JPS6250963B2 - - Google Patents

Description

Detailed Description of the Invention Object of the Invention (Field of Industrial Application) The present invention relates to a method of magnetizing a magnetic member after assembly of a magnetic circuit unit used in a speaker, etc. The so-called prepared
This invention relates to a magnetization method suitable for magnetizing an AV specification magnetic shield type magnetic circuit unit.

(Prior art) Generally, the magnetic circuit of a speaker is constructed using a single field magnet, but in recent years, the field magnet has been stacked with a demagnetizing field magnet that is magnetized with a polarity opposite to that of the field magnet. Various types of so-called AV (audio visual) specifications are available, which greatly reduce external leakage magnetic flux.

(Problem to be Solved by the Invention) However, when manufacturing this type of AV specification speaker unit, magnets magnetized in advance to a predetermined strength are sequentially stacked together with the top plate, but the top plate is not interposed. However, it is difficult to join the repulsing magnets together, and this has been a cause of decreased productivity.

Furthermore, since the magnet is pre-magnetized in an open circuit, there is a possibility that demagnetization after magnetization will be significant, making it impossible to obtain the required magnetic field.

For this reason, in the past, magnets with excellent coercive force were used to cope with the above-mentioned demagnetization, but this had the drawback of increasing costs. Furthermore, when assembling using a magnet that has been magnetized in advance, metal dust from the surrounding area tends to adhere during work, and there is a risk that this metal dust may come into contact with the voice coil or the like, resulting in malfunction.

Therefore, in order to solve the above-mentioned problems, it is desirable to assemble a magnetic circuit unit using unmagnetized magnetic members and then magnetize them. There was no suitable magnetization method for magnetizing it as a magnetic field magnet.

The present invention has been made in view of the above-mentioned points, and its object is to arrange an intermediate plate between the unmagnetized magnet members to assemble a magnetic circuit unit, and then to generate reciprocal energy between the unmagnetized magnets. The object of the present invention is to provide a method capable of magnetizing a magnetic field.

"Structure of the Invention" (Means for Solving Problems) The magnetization method in the magnetic circuit unit according to the present invention includes a top plate, one unmagnetized magnet, an intermediate plate, the other unmagnetized magnet, and a yoke. A magnetic circuit unit is assembled by sequentially stacking the magnetic circuit units, and this is housed in a magnetizing device composed of a main yoke, an excitation coil, and an excitation yoke. By applying a magnetic field passing through the intermediate plate, the one unmagnetized magnet member, and the top plate via the yoke, the one unmagnetized magnet member is magnetized, and in a second step, the By applying a magnetic field that passes through the intermediate plate, the other unmagnetized magnetic member, and the yoke via the excitation yoke, the other unmagnetized magnetic member is magnetized and the one unmagnetized magnetic member is magnetized. are magnetized so that they have opposite polarity.

(Function) A magnetic circuit unit is assembled by sequentially stacking the top plate, one unmagnetized magnet member, the intermediate plate, the other unmagnetized magnet member, and the yoke, and as a first step, for example, the intermediate plate, one of the A magnetic field passing through the unmagnetized magnetic member (for driving) and the top plate is applied to magnetize one unmagnetized magnetic member, and then, in a second step, the intermediate plate and the other unmagnetized magnetic member ( (for demagnetizing field), a magnetic field passing through the yoke is applied to magnetize the other unmagnetized magnet member.
As a result, the one and the other unmagnetized magnet members can be magnetized to polarities that repel each other.

(Example) An example of the magnetization method in a magnetic circuit unit according to the present invention will be described with reference to the drawings together with an apparatus used for the implementation.

In the figure, 1 indicates a magnetic circuit unit, which includes a top plate 2, one unmagnetized magnet member 3,
It is constructed by sequentially stacking an intermediate plate 4, the other unmagnetized magnet member 5, and a yoke 6 having a yoke pole 7. Reference numeral 8 designates the entire magnetizing device for magnetizing the one and the other unmagnetized magnet members 3 and 5 in the magnetic circuit unit 1 to mutually opposing polarities, and in the embodiment,
It is composed of a main yoke that also serves as a bottom plate, an excitation coil 10 wound around the outer surface of the main yoke 9, and an excitation yoke 11 for exciting the magnetic circuit unit 1.

The magnetizing device 8 accommodates the magnetic circuit unit 1 and magnetizes one and the other unmagnetized magnet members 3 and 5 by applying a high voltage to the excitation coil 10. Two types of arrangement conditions are required as shown in FIGS. 2 and 3. What is shown in FIGS. 1 and 2 shows an example of a configuration for applying excitation to the first unmagnetized magnet member 3, and the excitation yoke 1
1 is shown as a tubular body erected on the main yoke 9, and its upper edge 12 is constricted inwardly so as to correspond to the outer edge of the intermediate plate 4. In this case, in order to prevent the magnetic flux 15 generated by energizing the excitation coil 10 from directly passing through the main yoke 9 and entering the unmagnetized magnet member 5, there is a large magnetic resistance between the bottom surface of the yoke 6 and the top of the main yoke 9. Although it is necessary to provide a space, in this case, the space may be simply a space with a non-magnetic material sandwiched therebetween. Therefore, the excitation yoke 11
When setting the corresponding position between the upper edge 12 and the outer surface of the intermediate plate 4, it is necessary to take into account the height of the non-magnetic material, and based on this, the yoke 11
It is necessary to determine the height position of the On the other hand, FIG. 3 shows an example of a configuration for applying excitation to the second unmagnetized magnet member 5, in which the excitation yoke 11 has its outer peripheral side 13 joined to the upper edge of the excitation coil 10, and its inner surface 14 is formed into a disk shape so as to correspond to the intermediate plate 4.

In the above-mentioned configuration, to explain an example of its operation, first, as a first step, as shown in FIG.
The upper edge 12 of the excitation yoke 11 is held at a position corresponding to the intermediate plate 4. Next, the excitation coil 10 is energized, and the main yoke 9 and the excitation yoke 1 are
1. A magnetic flux 15 from the intermediate plate 4 and the first unmagnetized magnet member 3 to the top plate 2 is generated to magnetize the first unmagnetized magnet member 3. Subsequently, as a second step, as shown in FIG.
The inner surface 1 of the excitation yoke 11
4 corresponds to the intermediate plate 4. In the above state, the excitation coil 10 is energized with a polarity opposite to that in the first step to generate a magnetic flux 16 from the intermediate plate 4 to the second unmagnetized magnet member 5 to the yoke 6 to the main yoke 9. The second unmagnetized magnet member 5 is magnetized. By performing the magnetization process as described above, the first and second unmagnetized magnet members 3, 5
The opposing surfaces are magnetized with the same polarity, that is, with opposite polarities, so that external leakage magnetic flux can be canceled out.

In the above embodiment, an example was described in which the first unmagnetized magnet member 3 was magnetized first, but it is of course possible to magnetize the second unmagnetized magnet member 5 first. It is.

In short, a strong magnetic field is applied from the outside to a magnetic circuit unit assembled by sequentially stacking the top plate 2, one unmagnetized magnet member 3, the intermediate plate 4, the other unmagnetized magnet member 5, and the yoke 6. Since the magnet is magnetized by applying a magnet to the magnet, various problems caused by conventional assembly using magnets that are magnetized can be solved.

``Effects of the Invention'' According to the method of magnetizing a magnetic circuit unit according to the present invention, the magnetic circuit unit assembled using unmagnetized magnet members is instantly magnetized in a post-process, so that production can be reduced. Not only does it have extremely good properties, but there is no risk of metal dust adhering to the magnet during the assembly process, and the product defect rate can be greatly reduced. Moreover, not only can the magnetic circuit unit be magnetized in a closed circuit state, resulting in a good magnetization rate, but also only slight demagnetization occurs after magnetization, so a magnetic member with high coercive force is used. It has excellent features such as being unnecessary and can be manufactured at low cost.

[Brief explanation of the drawing]

The drawings show an embodiment of the magnetization method in the magnetic circuit unit according to the present invention, and FIGS. 1 and 2 show an apparatus for magnetizing one unmagnetized magnet member, and FIG. Partially cut away perspective view, 2nd
The figure is a sectional view, and FIG. 3 is a sectional view showing an apparatus for magnetizing the other unmagnetized magnet member. 1...Magnetic circuit unit, 2...Top plate,
3...One unmagnetized magnet member, 4...Intermediate plate, 5...Other non-magnetized magnet member, 6...Yoke, 8...Entire magnetizing device, 9...Main yoke, 10...
Excitation coil, 11...excitation yoke.

Claims (1)

[Claims] 1 Top plate, one unmagnetized magnet,
The intermediate plate, the other unmagnetized magnet, and the yoke are stacked one on top of the other to assemble a magnetic circuit unit, which is housed in a magnetizing device composed of a main yoke, an excitation coil, and an excitation yoke. In this step, the one unmagnetized magnetic member is attached by applying a magnetic field passing through the intermediate plate, one unmagnetized magnetic member, and the top plate via the excitation yoke in the magnetizing device. In a second step, a magnetic field passing through the intermediate plate, the other non-magnetized magnet member, and the yoke is applied to the other non-magnetized magnet member through the excitation yoke. 1. A method for magnetizing a magnetic circuit unit, characterized in that magnetization is performed so as to have a polarity opposite to that of magnetizing an unmagnetized magnet member.