JPH0332895B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing a magnet roll for magnetic brush development used in electrophotographic copying machines, facsimile receivers, and the like.

Construction of a conventional example and its problems A method of manufacturing a roll-shaped magnet with an asymmetrical pole arrangement in a conventional magnetic brush developing magnet roll will be briefly explained with reference to FIGS. 1 to 5. Ferrite particles 1 subjected to magnetic anisotropy treatment and ferrite particles 1 in a medium 2 that joins the ferrite particles 1
is magnetically oriented in the rolling direction to obtain an anisotropic magnet sheet 4 exhibiting ferromagnetism in the thickness direction _Y1 from the length direction X1 as shown in the characteristic diagrams of FIGS _. 2a and 2b. Then, as shown in FIG. 3a, the magnetic sheets 4 are laminated in a flat plate shape by the required thickness.

This magnetic sheet laminate 5 is placed on a lower mold 6 in which fan-shaped grooves are provided at regular intervals as shown in FIG. Press-formed in Figure 3c.
After forming the wave-shaped magnet 8 as shown in FIG.
Cut and separate at C ₁ in Figure c to obtain fan-shaped magnetic pole pieces 9 as shown in Figures 3 d and e, and similarly in Figure 4 a.
The magnetic sheet laminate 10 as shown in FIG.
As shown in Figure b, the material is placed on a lower mold 11 having V-shaped grooves at regular intervals, and press-formed with an upper mold 12 having V-shaped convex portions at positions where the material is squeezed at regular intervals. After molding the zigzag-shaped magnet 13 shown in FIG. 4c, it is cut and separated at _C2 in FIG. 4c to obtain a wedge-shaped directional magnetic pole piece 14. Two types of magnetic pole pieces 9 obtained by the above method,
In order to obtain the necessary magnetic pole arrangement as shown in Fig. 5 based on 14, for example, magnetic pieces with different angles of R ₁ and R ₂ were required, which was a problem in terms of both man-hours and equipment. .

OBJECTS OF THE INVENTION In view of the above-mentioned drawbacks, the present invention provides a method for manufacturing a magnet roll for magnetic brush development, which allows the angle of magnetic pole arrangement to be arbitrarily set and further reduces the number of work steps.

Structure of the Invention In order to achieve the above-mentioned object, the present invention has a plurality of poles on the surface and divides a cylindrical cross section into arbitrary angles with the pole position as the center. A method for manufacturing a magnet roll for magnetic brush development, in which a cylindrical magnet with an asymmetric pole arrangement in which ferromagnetic axes are arranged radially around positions shifted by a necessary angle for each magnetic pole is rotatably and concentrically incorporated into a cylindrical non-magnetic sleeve. It is related to.

DESCRIPTION OF EMBODIMENTS Hereinafter, a method for manufacturing a magnet roll for magnetic brush development according to an embodiment of the present invention will be described with reference to the drawings.

First, as shown in FIG. 6, ferrite particles 15 subjected to magnetic anisotropy treatment and
The ferrite particles 15 in the medium 16 are magnetically oriented in the rolling direction by passing the composite material with the medium 16 that joins the ferrite particles 16 through the rotating rolls 17, so that the ferrite particles 15 in the medium 16 are magnetically oriented in the longitudinal direction Thickness direction Y from _{1 1}
An anisotropic magnet sheet 18 exhibiting ferromagnetism is obtained. Then, this magnetic sheet 18 is shown in Fig. 8a.
Laminate the required material thickness in a flat plate as shown in .

As shown in FIG. 8b, this magnetic sheet laminate 19 is placed on a lower die 20 in which a plurality of fan-shaped concave grooves with a total angle of 360° are continuously provided in a plane, and each fan-shaped groove is Press-forming is performed with an upper mold 22 having an inverted trapezoidal protrusion 21 in consideration of the orientation of the material at the center of the outer periphery or at a position shifted from the center by a required angle R ₃ to R ₆ for each magnetic pole individually, each having a different angle. A fan-shaped continuous integral piece 23 is formed. The fan-shaped continuous integral piece 23 thus formed is continuously wound around the shaft 24 as shown in FIG. 8c, and its outer periphery is cut to obtain a cylindrical magnet 25 as shown in FIG. 8d. . As shown in FIG. 9, the cylindrical magnet 25 obtained in this way has a magnetic flux flow as shown in the figure, for example, in the magnetic pole arrangement on the outer circumferential surface θ ₁ to θ ₄ , and a cylindrical nonmagnetic sleeve 26 A magnet roll for magnetic brush development according to an embodiment of the present invention can be obtained by rotatably attaching the roller to the inside of the roller.

Effects of the Invention As described above, in the present invention, the angles of the plurality of magnetic poles in a cylindrical magnet can be arbitrarily selected in the pole arrangement necessary for toner conveyance, pumping and development, etc., and they can be obtained by integral molding. The magnetic flux of the magnetic poles flows smoothly and effectively, improving the magnetic force of each magnetic pole, and it is also possible to integrally mold and wind it, dramatically improving workability and having great industrial value.

[Brief explanation of drawings]

Fig. 1 is a process diagram showing the conventional manufacturing process of a magnetic sheet, Fig. 2 a and b are characteristic diagrams of the magnetic sheet, and Figs. 3 a to e show the conventional manufacturing process of a fan-shaped magnet. Process diagram, Figure 4 a-d
is a manufacturing process diagram of a wedge-shaped magnet, FIG. 5 is a cross-sectional view of a conventional cylindrical magnet that combines a fan-shaped magnet and a wedge-shaped magnet, and FIG. 6 is a diagram of a magnetic brush developing magnet roll in an embodiment of the present invention. Figures 7a and 7b are characteristic diagrams of the magnetic sheet used in the magnet roll, and Figures 8a to d show the manufacturing process of the ferromagnetic material that constitutes the magnet roll. FIG. 9 is a process diagram showing the process, and is a sectional view showing an example of the flow of magnetic flux and the arrangement of magnetic poles of the magnetic brush developing magnet roll. 15... Ferrite particles, 16... Medium, 17
...Roll, 18...Magnetic sheet, 19...
...Magnetic sheet laminate, 20...Lower mold, 21
... protrusion, 22 ... upper mold, 23 ... continuous integral piece, 24 ... shaft.

Claims (1)

[Claims] 1 A composite consisting of magnetically anisotropically treated ferrite particles and a medium for bonding the ferrite particles is magnetically oriented in the rolling direction to form a magnetic sheet, and the stack of magnetic sheets is formed into a plurality of fan-shaped sheets. A lower mold with continuous flat grooves,
Press molding is performed using an upper mold having an inverted trapezoidal protrusion that takes orientation into consideration at the center of each fan-shaped outer periphery or at a position shifted by a necessary angle from this center for each magnetic pole to obtain a continuous integral piece in the fan shape. is wound around a shaft to form a cylindrical magnet with an asymmetric pole arrangement in which magnetic axes are arranged radially, and this cylindrical magnet is rotatably and concentrically incorporated into a cylindrical non-magnetic sleeve. .