JPH04313999A - Speaker employing ultra magnetostrictive vibrator - Google Patents

Abstract

PURPOSE:To realize the vibrator driver employing the ultra magnetostrictive vibrator in which a permanent magnet being a magnetic source of applied magnetic field, a voice coil of a drive source and one terminal of the ultra magnetostrictive vibrator are all fixed to a housing and a tip of the ultra magnetostrictive vibrator at a free end is directly coupled and fixed to a body to be vibrated. CONSTITUTION:The speaker employs an ultra magnetostrictive vibrator 1 in which magnetic sources 3a, 3b applying a static magnetic field in the axial direction and the vertical direction to the axis of the long ultra magnetostrictive vibrator 1 are provided, a voice coil 2 acting dynamic magnetic field in the lengthwise axis direction of the said ultra magnetostrictive vibrator 1 is wound therearound fixedly, a base 1a is fixed to an inner bottom 4b of a housing 4, and fitted while being suspended to a frame 6 and a free tip end 1b of the above ultra magnetostrictive vibrator 1 is fixed and fitted to the middle of a diaphragm 5 supported by a concentric support fixed to the frame 6.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION The present invention is a speaker using a giant magnetostrictive vibrator with positive or negative magnetostrictive characteristics as a vibration driving source.

0002

[Prior Art] Conventional speakers of this type have an inductive effect with an alternating magnetic field generated by a sound current flowing through a moving voice coil supported within a static magnetic field of an annular magnetic gap of a magnetic circuit incorporating a permanent magnet. Dynamic speakers are common in which the vibration force generated within a voice coil drives and vibrates a conical diaphragm directly connected to the voice coil. Furthermore, as a device using a fixed solid-state vibration drive source, a voltage is applied to a piezoelectric element to change its external shape and transmit the temporal change to a diaphragm as a vibration source and magnify it, making it audible to the normal ear. There are piezoelectric (ceramic) speakers and the like that have the function of generating sound in a frequency range.

0003

[Problems to be Solved by the Invention] Therefore, in the drive using this type of dynamic vibration source described above, the magnetic field space within the magnetic gap is interposed between the voice coil and the voice coil, which is movably suspended. Since it is connected directly to the diaphragm, the vibration mass is extremely low, and the driving impedance of the diaphragm is extremely low in the above-mentioned audio frequency range, so the electric-acoustic conversion efficiency is usually 3.
There was a problem that it was only less than %.

[0004] Therefore, in order to solve such conventional problems, the present invention is designed to integrate the permanent magnet as the magnetic force source of the applied magnetic field, the voice coil as the drive source, and the giant magnetostrictive vibrator as the vibration source into one unit. The object of the present invention is to provide a speaker using a giant magnetostrictive oscillator with positive or negative magnetostrictive characteristics, which is fixed to a housing and further has a tip of the free end of the giant magnetostrictive oscillator directly connected to a diaphragm. do.

[0005]

[Means for Solving the Problems] The structure of the present invention for achieving the object will be explained using FIGS. 1 to 17 corresponding to the embodiments. [1] Negative magnetostrictive property The magnetic force sources (3a) and (3b) apply a static magnetic field in the long axis direction of the long columnar giant magnetostrictive vibrator (1'), and the magnetic force sources (3a) and (3b) apply an alternating magnetic field in the longitudinal axis direction of the giant magnetostrictive vibrator (1'). The voice coil (2) to be applied is fixedly wound around the base (1a
) is fixed to the inner bottom (4b) of the housing (4), and the actuator (11) is attached to the frame (6), and a small circular support (6a) is fixed to the actuator (11) side of the frame (6). At the support part (6b) of
The back side of a circular diaphragm (5) whose outer periphery is attached to the frame (6) is supported concentrically, and the tip free end (1
This is a speaker with b) attached and fixed. [2] Magnetic force source (3a) that applies a static magnetic field in the long axis direction of the long columnar giant magnetostrictive oscillator (1') having positive magnetostrictive characteristics
, (3b), a voice coil (2) for applying an alternating magnetic field in the longitudinal axis direction of the giant magnetostrictive vibrator (1') is fixedly wound around the base (1a), and the base (1a) is attached to the housing (4). The actuator (11') fixed to the inner bottom (4b) of the diaphragm (5) is attached to the frame (6), and the actuator (11') is attached to the holding frame (6') whose outer periphery is attached to the frame (6) on the front side of the diaphragm (5). fixed concentric circular supports (
The small circular support part (6b) of 6a) fixedly supports the front surface of the diaphragm (5), which is suspended from the frame (6) and has its outer periphery attached, and the giant magnetostrictive vibrator (1) is attached to the center of the diaphragm (5).
The free end (1b) of the diaphragm (5) is attached and fixed to the rear surface of the diaphragm (5). [3] The shape of the diaphragm (5) is elliptical [
2]. [4] The shape of the diaphragm (5) is rectangular [
2]. [5] The free end of the giant magnetostrictive vibrator (1') (
The speaker according to [3], wherein the mounting position of 1b) on the diaphragm (5) is an eccentric position. [6] The free end (1) of the giant magnetostrictive vibrator (1)
The speaker according to [3], wherein the mounting position on the diaphragm (5) in b) is an eccentric position. [7] Two flat diaphragms (5a) joined at one end
, (5b), a giant magnetostrictive vibrator (
This is a speaker equipped with an actuator (11") that uses a giant magnetostrictive vibrator (1") with both ends (1b) and (1b') of one end (1") fixedly attached. [8] One end (1") Actuators (11) and (11'
) is attached to the speaker. [9] Flat diaphragm (5g), (5h) 2 with one end (5d) larger in size than the other end (5e)
The ends (1b), ( 1b')
This is a speaker that is firmly attached. [10] A speaker in which the two joint parts (5c) and (5c) of the speaker described in [9] above are joined back to back.

[0006]

[Operation] Since the speaker [1] of the present invention has such a structure, the alternating magnetic field generated by the current flowing through the voice coil causes vibrations in the axial direction proportional to the alternating magnetic field to produce giant magnetostriction with negative magnetostrictive characteristics. Vibration occurs within the vibrator, its free end vibrates, and the vibration is transferred to the diaphragm that is directly connected and fixed to it with good transmission efficiency, and the center part is pulled in with the small diameter circular restraint support part of the diaphragm as the boundary. It is possible to emit sound by making nodal vibrations.

Since the speaker [2] of the present invention has such a structure, the alternating magnetic field generated by the current flowing through the voice coil causes vibration in the axial direction proportional to the alternating magnetic field to produce giant magnetostriction with positive magnetostrictive characteristics. Vibration occurs within the vibrator, its free end vibrates, and the vibration is transmitted to the circular diaphragm that is directly connected and fixed to it with good transmission efficiency. It is capable of emitting sound by making rapid nodal vibrations.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. 1 to 3 are diagrams showing one embodiment of [1] of the speaker of the present invention. In the embodiment [1], (11) is an actuator, and (1) is a built-in actuator. A giant magnetostrictive vibrator having negative magnetostrictive characteristics in the form of a long column such as a rare earth metal single crystal such as dysprosium, the base end (1a) of which is fixed to the inner bottom (4a) of the housing (4),
The other end (1b) is made to protrude as a free vibration end. In the vicinity of the base end (1a), an annular permanent magnet (3a) is attached to the housing (4) through the hole, and another similar annular permanent magnet (3b) is installed to perform the giant magnetostrictive vibration. its free end (1b) so that the child (1) does not touch it.
) Fixed and attached so as to surround the vicinity,
A bias static magnetic field is applied to the giant magnetostrictive oscillator (1) in its axial direction by a magnetic force source consisting of both permanent magnets (3a) and (3b). The giant magnetostrictive vibrator (1) described above can achieve efficiency several hundred times higher than that of conventional magnetostrictive vibrators. Permanent magnet (3a) of the magnetic force source
, (3b) may be replaced with a DC electromagnet.

[0009] A voice coil (4) is wound and fixed around the outer circumference of the giant magnetostrictive vibrator (1), and the voice current input to and flowing through the voice coil (2) causes the giant magnetostrictive vibrator (1) to
) so that an alternating magnetic field acts in the longitudinal axis direction. The actuator (11) used in the speaker of the present invention has the above structure, and the free vibration end (1b) of the giant magnetostrictive vibrator (1) is connected to the diaphragm (5).
It is constructed by being directly connected to and fixed to.

[0010] Actuator (11) having such a structure
The bottom surface of the housing (4) is attached to the inner surface of the frame (6), and the actuator (1) of the frame (6) is attached to the inner surface of the frame (6).
1) Concentric circular support part (
6b), supporting the back side of the circular diaphragm (5) suspended from the frame (6) in a small diameter circle;
This is a speaker in which the free tip end (1b) of the giant magnetostrictive vibrator (1) is attached and fixed to the center of the back side. (Negative) In such cases, the giant magnetostrictive oscillator (1) is in an axially shortened posture due to the action of the static magnetic field and the alternating magnetic field.
Since the diaphragm (5) simultaneously expands and contracts in the axial direction, the diaphragm (5) is restrained by small-diameter circular nodes and vibrates with its center retracted, so the acoustic radiation area of the diaphragm (5) becomes larger. High output playback becomes possible. Also,
As shown in FIG. 2, the actuator (11) includes a housing portion (
4) It may be fixed so as to be in close contact with the magnetic pole face of the permanent magnet (3a') instead of the inner bottom.

In the drawings, FIGS. 1 to 4 are diagrams showing an embodiment of the speaker [2] of the present invention. In the embodiment [2], (11') is an actuator, and (1') is a giant magnetostrictive vibrator having positive magnetostrictive characteristics in the form of a long column such as a single crystal of a rare earth metal such as dysprosium, and its base end (1a) is fixed to the inner bottom (4b) of the housing (4). The end (1b) is made to protrude as a free vibration end.
An annular permanent magnet (3a) is located near its base end (1a).
is attached to the housing (4) through the hole, and another similar annular permanent magnet (3b) is attached to its free end (3b) so that it does not touch the giant magnetostrictive vibrator (1').
1b) A bias static magnetic field is applied to the giant magnetostrictive oscillator (1') in its axial direction by a magnetic force source consisting of both permanent magnets (3a) and (3b), which are fixedly attached so as to surround the vicinity thereof. As if applying . The giant magnetostrictive oscillator (1') is several tens of times smaller than the conventional magnetostrictive oscillator.
A high efficiency of 0 times or more can be obtained. The permanent magnet of the magnetic force source (
3a) and (3b) may be replaced with DC electromagnets.

[0012] A voice coil (2) is wound and fixed around the outer circumference of the giant magnetostrictive vibrator (1'), and the voice current input to and flowing through the voice coil (2) causes the giant magnetostrictive vibrator (1') to
' ) is designed so that an alternating magnetic field acts in the longitudinal axis direction. The actuator (11') used in the speaker of the present invention has the above structure,
The free vibrating end (1b) of the giant magnetostrictive vibrator (1') is directly connected and fixed to the vibration plate (5) of the vibrating load.

[0013] An actuator having such a structure (11'
) of the housing (4) is attached to the inner surface of the frame (6), and a support (6a) fixed to the inner surface of the holding frame (6') attached to the front part of the diaphragm (5).
a concentric circular support (6b) of said frame (6);
The back side of a circular diaphragm (5) attached with its outer periphery suspended is supported in a small diameter circle, and the free tip end (1b) of the giant magnetostrictive vibrator (1') is attached to the center of the back side. The speaker is stuck. (Correct) In such a case, the giant magnetostrictive oscillator (1') simultaneously stretches and vibrates in the axial direction in an axially extended posture due to the action of the static magnetic field and the alternating magnetic field, so that the diaphragm (5) Since the diaphragm (5) is restrained by a small-diameter circular nodal circle and vibrates with the center part protruding, the acoustic radiation area of the diaphragm (5) becomes larger, making it possible to reproduce high output.

Furthermore, the actuator (11) is shown in FIG.
As shown in , the base end (1a) of the vibrator (1')
is the permanent magnet (3), not the inner bottom of the housing part (4).
It may be fixed so as to be in close contact with the magnetic pole surface of a').

The speaker shown in FIG. 7 uses an oval diaphragm instead of the circular diaphragm (5) of the speaker shown in FIG. This speaker eliminates peaks and troughs in the sound pressure frequency characteristic, making it flat and improving the reproduced sound.

The speaker shown in FIG. 8 has a rectangular diaphragm instead of the circular diaphragm (5) of the speaker shown in FIG.
Suppresses the split vibration of the diaphragm that occurs in the circular diaphragm (5), eliminates peaks and troughs in the sound pressure frequency characteristic, and makes it flat.
This is a speaker with improved reproduction sound quality, and the radiation space factor of the diaphragm can be improved.

The speaker shown in FIG. 9 is a speaker in which the driving fulcrum of the diaphragm (5) of the speaker shown in FIG. , are all different, so there is an effect that nodal circle division vibration occurs.

The speaker shown in FIG. 10 is a speaker in which the driving fulcrum (1b) of the diaphragm (5) of the speaker shown in FIG. Since the radial distances are all different, there is an effect that nodal circle division vibration does not occur.

The speaker shown in FIGS. 11 and 12 has a giant magnetostrictive vibrator (1") inside the joint (5c) of two flat diaphragms (5a), (5b) joined at one end. This is a speaker using an actuator (11") with both end portions (1b) and (1b') of the From both ends (1b), (1b') of the diaphragm (5a), (
5b), making it a highly efficient speaker with half the acoustic radiation resistance.

The speaker shown in FIG. 13 has one end (5d
) is a speaker in which an actuator (11) or (11') is attached to the smaller end (5e) of a flat diaphragm (5f) whose dimension is larger than the other end (5e). The speaker has a diaphragm (5f) on which standing waves are difficult to ride, and generates little resonance noise.

The speaker shown in FIG. 14 has one end (5d
) is larger than the other end (5e) of the flat diaphragm (5g), (5h), the smaller end (5e)
A speaker in which small ends (5e) of diaphragms (5g) and (5h) are joined (5c) to e) with actuators (11) or (11') attached, and resonance occurs where standing waves are difficult to ride. This is a speaker that generates little noise.

The speaker shown in FIG. 15 consists of two sets of the speakers shown in FIG.
) are connected back-to-back, and are capable of producing large acoustic output with a small amplitude.

Although the embodiments considered to be representative of the present invention have been described above, the present invention is not necessarily limited to the structures of these embodiments, and the present invention is not necessarily limited to the structures of these embodiments. It can be implemented with appropriate modification within the scope of achieving the purpose described above and having the effects described below.

[0024]

Effects of the Invention As is already clear from the above description, in the speaker of the present invention, an alternating magnetic field generated by a current flowing through a voice coil causes vibration in the axial direction in proportion to the alternating magnetic field inside a giant magnetostrictive vibrator with negative magnetostrictive characteristics. The vibrations are transmitted to the free end of the vibrator and vibrate, causing a low transmission impedance to the diaphragm that is directly connected and fixed to it.
Therefore, we have come to expect the remarkable effect of being able to transmit sounds with high efficiency and to emit sounds.

In addition, the structure is simple, the coils are fixed, and the vibrating part is restrained by the circular restraint part of the diaphragm, causing nodal vibration, so the peripheral part is amplified to a large amplitude by the principle of leverage. In addition, the speaker has the advantage of being able to reproduce efficiently due to its high impedance vibration transmission mechanism and high conversion efficiency, being highly reliable, and being small and easy to handle without requiring special care.

As is already clear from the above description, in the speaker of the present invention, an axial vibration proportional to the alternating magnetic field generated by the current flowing through the voice coil is generated inside the giant magnetostrictive vibrator having positive magnetostrictive characteristics. Then, the vibration is transmitted to the free end of the vibrator, vibrates, and is directly connected to the diaphragm that is fixed and has a low transmission impedance, so it is transmitted with high transmission efficiency, making it possible to emit sound. As a result, we can expect significant effects.

In addition, the structure is simple, the coils are fixed, and the vibrating part is restrained by the circular restraint part of the diaphragm, causing nodal vibration, so the peripheral part is amplified to a large amplitude by the principle of leverage. In addition, the speaker has the advantage of being able to reproduce efficiently due to its high impedance vibration transmission mechanism and high conversion efficiency, being highly reliable, and being small and easy to handle without requiring special care.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of an actuator used in the speaker of the present invention.

FIG. 2 is a sectional view showing another structure of the actuator used in the speaker of the present invention.

FIG. 3 is a plan view of an embodiment of the speaker of the present invention using a giant magnetostrictive vibrator with negative magnetostrictive characteristics.

FIG. 4 is a sectional view of one embodiment of the speaker of the present invention shown in FIG. 3 using a giant magnetostrictive vibrator with negative magnetostrictive characteristics.

FIG. 5 is a plan view of an embodiment of the speaker of the present invention using a giant magnetostrictive vibrator with positive magnetostrictive characteristics.

FIG. 6 is a sectional view of the embodiment shown in FIG. 5 using a giant magnetostrictive vibrator with positive magnetostrictive characteristics of the speaker of the present invention.

FIG. 7 is a partially cutaway plan view of an embodiment of the speaker of the present invention using an elliptical diaphragm.

FIG. 8 is a partially cutaway plan view of an embodiment of the speaker of the present invention using a rectangular diaphragm.

FIG. 9 is a partially cutaway plan view of an embodiment in which a circular diaphragm of the speaker of the present invention is used and an actuator is mounted eccentrically.

FIG. 10: Using the elliptical diaphragm of the speaker of the present invention,
FIG. 3 is a partially cutaway plan view of an embodiment in which the actuator is mounted eccentrically.

[Fig. 11] Rectangular flat diaphragm 2 of the speaker of the present invention
FIG. 3 is a front view of an embodiment in which both end portions of a giant magnetostrictive vibrator are fixedly attached to the inner side of the joint portion where the short end portions of the vibrator sheets are joined together.

[Fig. 12] Rectangular flat diaphragm 2 of the speaker of the present invention
FIG. 12 is a side sectional view of an embodiment (FIG. 11) in which both ends of the giant magnetostrictive vibrator are fixedly attached to the inner side of the joint where the ends of the short dimension sides are joined.

FIG. 13 is a front view of an embodiment in which a flat diaphragm is used in which one end of the speaker of the present invention is larger in size than the other end, and an actuator is attached to the smaller end.

FIG. 14: Two flat diaphragms, one end of which is larger than the other end of the speaker of the present invention, are joined together at their shortest ends, and giant magnetostrictive vibration is applied to the inner side of the joint. FIG. 2 is a front view of a speaker in which two speakers are attached with both end portions fixedly attached, with respective joint portions joined back to back.

[Fig. 15] Two flat diaphragms of the speaker of the present invention, one end of which is larger than the other end, are joined together at their shorter ends, and giant magnetostrictive vibration is applied inside the joint. FIG. 2 is a side cross-sectional view of a speaker in which two speakers are attached with both end portions fixedly attached, and the respective joint portions of the two speakers are joined back to back.

16 is an enlarged cross-sectional view of one side of the actuator of the speaker shown in FIG. 15. FIG. The other side is drawn with a dotted line, with some parts omitted.

[Explanation of symbols]

1 Giant magnetostrictive oscillator 1’ Giant magnetostrictive oscillator 1” giant magnetostrictive oscillator 1a Base 1b Free tip 1b’ Free tip 2 Audio input coil 3a Permanent magnet for applied magnetic field 3b Permanent magnet for applied magnetic field 4 Housing 4b Inner bottom 5　Vibration plate 5a Diaphragm 5b Diaphragm 5c Joint part 5d End 5e End 5g diaphragm 5h diaphragm 5f diaphragm 6 Frame 6a Support device 6b Support part 11 Actuator 11’ Actuator 11” actuator

Claims (1)

[Scope of Claims] [Claim 1] A magnetic force source (3
a) and (3b), a voice coil (2) that applies an alternating magnetic field in the longitudinal axis direction of the giant magnetostrictive vibrator (1') is fixedly wound around the base (1a), and the base (1a) is attached to the housing ( 4)
The actuator (11) fixed to the inner bottom (4b) of the frame (6) is attached to the frame (6).
A support (6a) fixed to the actuator (11) side of
a small circular support part (6b) of said frame (6);
The back side of a circular diaphragm (5) with its outer periphery attached suspended from the diaphragm (5) was supported concentrically, and the free tip end (1b) of the giant magnetostrictive vibrator (1') was attached and fixed at the center of the back side. speaker. (Negative) (Figs. 1, 3, 4) [Claim 2] A magnetic force source (
3a) and (3b), a voice coil (2) that applies an alternating magnetic field in the longitudinal axis direction of the giant magnetostrictive vibrator (1') is fixedly wound around the base (1a), and the base (1a) is attached to the housing ( 4
) Actuator (11') fixed to the inner bottom (4b) of
is attached to the frame (6), and the diaphragm (5) is attached to the frame (6).
Suspended from the frame (6) by a small circular support part (6b) of a concentric circular support (6a) attached and fixed to a holding frame (6') whose outer periphery is attached to the frame (6) on the front side of the frame (6). Vibration plate with outer periphery attached (5)
A speaker is fixed and supported on the front surface of a diaphragm (5), and the free end (1b) of the giant magnetostrictive vibrator (1') is attached and fixed to the rear surface of a diaphragm (5) at the center thereof. (Correct) (FIGS. 1, 5, 6) 3. The speaker according to claim 2, wherein the diaphragm (5) has an elliptical shape. (Correct) (FIG. 7).Claim 4: The speaker according to claim 2, wherein the diaphragm (5) has a rectangular shape. (Correct) (FIG. 8) [Claim 5] The free end (1) of the giant magnetostrictive vibrator (1')
The speaker according to claim 3, wherein the mounting position of b) on the diaphragm (5) is an eccentric position. (Correct) (Figure 9) [Claim 6
] Free tip end (1b) of the giant magnetostrictive vibrator (1)
The speaker according to claim 3, wherein the mounting position on the diaphragm (5) is an eccentric position. (Correct) (Figure 10) [Claim 7]
Two flat diaphragms (5a), (5
A giant magnetostrictive vibrator (1”) is placed inside the joint (5c) of b).
), the actuator (1
1”) installed. (Positive/Negative) (Figures 11, 12
, 16, 17) [Claim 8] A flat diaphragm (5) in which one end (5d) is larger than the other end (5e).
A speaker in which actuators (11) and (11') are attached to the end (5e) on the smaller dimension side of f). (Positive/Negative) (Fig. 13) [Claim 9] The dimensions of one end (5d) are different from those of the other end (5e).
) flat diaphragm (5g), (5g) with larger dimensions.
h) An actuator (1
Both ends (1b), (
1b') is firmly attached to the speaker. (Positive/Negative) (FIGS. 13, 14, 17) [Claim 10] A speaker in which the two joint parts (5c) and (5c) of the speaker according to claim 9 are joined back to back. (Positive/Negative) (Figures 15, 16, 17)