves the problems of the prior art as described above, and an object thereof is to provide a speaker device that is directly driven by the cabinet 4 and the throat body, which can reproduce low frequency ranges.

Structure of the Invention The present invention is a speaker device in which a gear vignette main body and a piezoelectric element are connected and fixed by a spacer for connecting the piezoelectric element to the middle part of the piezoelectric element, and only the central part of the piezoelectric element is connected and fixed to the cabinet. Therefore, the surrounding area is free☆;1
1i, the bending vibration in the bass range is easy9.
The driving force to the gear vignette body, which serves as the vibrating part, is increased, making it possible to reproduce low-frequency sounds.

DESCRIPTION OF EMBODIMENTS FIG. 3 is a small cross-sectional view of a structure in which a speaker device according to a first embodiment of the present invention is incorporated into a radio (1-). In the same figure, iI' in Figure 1 and Figure 2;
;I': The same number is attached to the same component as the previous example -6
be. In the 31st unit 1, the piezoelectric element 2 is a gabine) 1
・Hold the pressure between the main body 1 and the main body 1.
ilL: 4・) 6 of the joint between A and Ki・・Biino 1−
゛See Figure 4 for details. In the 41st number 1, j, ・piezoelectric; (・3 children are metallic intermediate ', tL+
1. It is a pie-circle type with piezoelectric elements 11 and 12 bonded to both sides, and between the piezoelectric element 11 and the gear 7'l body 1 is a joint 1 provided in the middle heat part of the piezoelectric element. -6 stub ii i, ``: + high rigidity of molecules, etc., 1 katai, 1 katai, by the subele 7 consisting of 1, it maintains the gi... d and feels firmly fixed 3, here, riden element.'' The vibration mode of r is shown in FIG. In the seventh part 1, ■ is one rotational motion 1- in the first J vibration, and the number of nodes generated in one force q movement plate is one. 11. 1, 2nd] 1. There are two clauses FJ in the j lin mote in the swing. 111 is -1- on the vibration in the third resonance, and there are three nodal circles. The resonance occurring in the vibrating element becomes higher-order as the frequency increases, and the number of nodal circles generated by the vibration mode also increases.

In the conventional method, the entire surface of one side of the piezoelectric element is placed in the cabinet.
11, the vibration mode described in -1- was suppressed. In the present invention, since the medium heating portion of the piezoelectric element is firmly supported, bending vibration of the piezoelectric element becomes easy. If we look at the relationship between the reproduction band of a speaker device and the resonant frequency of the piezoelectric element, the high-frequency limit frequency is generally the 3rd or higher resonant frequency of the 1/3"T3 element. It is true.

Therefore, as is clear from the vibration mode diagram of 7th iN:l, it is desirable that the outer diameter of the spacer 7 supporting the pressure L element be as small as possible. If the high frequency limit is set to third order, the outer diameter of the spacer must be selected to be equal to or smaller than the outer diameter of the diaphragm based on the vibration mode.

Speaker device/1 of this embodiment configured as follows
The operation of this will be explained below.

Pressure elements 11, 12 and 0/intermediate' are connected via lead wire 5.
1"i; When an electric signal is applied to the pole 10, power is generated in !lJ1 accompanied by bending vibration, and this driving force turns the system beam 7 into a), causing the gap 1 and main body 1 to vibrate. A movement of 4++V results in a power output of 1°1j, which is radiated into the air.

According to this embodiment, as shown in ``10'', ``1'' of the element is applied to the pressure.
1. Since the spacer in the center connects the support ML and the gear chain 111 jointly, pressures 1, 1. :element,l
The 1lr+ side becomes self-II mii, and the vibration mode is not limited to 4-11 as in the conventional system.

However, the bass range 75) is 11-/l or 111-capacity, and the wide-band Nubica device is the Jitsugi 1. Next, regarding the embodiment of the present invention at 21'52,
3 (I will explain while using 1<(.

FIG. 5 shows a second embodiment of the present invention.
'1 glue! :: 'i[element-[and cabinet 1-]1
This is a revised drawing with 1 x 81 chairs.

In the figure, 11 and 12 are piezoelectric elements, 10 is an intermediate electrode, 1 is the A-Yabinesoto main body, and 5 is! 4, these are similar to the configuration shown in FIG. The difference from Figure 4)'1 is that Nupesa 8 is molded into a cone shape.

According to the second embodiment configured as described above, the spacer diameter on the piezoelectric element side is small and the joint diameter with the gear vignette is large, so that the vibration motor of the piezoelectric element can be suppressed. It is possible to increase the adhesion strength between the spacer and the capacitor without causing any damage, and it is possible to more stably hold the element under pressure.

FIG. 8 shows a third embodiment of the invention.

In the same figure, 11.12 is the pressure surface element, 10 is the intermediate type, 1 is the cabinet I/main body, 5 is the lead wire,
These are the same as 111 to 111 of the above embodiment. In this example of actual strength Qi, the spacer 9 is integrated with the Gilbinet main body 1.

” If it is the f111j composition of the second book, is it a box? There is no need for any adhesive parts between the i-element and the cabinet 21, and adhesive is only required between the piezoelectric element and the Nupacer.

In the above embodiment, the shape of the piezoelectric element 2 is circular, but it may be square.

As described above, the present invention provides a cabinet main body and a pressure
Support the center part of FIT' + IL element between L element and
A base plate is provided that connects and fastens the main body. By using the center of one element as the support part, and making the periphery and the 111 ends of the element, Ll', ')L!
1) (The dynamic motion of the element is not suppressed and the bending motion is facilitated, so a wideband speaker device can be realized.

[Brief explanation of the drawing]

Fig. 1 is an external view of a radio set equipped with a conventional speaker device, Fig. 2 is a structural sectional view of the same set, and Fig. 3 is a radioseno I equipped with a speaker device according to the first embodiment of the present invention. -Structure section ii'+i diagram, Figure 4 (same speaker
Figure 5 is a detailed view of the 1111 attachment part of the speaker device according to the second embodiment of the present invention.
Detailed view of the opening part, No. 61 [is the third embodiment of the present invention]
,'(-Details, Figure 7 is the vibration mode diagram of the jX1''l element/]. 1... 7.Baillie 16 Lee 1・Spinning wheel, 11.12011.Pressure”1 element, 10...
intermediate electrode.

Claims (3)

[Claims] (1) A speaker device characterized in that a spacer is provided that firmly supports the center portion of a piezoelectric element at one end and is coupled to a part of the cabinet at the other end while maintaining a gap, and the piezoelectric element causes the cabinet to vibrate. (2) The speaker device according to claim 1, wherein the outer diameter of the spacer is 1/5 or less of the outer diameter of the piezoelectric element. (3) The shape of the spacer is cone-shaped, with a small diameter at the part where it is fixed to the piezoelectric element and a large diameter at the part where it connects to the cabinet. The speaker device according to claim 1, characterized in that it is formed integrally with the spacer groove. .