JP2866272B2 - 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 used for conveying a magnetic developer.

[0002]

2. Description of the Related Art In a conventional electrophotographic apparatus or electrostatic recording apparatus, a permanent magnet having a plurality of magnetic poles inside a non-magnetic sleeve is used as a means for transporting a magnetic developer, for example, as a developing roll or a cleaning roll. Magnet rolls in which members are arranged and both are relatively rotated are often used. Many of these magnet rolls have a structure as shown in FIG. 4, reference numeral 10 denotes a magnet 1 having a plurality of magnetic poles extending on the surface in the axial direction.
Is a magnet member fixed around the shaft 2.
The magnet 1 is formed, for example, by molding with a sintered ferrite magnet or by integrally molding a mixture of ferromagnetic powder and resin by a method such as injection molding or extrusion molding, and has a diameter of 15 to 60 mm and a length of 15 to 60 mm. Is 200-35
It is often 0 mm. At both ends of the shaft 2, flanges 42 are mounted via bearings 45.
A cylindrical sleeve 41 is fixed to 2. In many cases, a plurality of grooves are formed on the surface of the sleeve 41 in the axial direction in order to improve the transportability of the magnetic developer. The cylindrical sleeve 41 is fixed to the flange 42 by applying an adhesive to the flange 42 (injecting the adhesive into the circumferential groove 43 for storing the adhesive of the flange 42) and then applying the adhesive to the sleeve 4.
1 is inserted into the flange 42, and thereafter, the adhesive is cured by heat treatment or the like. As a related prior art, for example, Japanese Patent Publication No. 61-3027
1 and JP-A-2-50182.

[0003]

In the prior art, since the circumferential groove 43 for storing the adhesive provided in the flange 42 is small (for example, about 1 to 2 mm in width and about 0.5 to 1 mm in depth), the coating is performed. The adhered adhesive protrudes to the surface of the sleeve 41 and adheres to the surface of the sleeve. In this manner, the function of the magnet roll may be impaired due to the adhesive 44 adhered to the surface of the sleeve 41 (developer adheres to the protruding adhesive and the image quality deteriorates). . Therefore, the protruding adhesive 44 must be removed. Conventionally, the removal of the adhesive 44 is performed by a wiping operation using a solvent. Was.

Accordingly, the present invention has been made in view of the above-mentioned problems of the prior art, and has an object to fix a grooved sleeve to a flange without lowering workability. It is to prevent the adhesive from impairing the function of the magnet roll.

[0005]

In order to achieve the above object, according to a first aspect of the present invention, there is provided a cylindrical sleeve having grooves formed in the surface thereof at predetermined intervals in an axial direction, and provided inside the sleeve. A magnet member having a plurality of magnetic poles on the surface, and a flange having a flange on the outer peripheral surface of the end and being fixed to the sleeve by an adhesive with the end of the sleeve in contact with the flange. In the magnet roll in which the sleeve and the magnet member rotate relatively, the outer diameter of the flange of the flange is made smaller than the outer diameter of the sleeve, and the flange is formed between the flange and the end of the sleeve. The stepped portion was used as a reservoir for the adhesive. Further, in the second invention, a cylindrical sleeve having grooves formed in the surface thereof at predetermined intervals in the axial direction, a magnet member provided inside the sleeve and having a plurality of magnetic poles on the surface, A magnet having a flange on the outer peripheral surface thereof and having a flange fixed to the sleeve by an adhesive in a state where the end of the sleeve is in contact with the flange, wherein the sleeve and the magnet member rotate relatively. In the roll, the outer diameter of the flange portion of the flange is smaller than the groove bottom diameter of the groove formed in the sleeve, and the step formed between the flange portion and the end of the sleeve is formed with an adhesive reservoir. Department.

[0006]

According to the present invention, a step is formed between the flange of the flange and the end of the sleeve, and this step can be used as a reservoir where the adhesive protrudes and accumulates. In this case, since the adhesive does not protrude outside the outer peripheral surface of the sleeve, the adhesive used for fixing does not hinder the function of the magnet roll.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. The configuration of the magnet roll according to the present invention will be described with reference to FIG.
FIG. 1A is a longitudinal sectional view of the magnet roll, and FIG.
FIG. 2B is a sectional view taken along line AA of FIG. The magnet roll 100 is formed by arranging a magnet member 10 formed by fixing a magnet 1 having a plurality of magnetic poles on the surface around a shaft 2 inside a cylindrical sleeve 5. The sleeve 5 is formed of a non-magnetic metal material such as an aluminum alloy and stainless steel.

At both ends of the sleeve 5, a flange 3a for driving the sleeve and a flange 3b for maintaining the concentricity of the sleeve are mounted. The flanges 3a and 3b are formed of, for example, a non-magnetic metal material such as an aluminum alloy. Then, both ends of the sleeve 5 are inserted into the flanges 3a and 3b, respectively, and fixed with an adhesive. Here, the flange 3 a has a shaft 35 for transmitting a driving force from an external driving source (not shown) to the sleeve 5.
Bearings 4 are fitted into the flanges 3a and 3b, respectively, and the shafts 2 are supported by these bearings 4. With such a configuration, the sleeve 5 and the magnet member 10 can relatively rotate.

A photosensitive drum (not shown) is provided in parallel with the cylindrical sleeve 5, and the toner held on the outer periphery of the sleeve 5 is conveyed onto the electrostatic latent image on the developing portion of the photosensitive drum. Is attached to the electrostatic latent image.
As shown in FIG. 2A, a plurality of grooves 50 are formed in the surface of the sleeve 5 at predetermined intervals in the axial direction.
The reason why the grooves 50 are provided is to improve the transportability of the magnetic developer. FIG.
It is a cross section of a CC section of (a).

The groove 50 is particularly effective in improving the transportability of a two-component developer composed of a magnetic carrier and a toner. Here, examples of the magnetic developer used to transport the toner onto the latent image include a one-component magnetic toner or a two-component developer including a magnetic carrier and a toner. At this time, a rough surface is formed on the surface of the sleeve in order to improve the transportability. However, when a one-component magnetic toner is used as a developer, blast processing using spherical particles or irregular particles is performed. In many cases, a surface roughening process is performed. However, in the case of a two-component developer, the size of the carrier is large (average particle diameter of the carrier: about 50 to 100 μm, average particle diameter of the toner:
(Approximately 5 to 10 μm), so that the transportability of the developer is not so improved by the blasting. Therefore, in the case of a two-component developer, it is preferable to form the groove 50 on the surface of the sleeve 5 as described above. However, this means that the present invention
It does not mean that it is not applied to a developer other than the component developer.

A step B is formed between the flange 31 and the end 51 of the sleeve 5. This step B is formed by the flange 3
Is used as a storage portion for storing the protruding portion 6 of the adhesive applied to fix the sleeve 5 to the base. That is,
The fixing of the sleeve 5 to the flange 3 is performed by injecting an adhesive into a circumferential groove 33 for storing an adhesive provided in the flange 3 and then inserting the sleeve 5 into the flange 3.
At that time, the adhesive leaks out from the adhesive reservoir circumferential groove 33 and protrudes outside the flange 3. The protruding adhesive 6 accumulates in the step B.

The shape of the flange 3 and the sleeve 5 is determined so that the protruding portion 6 of the adhesive accumulated in the step B does not protrude outside the outer peripheral surface of the sleeve 5.
This is because if the protruding portion 6 of the adhesive protrudes outside the outer peripheral surface of the sleeve 5, the protruding adhesive impairs the function of the magnet roll (the protruding adhesive is filled with the developer. And the image quality deteriorates).

Next, the relationship between the shapes of the flange 3 and the sleeve 5 will be described with reference to FIGS. FIG. 3 (a)
Is a cross section cut along the plane passing through the groove bottom of the groove formed in the sleeve
FIG . The flange 3 supporting the end 51 of the sleeve 5 is provided on the flange 3b. The outer diameter (D1) of the flange 31 is smaller than the outer diameter (D2) of the sleeve 5. Further, it is preferable that the outer diameter (D1) of the flange portion 31 be smaller than the groove bottom diameter (D3) of the groove 50 formed in the sleeve 5. In this way, a step B is formed between the flange 31 and the end 51 of the sleeve 5, and the portion of the adhesive applied to fix the sleeve 5 to the flange 3 is formed on the step B. 6 accumulates. In FIG. 1, the flange 3b for holding the sleeve concentrically has been described as an example, but the same applies to the flange 3a for driving the sleeve.

[0014]

According to the present invention, since the adhesive does not protrude outside the outer peripheral surface of the sleeve, it is possible to prevent the adhesive used for fixing from impairing the function of the magnet roll. Performance can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a magnet roll according to the present invention.

FIG. 2 is a view showing a shape of a grooved sleeve.

FIG. 3 is a view showing a relationship between shapes of a flange and a sleeve.

FIG. 4 is a diagram showing a configuration of a conventional magnet roll.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnet 2 Shaft 3 Flange 4 Bearing 5 Sleeve 6 Extruded part of adhesive B Stepped portion 10 Magnet member 50 Groove 100 Magnet roll

Continuation of front page (56) References JP-A-58-59471 (JP, A) JP-A-1-248771 (JP, A) JP-A-2-50182 (JP, A) JP-A-5-197280 (JP) , A) Fully open sho 56-40550 (JP, U) Full open 56-154009 (JP, U) Full open 4-79368 (JP, U) Full open 30-30769 (JP, U) Full open 59-104153 (JP, U) JP-B 61-30271 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 15/08-15/095

Claims (2)

(57) [Claims] 1. A cylindrical sleeve having grooves formed in the surface thereof at predetermined intervals in the axial direction, a magnet member provided inside the sleeve and having a plurality of magnetic poles on the surface, and an outer peripheral surface of an end portion. A magnet roll having a flange portion and a flange fixed to the sleeve by an adhesive in a state where the end of the sleeve is in contact with the flange portion, wherein the sleeve and the magnet member rotate relatively. A magnet roll, wherein an outer diameter of a flange portion of a flange is smaller than an outer diameter of the sleeve, and a step formed between the flange portion and an end of the sleeve is a reservoir for an adhesive. . 2. A cylindrical sleeve having grooves formed in the surface thereof at predetermined intervals in the axial direction, a magnet member provided inside the sleeve and having a plurality of magnetic poles on the surface, and an outer peripheral surface of an end portion. In a magnet roll having a flange portion and a flange fixed to the sleeve by an adhesive in a state where the end of the sleeve is in contact with the flange portion, the sleeve and the magnet member rotate relatively. The outer diameter of the flange of the flange is smaller than the groove bottom diameter of the groove formed in the sleeve, and the step formed between the flange and the end of the sleeve is used as a reservoir for the adhesive. A magnet roll characterized by the following.