JP2537117Y2 - Magnet roll - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnet roll for developing a magnetic brush used in an electrophotographic copying machine, a laser beam printer, and a facsimile receiver.

[0002]

2. Description of the Related Art A magnet roll using magnetic pole pieces is constructed by attaching magnetic pole pieces of a required number of magnetic poles to a shaft in accordance with a copying machine process. At the same time, the trend of colorization has progressed,
Demands for image quality such as reproducibility of images or fine lines have become advanced and complicated, and specific poles of magnet rolls,
For example, the accuracy of the developing pole with respect to the shaft reference position is a major factor in its quality.

A typical conventional example will be described with reference to FIGS. FIG. 3A is a perspective view of a shaft constituting a magnet roll for magnetic brush development, and generally uses metal such as iron. FIG. 3B is a cross-sectional view of the magnet roll in which the pole pieces 8 having the required number of magnetic poles are attached to the shaft 7 . FIG. 4A shows a hollow shaft.
In the exploded perspective view , 9 is a hollow shaft main body made of an aluminum material or the like, and 10 is a shaft end. FIG.
4B is a perspective view of a shaft in which the members shown in the exploded perspective view of FIG.
(C) shows the magnetic pole piece 1 having the required number of magnetic poles in the hollow shaft body 9.
It is sectional drawing of the magnet roll which stuck 2 on it. FIG. 5 is a perspective view of a shaft in which the shaft center 14 and the concave portion 15 are provided in a metal portion by milling or the like.

[0004]

However, the conventional configuration shown in FIG. 3 does not restrict the pole position of the pole piece 8, particularly the specific pole piece 8 a, with respect to the reference surface 6 of the shaft 7. Therefore, it is extremely difficult to accurately attach the specific magnetic pole piece 8a. The recess for positioning the pole pieces 12a in hollow shafts bets shown in FIG 1
3 is provided, but the shaft end 10 is press-fitted into the shaft by the press-fitting step so that the shaft end 1 is inserted.
The positional accuracy of the concave portion 13 with respect to 0 becomes poor. In addition,
It is difficult to align the center axis of Yafuto end 10, the hollow with respect to the shaft end 10 of the support portion a shaft 9
The run-out accuracy is extremely poor, and a run-out correction process is required, which increases the cost of the shaft. Further, as shown in FIG. 5, there is a method of providing the shaft center 14 and the concave portion 15 in a metal portion by milling or the like. .

Accordingly, the present invention solves the above-mentioned problems, and allows a specific magnetic pole piece to be accurately adhered to a reference surface of a shaft. As a result, the accuracy of the magnetic pole position with respect to the reference surface of the shaft is reduced. An object of the present invention is to provide an improved and inexpensive magnet roll.

[0006]

In order to solve the above-mentioned problems, a magnet roll according to the present invention comprises a resin layer having a concave portion positioned on an outer periphery of a shaft center in a longitudinal direction of the shaft with respect to a reference surface of the shaft center. The specified shaft has a specific magnetic
The pole piece is configured by attaching a pole piece of the required number of magnetic poles to another portion .

[0007]

With this configuration, a specific magnetic pole piece is attached to the concave portion of the shaft , and the magnetic pole piece is attached to the outer peripheral surface of the remaining shaft , whereby a magnet roll with high pole position accuracy can be obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.

FIG. 1A is a perspective view of a shaft constituting a magnet roll according to the present invention. A shaft center 1 is provided with a reference surface 2 which serves as a reference for a specific magnetic pole position. Longitudinally of the axis 1 group Rijiku by the insert injection molding the outer circumference of the axis 1
Resin layer 4 having recess 3 positioned with respect to reference plane 2
Are provided integrally. Shape cross section a fan shape of the recess 3, and only set to be a predetermined angle from the center of axis 1 Oh
You . The recess 3 is located inside the recess 3 with respect to the reference surface 2.
The center axes are provided in a vertical positional relationship. Figure 1 (b) 90 is is shown a cross-sectional view of the magnet roll of the 5-pole asymmetric with adhered pole pieces 5 of necessary poles on the shaft, the center line of the particular pole piece 5a is the reference surface 2 of the shaft ° position. FIG. 2 shows a magnetic force characteristic diagram of the magnet roll having this configuration.

Positioning with respect to the reference plane 2 in the longitudinal direction of the shaft
As a method of providing the resin layer 4 having the recessed portion 3 formed, there is a method such as a compression molding method in addition to the insert injection molding. PE, PP, PA, ABS, PBT,
General thermoplastic resins such as PET or their fiber-reinforced resins can be used. It is sufficiently possible to integrate the shaft center 1 and the resin layer 4 with the same resin, and when the shaft center 1 needs to be conductive, it is possible to use a conductive resin to which carbon, metal powder or the like is added. Response is possible.

The shape of the concave portion 3 can be arbitrarily and precisely adjusted to the shape of the specific magnetic pole piece 5a by the insert injection molding.

[0012]

As is apparent from the above description, in the magnet roll of the present invention, the specific magnetic pole piece can be stuck to the concave portion of the resin layer provided accurately with respect to the reference surface of the shaft. accuracy is very good no longer, the image is well enough to accommodate relative demand for quality of reproduction or the like have fine lines, in which large consisting of industrial value which can realize the cost for only providing a resin layer on the axis is there.

[Brief description of the drawings]

1 (a) is <br/> perspective view of a shaft according to an embodiment of the present invention (b) is a sectional view of the present invention the magnet roll

FIG. 2 is a magnetic force characteristic diagram of the magnet roll of the present invention.

3A is a perspective view of a conventional shaft, and FIG. 3B is a cross-sectional view of a conventional magnet roll.

4A is an exploded perspective view of a conventional hollow shaft. FIG. 4B is a perspective view of a conventional hollow shaft. FIG. 4C is a sectional view of a magnet roll using the conventional hollow shaft.

FIG. 5 is a perspective view of a conventional machining shaft.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Axis 2 Reference surface 3 Concave part 4 Resin layer 5 Magnetic pole piece 5a Specific magnetic pole piece

Claims (1)

(57) [Scope of request for utility model registration] 1. A reference of an axis in the longitudinal direction of the axis on the outer periphery of the axis.
A magnet roll comprising a shaft integrally provided with a resin layer having a concave portion positioned with respect to a surface, and a specific magnetic pole piece attached to the concave portion and a magnetic pole piece of a required number of magnetic poles attached to other portions .