JP2555090Y2 - Magnet device - 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 device used for an electrostatic developing device such as a copying machine for plain paper, a printer, and a facsimile.

[0002]

2. Description of the Related Art Magnet devices are used in electrophotographic developing devices and cleaning devices such as copiers and facsimile machines. This magnet device is shown in FIG.
(B) As shown in the cross-sectional explanatory view, a magnet roll M formed by penetrating a shaft 2 through a cylindrical magnet body 1 has a cylindrical sleeve S having both ends closed by flanges 3a and 3b.
It is a configuration that is installed inside. The shaft portion 2b on one end side of the shaft 2 passes through the flange 3b while being supported by a bearing 4b incorporated in the flange 3b.
On the other hand, the other end side shaft portion 2a of the shaft 2 is supported by a bearing 4a incorporated in the flange 3a without penetrating the flange 3a, and protrudes from the outer surface of the flange 3a. By rotating the shaft portion 5 relatively to the shaft portion 2b on one end side of the shaft 2, the magnet roll M and the sleeve S can be rotated with respect to each other.

[0003]

By the way, in such a magnet device, the flanges 3a and 3b are made of a metal material, but there is a problem that the metal flange is heavy and the manufacturing cost is high. In order to cope with such a problem, it has been proposed to manufacture the flange using a synthetic resin. In particular, when the flange itself requires conductivity, an attempt has been made to mold the flange using a conductive resin. ing. Although the flange can be manufactured by injection molding or compression molding by using a synthetic resin flange, the dimensional accuracy required for the flange cannot be obtained by molding alone. Post-processing was required. In particular, since the fitting part of the flange to the sleeve also serves as a driving force transmission part to the sleeve, it is necessary to firmly fix it to the inner peripheral surface of the sleeve.However, the metal sleeve such as aluminum or stainless steel and the synthetic resin flange are firmly attached. Conventionally, there is no suitable adhesive that can bond to the flange, so conventionally, the only way to firmly fix the flange and the sleeve was to increase the fitting force on the sleeve by strictly setting the dimensional accuracy of the fitting portion of the flange. . If it is merely to increase the fitting force, it is considered that the flange whose outer diameter of the fitting portion is slightly larger than the inner diameter of the sleeve to be fitted is strongly pressed into the sleeve. As shown in FIG. 6, there is a problem that the sleeve end swells, which is not preferable.

As described above, in the conventional method of increasing the fitting force by bringing the outer diameter of the fitting portion of the flange closer to the inner diameter of the sleeve, extremely tight dimensional tolerance is required for the fitting portion of the flange. As a result, the processing cost increases, and the original purpose of reducing the cost of the magnet device by using a synthetic resin flange cannot be achieved.
The present invention has been made in view of such a situation, and uses a synthetic resin flange with low dimensional accuracy obtained only by molding as it is, and firmly fixes this to the metal sleeve without causing deformation of the metal sleeve. An object of the present invention is to provide a structure which can be provided, thereby contributing to providing an inexpensive magnet device.

[0005]

According to the present invention, which solves the above-mentioned problem, a synthetic resin molded product is used for one or both flanges, and the synthetic resin flange is supported on a shaft for supporting a shaft of a magnet roll. It is characterized in that it has an annular upright wall serving as a fitting portion for the hole and the sleeve, and the annular upright wall has a shape formed with a notch for elastic deformation. It is preferable that the flanges of the above configuration are arranged at both ends of the sleeve. However, it is also possible to employ the flanges of the above configuration only on one side of the flange that is a driving force transmitting portion.

It is preferable that a plurality of cuts provided at the fitting portion of the synthetic resin flange are provided at equal intervals along the axial direction of the flange. 0.03 than the inner diameter of the sleeve
It is preferable to set the distance to be larger by about mm to 0.06 mm.

[0007]

The flange is assembled to the sleeve in the magnet device having the above-described configuration by fixing the flanges having the fitting portions coated with the adhesive to both ends of the sleeve in which the magnet roll is inserted as in the conventional case. Done by
In the present invention, the annular upright wall, which is the fitting portion of the synthetic resin flange, is provided with a notch for elastic deformation, so that the fitting portion can be elastically contracted inward in the flange radial direction, and the sleeve end portion is formed. The fitting is easy, and after the fitting, the annular upright wall appropriately presses the end of the metal sleeve from the inner peripheral surface side by the elastic restoring force to firmly adhere the flange and the sleeve. Therefore, even when the rotational force is transmitted to the sleeve through the flange, the flange and the sleeve do not run idle due to poor bonding during use. In addition, the force for pressing the metal sleeve end from the inner peripheral surface side is based on the elastic restoring force, so that it is not too strong and does not cause deformation of the sleeve end. It is important to note that when such a flange is fitted inside the sleeve, the outer diameter of the fitting part elastically contracts and automatically matches the inner diameter of the sleeve. It is not necessary to make it strict, and it is possible to use a flange that has only been subjected to injection molding or compression molding but has not been subjected to post-processing, so that the cost of the flange can be reduced, which in turn contributes to the cost reduction of the magnet device. it can.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the illustrated embodiments. 1 to 3 show one embodiment of a synthetic resin flange used in the magnet device of the present invention. FIG. 1 is a perspective view, FIG. 2A is a front view, FIG. 2B is a side view, and FIG. It is a direction end view. The synthetic resin flange 6 has a shaft hole 7 at the center of the inner surface thereof for supporting the shaft 2 of the magnet roll M, and an annular upright wall 8 serving as a fitting portion to a sleeve is formed around the shaft hole 7. Are formed with a plurality of cuts 9, 9 ... at equal intervals along the axial direction,
The annular upright wall 8 has a shape obtained by dividing the annular upright wall 8 into a plurality of elastic pieces 10.

As shown in FIG. 2, the groove width d of the cut 9 is preferably set to 0.5 mm to 1.5 mm.
As shown in FIG. 4, the outer diameter r of the annular upright wall 8 which is the fitting portion of the synthetic resin flange is set to be slightly larger than the inner diameter R of the sleeve S to be fitted, so as to increase the fitting force to the sleeve. Preferably, the outer diameter r of the annular upright wall 8 is set to be larger than the inner diameter R of the sleeve S by about 0.03 mm to 0.06 mm. The outer diameter of the annular standing wall 8 is not strict, but care must be taken because if the outer diameter r of the annular standing wall is too large, the sleeve S may be deformed.

Examples of the material of the flange 6 include engineering plastics such as polyacetal, ABS resin, polyamide, polycarbonate, polyphenylene oxide, polyphenylene sulfide, polysulfone, polyethylene terephthalate, polybutylene terephthalate, polyether ether ketone, and other phenols. Thermosetting resins such as resin and epoxy resin can be used. These synthetic resins are suitable for use as flanges because of their excellent molding accuracy and mechanical strength and abrasion resistance.

It is also possible to disperse and mix a conductive filler in the synthetic resin to impart conductivity to the flange. As the conductive filler, for example, carbon fiber, metal powder, carbon powder and the like can be used. When conductivity is imparted to the flange in this manner, a potential can be applied to the sleeve via the flange, as in the case of using a conventional metal flange. It is also possible to fill the synthetic resin with other inorganic fillers together with the conductive filler for the purpose of increasing mechanical strength, for example, even if filled with glass fiber, talc, titanium oxide, alumina, carbon powder, molybdenum oxide, etc. Good.
In particular, when a suitable amount of a slidable filler such as talc or molybdenum oxide is filled, the sliding resistance of the magnet roll M with respect to the shaft 2 can be reduced, and the rotation operation becomes smoother.

Injection molding or compression molding can be employed as a method for molding such a synthetic resin flange 6, but injection molding is generally preferred. Then, the synthetic resin flange is used after being assembled to the sleeve as it is without performing post-processing such as cutting after molding.

To assemble the synthetic resin flange 6 to the sleeve, an adhesive is applied to the outer surface of the annular standing wall 8 of the synthetic resin flange 6, and then, as shown in FIG. This is done by fitting in. The annular upright wall 8 has a number of elastic pieces 10, 1 formed by cuts 9, 9,.
, And the annular upright wall 8 is configured to be able to contract radially inward, so that even if the outer diameter of the annular upright wall 8 is slightly larger than the inner diameter of the sleeve, the annular upright wall 8 can be easily attached to the sleeve. Can be fitted internally. In addition, since the annular upright wall 8 pressed into the sleeve presses the sleeve from the inside by the elastic restoring force, the fitting force of the flange to the sleeve becomes extremely strong.

[0014]

[Effects of the Invention] The magnet device of the present invention uses a synthetic resin molded product for one or both flanges, and a cut for elastic deformation is formed in the annular upright wall which is the fitting portion of the synthetic resin flange. It is possible to elastically contract the annular upright wall, which is the fitting portion, inward in the radial direction of the flange, so that the flange can be easily fitted to the end of the sleeve. Since the end portion is appropriately pressed from the inner peripheral surface side, the flange and the sleeve can be firmly adhered and fixed. In addition, the force for pressing the metal sleeve end from the inner peripheral surface side is based on the elastic restoring force, so that it is not too strong and does not cause deformation of the sleeve end. When such a flange is fitted inside the sleeve, the outer diameter of the fitting portion elastically shrinks and automatically matches the inner diameter of the sleeve. Therefore, it is not necessary to tighten the dimensional tolerance of the flange fitting portion. Instead, it is possible to use a flange that has only been subjected to injection molding or compression molding and has not been subjected to post-processing, so that the cost of the flange can be reduced and, consequently, the cost of the magnet device can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a synthetic resin flange used in the magnet device of the present invention.

FIG. 2 shows a synthetic resin flange of the embodiment, and FIG.
Is a front view, (b) is a side view

FIG. 3 is an axial end view of the synthetic resin flange of the embodiment.

FIG. 4 is an explanatory view showing a state in which the synthetic resin flange of the embodiment is assembled to a sleeve.

5A and 5B show a conventional magnet device, wherein FIG. 5A is an axial sectional view, and FIG. 5B is a radial sectional view.

FIG. 6 is an explanatory sectional view showing a state in which a flange having a fitting portion having an outer diameter slightly larger than the inner diameter of the sleeve in the conventional magnet device is strongly pressed into the sleeve.

[Explanation of symbols]

 S sleeve M Magnet roll 1 Magnet 2 Shaft 2a One end shaft 2b Other end shaft 3a, 3b Flange 4a, 4b Bearing 5 Shaft 6 Synthetic resin flange 7 Shaft hole 8 Annular upright wall 9 Cut 10 Elastic piece

Claims (3)

(57) [Scope of request for utility model registration] 1. A magnet device comprising a magnet roll rotatably housed in a cylindrical sleeve closed at both ends with flanges, wherein one or both flanges are molded products made of synthetic resin. A magnet device in which a synthetic resin flange has a shaft hole supporting a shaft of a magnet roll and an annular standing wall serving as a fitting portion for a sleeve, and a cutout for elastic deformation is formed in the annular standing wall. 2. The magnet device according to claim 1, wherein a plurality of cuts are provided in the fitting portion of the synthetic resin flange at equal intervals along the axial direction of the flange. 3. An outer diameter of a fitting portion of a synthetic resin flange,
0.03 mm to 0.1 mm larger than the inner diameter of the sleeve to be fitted.
3. The magnet device according to claim 1, wherein the magnet device is set to be about 0.6 mm larger.