JPH0531496U - Magnetic circuit for speaker - Google Patents

Abstract

(57) [Abstract] [Purpose] A magnetic circuit for loudspeakers, which has a structure that is easy to press-fit and has a strong coupling force. [Structure] For a speaker having a structure fixed to the inner surface of the outer peripheral portion of the bottom yoke by press-fitting by providing convex portions at multiple locations inside the circular portion of the outer periphery of the lower end of the cylindrical side surface of the yoke Magnetic circuit.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a magnetic circuit for a loudspeaker, which has a structure in which a side surface portion of a cylindrical yoke and a bottom yoke portion are fixed by fitting, which is easy to press-fit and has a strong coupling force.

[0002]

[Prior Art]

 As shown in FIG. 6, a conventional magnetic circuit for a speaker of this type has an inner bottom surface (2d ') magnet (5) mounted on a bottom yoke (2') and a center pole (6) mounted on the magnet. Looking out the tip magnetic pole part (6a), fit the cylindrical yoke side surface part (1a ') to the inner surface part (2b') of the rising side surface part (2a ') of the bottom yoke (2'), An annular magnetic gap (6b ') is formed. Thus, at the joint between the lower outer peripheral portion (1b ') of the side surface portion (1a') of the cylindrical tubular yoke (1 ') and the rising side surface portion (2a') of the bottom yoke portion (2 '), a cylindrical shape is formed. The lower outer periphery (1b ') of the yoke (1') was fitted and connected to the inner surface (2b ') of the side surface (2a') of the bottom yoke (2 '). ..

That is, the side surface portion (1a ′) of the cylindrical yoke (1 ′) and the bottom yoke portion (2 ′) are coupled to each other by the lower end side surface of the side surface portion (1a ′) of the cylindrical yoke (1 ′). Part (1b ') is thinned by cutting, etc. In the magnetic circuit (3 ') of the speaker having the above structure, the coupling shape of both of the fitting parts is circular.

[0004]

[Problems to be solved by the device]

 Therefore, in this type of conventional magnetic circuit, the press-fitting process for fitting is easy, but the mating part is loosely coupled, and the mating is disengaged with a slight impact, causing the magnetic circuit (3 ' There is a problem that the internal magnet (5) is broken or the pressing force is too large at the time of the fitting process and the magnet (5) is broken.

Therefore, in order to solve the problems of the conventional magnetic circuit (3 ′) for the speaker (4 ′), the present invention solves the problems of the rising side surface of the bottom yoke portion (2 ′). By forming the convex part (2c) as a caulking margin on the fitting part inside the part (2a '), the bonding force is maintained so that it is not disassembled by a slight impact for the purpose of improving and strengthening the bonding force. The present invention aims to provide a magnetic circuit (3) for a speaker.

[0006]

[Means for Solving the Problems]

 The structure of the present invention for achieving the object will be described with reference to FIGS. 1 to 3 corresponding to the embodiment. The first invention is that the outer circumference of the lower portion of the side surface portion (1a) of the cylindrical yoke (1). In the joint between the portion (1b) and the rising side surface portion (2a) of the bottom yoke portion (2), the inner surface portion (2b) of the side surface portion (2a) of the bottom yoke portion (2) is inward A speaker magnetic circuit (3) having a structure in which a convex portion (2c) protruding to the inside is provided and the two are coupled by fitting.

The second invention is, as shown in the cross section of FIG. 5, a lower peripheral portion (1b) of a side surface portion (1a) of a cylindrical yoke (1) and a rising side surface portion of a bottom yoke portion (2). At the joint with (2a), the outer surface (1b) of the side surface (1a) of the cylindrical yoke (1) is provided with convex parts (1c) protruding outward at multiple locations, and both are fitted. It is a magnetic circuit (3 ") for a speaker with a structure that is coupled by combining.

[0008]

[Action]

 Since the first invention has such a structure, when the outer periphery of the bottom yoke portion (2) is press-fitted, the convex portion (2c) provided so as to protrude inward at the corresponding portion is formed into the cylindrical yoke. It suffices to fit the outer circumference of the lower end portion (1b) of the side surface (1a) and press-fit the both so as to fit them.

In the magnetic circuit (3) of the first invention, the convex portion (2c) provided so as to project inward is provided at the corresponding location on the outer circumference of the bottom yoke portion (2), and the cylindrical yoke side surface portion is provided. It is possible to press into the circular portion on the outer periphery of the lower end portion (1b) of (1a) and crush and deform the convex portion (2c) to strengthen the binding force. As a result, the present invention can firmly join the bottom yoke portion (2) and the cylindrical yoke side surface portion (1a).

[0010]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 to 3 are sectional views of a yoke portion according to a first embodiment of the present invention.

That is, a magnet (5) is placed on the inner bottom surface (2d) of the bottom yoke (2), and a center pole (6) is fixed on the magnet (5). Inside, let the tip pole part (6a) of the center pole (6) look out, and fit the side part (1a) of the cylindrical yoke (1) to the bottom yoke (2). An annular magnetic gap (6b) is formed. Thus, the bottom yoke portion (2) is connected to the lower outer peripheral portion (1b) of the side surface portion (1a) of the cylindrical yoke (1) and the rising side surface portion (2a) of the bottom yoke portion (2). Magnetic circuit (3) for speaker (4) with a structure in which convex parts (2c) protruding inward are provided at multiple locations on the inner surface (2b) of the side surface (2a), and the two are combined and fixed by fitting. Is.

A cross-sectional view of the magnetic circuit (3 ′) shown in FIG. 4 is a modified example of the basic embodiment shown in FIG. 3 and shows a cylindrical yoke (1 ), A concave portion (1d) into which the convex portion (2c) is fitted is formed in the lower outer peripheral portion (1b). In this modified example, since the convex portion (2c) is inserted into the concave portion (1d), there is a gap between the inner surface portion (2b) of the bottom yoke (2) and the lower outer peripheral portion (1b) of the cylindrical yoke (1). The gap is narrowed and the magnetic resistance at the joint between the bottom yoke (2) and the cylindrical yoke (1) is reduced.

A magnetic circuit (3 ") of a second invention shown in FIG. 5 is a cross-sectional view of another embodiment different from the above-mentioned modified example, which is a side surface portion (1a) of a cylindrical yoke (1). On the outer periphery (1b) of the lower part of the outer diameter, the convex portion (1e) is provided outward, and it is fitted by contacting the inner surface (2b) of the side surface (2a) of the bottom yoke (2). In this example, as described above, the inner surface portion (2b) of the bottom yoke (2) is in contact with the convex portion (1e) of the cylindrical yoke (1), and the concave portion (Fig. (Not shown) does not change the effect at all.

Although the embodiments considered to be typical of the present invention have been described above, the present invention is not necessarily limited to only the structures of these embodiments, and has the above-mentioned constitutional requirements referred to in the present invention, and The present invention can be carried out with appropriate modifications within the scope of achieving the object of the present invention and having the following effects.

[0015]

[Effect of the device]

 As apparent from the above description, the magnetic circuit (3) of the first invention has the convex portions (2c) at a plurality of positions on the inner surface portion (2b) of the side surface portion (2a) of the bottom yoke portion (2). Since it is provided so as to project, the convex portion (2c) can be pressed into the cylindrical yoke side surface portion (1a), and the convex portion (2c) can be crushed and deformed to be fixed. .. As a result, it has become possible to expect a remarkable practical effect that the bottom yoke portion (2) and the cylindrical yoke side surface portion (1b) can be firmly joined by a small pressing force. Of.

Similarly, in the magnetic circuit (3 ") of the second invention, a convex portion is formed on the lower outer peripheral portion (1b) of the cylindrical yoke (1) having a small outer diameter on the side surface portion (1a). (1e) is provided so that the convex portion (1e) is fitted to the inner surface portion (2b) of the side surface portion (2a) of the bottom yoke (2) by fitting the inner surface portion (2e) to the inner surface portion of the bottom yoke (2). Since it comes into contact with (2b) and bites into it, it is crushed and deformed, so the effect of being able to fix both is no different from the former.

In addition, the speaker equipped with the magnetic circuit having the structure as in the present invention does not cause the fitting portion to be disassembled, the magnet (5) to drop off, or be destroyed by a slight impact force. It has come to be possible to expect an excellent effect.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention.

FIG. 2 is a transverse cross sectional view taken along the line II-II in FIG.

FIG. 3 is a transverse cross-sectional view taken along the line III-III in FIG.

FIG. 4 is a cross-sectional view corresponding to FIG. 3 of another application example.

FIG. 5 is a cross-sectional view corresponding to FIG. 3 of still another application example.

FIG. 6 is a vertical sectional view of a conventional example.

[Explanation of symbols]

 (1) Cylindrical yoke (1a) Side part (1b) Lower outer circumference (1c) Convex part (2) Bottom yoke (2a) Side part (2b) Lower inner surface (2c) Convex part (2d) Upper plate center hole (3) Magnetic circuit for speaker (3 ") Magnetic circuit for speaker (4) Speaker (5) Magnet

Claims (2)

[Scope of utility model registration request] 1. A bottom yoke portion (2) at a joint between a lower outer peripheral portion (1b) of a side surface portion (1a) of a cylindrical yoke (1) and a rising side surface portion (2a) of a bottom yoke portion (2). Inner surface (2a) of inner surface (2a)
In b), a magnetic circuit for a speaker having a structure in which convex portions (2c) projecting inward are provided at a plurality of locations and the two are coupled by fitting. 2. The cylindrical yoke (1) at the joint between the lower peripheral portion (1b) of the side surface portion (1a) of the cylindrical yoke (1) and the rising side surface portion (2a) of the bottom yoke portion (2). Outer surface of side surface (1a)
In (1b), by providing convex portions (1e) protruding outward at a plurality of locations,
A magnetic circuit for loudspeakers with a structure in which both are connected by fitting.