JPH05158349A - Working method for magnet roll and sleeve and working method for cylindrical body - Google Patents

Abstract

PURPOSE:To decrease the run-out of the sleeve and to obtain the magnet roll having high accuracy by assembling the magnet roll incorporating the sleeve and a permanent magnet member, then subjecting the surface of the sleeve to specific machining. CONSTITUTION:The magnet roll 1 has the cylindrical sleeve 2 consisting of a nonmagnetic metallic material and the permanent magnet member having plural pieces of magnetic poles on the surface. The permanent magnet member is formed by fixing the permanent magnet around a shaft having reduced diameter parts at both ends. The surface of the sleeve 2 is machined approximately parallel with the axial direction. The working grains in the axial direction may be spirally grained in some cases by the rotating speed of the sleeve 2 and the rotating speed and feed speed of an end mill and is <=10 deg. with the direction of the machining grains by selecting rotating conditions. The machining grains are thus lowered to the level negligible in function. A blade edge coming into contact with the surface of the sleeve 2 moves axially while rotating in such a manner and, therefore, the blade edge does not escape from the surface of the sleeve. The sleeve surface is thus worked with the high accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing a magnet roll incorporated in an electrophotographic apparatus, an electrostatic recording apparatus, etc., a sleeve forming the magnet roll, and a cylindrical body.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electronic copying machine, a facsimile machine or a printer, a magnetic developer such as a one-component toner or a two-component developer composed of a magnetic carrier and toner, such as a developing roll or a cleaning roll, is used. A magnet roll is often used in which a permanent magnet member having a plurality of magnetic poles is arranged inside a non-magnetic sleeve, and both are relatively rotated.

In a normal magnet roll, side plates (hereinafter referred to as flanges) made of a non-magnetic material are attached to both ends of a cylindrical sleeve made of a non-magnetic metal material such as aluminum alloy, austenato stainless steel or brass. The structure is such that the permanent magnet member is supported by the bearing fitted to the flange. As the permanent magnet member, a cylindrical magnet made of hard ferrite is fixed to the shaft (see, for example, JP-B-55-6907), and a block-shaped anisotropic ferrite magnet is fixed to the shaft (for example, JP-B-57-57). 9758) or using a cylindrical resin magnet (for example, Japanese Patent Publication No. 2-59993).
(See Japanese Patent Publication) and the like are used.

When the above magnet roll is used as a developing roll, the surface of the image carrier and the surface of the sleeve are opposed to each other and the magnet roll is arranged so that a developing gap is formed between the two, and the magnetic surface is developed on the sleeve. It is general that the magnetic developer is fed to the developing gap by supplying the agent and rotating at least one of the sleeve and the permanent magnet member. In this case, if the sleeve deflection is large, the magnetic brush will not evenly contact the surface of the photoconductor, so
This causes a problem of image quality deterioration, which is an important problem particularly in printers and full-color copying machines that require high-definition printing quality.

For this reason, in recent years, the demands on the accuracy of the sleeve deflection have become increasingly strict. For example, when a magnetic toner or a magnetic toner and a magnetic carrier are used as a developer, the deflection of the sleeve is currently 0.03 to 0.0.
It is 5 mm, but recently, there is a demand for 0.01 mm or less. When a two-component developer containing a magnetic carrier and a non-magnetic (or weakly magnetic) toner is used as the developer, the sleeve deflection is currently allowed to be 0.05 to 0.15 mm. However, there is also a demand for making it 0.02 mm or less.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
As a method for achieving a deflection accuracy of 0.02 mm, first, it is conceivable to increase the processing accuracy when the sleeve (drawing material) is processed alone. However, even if the sleeve is centerless processed to improve the deflection accuracy, when the sleeve is assembled with other members to manufacture the magnet roll, the processing accuracy and assembly error of each component are accumulated,
The frame after assembly is usually about 0.05 mm. Therefore, by machining the surface of the sleeve after assembling the magnet roll, a deflection accuracy of about 0.01 mm may be obtained in the case of an aluminum alloy sleeve having good machinability. However, the sleeve is thin (normal thickness
(t) is 0.5 to 1.0 mm and t / D is 0.015 to 0.
(025th place) and the ratio of diameter (D) / length (L) is 5
Since the cylindrical body is longer than twice as long, there is a problem that the cutting edge of the tool escapes from the sleeve surface during processing, and a highly accurate sleeve cannot be stably obtained.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the problems existing in the above-mentioned prior art, and to provide a magnet roll having a high precision sleeve. Another object of the present invention is to provide a method for processing a sleeve that can obtain a sleeve with less deflection. Another object of the present invention is to provide a method for processing a cylindrical body, which is capable of obtaining a hollow or solid cylindrical body with less deflection.

[0008]

In order to achieve the above object, first, in the first invention, a cylindrical sleeve made of a non-magnetic metal material, and a plurality of surfaces arranged inside the sleeve are provided. In a magnet roll having a permanent magnet having individual magnetic poles, a technical means is adopted in which the sleeve is machined on its surface substantially parallel to the axial direction.

Next, in a second aspect of the invention, there is provided a magnet roll having a cylindrical sleeve made of a non-magnetic metal material and a permanent magnet member disposed inside the sleeve and having a plurality of magnetic poles on its surface. Both ends are axially supported, the front or side cutting edge of the end mill is brought into contact with the surface of the sleeve, the sleeve is rotated, and the end mill is moved at a high speed while moving relatively in the axial direction with respect to the sleeve. The technical means of letting it happen.

Next, in a third aspect of the present invention, both ends of a cylindrical body having a hollow or solid cylindrical portion are supported, and the front or side cutting edge of the end mill is brought into contact with the surface of the cylindrical portion, and the end mill is moved. The technical means of moving in the axial direction relative to the cylindrical portion while rotating at high speed was adopted.

[0011]

With the above construction, the blade edge which is in contact with the surface of the sleeve moves in the axial direction while rotating, so that the blade edge can be processed with high precision without escaping from the sleeve surface. Further, since a processed grain along the axial direction can be formed on the sleeve surface, when the magnetic developer is supplied to the sleeve surface and then the sleeve and / or the permanent magnet member is rotated to convey the developer, the development is performed. The agent conveying power is improved.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the drawings.
1 is a plan view showing a magnet roll according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. In both figures, the magnet roll 1 has a cylindrical sleeve 2 made of a non-magnetic metal material, and a permanent magnet member 3 having a plurality of magnetic poles on its surface. The permanent magnet member 3 includes a permanent magnet 5 around a shaft 4 having reduced diameter portions 4a and 4b at both ends.
It is formed by fixing. A shaft 7 is provided at both ends of the sleeve 2.
And a flat plate-shaped flange 8 are fixed to each other. The flanges 6 and 7 have bearings 9 and 9 respectively.
Is mounted and supports the reduced diameter portions 4a and 4b. The magnet roll 1 is manufactured by the following procedure. First, the sleeve material (pipe) cut into a specified length
, The flange 6 is fixed to one end of the sleeve 2, the permanent magnet member 3 is inserted into the sleeve 2, and then the flange 8 is fixed to the other end of the sleeve 2 to obtain the magnet roll 1. When the fitting accuracy of the flange and the sleeve is a problem, the inner diameter of both ends of the sleeve may be spigot processed. Then, by setting this magnet roll in a processing device described later and cutting the surface of the sleeve 2, the deflection of the sleeve can be kept within a predetermined range.

What is important here is to machine the surface of the sleeve substantially parallel to the axial direction. As shown in FIG. 3, the axial machining 8 may have a spiral shape depending on the rotation speed of the sleeve, the rotation speed of the end mill, and the feed rate. It can be set to a level of 10 degrees or less that does not cause a functional problem. The processing scratch depth is 1 at 10 degrees or more
If the thickness is 0 μm or more, the toner may be dragged into a spiral and deviated during operation. In order to prevent this, the end mill may be reciprocated with the feed direction reversed, and the machined lines may be crossed as shown in FIG. When there is a processed stitch as shown in FIG. 1, FIG. 3 or FIG. 4, magnetic developer is supplied to the sleeve surface as shown in FIG. 5, and the sleeve 15 is rotated in the direction of arrow X to develop the developer 15. When transporting to the area,
The developer transporting power can be improved. In FIG. 5, the developing device 12 includes a magnet roll 1 that forms a developing area D between the developing roller 12 and the photosensitive drum 11, and a developer 15.
And a doctor blade 14 that regulates the thickness of the developer 15 on the sleeve 2.

FIG. 6 is a plan view showing an example of an apparatus for carrying out the processing method of the present invention. In the figure, a tailstock 17 and a support 19 are provided on a substrate 16. The tailstock 17 has a center 15 that supports the reduced diameter portion 4 a of the magnet roll 1. The other reduced diameter portion 4b of the magnet roll 1 is supported by the chuck 20 of the support base 19 and is also connected to a drive source (not shown). 21
Is an end mill having a cutting edge on its side surface, and is configured to rotate in the direction of the arrow shown and move along the axial direction of the magnet roll. The end mill 18 can be moved specifically by, for example, setting the substrate 16 on a table of a machining center (not shown) and moving the table in the direction of the arrow shown. After setting the magnet roll 1 as shown in the figure (position the end mill at the left end of the sleeve), set the end mill 2
While rotating 1 at high speed from left to right in the drawing and rotating the magnet roll, the sleeve 2
Will be machined on the entire circumference. End mill 1 here
Since 8 moves in the axial direction while rotating, a machined line in the axial direction as shown in FIG. 1 is formed.

FIG. 7 is a side view showing another example of the apparatus for carrying out the processing method of the present invention, and the same portions as those in FIG. 6 are designated by the same reference numerals. This processing apparatus has the same configuration as the apparatus of FIG. 6 except that the end mill 22 having a cutting edge on the front surface is used, and the processing may be performed in the same procedure as described above. The material of the tip of the tool (end mill) may be appropriately selected according to the material of the work. For example, when the sleeve is an aluminum alloy, the diamond sintered body is used, and when the sleeve is stainless steel, the CBN is used. A (cubic boron nitride) sintered body is desirable.

(Experimental example) For example, the sleeve 2 has an outer diameter of 20.
2 mm industrial diamond end mills with an outer diameter of 16 mm made from aluminum alloy pipe (A5056)
The magnet roll 1 is rotated at a high speed of 000 rpm or more and the feed speed is 10 m / min, and the magnet roll 1 is 300 rpm.
Magnet roll 100 by rotating at pm
The book was processed and the sleeve deflection was measured. As a result, the deflection of all the magnet rolls was 10 μm or less, and 55 out of 100 rolls could contain the deflection of 3 to 5 μm or less.

In the above examples, the processing of the sleeve of the magnet roll has been described, but the present invention is not limited to this, and it goes without saying that the present invention can be applied to the processing of a cylindrical body having another hollow or solid cylindrical portion. is there. More specifically, the machining method of the present invention does not require high-speed rotation of the workpiece in the outer periphery machining of a hollow or solid cylindrical body, the cutting speed can be increased, and the main cutting force is directed in the axial direction of the workpiece. It has advantages such as being able to. Therefore, the present invention is an effective method for a work in which a desired machining accuracy cannot be obtained by ordinary machining in terms of machinability and rigidity of the work, and has the above-mentioned advantages. It is possible to exert an excellent effect when it is applied to the outer peripheral processing of a cylindrical body that wants to take advantage of the high degree of freedom.

[0018]

As described above, according to the present invention, after the magnet roll including the sleeve and the permanent magnet member is assembled, the surface of the sleeve is subjected to the specific cutting process, so that the sleeve is prevented from being shaken with high accuracy. You can get the magnet roll. Further, since the magnet roll of the present invention has axially machined lines on the surface of the sleeve,
The developer transportability can be improved.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a plan view showing another embodiment of the present invention.

FIG. 4 is a plan view showing another embodiment of the present invention.

FIG. 5 is a sectional view of a developing device incorporating the magnet roll of the present invention.

FIG. 6 is a plan view showing an example of an apparatus for carrying out the processing method of the present invention.

FIG. 7 is a side view showing another example of an apparatus for carrying out the processing method of the present invention.

[Explanation of symbols]

 1 Magnet Roll 2 Sleeve 3 Permanent Magnet Member 10 Machining 21 End Mill

Claims (4)

[Claims] 1. A cylindrical sleeve made of a non-magnetic metal material, and a permanent magnet member disposed inside the sleeve and having a plurality of magnetic poles on the surface thereof. A magnet roll characterized by being cut approximately parallel to. 2. The magnet roll according to claim 1, which has cross-shaped processing lines that are substantially parallel to the axial direction or that are inclined in directions opposite to each other with respect to the axial direction. 3. A magnet roll having a cylindrical sleeve made of a non-magnetic metal material and a permanent magnet member disposed inside the sleeve and having a plurality of magnetic poles on its surface is pivotally supported at both ends, The front or side cutting edge of the end mill is brought into contact with the surface of the sleeve to rotate the sleeve, and the end mill is rotated at a high speed to be moved in the axial direction relative to the sleeve. Processing method. 4. A cylindrical body having a hollow or solid cylindrical portion is supported at both ends thereof, a front or side cutting edge of an end mill is brought into contact with a surface of the hollow cylindrical portion, and the end mill is rotated at a high speed. A cylindrical body processing method characterized in that the cylindrical body is moved in the axial direction relative to the hollow cylindrical portion.