JPS58215199A - Coil type adapted for voice coil for speaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a winding type that can be used in an acoustic transducer commonly known as a voice coil. In such devices, a cone or diaphragm is driven by an electrical signal at audio frequencies so that the diaphragm does not move the air to reproduce sound. . The diaphragm is driven by a voice coil assembly bonded to the diaphragm, with the voice coil located within an air gap formed within the permanent magnet assembly. When the voice coil is energized by an audio frequency current, the coil moves translationally to impart the desired motion to the diaphragm.

In the conventional method of designing a voice coil, the typical idea was to design the coil with the idea that it would be preferable to make the coil lightweight by winding a circular electric wire on a bobbin. However, it has been observed that the use of circular wires results in relatively inefficient converters in that circular wires leave significant gaps between adjacent coil turns and between successive turns of the wire. Served.

Given a fixed volume of magnetic air gap, the sensitivity of a moving coil transducer depends on the number of turns of wire that can be placed within the given space.

There are additional factors related to the power handling capability of the transducer voice coil. It has long been known that such converters can be made to handle more power by adding more metal within the coil which acts to dissipate the heat generated within the voice coil. It was possible to produce it in

Early solutions were to use wires of rectangular cross section, typically wires with side to edge ratios in the range of 4:1 to 7:1. The wire is then wound onto the edge surface, thereby achieving a large number of turns within the coil, as well as with very little air gap, so as to be able to handle even more power, and also to achieve greater sensitivity. would result in a dense coil.

Edge-wound (flat-wound) voice coils have been conventionally used for many years, particularly in high fidelity straight power applications.

Typical prior art is US #'f, f; 3,9
No. 35.402 G 8 n III 70H patent, which describes a high power consumption voice coil using the flat wound principle and disclosing improvements in its power handling capabilities. Flat wound coil was first disclosed in 192
F. C. Wente and A. L. in the January 1988 issue of Bell System Technical Journal.

In a paper titled ``A high-efficiency receiver for a horn-type loudspeaker with a large power capacity by Thuraθ''.

As expected, some problems were encountered in fabricating the flat wound voice coil. Patent s 1.956
．． It is difficult to obtain a flat cylindrical profile for the coil as discussed in the '826 B, A, Rngholm patent. Although the wires are small and flat, it is difficult to maintain the sides in a strictly parallel relationship and precludes the use of automatic coil winding machines.

Additionally, although higher coil densities can be obtained, the wire tends to overlap so much that it is difficult to wind the coil tightly and tightly without distorting the profile. Furthermore, since only one turn of wire is utilized, the resulting coil must deal with the problem of having the leads tailored, thereby adding to the manufacturing cost of the coil. It will be apparent that the opposite edge has lead solid gold.

The object of the invention is to provide a voice coil with performance comparable to more expensively fabricated flat-wound coils, including higher power handling capabilities, where the sides or large dimensions of the wire are located on the bobbin rather than on the edge surface. By selecting rectangular wires having various side-to-edge aspect ratios, which are placed oppositely, they can be manufactured more easily and at lower cost. There are several advantages to this discovery. The coils are wound more tightly than flat-wound products, which provides greater density and thus increases power handling capacity, as opposed to the surface of the bobbin and the nine wires have larger dimensions. obtain. The other performance characteristics are exactly the same as the Iuchi-maki product.

Additional advantages of the present invention are low manufacturing costs based on various factors, firstly, the coil can be wound on an automatic coil winding machine; and secondly, the coil can be wound with an even number of multiple layers. In use, the leads or ends of the coil are both on the same side, which eliminates the need for inserts around the ends or leads due to the breakage, thus eliminating the manufacturing process. Third, this thousand-turn coil is wound directly onto the winding form. A flat wound coil, on the other hand, is wound onto a long rod on a mandrel, which is then separated, cut and a paper form inserted. The 1,000-turn coil therefore eliminates several manufacturing steps.

Another object and advantage of the present invention is that the wires are wound on a bobbin such that following the winding process, the adhesive is adjusted to coat and bond all wires in a safe manner. The purpose is to obtain a coil wire coated with an adhesive or the like.

Further objects and advantages of the present invention will become readily apparent by reference to the detailed description and the following drawings: FIG. 1 shows a partial isometric view of a prior art flat-wound voice coil; show.

2 and 6 show selected forms of partial cross-sectional views of the voice coil profile of the present invention.

Referring to FIG. 1, the narrow end surface 12 of the bobbin 14 is placed on the bobbin 14 until a sufficient number of turns have been deposited as desired to form the accumulated windings forming the voice coil.
A flat rectangular electrical wire 10 is shown wound to form a . As is conventionally known, the voice coil should be wired within an air gap, and the smaller the gap between the magnetic pole piece of the magnet and the cylindrical surface of the voice coil, the better.
1. Since it is known that the temperature dissipation ability of a mass unit is poor, a very small amount of separation is required between the bobbin on one side and the edge of the voice coil on the other side. Leaving a distance is the customary method. However, in order to support the translational movement of the voice coil, some air gap must be left, so a certain volume is provided to operate within the air gap, and as mentioned above, that volume must be expanded into as many windings as possible. It is desired to fill the wire with as many turns as possible and with as much metal material as possible.

FIGS. 2 and 6 show formats in which one of the methods of the present invention should be selected. It should be noted that the volume of the air gap occupied by the windings is the same, or could just as easily be the same in FIGS. 2 and 6 as in FIG.

First, if you open FIG. 6, the bobbin 14 has various aspect ratios,
That is, it has a plurality of turns of wire 20 with an edge-to-side ratio, which may vary substantially for various reasons explained in detail below, but the sides 22 are similar to the bobbin 14. located along the

By selecting the ratio of side surfaces 22 to edge surfaces 24, the desired number of wire turns can be completed to fill the volume of the air gap to obtain the desired sensitivity for the transducer. The rectangular cross-section wire is coated with enamel for insulation. A helical coil is formed by winding the wire 20 onto the bobbin 14 using a coil winding machine, which allows the multilayer coil to be wound tightly. By providing an even number of layers within the coil, the finished coil will have edge surfaces and conductors coming from the same side of the coil, allowing the rear of the conductors to run around and outside the coil shape for connection to the input terminals. The additional problem mentioned above is solved, that is, there is no need to provide a means for inserting the implant. Although it is possible to produce a coil with high efficiency and low manufacturing cost even with an odd number of layers,
Another additional advantage of this invention is that an even number of layers is believed to contribute to further reducing manufacturing costs;
This is an advantage over prior art flat wound coils.

FIG. 2 shows what can be considered at the lower limit of the invention, where the wire 30 has a square cross section. This profile further deceives automatic winding in relation to coil machines,
Furthermore, a number of turns can be tightly wound onto the bobbin 14 without damaging the winding or the composite coil cylinder. What appears to be clear is that the various aspect ratios of the end-to-side dimensions depend in part on the desired turn ratio;
Moreover, it is possible to select from square to rectangular shapes, substantially filling the volume of the attached magnet air gap, leaving a minimum air gap between the windings.

Another feature of the invention is the provision and use of an adhesive or thermoset plastic material to securely secure the windings within the finished coil cylinder. This could be accomplished in a variety of ways: one would be to apply an additional layer of thermoset adhesive before winding onto the bobbin, as is conventionally done for voice coil wire. The first step is to prepare a rectangular or square wire with pre-applied enamel. The option is to wind a first layer of winding on a bobbin, then add a thin coating of thermosetting material to that first layer, and then wind a second layer of winding on top of that. Probably. More could be done with additional layers if additional layers could be fabricated. Once the winding is complete, a current is briefly applied to the end of the coil to heat it and cure the adhesive. Instead of thermoset adhesives, adhesive reactive agents in solvents such as acetone or methyl ethyl ketone can be used.

The invention illustrated herein is an iskoil with improved power handling capability that has the potential for high performance and the potential to be substantially less expensive to manufacture.

Furthermore, these and other modifications may be used by those skilled in the art without departing from the spirit and scope of the invention as defined by the claims.

[Brief explanation of the drawing]

FIG. 1 shows a partial isometric view of a prior art flat-wound voice coil, and FIGS. 2 and 5 show selected forms of partial cross-sectional views of the voice coil profile of the present invention. 10...Flat rectangular electric wire 12...Narrow edge portion 14...Bobbin 20...Number of turns of wire 22...Side surface 24...Edge portion 30...Wire agent Hajime Asamura Outside 4 menin θ3

Claims (1)

[Claims] (1) comprising windings of electrical wire tightly secured to each other;
The electric wire has an aspect ratio of 1:1 or more between the side surface and the edge surface, and the side surface of the electric wire is arranged in a line in the same direction as the solid axis of the coil. voice coil. (2) comprising a winding of two or more layers of electric wire, where the electric wire has a side to edge surface ratio of at least 1:1 and whose edge surfaces are aligned in a line with the axis of the coil; A voice coil for a speaker, characterized in that it has a rectangular cross-sectional area. (3) comprising windings of an even number of layers of wire, said wire comprising:
1. A voice coil for a speaker, characterized in that the wire has a rectangular cross-sectional area with a side to edge ratio of at least 1:1, and the side surfaces of the wire are aligned with the axis of the coil. (4) The voice coil for a single force as set forth in claim 5, wherein the electric wires are tightly fixed to each other with an adhesive. (5) first forming a length of wire whose side surface has a rectangular cross-sectional area equal to or larger than the end surface, covering said wire with insulation means, and covering said wire with insulation means on its side surface adjacent to said coil form; whereas a first layer is formed by winding the wire on a cylindrical coil format, and a second layer is formed by winding an additional number of turns of the wire on top of the first layer in the same manner. A voice coil for a speaker, characterized in that it is manufactured by forming. 16+ Covering the electric wire with an adhesive, and then applying and curing the adhesive after forming the layer 1
(7) The adhesive is a thermosetting compound, and the adhesive is capable of passing a current through the electric wire. A voice coil for a speaker formed as claimed in claim 5, characterized in that it is hardened. (8) A chair coil for a speaker formed as set forth in claim 6, wherein the adhesive is cured by immersing the coil in a solvent.