JPS589305A - Magnetized yoke - Google Patents

Abstract

PURPOSE:To make it possible to make a permanent magnet in which magnetic poles of the same kind are laid close to each other simply with a few production processes by providing a groove in the magnetized end of a yoke with a magnet. CONSTITUTION:A groove 21 is provided in a magnet that is attached to a yoke 20, so that the magnet has two ridges. When direct current is passed through the coil 8 of the yoke 20, the magnetic field in the radial direction at the tip end face of the yoke 20 has two peaks. Accordingly, the magetic field generated by the poles of the permanent magnet that is attached to the yoke 20 has two peaks with the same effect as arranging magnetic poles of the same kind close to each other.

Description

[Detailed description of the invention] The present invention relates to a magnetizing yoke of permanent magnetic material.

In recent years, a magnetic brush phenomenon method has been commonly used as a developing method for electronic copying machines and printers.

There is a two-component developing method that uses a two-component developer consisting of a carrier mainly made of magnetic material and a non-magnetic toner as a magnetic developer, and a two-component developer that uses a magnetic powder as a component of the toner itself. There is a one-component moat method that uses magnetic toner contained in the magnetic toner. In either method, a developing roll containing a built-in magnet means is rotated to supply developer to the latent III carrier to create an image. As the magnet means of this developing roll, (! By variously changing the arrangement of the magnetic poles, it is possible to change the magnetic properties of the developing roll, such as the magnetic flux density, magnetic lines of force, and magnetic attraction near the surface of the l1m roll.
Furthermore, the transport characteristics and development characteristics of the developer can be adjusted to values that allow desired effects to be obtained.

The O-magnetized eye according to the present invention and the magnetic pole arrangement of a permanent magnet magnetized using the same will be described by way of example.

FIG. 1 shows an example of the developing device shown in Utility Model Publication No. 44-11192, in which bar magnets 3a431) and 3C are arranged so that the same kind of poles are lined up on the side where the developing roll 2 faces the surface of the latent image carrier l. are arranged. It is said that by arranging the magnetic poles in this manner, a uniform, soft and gentle distribution of the developer is formed, and a good image uniformity can be obtained. However, in order to assemble the same poles facing the same side as shown in Figure 1, it is necessary to devise a strong adhesive fixing means that can be fixed against the repulsive force of the same poles of each bar magnet. There were problems such as requiring special equipment, requiring a large number of man-hours, and limiting the strength of the magnetic force of the magnet.

FIG. 2(a) is an example of the developing magnetic pole shown in 1% Patent Publication No. 54-95243, in which a groove 10 is formed near the center of the surface of the magnet 30 to generate a magnetic field as shown in FIG. 2(b). By using this as a developing magnetic pole, it is said that an effect similar to that obtained by arranging magnetic poles of the same type as shown in FIG. 1 can be obtained. The magnet shown in FIG. 2 is said to be simpler in structure and assembly than the magnet shown in FIG. 1, which is made by arranging a plurality of magnets, but the magnet material is generally hard and brittle.

It is not easy to form the groove 10, and it may be damaged during processing.

FIG. 3 is an example of a phenomenon device shown in Japanese Patent Application Laid-Open No. 110642/1982, in which a cylindrical permanent magnet roll 5 is magnetized so that a plurality of magnetic poles are formed on its surface. The portion fixed toward the latent image carrier 1 is magnetized so that the same polarity is arranged close to each other. This developing device is also expected to have the same effects as the examples shown in FIGS. 1 and 2 described above.

FIG. 4 is a diagram showing a method of magnetizing a magnet roll as used in the example of FIG. 3. 6 is a permanent magnet material formed into a cylindrical shape, and 7 is an electromagnetic yoke provided with a coil winding 8. The yoke iron core functions to guide the magnetic flux generated by the coil to the permanent magnet material and magnetize the permanent magnet material according to the direction of the magnetic flux. Therefore, the end surface of the yoke that contacts the permanent magnet material is in close contact with the permanent magnet material, and the curvatures of both are formed to be the same so that magnetic flux does not leak. The electromagnetic yoke for magnetization has a coil winding at its base, so if you try to bring two adjacent magnetic poles closer together, the windings will collide with each other, so the distance will increase. has a lower limit. In order to reduce this distance using the method shown in Figure 144, it was necessary to increase the length from the winding to the tip of the yoke, or to make the yoke a special bent shape.0 Another method of magnetization FIG. In this method, adjacent magnetic poles of the same type are magnetized twice, and the distance between the magnetic poles can be reduced until the magnetic poles completely overlap. However, even with this method, the distance between the magnetic poles must be set by changing the angle two or more times, and the material must be adjusted. There were problems such as:

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetizing yoke that improves the above-mentioned problems and allows permanent magnets with adjacent magnetic poles of the same type to be easily produced with a small number of man-hours. Another object of the invention is to provide a permanent magnet having adjacent magnetic poles of the same type,
It is an object of the present invention to provide a magnetizing yoke capable of producing a small-sized magnet with a dense magnetic pole structure 1 and less variation in characteristics.

The invention will be explained below with reference to the accompanying drawing EiiK.

Figure 6 is a diagram showing an example of magnetization according to the present invention. It is desirable that the yoke be made of a so-called magnetically soft material that has high magnetic susceptibility and saturation magnetic flux density and low coercive force, and soft iron for electromagnets. , magnetic stainless steel, permalloy, and other materials for electromagnetic equipment are used. The coil winding 8 is made by winding an electric wire such as an enameled wire several thousand times, and generates a magnetic field of about 1,000 to 10,0000 e at the tip of the yoke depending on the value of the current applied. A groove 4 is formed on the magnetized surface at the tip of the magnetization surface 5, and the magnetization surface 5 has two chevron shapes.

When direct current is applied to the winding of this yoke, Fig. 87 (a)
The magnetic field in the radial direction on the A plane has two peaks as shown in FIG. 7 (1+). However, the magnetic field created by the magnetic poles of a permanent magnet magnetized by the lever magnetization still has two peaks and produces the same effect as the magnet shown in Figures 1 to 3. can.

Furthermore, the distribution of the magnetic field on the magnetic pole magnetized by the magnetizing yoke of the present invention can be made into a desired shape by changing the width and depth. For example, if the width of the groove 4 is widened and the depth is made deep, the distance between the two peaks will be wide and the valley will be deep, as shown in Figure 8 (,), and conversely, if the width is made narrow
If the depth is made shallow, a shape as shown in (b) can be obtained.

FIG. 9 is a diagram showing another embodiment of the magnetizing yoke of the present invention. In the example shown in FIG. 9, two #$21 poles are formed on the magnetized surface, and three similar magnetic poles are formed on the magnetized permanent magnet.

FIG. 10 is a diagram showing still another embodiment of the magnetizing yoke of the present invention. In the example shown in FIG. 10, the magnetized surface of the yoke is concave, and a magnet having a convex surface with approximately the same curvature as the cylindrical surface is magnetized.

Adjacent magnetic poles of the same type can be formed on six sides using a magnetizing yoke that can be easily and efficiently carried out.

As described above, if the magnetizing yoke of the present invention is used, adjacent magnetic poles of the same type can be magnetized without using a large number of magnetizing yokes or repeating magnetization multiple times as in conventional methods. can form a repulsive magnetic pole. Furthermore, according to the magnetizing yoke of the present invention, it is possible to create a magnet with a small distance between multiple magnetic poles of the same type, or a magnet with a large number of magnetic poles of the same type adjacent to each other, compared to conventional methods. It is very simple and can be produced in large quantities at low cost.

As an example of the use of the permanent magnet of the present invention, a magnetic brush l
Although the description has been made regarding the developing roll of an ie device, it goes without saying that the present invention can be applied to other cases as well.

FIG. 6 is a sectional view showing a conventional magnetization method, and FIG. 6 is a perspective view showing an example of the magnetization yoke of the present invention.

FIG. 7(a) is a cross-sectional view of the magnetized wire in FIG.
(b) is a graph showing the magnetic field of the magnetizing yoke, and No. 8@l is a graph showing an example of the magnetic flux density of the permanent magnet by the magnetizing yoke of the present invention. Figure 6 is a cross-sectional view showing another embodiment of the magnetizing yoke of the present invention, and Figures 11 (1) and (i =) are cross-sectional views showing an example of a permanent magnet using the magnetizing yoke of the present invention. .

Code in the figure: 1...a Image carrier: 2-...Developing roll; 3 m
g3k.

3c, 4... Bar magnet; s = 26... Cylindrical magnet; 6... Cylindrical magnet material: 7, 2G... Magnetizing yoke; 8... Coil winding; 9... Magnet material; 1
0,21...#: 25...Horse-shaped magnet.

@411 Figure 5 Figure 6

Claims (1)

[Claims] Magnetization 5-1k is characterized in that a chisel magnet magnetization yoke is provided with a groove at the tip of the magnetization surface to create a permanent magnet by magnetizing a magnetic material.