CN2882177Y - Pizeoelectric loudspeaker system - Google Patents

Abstract

The utility model relates to a piezoelectric acoustic system, which comprises a power amplifier, a balancer, a transformer, a piezoelectric ceramic and a sounding board. The piezoelectric ceramic is connected with the sounding board through a mechanism. The utility model employs a column-like piezoelectric ceramic or sheet-like bi-crystal piezoelectric ceramic or sheet-like multi-layer piezoelectric ceramic. The sound-source signals drive the piezoelectric ceramic through a controlling circuit to move and generate inertial force, so as to excite an elastic board to vibrate and generate sound. The utility model is of simple structure and compact, has a high electricity sound conversion efficiency, wide response frequency band, and a plurality of options of the sounding boards. The utility model allows developing acoustic systems for different applications.

Description

The piezoelectricity sound system

Affiliated technical field

The utility model relates to a kind of sound system, especially a kind of piezoelectricity sound system.

Background technology

Traditional sound system often utilizes electromagnetic force to drive tapered basin and produces the piston motion, sounds with the air coupling.It comprises casing, moving-coil speaker, circuit three parts.Moving-coil speaker is its core.Yet because the restriction of structure, the frequency response of a moving-coil speaker is difficult to reach whole tone scope (20Hz～20kHz) frequently.Therefore, the sound system of a high-fidelity mostly adopts dividing network to connect several basses, middle pitch and loudspeaker.It is big that the space is taken up an area of in such system.In addition, its layout and it are also very strict to the requirement of Zhou Bianhuan mirror.

Piezoelectric ceramic is a kind of functional material.When control signal drove a piezoelectric element by amplifier, it can produce mechanical movement.Utilize this principle, people have developed piezoelectric speaker.For example, a piezoelectric speaker is disclosed in CN1277531A.Here the piezoelectric patches periphery is fixed on the frame valency, drives tapered film sounding by central motion.Because the displacement amplitude of piezoelectricity very little (micron or nanoscale), this project organization can not produce the effect of middle pitch and bass.Promptly be used in the reproduction high-frequency sound, single such acoustic pressure that loud speaker produced is also very low.Another piezoelectric speaker is disclosed in CN1291854A.Here piezoelectric patches directly is bonded on the thin plate by integral body, and the distortion by piezoelectric patches directly drives the crooked sounding of plate.Because very little, the such loud speaker of amplitude of deformation of piezoelectric element, its electro-acoustic conversion efficiency is very low, is difficult to produce enough acoustic pressures.

Summary of the invention

In order to overcome the shortcoming of existing sound system, the utility model provides a kind of compact conformation, Hz-KHz is wide, electro-acoustic conversion efficiency is high sound system.

The technical scheme that its technical problem that solves the utility model adopts is: a kind of piezoelectricity sound system comprises power amplifier, balancer, transformer, piezoelectric ceramic, phonation board; Described piezoelectric ceramic is connected on the phonation board by a mechanism.The utility model adopts the column piezoelectric ceramic, or sheet twin crystal piezoelectric ceramic, or the sheet multilayer piezoelectric ceramic.Sound source signal produces inertia force by the motion of control circuit drive pressure electroceramics, encourages elasticity plate vibration sounding, can reach the high target of electro-acoustic conversion efficiency.Adopt board-like design, compact overall structure, to take up an area of the space little.Its phonation board has multiple choices, can satisfy the wide requirement of Hz-KHz.

Description of drawings

Fig. 1 is embodiment one of the present utility model.

11. power amplifier, 12. balancers, 13. transformers, 21. piezoelectric ceramic, 22. mechanisms, 23. phonation boards

Fig. 2 is embodiment two of the present utility model.

31. lock-screw, 32. quality are fast, 33. elastic caoutchoucs

Fig. 3 is embodiment three of the present utility model.

Embodiment

Comprise control circuit part (1) and actuator's part (2) with reference to one, one piezoelectricity sound system of figure; Described control circuit part (1) comprises power amplifier (11), balancer (12) and transformer (13).Described actuator's part (2) is by stacked piezoelectric pottery (the 21) (d of column ₃₃Mode of operation), mechanism (22), phonation board (23) are formed.On phonation board (23), can paste damping material (24) as required, be used to suppress undesired vibration component, improve acoustics.By a preload lock-screw (not showing), piezoelectric ceramic (21) is fixed in the mechanism (22).Basically, this incorporate mechanism (22) comprises front end (22a), flexure spring (22b) and rear end (22c).The surface of front end (22a) contacts with elasticity plate (23), and the other parts of mechanism (22) are unsettled.When the sound source signal from broadcasting, TV, computer, VCD/DVD/MP3 player or microphone, by circuit part (1), when being input to piezoelectric ceramic (21), the motion that it produced can be expressed as:

x(t)＝nd ₃₃v(t) (1)

Here x (t) representative output displacement; N represents the piezoelectricity number of plies; d ₃₃Represent piezoelectric constant: v (t) represents input voltage.The rear end (22c) that the motion of piezoelectric ceramic (21) drives flexible hinge produces motion.Because there is certain quality hinge rear end (22c), is assumed to m,, can be expressed as so its motion produces an inertia force:

$F\left(t\right)=m\stackrel{\·\·}{x}\left(t\right)$ (2)

The reaction force of this inertia force will encourage rigidly connected plate (23) to produce vibration; This vibronic coupling forms sound wave in air.In this utility model application, we are converted into " power " to " displacement " or " distortion " that piezoelectric element produces, and produce flexural vibrations by piezoelectric inertia power excitation elasticity plate and come sounding.The benefit of doing like this is: can overcome the shortcoming that piezoelectricity output displacement or distortion bring for a short time.Let us illustrates this point with the single-frequency input-output.Suppose x (t)=Asin (2 π ft), so $\stackrel{\·\·}{x}\left(t\right)=4A{\mathrm{\π}}^2{f}^2\sin \left(2\mathrm{\πft}\right),$ F(t)＝4Amπ ²f ²sin(2πft)。The signal amplitude of noticing " power " is the 4m π of " displacement " ²f ²Doubly; That is to say that with piezoelectric inertia power excitation plate vibration sounding, its efficient and effect will be better than traditional piezoelectric speaker far away.Our experiment has also proved this point.

With reference to figure two, circuit part and embodiment one are basic identical, therefore are omitted here.Stacked piezoelectric pottery (the 21) (d of a column ₃₃Mode of operation), an end withstands on the plate (23), and the other end links to each other with mechanism (22) by a pretension screw (31).Mechanism (22) comprises an inertial mass (32) and an elastic caoutchouc (33) or similar medium.Regulate pretension screw (31), allow elastic caoutchouc (33) present extended state.Like this, the motion of piezoelectric ceramic (21) will drive mass generation inertia force and encourage plate generation flexural vibrations sounding.

With reference to figure three, we use sheet twin crystal piezoelectric ceramic (21) to be exciter (d here ₃₁Mode of operation).Two opposite piezoelectric ceramic of polarization securely bond together.Under same signal effect, one deck is upheld, and another layer shrinks, and whole piezo ceramic element (21) produces bending motion, drives the mass (32) that adheres at two ends and moves up and down.Piezoelectric ceramic (21) is connected on the phonation board (23) by mechanism (22).The inertia force that motion produces is by middle little bindiny mechanism (22) excitation elasticity plate (23) vibration sounding.Same structure, can adopt the bonding monometallic thin slice of single piezoelectric ceramic wafer is exciter, also can adopt sheet multilayer piezoelectric ceramic wafer is exciter.

In the utility model, the size of mass, weight can design according to the size and the bandwidth requirement of exciting force, even can ignore the mass among the embodiment three for example.Utilize the motion and the quality of piezoelectric ceramic self, also can produce piezoelectric inertia power, encourage the plate vibration sounding, additional mass can further be strengthened this effect.The elasticity phonation board can be light metal plate, cardboard, plastic plate or the composite plate of separately design, or table, floor, glass plate, or the housing of electronic apparatus device etc.By encouraging these surface vibration sounding, reproduce original music or sound effect.Piezoelectric inertia power exciter can adopt one, two or more.By circuit and execution architecture optimization, the described piezoelectricity sound system of the utility model can be realized stereophonic effect, can cover wider frequency, and it is little to take up an area of the space, even reaches and do not account for any space.

Claims (4)

1, a kind of piezoelectricity sound system comprises power amplifier (11), balancer (12), transformer (13), piezoelectric ceramic (21), phonation board (23); It is characterized in that piezoelectric ceramic (21) is connected on the elasticity phonation board (23) by a mechanism (22).

2, sound system as claimed in claim 1 is characterized in that sound source signal, produces inertia force by control circuit drive pressure electroceramics (21) motion and encourages elasticity plate (23) vibration sounding.

3, sound system as claimed in claim 1 is characterized in that described piezoelectric ceramic (21) is the stacked piezoelectric pottery of column, or the twin crystal piezoelectric ceramic of sheet, or the multilayer piezoelectric ceramic of sheet.

4, sound system as claimed in claim 1 is characterized in that described elasticity phonation board (23) for independent light metal plate, cardboard, plastic plate or composite plate, or table, floor, glass plate, or the housing of electronic apparatus device.