JP2001169390A - Speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems of a conventional speaker where many man-hours have been required to adhere a voice coil to a diaphragm and there has been fluctuation in positional accuracy resulting in causing instability in the characteristics. SOLUTION: A yoke 2 is fixed to a frame 1, one magnetic pole of a permanent magnet 3 is fixed to the yoke 2, a top plate 4 is fixed to the other magnetic pole of the permanent magnet 3, and a circumferential part 5b of the diaphragm 5 is fixed to the frame 1. A projection 5c acting like a coil winding frame is provided adjacent to a circumferential part of nearly a spherical part in the middle of the diaphragm 5 through integral molding and a coil winding is wound directly onto the projection 5c to form a voice coil 6. The voice coil 6 is inserted to a gap between the yoke 2 and the top plate 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an electrodynamic speaker,
More specifically, it relates to the structure of a voice coil.

[0002]

2. Description of the Related Art In recent years, a thin and high-performance electrodynamic speaker has been widely used as an acoustic device of a mobile communication device such as a portable telephone. An example of such a conventional speaker will be described with reference to the drawings. FIG. 4 is a sectional view of a conventional electrodynamic speaker.

[0003] First, the configuration of this speaker will be described. FIG. 4 shows a longitudinal section at the center of the speaker, and the symmetrical right half is omitted. Reference numeral 1 denotes an annular frame having an inner peripheral step 1a and an intermediate step 1b. 2
Is a dish-shaped yoke made of a magnetic material fixed to the inner peripheral step 1a. Reference numeral 3 denotes a disk-shaped permanent magnet fixed to the center of the bottom surface of the yoke 2 and having magnetic poles above and below. Reference numeral 4 denotes a disk-shaped top plate fixed to the other magnetic pole side surface of the permanent magnet 3. A magnetic circuit is formed by the permanent magnet 3 through a gap between the upper end of the yoke 2 and the peripheral edge of the top plate 4.

Reference numeral 15 denotes a substantially spherical diaphragm integrally formed of a plastic material having a flat portion 15a near the periphery and a curved portion following the flat portion 15a. It is adhesively fixed to the step 1b. 1
Reference numeral 6 denotes a voice coil which is a cylindrical air-core coil in which coil windings, which are enamel-coated copper wires, are wound in a rectangular cross section and solidified with paint, and the upper surface thereof is bonded to the lower surface of the flat portion 15a of the diaphragm 15. Fixed. The voice coil 16 is fitted into a gap between the peripheral edge of the top plate 4 and the upper end of the yoke 2 to a depth of approximately half the coil length.

Next, a method of assembling the speaker will be described. First, the surface on one magnetic pole side of the permanent magnet 3 is bonded to the center of the yoke 2, and then the top plate 4 is bonded and fixed with its center positioned on the surface on the other magnetic pole side of the permanent magnet 3. On the other hand, the voice coil 1 is placed on the flat portion 15a of the diaphragm 15.
6 is centered and adhered. Next, the yoke 2 is attached to the inner peripheral step 1a of the frame 1, and finally the diaphragm 15 to which the voice coil 16 is adhered is attached to the intermediate step 1b. When an audio signal is input to the voice coil 16 of the speaker, the diaphragm 15 is driven according to Fleming's left hand rule.
Vibrates up and down and emits sound.

[0006]

However, in the above-described speaker, in the step of bonding the voice coil 16 to the diaphragm 15, it is necessary to first apply an appropriate amount of adhesive to the flat portion 15a of the diaphragm 15. At this time, the nozzle of the dispenser containing the adhesive is operated so as to draw an arc trajectory on a plane. In this operation, it is difficult to maintain a coating position so as not to deviate from an accurate trajectory. Therefore, it is difficult to keep the amount of the adhesive applied along the track constant. Further, when aligning the center positions of the diaphragm 15 and the voice coil 16, planes having no alignment guide are abutted against each other, so that accurate positioning is difficult. From the above, it takes a lot of man-hours for bonding work,
Since there is a large variation in the accuracy of the bonding position of the voice coil, there is a problem that stability due to variation in the characteristic surface is lacking, which leads to an increase in the cost of the speaker. Further, since the air-core voice coil 16 is used, the aligned coil winding may be broken during handling.

[0007] The present invention has been made to solve such a conventional problem, and an object of the invention is to eliminate the voice coil bonding step to eliminate various problems associated with bonding. It is an object of the present invention to provide an inexpensive speaker by reducing the number of bonding steps, preventing winding collapse of the voice coil, and stabilizing the quality by improving the voice coil position accuracy.

[0008]

In order to solve the above-mentioned problems, the present invention provides a permanent magnet, a yoke fixed to one magnetic pole side of the permanent magnet, and a top plate fixed to the other magnetic pole side. In a dynamic speaker including a frame to which the yoke is fixed, a diaphragm fixed to the frame, and a voice coil fixed to the diaphragm, a protrusion is formed on the diaphragm, and the voice coil is The coil winding is formed around the projection.

According to a second aspect of the present invention, in the first aspect, the protrusion is formed integrally with the diaphragm.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a speaker according to a first embodiment of the present invention, FIG. 2 is an enlarged view of a main part of FIG. 1, and FIG. 3 illustrates a method of winding a coil winding in the first embodiment. FIG.

First, the configuration of an electrodynamic speaker according to a first embodiment of the present invention will be described. In FIG. 1, reference numeral 5 denotes a diaphragm, and the diaphragm 5 is formed so that a projection 5c is fitted into a gap between the top plate 4 and the yoke 2 following the periphery of the central substantially spherical portion. The flat peripheral portion 5b is adhesively fixed to the frame 1 intermediate step portion 1b. Reference numeral 6 denotes a voice coil, which is formed by winding a coil winding 7 around the outer periphery of the projection 5c as shown in FIG. That is, the protrusion 5c plays a role of a winding frame of the voice coil 6.
Other configurations are the same as those of the related art, and thus the same reference numerals and names are assigned to the respective constituent elements, and the description is omitted. The protrusion 5c may be a cylindrical protrusion continuous on the circumference or a discontinuous protrusion.

Next, a method of manufacturing the diaphragm 5 of the present embodiment will be described. First, the diaphragm 5 is integrally formed by hot press molding in a mold heated from a plastic material such as polycarbonate, polyetherimide, polyimide, and pen, and then the outer shape is cut by an outer shape punching die.
Next, a winding method of the voice coil 6 will be described with reference to FIG. In FIG. 3, reference numeral 21 denotes a spindle motor of a winding machine, and reference numeral 22 denotes a jig attached to the spindle 21 of the spindle motor. 23 is a wire guide for guiding the coil winding 7 in the rotation axis direction. The upper surface of the diaphragm 5 is attached to the jig 22. The coil winding 7 fixes the winding start side coil terminal 7 a to the spindle motor 21. With the rotation of the spindle motor 21, the coil winding 7 is wound along the outer periphery of the projection 5 c protruding from the jig 22 while being guided by the wire guide 23. The terminal treatment of the coil winding 7 and the coating with the adhesive are performed, and the diaphragm 5 with the voice coil 6 is completed.

Next, the effect of this embodiment will be described. Since the diaphragm 5 has a role corresponding to the winding frame of the voice coil 6, the voice coil 1 to the conventional diaphragm 15 can be used.
6 The number of bonding steps was reduced, and the problems associated with this step were eliminated. In addition, since the projection 5c plays a role corresponding to a winding frame, winding collapse does not occur, and the positional accuracy of the voice coil is improved, leading to stability and quality improvement of the voice coil. It leads to reduction.

[0014]

As described above, according to the present invention,
Since the diaphragm has the role of a coil winding frame, the voice coil bonding process can be reduced, and since the coil winding is wound directly on the diaphragm, the winding collapse of the voice coil can be prevented, Eliminating the voice coil bonding process and improving the position accuracy of the voice coil, leading to stabilization and quality improvement of the characteristics, and consequently the man-hour of the whole speaker can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a speaker according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part of FIG.

FIG. 3 is a partial sectional side view showing a method of winding a coil winding.

FIG. 4 is a cross-sectional view showing a conventional speaker.

[Explanation of symbols]

 Reference Signs List 1 frame 2 yoke 3 permanent magnet 4 top plate 5 diaphragm 5c projection 6 voice coil 7 coil winding

Claims (2)

[Claims] 1. A permanent magnet, a yoke fixed to one magnetic pole side of the permanent magnet, a top plate fixed to the other magnetic pole side, a frame fixed to the yoke, and a diaphragm fixed to the frame. An electrodynamic loudspeaker comprising a voice coil fixed to the diaphragm, wherein a projection is formed on the diaphragm, and the voice coil is formed by winding a coil winding around the projection. Speaker. 2. The speaker according to claim 1, wherein the projection is formed integrally with the diaphragm.