JP2002186091A - Micro speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a micro speaker where mounting a voice coil to a diaphragm of the micro speaker and coil end processing of coil wires can be automated. SOLUTION: A case of the micro speaker consists of upper and lower cases A, B. The case A (22) contains a magnetic circuit section, the diaphragm 6 is fixed to a lower face of the case B (23) and both cases A, B are integrally joined. The lower side of the diaphragm is open when the diaphragm is joined with the case B and the voice coil 5 directly supplied from a wire winding head is automatically mounted to the diaphragm. Since the winding end 9 of the coil is not clipped between the diaphragm and the joined face of the case B, the outer circumferential part of the diaphragm is uniformly joined and no stress is exerted to the winding end even when the cases are pressed for joining. Provision of a board to the speaker and soldering of the winding end to the board are avoided not like in a conventional speaker, a lead 21 is insert- formed to the case A, the winding end is clamped by an end 21a of the lead to join them by soldering or welding. Lead frames are used to produce the cases efficiently and the winding end processing can be automated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro-speaker used in a mobile communication device such as a portable telephone and other devices.

[0002]

2. Description of the Related Art FIG. 4 shows an example of a conventional micro speaker, which is of an electrodynamic type. FIG. 4 (A) is a sectional view, FIG. 4 (B) is a bottom view, and FIG. A section. A pot-like yoke 2 made of a magnetic material is insert-molded in a plastic case 1, a magnet 3 is fixed to the yoke 2, and a top plate 4 made of a magnetic material is joined to an upper surface of the magnet. Thereby, a magnetic circuit is formed, and a magnetic gap is generated between the outer periphery of the top plate 4 and the inner periphery of the upper end of the short cylindrical portion of the yoke 2.

[0003] The outer periphery of the diaphragm 6 is fixed to the upper part of the case 1, and the voice coil 5 is fixed to the lower surface of the diaphragm 6. The voice coil 5 includes the top plate 4 and the yoke 2.
Located in the magnetic gap created by A protector 7 made of light metal or the like is fixed on the upper portion of the case 1 so as to cover the diaphragm 6. The case 1 and the protector 7 are provided with a plurality of sound emission holes, respectively.

[0004] The two winding terminals 9 of the voice coil 5 are:
As shown in FIG. 4A, the adhesive is adhered along the lower surface of the diaphragm 6, pulled out of the case 1, and guided to the lower surface of the case 1 through a recess provided on the side surface of the case 1. A substrate 8 such as a glass-containing epoxy resin is adhered to the lower surface of the case 1, and two terminal patterns 10 are provided on the substrate 8 as shown in FIG. The terminal pattern 10 has a bifurcated shape. One end of the terminal pattern 10 is connected to the end of the winding terminal 9 by solder 11, and the other branch is used for connecting the speaker to a device.

The operation of such a loudspeaker is well known. When a signal current is applied to the voice coil 5, the voice coil 5 and a diaphragm integrated therewith are generated by the electromagnetic action of the current and the magnetic flux generated in the magnetic gap. 6 vibrates to generate sound.

[0006]

In the above conventional example, the substrate 8 is adhered to the case 1 and the winding terminals 9 are soldered to the terminal patterns 10 of the substrate 8. The use of a simple substrate 8 is eliminated to reduce the number of components, and accordingly, the step of bonding the substrate 8 to the case 1 and the step of soldering the winding terminals 9 to the substrate 8 are not required.

In the above conventional example, the voice coil 5
If the diaphragm 6 is bonded to the case 1 before fixing the
Since the lower surface of diaphragm 6 is sealed inside case 1 and voice coil 5 cannot be fixed, voice coil 5 must be fixed before bonding diaphragm 6 to case 1. The diaphragm 6 is made of a plastic film or the like having low rigidity and is inconvenient to handle, and it is difficult to automate the bonding process of the voice coil 5.

The outer periphery of the diaphragm 6 is adhered to the upper part of the case 1, but the winding terminal 9 of the voice coil 5 is
The diaphragm 6 is slightly lifted from the case 1 at that point, and the bonding becomes non-uniform. When the outer periphery of the diaphragm 6 is pressed during bonding, stress is applied to the winding terminal 9. The present invention solves these problems, and also enables automation of winding terminal processing.

[0009]

In the present invention, the case is divided into two parts, A and B, vertically. Lower case A
Accommodates a magnetic circuit unit such as a yoke and a magnet, and a diaphragm, a voice coil, and a protector are fixed to the upper case B. The upper case B is an annular frame, and the outer peripheral upper surface of the diaphragm is joined to the lower surface thereof. Since the voice coil is fixed to the lower surface of the diaphragm, the winding terminal is guided out of the case without being sandwiched between the diaphragm and the case B.

A lead made of a metal material is fixed to a case A that houses the magnetic circuit portion, and one end of the lead is connected to a winding terminal of a voice coil. The other end of the lead serves as a connection terminal when assembling the micro speaker to the device. The connection of the winding terminal is performed by bending the end of the lead and sandwiching the winding terminal, so that the conventional substrate for connecting the winding terminal of the coil is eliminated.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. For the sake of convenience, the same reference numerals are used for the same kind of parts and parts including the above description. FIG. 1 shows an embodiment of a microspeaker according to the present invention, wherein FIG.
(B) is a bottom view, and (A) is an AA cross section of (B). The case is formed by joining two parts of a lower case A (22) and an upper case B (23) by bonding with an adhesive or ultrasonic welding. The basic operation of the speaker using the yoke 2, the magnet 3, the top plate 4, the voice coil 5, the diaphragm 6, and the like is the same as that of the conventional example of FIG. The magnetic circuit parts such as the yoke 2 and the magnet 3 are attached to the case A, and the outer periphery of the diaphragm 6 has a case A (22) and a case B
It is sandwiched between the mating surfaces of (23).

A lead 21 made of phosphor bronze or the like is insert-molded in the case A (22). There are two leads 21 which are substantially semicircular, as shown by the outline in broken lines in FIG. 1 (B), and both ends 21a and 21b are substantially opposite to each other with the center therebetween. As can be seen in FIG.
“a” is along the side surface of the case A (22), and sandwiches the winding terminal 9 that is protruded outside from a cutout provided in a part of the mating surface of the upper and lower cases. Opposite end 21b
Are connection terminals that are exposed along the lower surface of the case and are used when a micro speaker is incorporated in a device.

FIG. 2 shows a state before assembly of the embodiment. FIG. 9A shows the relationship between the blocks of the case A (22) and the blocks of the case B (23). As described above, the magnetic circuit unit is mounted on the case A (22). The outer peripheral upper surface of the diaphragm 6 is joined to the lower surface of 23). The voice coil 5 is fixed to the lower surface of the diaphragm 6. The two winding terminals 9 of the voice coil are adhered or hampered along the lower surface of the diaphragm 6. When the diaphragm 6 is adhered to the lower surface of the case B (23) in this manner, the winding terminal 9 extends along the lower surface of the diaphragm 6 and is sandwiched between the joining surfaces of the diaphragm 6 and the case B (23). Since there is no diaphragm, the entire periphery of diaphragm 6 can be uniformly joined to the lower surface of case B (23).

The end 21a of the lead 21 inserted into the case A (22) is open in an L-shape before assembly, as shown in FIG. Case A (22) in FIG. 2 (A)
And the case B (23) are joined by bonding or welding, and then, as shown by a wavy line on the right end of the case A (22), the winding terminal 9 is formed.
To the inner corner of the L-shape of the end 21a of the lead 21,
The end is bent and pinched as indicated by the arrow in FIG. Then, soldering is performed, or an electrode is applied to the end portion 21a and current is applied to perform welding. This completes as shown in FIG.

In the conventional example shown in FIG. 4, when the diaphragm 6 is attached to the case 1, the lower surface of the diaphragm 6 for fixing the voice coil 5 faces the inside of the case 1, so that the diaphragm 6 is fixed to the case 1. Prior to this, the voice coil 5 must be fixed to the diaphragm 6, and a free process formation such as mounting the voice coil 5 after fixing the diaphragm 6 to the case 1 cannot be performed. The diaphragm 6 is made of a plastic film or the like and has low rigidity, so that the work of attaching the voice coil is not always easy.

In this regard, in the embodiment of the present invention, FIG.
As is clear from (A), the voice coil 5 side is open even if parts are attached to the case B (23).
After fixing the diaphragm 6 to the case B (23), the voice coil 5 can be joined to the lower surface thereof. Therefore, the winding head of the coil winding machine is brought close to the diaphragm 6 joined and reinforced by the case B (23), and the wound voice coil 5 is joined to the diaphragm 6 directly from the winding machine. Such work is also possible.

FIG. 3 shows a case A (22) prior to FIG.
In a state where the lead 21 is insert-molded, the end 21a of the lead is bent along the side surface of the case in FIG. 2, but immediately after the molding, the L-shaped end 21a is connected to the case A (22) as shown in FIG. Projecting radially from In a subsequent step, this is bent as shown by the arrow in FIG. 3A and directed to the side surface of the case A (22) as shown in FIG. In the present invention, the substrate 8 as in the conventional example shown in FIG. 4 is not required, but two leads 21 are inserted and provided in the case A (22). The case A (22) can be formed by inserting the lead portion as it is and using the one to which the lead 21 is connected, so that the substrate 8 for terminal processing is separately prepared as in the related art. Is more advantageous than bonding to individual cases.

The loudspeaker of the above embodiment is a so-called inner magnet type magnetic circuit using a disc-shaped magnet, but it is of course possible to form an outer magnet type magnetic circuit using a short cylindrical magnet. It is. Furthermore, the magnetic circuit portion is supported by an elastic member to form a vibrating portion. When a current having an audible frequency is supplied to the voice coil, the diaphragm vibrates and sounds as a speaker. Instead, the present invention can be applied to a so-called multi-function sounding body in which a vibrating portion including a magnetic circuit portion vibrates and transmits vibration to the outside.

[0019]

As is apparent from the above description, the micro speaker of the present invention has the following effects. 1. The restriction that the voice coil must be fixed to the diaphragm before the diaphragm is attached to the case as in the related art is eliminated, and the degree of freedom in the process organization is increased, and the coil mounting operation can be automated. 2. Since the winding terminal of the voice coil is drawn out without passing through the joint surface between the diaphragm and the case B, the diaphragm can be uniformly adhered to the case B over the entire circumference, and the outer periphery of the diaphragm faces the case B at the time of adhesion. Even if pressure is applied, the winding ends are not pinched and stressed. 3. A board for terminal processing of a conventional winding is abolished, and the number of components can be reduced, and a process of bonding the board to the case and an associated adhesive cost are not required. 4. Since the winding terminal is not soldered to the terminal pattern but is fixed between the ends of the leads, automation of the terminal processing becomes easy. In the completed state, the winding ends are covered with the ends of the leads, and are not exposed to the case surface as in the conventional case, so that they are better protected against damage. In this way, a low-cost, high-performance, and highly reliable microspeaker can be obtained.

[Brief description of the drawings]

1A is a cross-sectional view of an embodiment of the present invention, and FIG.
FIG. 3 is a bottom view, and FIG. 3A is a cross-sectional view taken along line AA of FIG.

FIG. 2A shows a state before assembly of the embodiment of FIG. 1;
Is a sectional view, (B) is a bottom view, and (A) is A of (B).
-It is an A section.

FIG. 3 (A) shows a state when parts are manufactured in the embodiment of FIG. 1;
Is a sectional view, (B) is a bottom view, and (A) is A of (B).
-It is an A section.

4A is a cross-sectional view, FIG. 4B is a bottom view, and FIG. 4A is a cross-sectional view taken along line AA of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 2 Yoke 3 Magnet 4 Top plate 5 Voice coil 6 Diaphragm 7 Protector 8 Substrate 9 Winding terminal 10 Terminal pattern 11 Solder 21 Lead 21a, 21b End 22 Case A 23 Case B

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshizumi Ota 1-23-1 Kagurechi, Fujiyoshida-shi, Yamanashi F-term in Citizen Electronics Co., Ltd. (Reference) 5D012 BC02 BC04 CA04 CA09 FA10

Claims (2)

[Claims] 1. A micro-speaker comprising parts such as a permanent magnet, a yoke, a voice coil, a diaphragm, and a protector attached to a case.
With a permanent magnet, yoke, etc., and a diaphragm, a voice coil, etc. attached to the upper case B. The outer peripheral upper surface of the diaphragm is joined to the lower side of the case B, and the voice coil is fixed to the lower surface of the diaphragm. By doing so, the winding terminal of the voice coil is pulled out of the case along the lower surface of the diaphragm, a conductive lead is attached to the case A by insert molding, and the winding terminal of the voice coil is connected thereto. A micro speaker characterized by the following. 2. The micro-speaker according to claim 1, wherein the connection between the winding terminal of the voice coil and the lead is joined by soldering or welding after bending the end of the lead to sandwich the winding terminal. A micro-speaker, characterized in that: