JPH0456599A - 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 Field of Industrial Application The present invention relates to speakers used in various types of audio equipment.

BACKGROUND ART Conventionally, this type of speaker has a structure as shown in FIG. 4, and its magnetic circuit has a structure as shown in FIGS. 5 and 6. 4 to 6, 31 is a cylindrical center pole made of iron, 32 is a plastic magnet mainly composed of neodymium iron alloy powder formed on the outer periphery of the upper part of the center pole 31 by a bonding method or the like; Reference numeral 33 denotes an outer yoke made of iron, with the center pole 31 disposed at the center thereof so as to form a magnetic gap 34 outside the plastic magnet 32. The ring-shaped plastic magnet 32 is magnetized in the radial direction and forms a magnetic circuit. A speaker equipped with a magnetic circuit having such a structure and magnetization direction (hereinafter referred to as a radially magnetized magnetic circuit) is shown in FIG. 4, and has many advantages. That is, the voice coil 35 is placed in the magnetic gap of the radially magnetized magnetic circuit with its center held by the damper 36, and its upper part is joined to the inner peripheral part of the diaphragm 37, and the peripheral part of the diaphragm 37 is connected to the frame 39. It is joined. 40 is a gasket, and 41 is a dust blue. In the configuration of such a brush magnetized magnetic circuit, since the magnetic flux generated from the plastic magnet 32 is directly guided to the magnetic gap 34, most of the magnetic flux generated from the plastic magnet 32 is effectively used as magnetic flux for the magnetic gap. There are advantages to using it. Therefore, compared to the generally used ferrite external magnet type, speakers using a radially magnetized magnetic circuit have extremely little magnetic leakage outside the magnetic circuit and around the speaker.
Therefore, to obtain the same performance, less than half the amount of magnets are used compared to conventional methods, and because there is little magnetic leakage, there is no need for special magnetic shielding structures when used as speakers for television receivers. It was an extremely effective means of achieving this goal.

Problems to be Solved by the Invention However, in the magnetic circuit shown in FIGS. 5 and 6 and the speaker shown in FIG. Therefore, when configuring the speaker, only one set of diaphragms 37 could be attached.

In view of these problems, the present invention aims to provide a speaker using a magnetic circuit to which a plurality of diaphragms can be attached.

Means for Solving the Problem In order to solve this problem, the present invention provides a plastic magnet bonded between a center pole and an outer yoke that are arranged concentrically, and a plastic magnet that is arranged concentrically between the outer periphery of the center pole and the inner part of the outer yoke. In addition to molding each on the periphery, a gap is provided between the two inner and outer plastic magnet parts to form a magnetic gap, and a magnetic circuit is formed with a plurality of magnetic gaps in which the inner and outer plastic magnets are magnetized in the radial direction. A voice coil that fits into the air gap is provided, and a diaphragm is coupled to this voice coil.

Effect: With this configuration, two or more radially magnetized magnetic circuit gaps can be provided on one magnetic circuit, and two different diaphragms can be operated with one magnetic circuit.

EXAMPLE Hereinafter, an example of the present invention will be explained using the drawings of FIGS. 1 to 4. FIG. 1 is a sectional view of a speaker using the magnetic circuit of the present invention. 2 to 4 are cross-sectional views showing the structure of the magnetic circuit of the present invention. First, Figures 2 to 4
The configuration of the magnetic circuit of the present invention will be explained with reference to the drawings. 1 is a cylindrical center pole made of steel; 2 is a cylindrical outer yoke also made of steel and arranged coaxially with the center pole 1; Reference numeral 3 denotes a ring-shaped inner yoke made of steel and externally mounted on the center pole 1 and inscribed in the outer yoke 2. Reference numerals 4 and 5 are ring-shaped inner circumference magnets, which are provided on the outer circumference of the upper and lower ends of the center pole 1. The inner magnet 4.5 is made of neodymium-based material.
A fine powder of iron alloy is press-molded by a bonding method and integrally formed around the center pole 10. In the embodiment, the inner peripheral magnets 4 and 5 are arranged on both sides of the inner yoke 3, but it is not necessary to sandwich the inner yoke 3, and the two magnets may be concentrated on one side. Further, in this embodiment, the ring magnets 4 and 5 circumscribing the center pole 1 are configured to have different outer diameter values, but they may have the same diameter. Similarly, numerals 6 and 7 are ring-shaped outer circumferential magnets provided on the inner circumferential surface of the outer yoke 2 at positions facing the aforementioned magnets 4 and 5 on the inner circumferential side. Similarly, the outer circumferential side magnets 6 and 7 are also bonded to the outer yoke 2 by pressure molding.
Obtained by integral molding. The combination of two sets of four magnets 4 to 7 thus arranged constitutes two magnetic gaps (magnetic gaps). That is, the outer circumference of the inner circumference side magnet 4 and the inner circumference of the outer circumference side magnet 6 constitute one magnetic gap, and similarly the inner circumference side magnet 5 and the outer circumference side magnet 7 constitute another magnetic gap. The magnetization directions of these magnets are aligned in the radial direction. That is, magnetization is performed in the radial direction so that the inner circumferential side magnet 4 and the outer circumferential side magnet 6 have the same polarity on their inner diameter sides, and the same polarity on their outer diameter sides. Similarly, in the combination of the inner circumferential side magnet 5 and the outer circumferential side magnet 7, magnetization with the same configuration is performed. However, the set of magnets 4 and 6 and the set of magnets 5 and 7 are independent from each other, and the inner peripheral side of the ring magnet may be the north pole or the south pole. As described above, it is possible to provide a plurality of magnetic circuits by simultaneously molding two sets of radially magnetized magnetic circuits (hereinafter referred to as double radial magnetic circuits) on the inner and outer peripheries of the yoke material by bonding. Next, an embodiment of a speaker using the above magnetic circuit will be described with reference to FIG. With the above-mentioned magnetic circuit shown in FIG. 2 in the center, two sets of speakers are constructed corresponding to the upper and lower magnetic gaps, respectively. That is, the voice coil 8 is fitted into the magnetic gap corresponding to the magnets 4 and 6 with its center held by a damper 9, and is joined to the diaphragm 10 at its upper part. An outer peripheral portion of the diaphragm 10 is fixed to a frame 11. 12 is dust blue, 13
is a gasket. Similarly, the voice coil 18 is fitted into the magnetic gap corresponding to the magnets 5 and 7 with its center held by a damper 19, and is joined to the diaphragm 20 at its upper part. An outer peripheral portion of the diaphragm 20 is fixed to a frame 21. 22 is a dust blue, and 23 is a gasket.

The operation of the speaker having the double radial magnetic circuit configured as described above will be described below. Inputs from the same or independent signal sources are applied to the voice coils 8 and 18, respectively, so that the diaphragms 10 and 20 can be driven independently. Therefore, in this embodiment using a double radial magnetic circuit, a magnetic circuit capable of operating two speakers can be manufactured with the same number of man-hours as it takes to manufacture one magnetic circuit.

As described above, according to this embodiment, by forming bonded plastic magnets concentrically on the outer periphery of the center ball 1 and the inner periphery of the outer yoke 3, a gap is created between the two inner and outer plastic magnet parts. By providing a magnetic circuit having a plurality of magnetic gaps in which the inner and outer ring-shaped magnets are mutually magnetized in the radial direction to form a magnetic gap, it is possible to operate two sets of speakers with one magnetic circuit. Being able to operate these two speakers has many advantages. That is, if one is used for low-pitched sounds and the other is configured for high-pitched sounds, it is possible to reproduce sound as a two-way speaker with extremely better sound quality in terms of high-fidelity reproduction than a one-unit speaker. moreover,
By attaching different types of speakers to each magnetic circuit, there are great benefits, such as being able to reproduce a variety of sound qualities with various acoustic effects.

Effects of the Invention As described above, the present invention has a plastic magnet formed by bonding into a concentric ring shape on the outer periphery of the center ball and the inner periphery of the outer yoke.
By creating a magnetic gap by creating a magnetic gap in two plastic magnet parts, and creating a magnetic circuit that magnetizes the inner and outer ring-shaped magnets in the radial direction to create multiple magnetic gaps, this technology is more effective in terms of high-fidelity reproduction than a single unit speaker. It is possible to realize an excellent magnetic circuit for a speaker that can produce a two-unit speaker capable of reproducing sound with good sound quality with the same number of man-hours as assembling one unit.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a speaker in an embodiment of the present invention;
Figures 2 to 4 are top views, cross-sectional views, and bottom views of the magnetic circuit of the same speaker, Figure 5 is a cross-sectional view of the conventional Swatby force, and Figure 6 is a cross-sectional view of the magnetic circuit of the same speaker. FIG. 4 is a top view of the same. 1...Center ball, 2...Outer yoke, 3...Inner yoke, 4.5...
Inner circumference side magnet, 6.7...Outer circumference side magnet, 8.18
...Voice coil, 9.19...Damper 10.20...Diaphragm, 11.21...
...Frame, 12.22...Dust blue, 13.23...Gasket. Name of agent: Patent attorney Shigetaka Awano and one other person Figure 7-Hole

Claims (1)

[Claims] Plastic magnets are bonded between the center pole and the outer yoke, which are arranged concentrically, and molded concentrically around the outer periphery of the center pole and the inner periphery of the outer yoke, and a gap is formed between the two plastic magnets, the inner and outer parts. A magnetic circuit having a plurality of magnetic gaps in which inner and outer plastic magnets are mutually magnetized in the radial direction is provided with a voice coil that fits into each magnetic gap, and a diaphragm is coupled to this voice coil. A loudspeaker.