JPH0954498A - Magnet roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain such a magnet roll that a faucet joint working of the sleeve can be omitted and the production cost can be decreased. SOLUTION: This magnet roll consists of a permanent magnet member 1 having plural magnetic poles along the axial direction formed on the outer surface, a hollow cylindrical sleeve 6 produced by using a nonmagnetic metal which enables plastic processing, and flanges 3, 4 fixed to the both ends of the sleeve 6 so that the roll can be relatively rotated. The sleeve 6 is produced by at least three times of drawing to obtain a uniform thickness all over the length of the sleeve with <=0.04mm fluctuation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnet roll used as a developing roll or a cleaning roll in electrophotography, electrostatic recording and the like.

[0002]

2. Description of the Related Art Conventionally, many magnet rolls used as a developing roll or a cleaning roll in electrophotography, electrostatic recording and the like have a structure as shown in FIG. In FIG. 2, reference numeral 1 denotes a permanent magnet member, which is integrally molded into a cylindrical shape with a sintered powder magnet material such as hard ferrite, or a cylindrical shape with a mixture of a ferromagnetic material and a binder. The shaft 2 is coaxially fixed to the shaft.

A plurality of magnetic poles (not shown) extending in the axial direction are provided on the outer peripheral surface of the permanent magnet member 1. Next, flanges 3 and 4 are rotatably attached to both ends of the shaft 2 via bearings 5 and 5, and a sleeve 6 formed in a hollow cylindrical shape is fitted to the flanges 3 and 4. The flanges 3 and 4 and the sleeve 6 are made of a non-magnetic material such as aluminum alloy or stainless steel. Reference numeral 7 denotes a seal member which is fitted between the flange 3 and the shaft 2. The permanent magnet member 1 has a diameter of 20 to 60 mm and a length of 200 to 350 mm.
In many cases

With the above structure, the magnetic developer is attracted to the outer peripheral surface of the sleeve 6 by the relative rotation between the permanent magnet member 1 and the sleeve 6 (for example, the permanent magnet member 1 is fixed and the shaft 8 is rotated). Then, a magnetic brush is formed and a predetermined developing operation or the like is performed, or a surplus magnetic developer after transfer is adsorbed from the surface of the photoconductor to perform a predetermined cleaning operation.

[0005]

Since the conventional magnet roll has a large number of constituent parts, it takes a lot of time and man-hours to manufacture, and inevitably causes a problem of cost increase. In particular, the sleeve 6 and the flanges 3 and 4 need to be integrally fixed so as not to rotate relative to each other.
In this case, the most common means is to integrate them by interposing an adhesive between them.

However, since the adhesive application area between the two is relatively small, it is difficult to secure a uniform thickness, and an excess is required when the flanges 3 and 4 are fitted in the sleeve 6. The adhesive may adhere to an undesired portion, the adhesive strength may not be secured, and relative movement may occur in the circumferential direction or the axial direction.

When a powdery adhesive is used,
Masking must be performed to prevent adhesion to undesired parts. In any case, an adhesive is used for the sleeve 6
The work of fixing and integrating the flanges 3 and 4 with each other is extremely complicated, requires a lot of time and man-hours, and has a problem that not only productivity is low but also improvement in quality cannot be expected. Particularly in recent years, the advent of a low-priced and compact copying machine or printer has been strongly desired, and there is also a problem that the above-mentioned conventional structure cannot meet the above-mentioned demand.

On the other hand, as means for mechanically fixing without using the above-mentioned adhesive, means for fixing to the flanges 3 and 4 by caulking, narrowing, curling or the like at the end of the sleeve 6 is disclosed ( For example, the actual exploitation 59-161
No. 156, Jitsukō Sho 60-5537, No. 62-3229.
5, No. 62-32296, No. 62-35090, etc.). However, even with these means, the processing of the fixed portion is complicated, and the joint strength is insufficient, and the dimensional accuracy is insufficient, and there is room for further improvement.

Particularly, in the one described in the above publication, for positioning the sleeve 6 and the flanges 3 and 4, for example, FIGS. 6, 7, 8, and 14 of Japanese Utility Model Laid-Open No. 59-161156 are disclosed. As shown in FIG. 15 and FIG. 15, it is necessary to form the flange locking thin portions 7 and 20, and the inner surfaces of both ends of the sleeves 1 and 1A to 1D must be subjected to so-called brazing. Therefore, the cost becomes high, and there is a problem that the demand for cost reduction in recent years cannot be met.

The reason why the brazing process is performed on the sleeve 6 as described above is that the inner diameter error and uneven thickness of the sleeve 6 are eliminated and the sleeve 6 is assembled as a magnet roll.
This is to reduce the shake value of the outer surface. That is, in the conventional one, for example, in order to manufacture the sleeve 6 having an outer diameter of 16 mm from A3003 aluminum alloy, first, an extruded material having an outer diameter of 18 mm and an inner diameter of 16 mm was formed into a predetermined size by two drawing processes. The error in the inner diameter and the uneven thickness were large.

In this case, the outer diameter is 17 mm and the inner diameter is 15.3 mm (the wall thickness is 0.85 mm) by the first drawing process, and the outer diameter is 16 ± 0.04 mm and the inner diameter is 14.8 ± 0.1 by the second drawing process.
mm (wall thickness 0.6 mm) and uneven thickness 0.07 mm. And in order to ensure the deflection accuracy of the outer surface of the sleeve 6, it is necessary to perform the pillbox machining an inner diameter of 15.1 ₀ ^+0.02 mm at both end portions in the circumferential surface of the sleeve 6. For this reason, the processing cost for the waxing process becomes high and the cost becomes high, and the process cost is particularly complicated for the sleeve having a small diameter.

An object of the present invention is to solve the problems existing in the above-mentioned prior art and to provide a magnet roll which can reduce the cost by omitting the brazing process of the sleeve.

[0013]

In order to solve the above-mentioned problems, in the first invention, a permanent magnet member having a plurality of magnetic poles extending in the axial direction on its outer peripheral surface and a non-plasticizable non-magnetic member. In a magnet roll in which a hollow cylindrical sleeve made of a magnetic metal material is configured to be rotatable relative to each other via flanges fixed to both ends of the sleeve, the sleeve is made full length by at least three drawing processes. We adopted the technical means of forming the same wall thickness across the entire surface, and forming the deflection value to 0.04 mm or less.

In the present invention, it is preferable that the sleeve is made of an aluminum alloy, the outer diameter of the sleeve is 10 to 20 mm, and the wall thickness is 0.5 to 1.5 mm. Second
In the invention of claim 1, a permanent magnet member having a plurality of magnetic poles extending in the axial direction on the outer peripheral surface thereof and a hollow cylindrical sleeve made of a non-magnetic metal material capable of being plastically worked are fixed to both ends of the sleeve. In a magnet roll that is configured to be rotatable relative to each other through a flange that is formed with a sleeve, the sleeve has the same wall thickness over the entire length and a runout value of 0.1.
We adopted the technical means of forming it to less than mm.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a partially omitted vertical sectional view showing an embodiment of the present invention, and the same parts are designated by the same reference numerals as those in FIG. In FIG. 1, the shaft 2 has the same diameter over its entire length. The flange 3 is formed of, for example, a copper-based sintered alloy to serve also as a bearing, forms an abutting portion 9 with the permanent magnet member 1, and positions the permanent magnet member 1 in the axial direction. The bearing 5 is, for example, a sintered oil-impregnated bearing, is formed in a hollow cup shape, and is fitted to the inner end portion of the flange 4. The flanges 3 and 4 are provided with flanges 3a and 4a at the outer peripheral end,
The sleeve 6 can be brought into contact with the end of the sleeve 6.

Next, the sleeve 6 is made of, for example, A3003 aluminum alloy and has the same wall thickness over the entire length.
Also, the deflection value is formed to be 0.04 mm or less. That is, first, for example, an extruded material having an outer diameter of 20 mm and an inner diameter of 17
mm (wall thickness 1.5 mm), material with uneven thickness 0.05 mm, outer diameter 16 mm, inner diameter 14.8 by the following three drawing processes.
mm (thickness 1.1 mm) and uneven thickness 0.03 mm.

(1) Outer diameter 18.5 mm, inner diameter 16.2 mm, wall thickness 1.15 mm (2) Outer diameter 17 mm, inner diameter 15.3 mm, wall thickness 0.85 mm (3) Outer diameter 16 mm, inner diameter 14.8 mm, wall thickness 0.6 mm Above The accuracy of outer diameter error ± 0.03mm and inner diameter error ₀ ^+0.027 can be achieved by drawing three times.

Next, the leveler has a runout value of 0.04 mm.
Corrected to the following, after cutting to a standard size, both end surfaces are processed,
It is assembled as shown in FIG. The flanges 3 and 4 can be fixed to each other by press fitting, an adhesive, a combination of press fitting and an adhesive, or other fixing means.

With the above construction, the inner diameter of the sleeve 6 is 3
The accuracy of the drawing is greatly improved as compared with the conventional one by the drawing process, so that the brazing process of the sleeve 6 as shown in FIG. 2 can be omitted.

In this embodiment, an example in which the sleeve is made of an aluminum alloy is described, but it may be made of other non-magnetic material, and an appropriate material can be selected as long as it can be plastically worked.

[0021]

Since the present invention has the structure and operation as described above, the dimensional accuracy of the inner surface of the sleeve can be greatly improved, and therefore, it is possible to eliminate the conventional embossing work.
Even if the sleeve is directly fixed to the flange, the deflection value of the outer surface of the sleeve can be kept within a predetermined specification range. Therefore, as a result of eliminating the brazing process, the manufacturing efficiency can be improved and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a partially omitted longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a partially omitted vertical sectional view showing an example of a conventional magnet roll.

[Explanation of symbols]

 1 permanent magnet member 6 sleeve

Claims (4)

[Claims] 1. A permanent magnet member having a plurality of magnetic poles extending in the axial direction on the outer peripheral surface thereof, and a hollow cylindrical sleeve made of a non-magnetic metal material capable of being plastically worked, fixed to both ends of the sleeve. In a magnet roll that is configured to be rotatable relative to each other via a flange that is formed, the sleeve is formed to have the same wall thickness over the entire length and a deflection value of 0.04 mm or less by drawing at least three times. A magnet roll featuring. 2. The magnet roll according to claim 1, wherein the sleeve is made of an aluminum alloy. 3. The sleeve has an outer diameter of 10 to 20 mm and a wall thickness dimension.
The magnet roll according to claim 2, wherein the magnet roll is formed to have a thickness of 0.5 to 1.5 mm. 4. A permanent magnet member having a plurality of magnetic poles extending in the axial direction on the outer peripheral surface thereof, and a hollow cylindrical sleeve made of a non-magnetic metal material that can be plastically worked are fixed to both ends of the sleeve. A magnet roll that is configured to be rotatable relative to each other via a flange that is formed by forming a sleeve with the same wall thickness over the entire length and a deflection value of 0.1 mm or less.