Voice coil and voice coil manufacturing method

Abstract

To provide a voice coil and manufacturing method thereof capable of suppressing a manufacturing cost while keeping quality.SOLUTION: Two end parts 5A, 5B of an electric wire 4 constituting a voice coil 2 are non-isolated by removing coating. The two end parts 5A, 5B are bent along front surfaces of respectively corresponding conductive foils 3A, 3B to be in a winding state by including portions of the succeeding electric wire 4. The two end parts 5A, 5B in the bending state are stored within a range of the corresponding conductive foils 3A, 3B, and electrically connected by fixing with the conductive foils 3A, 3B by soldering and welding, or the like. The two conductive foils 3A, 3B are attached to a coil bobbin 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a voice coil and a method for manufacturing a voice coil. [Background technology]

[0002] A speaker unit typically uses a voice coil as a sound generating source. This voice coil has a structure in which an insulated electric wire is wound around a core material called a coil bobbin, and the non-insulated end of the coil (electric wire) is electrically connected to a lead wire, such as a tinsel wire. The end and the lead wire are typically electrically connected by attaching a conductive foil such as copper foil to the coil bobbin and then soldering the conductive foil (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-284188 Summary of the Invention [Problem to be solved by the invention]

[0004] Typically, wires are de-insulated by removing the coating that insulates them. The areas where the coating has been removed are prone to rust and other problems. The occurrence of rust and other problems shortens the lifespan of the voice coil. For this reason, in the past, the coating has been removed with precision so that the removed areas are not exposed. However, removing the coating with precision requires a long time. This increases the time required to manufacture a voice coil (takt time), which in turn increases manufacturing costs. For these reasons, it is considered important to maintain quality and prevent things that shorten the lifespan of the voice coil while also reducing manufacturing costs.

[0005] An object of the present invention is to provide a technique for reducing the manufacturing cost of a voice coil while maintaining its quality. [Means for solving the problem]

[0006] A voice coil according to one embodiment of the present disclosure comprises a coil bobbin, a coil wound around the coil bobbin, two conductive foils attached to the coil bobbin and each electrically connected to one of the two ends of the coil, and two fixed connection parts that fix each of the two ends while electrically connecting it to the conductive foil in a state where the two ends are wound along the surface of the corresponding conductive foil.

[0007] A method for manufacturing a voice coil according to one embodiment of the present disclosure involves winding each of the two non-insulated ends of a coil wound around a coil bobbin along the surface of a corresponding conductive foil attached to the coil bobbin, and then electrically connecting and fixing each of the two wound ends to the corresponding conductive foil. [Effects of the Invention]

[0008] In the present invention, the manufacturing cost can be reduced while maintaining the quality of the voice coil. [Brief explanation of the drawings]

[0009] [Figure 1] 10A to 10C are diagrams illustrating an example of a state during the manufacturing process of a voice coil according to an embodiment of the present invention. [Figure 2] 2 is an enlarged view showing an example of part A and part B shown in FIG. 1. [Figure 3] 1. FIG. 4 is an enlarged view showing another example of the parts A and B shown in FIG. [Figure 4] 1A and 1B are diagrams illustrating an example of a voice coil according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Note that the embodiment described below is merely an example, including modifications, and the technical scope of the present invention is not limited to this. Various modifications are also included within the technical scope of the present invention.

[0011] FIG. 1 is a diagram illustrating an example of a state during the manufacturing process of a voice coil according to an embodiment of the present invention. As shown in the front view of Figure 1, this voice coil has a structure in which a coil 2 is wound around the bottom of a hollow cylindrical coil bobbin 1. Two conductive foils 3A and 3B are attached to the coil bobbin 1 above the coil 2.

[0012] The coil 2 is obtained by winding an electric wire 4 insulated by, for example, a coating. Both ends (two ends) 5A, 5B of the electric wire 4 constituting the coil 2 are non-insulated portions where the coating has been removed and the portions are non-insulated for electrical connection with the conductive foils 3A, 3B. The types of the electric wire 4 and the conductive foils 3A, 3B are not particularly limited. For example, enameled copper clad aluminum wire (CCAW) may be used for the electric wire 4. The material, shape, etc. of the coil bobbin 1 are not particularly limited.

[0013] Figure 2 is an enlarged view showing examples of parts A and B shown in Figure 1. Figure 2(a) shows an example of an enlarged view of part A, and Figure 2(b) shows an example of an enlarged view of part B. As shown in Figure 2(a), the end 5A associated with the conductive foil 3A is wound along the surface of the conductive foil 3A, more specifically, in a spiral shape. Because the end 5A is wound in this manner, the length of the end 5A, i.e., the length from which the coating should be removed, has a large margin and a wide tolerance range. As this margin increases, the tolerance range for the position on the wire 4 from which the coating should be removed also increases, and the required precision is lower.

[0014] This allows for a method of, for example, moving the position where the coating should be removed closer to the edge and increasing the length of the coating to be removed. Even if such a method is used, as shown in FIG. 2(a), it is easy to keep the entire end 5A within the range of the conductive foil 3A without exposing the end 5A from the conductive foil 3A. This allows workers to more easily and reliably perform the appropriate work of removing the coating from the electric wire 4. This also makes it more reliably and easily possible to avoid problems such as the end 5A being exposed from the conductive foil 3A. This also makes it more reliably possible to avoid the need to redo the coating removal.

[0015] The same applies to part B. Therefore, it is possible to avoid or further reduce the production of voice coils that are expected to have a shorter lifespan than anticipated at the time of design. Appropriate removal of the coating from both ends of the electric wire 4 can be performed more easily and reliably, thereby shortening the takt time. Therefore, it is possible to maintain the quality of the voice coil while further reducing its manufacturing costs.

[0016] Figure 3 is an enlarged view showing another example of part A and part B shown in Figure 1. Figure 3(a) shows an example of an enlarged view of part A, and Figure 3(b) shows an example of an enlarged view of part B. The example shown in Figure 3 is a case where the position where the coating is removed is closer to the front, that is, closer to the coil 2 around which the electric wire 4 is wound, and the length of the coating to be removed is also longer. As shown in Figures 3(a) and 3(b), even if the position where the coating is removed and the length of the coating to be removed are different, the ends 5A and 5B and the subsequent portion of the electric wire 4 can be contained within the range of the conductive foils 3A and 3B. For this reason, bending the ends 5A and 5B is effective in reducing the required precision.

[0017] FIG. 4 is a diagram illustrating an example of a voice coil according to an embodiment of the present invention. 4 shows a front view of an example in which a lead wire 6A is electrically connected to an end 5A on the conductive foil 3A, and a lead wire 6B is electrically connected to an end 5B on the conductive foil 3B by solder welding, and these are fixed to the conductive foils 3A and 3B. As a result, solders 7A and 7B, which are fixed connections, are present on the conductive foils 3A and 3B, respectively.

[0018] As shown in Figures 2 and 3, the ends 5A and 5B are bent in a coiled manner and entirely covered with solder 7A and 7B. This is done to prevent the exposed portions of the ends 5A and 5B from rusting or corroding. Because the bent ends 5A and 5B are electrically connected to the lead wires 6A and 6B by solder 7A and 7B, respectively, the same conductive foils 3A and 3B as in the past can be used. This allows the outer shape of the voice coil 10 to be the same as or substantially the same as the past. Both solders 7A and 7B correspond to fixed connection portions in this embodiment.

[0019] If the exposed portions of the ends 5A, 5B are all covered with solder 7A, 7B, the solder 7A, 7B will get on the portions of the wire 4 where the coating has not been removed. If the wire 4 is covered with an insulating material, the insulating material may melt due to the solder, which may adversely affect the adhesive strength. For this reason, particularly when using such an electric wire 4, it is desirable to wrap each end 5A, 5B more than once, as shown in Figure 2 or Figure 3, to ensure a more reliable electrical connection.

[0020] In this embodiment, solder welding is used to electrically connect the end portions 5A, 5B, the conductive foils 3A, 3B, and the lead wires (e.g., tinsel wires) 6A, 6B, but the electrical connections may be achieved by methods other than solder welding. Furthermore, while the electrical connections between the end portions 5A, 5B and the lead wires 6A, 6B are achieved directly or via solder 7A, 7B, they may also be achieved via the conductive foils 3A, 3B. In other words, the end portions 5A, 5B and the lead wires 6A, 6B may be electrically connected at different positions on the conductive foils 3A, 3B.

[0021] There are no particular limitations on the procedures or steps in the manufacturing method for manufacturing the voice coil 10, and various variations are possible. For example, after preparing the ends 5A and 5B of the conductive foils 3A and 3B, the locations where the ends 5A and 5B should be placed may be determined based on the positions or lengths of the ends 5A and 5B, and the ends 5A and 5B may be placed in the determined locations. [Explanation of symbols]

[0022] 1 coil bobbin, 2 coil, 3A, 3B conductive foil, 4 electric wire, 5A, 5B end, 6A, 6B lead wire, 7A, 7B solder, 10 voice coil

Claims

1. A coil bobbin, a coil wound around the coil bobbin; Two conductive foils attached to the coil bobbin and electrically connected to one of the two ends of the coil, respectively; two fixed connection parts that fix the two end portions while electrically connecting them to the conductive foils in a state where the two end portions are wound along the surfaces of the corresponding conductive foils; A voice coil comprising:

2. The two ends are fixed by the two fixed connection portions in a state where they are wound around the surface of the corresponding conductive foil by one or more turns.

2. The voice coil of claim 1.

3. each of the two ends being an uninsulated portion of the wire used as the coil; Each of the two fixed connection portions fixes one of the two end portions and a portion of the electric wire continuing to the one end portion.

3. The voice coil according to claim 1 or 2.

4. The two uninsulated ends of the coil wound on the coil bobbin are wound along the surface of a corresponding conductive foil attached to the coil bobbin, the two ends in the rolled state are fixed while being electrically connected to the corresponding conductive foils; How to manufacture a voice coil.

Images