JPS5912694A - Voice coil for speaker - Google Patents

Abstract

PURPOSE:To select freely the number of turn and the like, by providing a lower layer coil having a flat surface on a common voice coil bobbin and an upper layer coil having different wire diameter from that used for the lower layer coil on the lower layer coil for guaranteeing the adhesive performance of the upper layer coil. CONSTITUTION:The lower layer coil 14 is wound on the common voice coil bobbin 11. Since a rectangular wire having a rectangular cross section is wound edgewise for the lower layer coil 14, not using a round wire, the surface is made flat. The upper layer coil 13 having different wire size is wound on the lower layer coil 14 to constitute a dual driving system coil. Thus, since the surface of the lower layer coil 14 is flat, the winding is attained so as to wind coil on a conventional bobbin in winding the upper layer coil 13. Thus, no limitation of the number of turn exists and the adhesive force is not weakened.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a voice coil for a speaker, which is supported in a magnetic gap of a magnetic circuit so as to be movable as a piston, and is used to drive a diaphragm.

Conventional Structures and Problems Generally speaking, voice coils for dual-drive speakers have a multilayer structure in which two voice coils are wound around a common voice coil bobbin. In this way, a speaker voice coil with two voice coils can be connected in series or in parallel to obtain the desired impedance, or by changing the force coefficient by connecting the two voice coils in series or in parallel. It has the feature of being able to selectively use various sound pressure characteristics. In this case, depending on the purpose of use, wires of the same diameter may be used for the two coils, or wires of different diameters may be used for the two coils. By the way, in the case of double-wound voice coils with different wire diameters, if coils/L'2.3 with different wire diameters are wound on a common bobbin 1 as shown in Figs. 1 and 2, the above Since carp/I/3 is wound along the carp/I/2 below,
The disadvantage was that the line length and number of turns could not be adjusted freely. That is,
FIG. 1 shows a case where a coil 2 with a small wire diameter is wound, and FIG. 2 shows a case where a coil 3 with a large wire diameter is wound. As shown in the diagram, the coil 3 wound on the top is wound in the Irisa-like manner between the bottom coil /I/2, so the coil 3 with a smaller wire diameter can only be wound with the same number of turns as the bottom coil LV3. Furthermore, the thick carp (V3 in Figure 2) had the disadvantage that it could only be wound with fewer turns than the lower carp (V2). Moreover, if the coil was wound without following the lower coil 2, the bonding area between the coils)v2 and 3 would be reduced, and there was a risk that the upper coil/L/3 would come off during vibration. If the number of turns and wire length of the carp/L'3 cannot be changed freely in this way, the desired force coefficient and impedance cannot be obtained, and the features of the dual drive system cannot be fully utilized. I have a problem.

OBJECT OF THE INVENTION The present invention solves these conventional drawbacks.
When obtaining a dual-drive voice coil in which two coils with different wire diameters are wound on the same bobbin, the adhesiveness of the upper coil that is wound over the lower coil is guaranteed, and the number of turns and wire length are flexible. The purpose of the present invention is to provide a voice coil for a speaker that can be selected from the following.

Structure of the Invention The voice coil for a speaker of the present invention includes a lower layer coil with a flat surface provided on a common boinu coil bobbin, and an upper layer coil with a wire diameter different from that of the lower layer coil provided on the flat surface of the lower layer coil. It is something that According to this configuration, since the surface of the lower layer coil is flat when winding the upper layer coil, the wire can be wound like a normal bobbin coil.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described. FIG. 3 shows an embodiment of the present invention, in which a lower layer coil 14 is wound around a common bobbin coil bobbin 1. In FIG.

This lower layer coil/L'14 has a flat surface because the coil wire is not a round wire but a flat wire with a rectangular cross section wound edgewise.

The upper layer coil (I/13) is wound on top of the lower layer coil (I/13) made of the rectangular wire to form a dual drive system coil.

FIG. 4 shows another embodiment of the present invention, in which a common bobbin 11
A lower carp/I/12 is wound on top. Since the coil wire of this lower layer coil 12 is a round wire, a synthetic resin layer 16 is formed on the surface in order to eliminate irregularities of the coil and flatten the surface. As the resin, thermosetting resins such as epoxy and melamine are suitable. Then, the upper layer coil (v13) is wound on top of this resin layer 16 to constitute a dual drive system coil.

Effects of the Invention As described in detail above, according to the present invention, when winding the upper layer coil, since the surface of the lower layer coil is flat, winding can be performed as if winding a coil around a normal bobbin.

Therefore, the number of turns is not limited or the adhesive strength is not weakened as in the conventional case. That is, since the upper layer coil can be configured arbitrarily, it is possible to create a design that maximizes the effect of the double drive yarn. Furthermore, since the adhesive strength of the upper layer of the coil does not decrease, it has the advantage of improving large J-resistance characteristics.

[Brief explanation of drawings]

1 and 2 are cross-sectional views of a conventional dual-drive voice coil, and FIG. 3 is a cross-sectional view of a voice coil for a speaker according to the present invention.
FIG. 4 is a sectional view showing another embodiment of the same voice coil. 11...Bobbin, 12.14... River/lower layer coil, 13... Upper layer coil, 16... River/synthetic resin layer. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure? / Figure 3 Figure 4

Claims (3)

[Claims] (1) A voice coil for a speaker, in which a lower layer coil with a flat surface is provided on a common voice coil bobbin, and an upper layer coil with a wire diameter different from that of the coil wire of the lower layer coil is provided on the flat surface of the lower layer coil. (2) The voice coil for a speaker according to claim 1, wherein the lower layer coil is a flat wire wound edgewise. (3) Claim 1, characterized in that the lower layer coil is a round wire wound and the surface is flattened with thermosetting resin.
Voice coil for the speaker described in section.