JP2004186912A - Electromechanical vibration acoustic transducer and portable terminal equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromechanical vibration acoustic transducer capable of coping with its thinning while securing the sufficient amplitude in the magnetic circuit. <P>SOLUTION: An internal magnet electromechanical vibration acoustic transducer 1 is provided with a magnetic circuit 2 constituted by piling up a yoke 3, a magnet 4 and a pole piece 5 on a concentric shaft, a suspension 6 for supporting the magnetic circuit 2, a diaphragm 7 and a voice coil 8 inserted into the annular gap of the magnetic circuit part 2. The internal magnet electromechanical vibration acoustic transducer 1 is provided with a nonmagnetic rivet 9 which passes through the concentric shaft of the magnetic circuit 2 and calks and fixes the magnetic circuit 2, and a first counter bored hole 3a which is provided around the concentric shaft of one of the pole piece 5 and the yoke 3 and houses the calking part 9a of the rivet 9. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electromechanical vibration-acoustic transducer mounted on a mobile terminal device such as a mobile phone or a small information communication terminal and notifying a user of an incoming call by sound or vibration, and particularly to a fixing structure of a magnetic circuit unit.
[0002]
[Prior art]
Conventionally, a multifunctional vibration actuator in which a magnetic circuit portion is fixed with bolts and pins (see Patent Document 1), and a vibration actuator in which a central shaft shaped like a bolt or pin penetrates a center hole of a magnetic circuit (Patent Document 2) ), An acoustic vibration generator in which a first vibrating member, a holder and a yoke are fixed with a tent (see Patent Document 3), and an acoustic vibration generating device in which a magnetic circuit portion and a first vibrating member are fixed with a tent (see Patent Document 3). Reference 4), a vibration actuator for generating sound and low-frequency vibration in which a magnetic circuit and a vibrating body are fixed by a non-magnetic supporting column (see Patent Document 5), and a magnetic circuit and a vibrating body are fixed by a non-magnetic supporting column. There is known a vibrating actuator for a pager (see Patent Document 6).
[0003]
[Patent Document 1]
JP-A-2002-3070013 (FIGS. 1, 2, 5, and 6)
[Patent Document 2]
JP-A-2002-239559 (FIGS. 1 to 3)
[Patent Document 3]
US005956622A (FIG. 2)
[Patent Document 4]
US005861686A (FIG. 2)
[Patent Document 5]
Japanese Patent Application Laid-Open No. 2000-308849 (FIGS. 1 to 4)
[Patent Document 6]
JP-A-11-27921 (FIGS. 1 to 4)
[0004]
[Problems to be solved by the invention]
However, conventional multifunctional vibration actuators (Patent Document 1), vibration actuators (Patent Document 2), acoustic vibration generators (Patent Document 3), acoustic vibration generators (Patent Document 4), and vibration actuators for low-frequency vibration generation ( In Patent Literature 5) and a vibration actuator for a pager (Patent Literature 6), the rivet is caulked on the end surface of the yoke or the pole piece, and the thickness of the electromechanical vibration-acoustic transducer increases by the thickness of the caulked portion. There is a problem. On the other hand, when the thickness of the electromechanical vibration-acoustic transducer is reduced, a gap between the magnetic circuit portion and the end face of the housing is reduced, so that there is a problem that a sufficient amplitude of the magnetic circuit portion cannot be secured.
[0005]
[Means for Solving the Problems]
The present invention has been made in view of the above problems, and an object of the present invention is to provide an electromechanical vibration-acoustic transducer capable of ensuring a sufficient amplitude of a magnetic circuit portion and being thin. It is.
[0006]
According to a first aspect of the present invention, there is provided a magnetic circuit unit configured by stacking a yoke, a plate-shaped magnet, and a plate-shaped pole piece on concentric axes, a suspension supporting the magnetic circuit unit, and a magnetic circuit unit. In an inner-magnet type electromechanical vibration-acoustic transducer including a diaphragm disposed to face and a voice coil provided in the diaphragm and inserted into an annular gap of the magnetic circuit unit, a concentric axis of the magnetic circuit unit And a non-magnetic rivet for caulking and fixing the magnetic circuit portion, and a first counterbore provided around the concentric axis of one of the pole piece and the yoke and accommodating the caulked portion of the rivet. And an inner-magnet type electromechanical vibration-acoustic transducer comprising:
[0007]
The caulked portion is accommodated in a first counterbore provided in the pole piece or the yoke. The depth of the first counterbore hole may be a depth that can completely accommodate the swaged portion, or may be smaller than the height of the swaged portion.
[0008]
According to a second aspect of the present invention, in addition to the configuration of the first aspect, the suspension has an inner-magnet type electromechanical vibration-acoustic conversion structure that supports the magnetic circuit portion at a position facing the diaphragm. It is a vessel.
[0009]
According to a third aspect of the present invention, in addition to the configuration of the second aspect of the invention, the yoke is formed in a bottomed cylindrical shape, and is separated from the inner wall surface of the housing that houses the magnetic circuit portion by a minute gap. An inner-magnet type electromechanical vibration-acoustic transducer having a protruding portion positioned in a vertical direction.
[0010]
Since the projecting portion of the yoke is located at a small gap from the inner wall surface of the housing, air braking occurs.
[0011]
According to a fourth aspect of the present invention, there is provided a magnetic circuit unit configured by stacking a yoke, a plate-shaped magnet, and a plate-shaped pole piece on concentric axes, two upper and lower suspensions supporting the magnetic circuit unit, An inner-magnet type electromechanical vibration-acoustic transducer comprising: a diaphragm opposed to a magnetic circuit portion; and a voice coil provided in the diaphragm and inserted into an annular gap of the magnetic circuit portion. A nonmagnetic rivet that penetrates the concentric axis of the section and caulks and fixes the magnetic circuit section; and a non-magnetic rivet that is provided around the concentric axis of one of the pole piece and the yoke and accommodates the caulked section of the rivet. An inner magnet type electromechanical vibration-acoustic transducer having one counterbore.
[0012]
According to a fifth aspect of the present invention, the yoke and the pole piece according to any one of the first to fourth aspects are provided with a counterbore for positioning the magnet. It is an acoustic transducer.
[0013]
A second aspect of the present invention is provided around the concentric axis of one of the pole piece and the yoke according to any one of the first to fifth aspects, and accommodates a head of the rivet. It is an inner magnet type electromechanical vibration acoustic transducer having a counterbore.
[0014]
A seventh aspect of the present invention is a portable terminal device provided with the electromechanical vibration-acoustic transducer according to any one of the first to sixth aspects.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
As shown in FIG. 1, an electromechanical vibration-acoustic transducer 1 according to an embodiment of the present invention includes a magnetic circuit unit 2, a suspension 6 supporting the magnetic circuit unit 2, and a diaphragm disposed to face the magnetic circuit unit 2. 7 and a voice coil 8 inserted into the annular gap G1 of the magnetic circuit unit 2. In the electromechanical vibration-acoustic transducer 1, when a signal current of an audible frequency flows through the voice coil 8, the diaphragm 7 vibrates and emits an audible sound such as a ringtone, a melody, and a voice. Further, in the electromechanical vibration-acoustic transducer 1, when a signal current having a frequency of 120 to 160 Hz flows through the voice coil 8, a mechanical vibration system including the magnetic circuit unit 2 and the suspension 6 vibrates.
[0016]
The magnetic circuit section 2 is configured by stacking a bottomed cylindrical yoke 3, a disk-shaped magnet 4, and a disk-shaped pole piece 5 on concentric axes. The magnetic circuit section 2 is fixed with a rivet 9 penetrating through the central axis.
[0017]
The rivet 9 is formed of a non-magnetic member such as nickel silver, copper, aluminum, brass, and tungsten. The rivet 9 is inserted from the pole piece side, penetrates the magnet 4 and the yoke 3, and has an end portion caulked toward the outer diameter direction of the yoke 3. The caulking portion 9 a is housed in the first counterbore 3 a of the yoke 3 and caulked so as not to protrude toward the cover 12 with respect to the lower end surface of the yoke 3.
[0018]
As shown in FIGS. 1 and 2, the yoke 3 is formed in a cylindrical shape with a bottom, and is formed so as to have an overhang so as to be located at a small gap with respect to the inner wall surface of the housing 10. I have. The yoke 3 has a first counterbore hole 3a, a stepped surface 3b, a suspension relief portion 3c, a relief portion 3d of a mold portion, a through hole 3e, and a counterbore portion 3i for magnet positioning. And made of a magnetic material. The through hole 3 e is formed on the center axis of the yoke 3, and the rivet 9 passes therethrough.
[0019]
The first counterbore hole 3a is a cylindrical concave portion, and is provided on the lower end surface of the yoke 3 so as to accommodate the caulked portion 9a of the rivet 9. The concave shape of the first counterbore hole 3a is not limited to a column shape. Further, in FIG. 1, the swaged portion 9a is completely accommodated in the first counterbore 3a, but the depth of the first counterbore 3a may not be so deep as to completely accommodate the swaged portion 9a. Therefore, the depth of the first counterbore hole 3a may be smaller than the height of the caulked portion 9a.
[0020]
A counterbore 3 i for positioning the magnet 4 is provided on the yoke 3. The diameter of the counterbore 3i is substantially the same as the diameter of the magnet 4 so that the magnet 4 can be positioned.
[0021]
The step surface 3b is formed so as to be stepped down from an outer end surface 3g to which the annular portion of the suspension 6 is applied and fixed. The step surface 3b comes into contact with the annular step 10a of the housing 10 when the magnetic circuit section 2 vibrates. A ring-shaped stop frame 3h having an outer diameter that fits with the annular portion of the suspension 6 is provided upright from the outer end surface 3g. Notches 3f are provided in the retaining frame 3h at intervals of 120 degrees, and are fitted with the fitting portions 6a of the suspension 6 to restrict the displacement of the suspension 6 in the circumferential direction.
[0022]
The suspension escape portion 3c is formed in a concave shape along the circumferential direction of the yoke 3 at a position facing the arm 6b of the suspension 6 shown in FIG. The suspension escape portion 3c functions as a space for bending the arm 6b. For this reason, when the magnetic circuit portion 2 vibrates, the yoke 3 does not hinder the vibration of the magnetic circuit portion 2 even if the arm 6b is bent.
[0023]
As shown in FIGS. 1 and 2, the relief portion 3 d of the mold portion is provided further on the outer peripheral side of the suspension relief portion 3 c, and is formed by cutting out the outer peripheral edge of the yoke along the circumferential direction of the yoke 3. .
[0024]
As shown in FIGS. 1 and 3, the suspension 6 has a protruding piece 6 d fixed by a mold portion 10 b of the housing 10, and supports the magnetic circuit portion 2 at a position facing the diaphragm 7. . The suspension 6 is a ring-shaped leaf spring that elastically supports the magnetic circuit section 2 as shown in FIG.
[0025]
When the annular portion 6c is fitted to the outside of the stop frame 3h so that the fitting portion 6a is fitted to the notch portion 3f of the yoke, the suspension 6 is adjusted so that the position of the arm 6b corresponds to the position of the suspension escape portion 3c. Has become. For this reason, the yoke 3 is attached to the suspension 6 by joining the outer end surface 3g and the annular portion 6c.
[0026]
A counterbore 5 a for positioning the magnet 4 is provided on the pole piece 5. The diameter of the counterbore portion 5a is substantially the same as the diameter of the magnet 4 so that the magnet 4 can be positioned. When the counterbore portions 3a and 5a for positioning the magnet 4 are provided on the yoke 3 and the pole piece 5, the magnet 4 can be positioned and the displacement of the magnet 4 in the radial direction can be restricted.
[0027]
The diaphragm 7 and the cover 12 are supported and fixed to the housing 10 at respective outer peripheral edges. The diaphragm 7 is provided with a voice coil 8. The voice coil 8 is formed in an annular shape, and is inserted into the annular gap G1 of the magnetic circuit portion 2.
[0028]
The housing 10 is an annular housing that houses the magnetic circuit unit 2. An annular step 10a is provided on the inner surface of the housing. The annular step 10a abuts the step surface 3b of the yoke 3 when the magnetic circuit section 2 vibrates, and the vibration of the magnetic circuit section 2 is reduced. They are restricted.
[0029]
The terminal fitting 11 is provided outside the housing 10 as shown in FIGS. The terminal fitting 11 is electrically connected to a lead wire of the voice coil 8.
[0030]
Next, the clearance G2 of the electromechanical vibration acoustic transducer 1 according to the present embodiment will be described in detail. The clearance G2 is formed by bringing the outer peripheral surface of the yoke 3 as close to the inner peripheral surface of the housing 10 as possible. Therefore, when the magnetic circuit section 2 vibrates up and down, the air in the housing applies air pressure due to the vibration of the magnetic circuit section 2 to the minute clearance G2. Since the air to which the air pressure is applied hardly passes through the minute clearance G2, the moving amount of the air in the housing 10 is limited. The air whose movement amount is restricted functions as a damper that receives the movement of the vibration of the magnetic circuit unit 2.
[0031]
Thereby, the acceleration required for the bodily sensation vibration can be obtained in a wide frequency band. For this reason, the resonance point is hard to deviate from the bandwidth, and the resonance point is easily determined.
[0032]
Since the electromechanical vibration-acoustic transducer 1 also has a sound generating function of generating sound from the diaphragm 7, if all the outer frames formed by the diaphragm 7, the housing 10, and the cover 12 are airtight, a low level is obtained. This has an adverse effect on the vibration characteristics of the diaphragm 7 when a range sound is generated, and deteriorates the acoustic characteristics. However, on the other hand, it is necessary to restrict the outflow of air in order to use the air inside the electromechanical vibration-acoustic transducer 1 as a damper. In order to realize these contradictory elements with one electromechanical vibration-acoustic transducer 1, as shown in FIG. 4B, a through hole 13 for air inflow / outflow is provided on a side surface of the housing 10. As a result, the air enters and exits smoothly, and the acoustic characteristics are kept good. Note that the housing 10 may have an airtight structure, and the cover 12 may have a through hole for air inflow and outflow.
[0033]
The operation of the electromechanical vibration acoustic transducer 1 according to the present embodiment will be described based on the above configuration. When the voltage is applied to the voice coil 8, an electromagnetic force acts between the voice coil 8 and the magnetic circuit portion 2 to start vibration by repeating magnetic attraction and repulsion. At this time, if the frequency of the current is somewhat high and in the audible frequency range, the vibration of the diaphragm 7 to which the voice coil 8 is joined increases, and the vibration generates an audible sound such as a ringtone, a melody sound, and a voice. .
[0034]
On the other hand, the suspension 6 hardly vibrates because of its lower natural frequency. If the frequency of the current is a relatively low frequency of 120 to 160 Hz, the diaphragm 7 does not vibrate, so that no sound is produced, and instead, the vibration of the suspension 6 to which the magnetic circuit unit 2 is fixed increases. Then, the mechanical vibration system constituted by the magnetic circuit unit 2 and the suspension 6 vibrates, and the vibration energy increases due to the total mass of the mechanical vibration system. For this reason, the generated vibration is transmitted to the mobile telephone equipped with the electromechanical vibration-acoustic transducer 1 via the housing 10 to notify the user of the incoming call.
[0035]
As described above, the electromechanical vibration-acoustic transducer 1 enables two kinds of operations, sound generation and vibration.
[0036]
In the present embodiment, the air damper type electromechanical vibration acoustic transducer 1 has been described as an example, but the electromechanical vibration acoustic transducer 1 according to the present invention is limited to the air damper type electromechanical vibration acoustic transducer 1. Instead, an electromechanical vibration-acoustic transducer having a wide clearance G2 may be used.
[0037]
Also, in the present embodiment, the electromechanical vibration-acoustic transducer 1 in which the suspension 6 is one type has been described as an example. The transducer is not limited to the vibro-acoustic transducer 1, but may be a double suspension type electromechanical vibro-acoustic transducer. This electromechanical vibration-acoustic transducer includes two upper and lower suspensions that support a magnetic circuit unit.
[0038]
Furthermore, in this embodiment, the head 9b of the rivet 9 slightly protrudes from the upper surface of the pole piece 5, but a second counterbore hole is provided in the upper surface of the pole piece 5 to accommodate the head 9b of the rivet 9. The structure may be as follows. By accommodating the head 9b of the rivet 9 in the second counterbore provided in the pole piece 5, the thickness of the electromechanical vibration-acoustic transducer 1 according to the present invention can be maintained while maintaining the amplitude of the magnetic circuit portion 2. Can be further reduced.
[0039]
In this embodiment, the case where the first counterbore hole 3a is provided in the yoke 3 has been described as an example. However, the first counterbore hole is not limited to the case where the first counterbore hole is provided in the yoke 3. The pole piece 5 may be provided. The first counterbore hole for accommodating the caulked portion 9 a of the rivet 9 may be provided in either the yoke 3 or the pole piece 5.
[0040]
【The invention's effect】
According to the present invention, since the swaged portion of the rivet can be accommodated in the first counterbore, there is an effect that it is possible to cope with a reduction in thickness while securing a sufficient amplitude of the magnetic circuit portion.
[Brief description of the drawings]
FIG. 1 is an AA cross-sectional view (see FIG. 4A) of an electromechanical vibration-acoustic transducer according to an embodiment.
FIG. 2 is a diagram illustrating a yoke of the electromechanical vibration acoustic transducer according to the embodiment.
FIG. 3 is a diagram illustrating a suspension of the electromechanical vibration acoustic transducer according to the embodiment.
FIG. 4 is a diagram schematically illustrating an electromechanical vibration-acoustic transducer according to the embodiment.
FIG. 5 is a cross-sectional view (see FIG. 4A) of the electromechanical vibration-acoustic transducer according to the embodiment taken along line BB.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electromechanical vibration-acoustic transducer 2 Magnetic circuit part 3 Yoke 3a First counterbore hole 3b Step surface 3b
3c Suspension relief part 3d Mold relief part 3e Through hole 3f Notch 3g Outer end face 3h Stop frame 3i Magnet positioning counterbore 4 Magnet 5 Pole piece 5a Magnet positioning counterbore 6 Suspension 6a Fitting Part 6a
6b Arm 6c Ring 6d Protrusion 7 Diaphragm 8 Voice coil 9 Rivet 9a Caulking 9b Head 10 Housing 10a Annular step 10b Mold 11 Terminal 12 Cover 13 Through hole G1 for air inflow / outlet G1 Gap G2 Clearance

Claims (7)

A yoke, a plate-shaped magnet, and a plate-shaped pole piece stacked on a concentric axis to form a magnetic circuit unit, a suspension supporting the magnetic circuit unit, a diaphragm arranged to face the magnetic circuit unit, An inner-magnet type electromechanical vibration-acoustic transducer including a diaphragm and a voice coil inserted into an annular gap of the magnetic circuit unit.
A non-magnetic rivet that penetrates a concentric axis of the magnetic circuit portion and caulks and fixes the magnetic circuit portion;
A first counterbore provided around the concentric axis of one of the pole piece and the yoke and accommodating a caulked portion of the rivet;
An inner-magnet type electromechanical vibration-acoustic transducer comprising: 2. The inner-magnet type electromechanical vibration-acoustic transducer according to claim 1, wherein the suspension has a structure that supports the magnetic circuit portion at a position facing the diaphragm. The inner magnet type electric device according to claim 2, wherein the yoke is formed in a bottomed cylindrical shape, and has a projecting portion located at a minute gap from an inner wall surface of a housing that houses the magnetic circuit portion. Mechanical vibration sound transducer. A magnetic circuit portion configured by stacking a yoke, a plate-shaped magnet, and a plate-shaped pole piece on concentric axes, two upper and lower suspensions supporting the magnetic circuit portion, and disposed to face the magnetic circuit portion In an inner-magnet type electromechanical vibration-acoustic transducer including a diaphragm and a voice coil provided in the diaphragm and inserted into an annular gap of the magnetic circuit unit,
A non-magnetic rivet that penetrates a concentric axis of the magnetic circuit portion and caulks and fixes the magnetic circuit portion;
A first counterbore provided around the concentric axis of one of the pole piece and the yoke and accommodating a caulked portion of the rivet;
An inner-magnet type electromechanical vibration-acoustic transducer comprising: 5. The inner-magnet type electromechanical vibration-acoustic transducer according to claim 1, wherein the yoke and the pole piece include a counterbore for positioning the magnet. 6. The inner magnet type according to any one of claims 1 to 5, further comprising a second counterbore provided around the concentric axis of one of the pole piece and the yoke, and configured to receive a head of the rivet. Electromechanical vibration acoustic transducer. A portable terminal device comprising the electromechanical vibration acoustic transducer according to claim 1.

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